CephaLopod Biodiversity EcoLogy and EvoLutionPayne A I L Lipinski M R Clarke M R and M A C Roeleveld (Eds) S Afr J mar Sci 20 463-4691~8 4~

CEPHALOPOD FISHERIES A FUTURE GLOBAL UPSIDE TO PASTOVEREXPLOITATION OF LIVING MARINE RESOURCES RESULTS OF

AN INTERNATIONAL WORKSHOP 31 AUGUST - 2 SEPTEMBER 1997CAPE TOWN SOUTH AFRICA

I 2middot 1 3M R LIPINSKI D S BUTTERWORTH C J AUGUSTYN J K T BRODZIAK G CHR1STY4

S DES CLERS5 G D JACKSON6

R K ODOR D PAULy8

L V PURCHASE9 M J ROBERTSI

B A ROELl Y SAKURAIIO

and tv H H SAUER I I

Management strategies for cephalopod fisheries present similar challenges to those encountered in fisheriesfor finfish Peculiarities of cephalopod life cycles and the fact that cephalopod fisheries can benefit frommanagement experiences gained in other fisheries may help to preclude mistakes and management failuresDuring a three-day workshop features of cephalopod biology recommended areas of research and key con-clusions for management were identified and points of differences between cephalopods and fish were high-lighted Among these life-cycle understanding spatial distribution stock-recruitment relationship and agedeterminationgrowth studies were idenlified as key priorities for research Physiological and geneticapproaches to understanding basic aspects of the life cycle and their importance for understanding popula-tion dynamics were stressed Similarly theoretical ecology has a role to play in management eg the role ofa spatial distribution strategy in survival Environmental studies are also emerging as being important in thepossible prediction of population trends through links that operate at the level of spawning biology In theinterim cephalopods can be managed using similar principles to those applied to short-lived fish speciesAmong these constant proportion harvest strategies were identified as the most effective

Recently several critical accounts of marine fish-eries management have been published (eg Roberts1997 Rose 1997 Pauly et at 1998) In them theauthors agreed that successes were limited and that ingeneral fisheries management has a poor record ofsustainable utiLizationIndeed the observation was madethat on a global scale human exploitation proceedsmore or less involuntarily down the trophic pyramidand the more sought-after species are being replaced byless valuable smaller ones that grow more quickly

Fishing for cephalopods is not new but large-scalecommercial fisheries developed only in the 1950s and1960s Since then production and demand have increasedsteadily and cephalopod fisheries have begun to dom-inate on some fishing grounds Therefore it may be

useful to draw lessons from past finfish exploitationand thereby to try to avoid similar possible disastersin the field of cephalopod exploitation To do this itis considered worthwhile to look at the current statusof cephalopod fisheries and at existing data and man-agement options

These were the aims of a workshop held at theSouth African Museum in Cape Town (31 August -2 September 1997) during which more than 70 partici-pants from at least 20 countries most of them biologistsbut also some mathematicians and modellers sharedtheir experiences and ideas about cephalopod biologyand exploitation The industry was represented by thePresident of SASMIA (the South African SquidManagement Industrial Association)

Sea Fisheries Private Bag X2 Rogge Bay 8012 Cape Town South Africa Email lipinskisfriwcapegovzaDepartment of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch 7701 South AfricaEmail dllmathsuctacza

3 NMFSINWFSC Fishery Analysis amp Monitoring Division Hatfield Marine Science Center 2030 Marine Science Drive Newport OR97365-5296 USA

4 South African Squid Management Industrial Association (SASMIA) Christy amp Sons PO Box 452 Humansdorp 6300 South Africa5 Department of Biological Sciences University of Warwick Coventry CV4 7AL United Kingdom6 Department of Marine Biology James Cook University Townsville 4811 Queensland Australia Biology Department Dalhousie University Halifax Nova Scotia Canada B3H 4J18 Fisheries Centre 2204 Main Mall University of British Columbia Vancouver BC Canada V6T lZ49 Renewable Resources Assessment Group Imperial College 8 Princes Gardens London SW7 INA United Kingdom10 Faculty of Fisheries Hokkaido University 3-1-1 Minato-cho Hakodate Hokkaido 041 Japan11 Department of Ichthyology and Fisheries Science Rhodes University PO Box 94 Grahamstown 6140 South Africa

Manuscript received May 1998

CephaLopod Biodiversity EcoLogy and EvoLutionPayne A I L Lipinski M R Clarke M R and M A C Roeleveld (Eds) S Afr J mar Sci 20 463-4691~8 4~

CEPHALOPOD FISHERIES A FUTURE GLOBAL UPSIDE TO PASTOVEREXPLOITATION OF LIVING MARINE RESOURCES RESULTS OF

AN INTERNATIONAL WORKSHOP 31 AUGUST - 2 SEPTEMBER 1997CAPE TOWN SOUTH AFRICA

I 2middot 1 3M R LIPINSKI D S BUTTERWORTH C J AUGUSTYN J K T BRODZIAK

G CHR1STY4 S DES CLERS 5

G D JACKSON6 R K ODOR D PAULy8

L V PURCHASE9 M J ROBERTS I

B A ROELl Y SAKURAI IO

and tv H H SAUER I I

Management strategies for cephalopod fisheries present similar challenges to those encountered in fisheriesfor finfish Peculiarities of cephalopod life cycles and the fact that cephalopod fisheries can benefit frommanagement experiences gained in other fisheries may help to preclude mistakes and management failuresDuring a three-day workshop features of cephalopod biology recommended areas of research and key conshyclusions for management were identified and points of differences between cephalopods and fish were highshylighted Among these life-cycle understanding spatial distribution stock-recruitment relationship and agedeterminationgrowth studies were idenlified as key priorities for research Physiological and geneticapproaches to understanding basic aspects of the life cycle and their importance for understanding populashytion dynamics were stressed Similarly theoretical ecology has a role to play in management eg the role ofa spatial distribution strategy in survival Environmental studies are also emerging as being important in thepossible prediction of population trends through links that operate at the level of spawning biology In theinterim cephalopods can be managed using similar principles to those applied to short-lived fish speciesAmong these constant proportion harvest strategies were identified as the most effective

Recently several critical accounts of marine fishshyeries management have been published (eg Roberts1997 Rose 1997 Pauly et at 1998) In them theauthors agreed that successes were limited and that ingeneral fisheries management has a poor record ofsustainable utilization Indeed the observation was madethat on a global scale human exploitation proceedsmore or less involuntarily down the trophic pyramidand the more sought-after species are being replaced byless valuable smaller ones that grow more quickly

Fishing for cephalopods is not new but large-scalecommercial fisheries developed only in the 1950s and1960s Since then production and demand have increasedsteadily and cephalopod fisheries have begun to domshyinate on some fishing grounds Therefore it may be

useful to draw lessons from past finfish exploitationand thereby to try to avoid similar possible disastersin the field of cephalopod exploitation To do this itis considered worthwhile to look at the current statusof cephalopod fisheries and at existing data and manshyagement options

These were the aims of a workshop held at theSouth African Museum in Cape Town (31 August shy2 September 1997) during which more than 70 particishypants from at least 20 countries most of them biologistsbut also some mathematicians and modellers sharedtheir experiences and ideas about cephalopod biologyand exploitation The industry was represented by thePresident of SASMIA (the South African SquidManagement Industrial Association)

Sea Fisheries Private Bag X2 Rogge Bay 8012 Cape Town South Africa Email lipinskisfriwcapegovzaDepartment of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch 7701 South AfricaEmail dllmathsuctacza

3 NMFSINWFSC Fishery Analysis amp Monitoring Division Hatfield Marine Science Center 2030 Marine Science Drive Newport OR97365-5296 USA

4 South African Squid Management Industrial Association (SASMIA) Christy amp Sons PO Box 452 Humansdorp 6300 South Africa5 Department of Biological Sciences University of Warwick Coventry CV4 7AL United Kingdom6 Department of Marine Biology James Cook University Townsville 4811 Queensland Australia Biology Department Dalhousie University Halifax Nova Scotia Canada B3H 4J18 Fisheries Centre 2204 Main Mall University of British Columbia Vancouver BC Canada V6T lZ49 Renewable Resources Assessment Group Imperial College 8 Princes Gardens London SW7 INA United Kingdom10 Faculty of Fisheries Hokkaido University 3-1-1 Minato-cho Hakodate Hokkaido 041 Japan11 Department of Ichthyology and Fisheries Science Rhodes University PO Box 94 Grahamstown 6140 South Africa

Manuscript received May 1998

464 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

Table I FAO catch statistics 1993-1995 and an evaluation of whether a taxon was covered during the Cape Town workshop

Catch (tons) RepresentativeTaxon Region coverage1993 1994 1995

Sepioidea 229662 239001 242079 All NoOctopus spp 4799 8397 4191 Senegal YesOctopoda 318200 287721 317706 All except Senegal NoLoligo gahi 5305 5859 22325 Falklands YesLoligo pealei 22200 22502 18926 NW Atlantic YesLoligo vulgaris reynaudii 6271 5814 7047 South Africa YesLoligo spp 253533 236928 219827 All (Thailands share -30) YesIllex illecebrosus 26353 31327 19072 NW Atlantic YesIllex argentinus 330300 310075 310000 SW Atlantic YesDosidicus gigas 122431 194631 99773 E Pacific NoTodarodes sagittatus 6862 6145 5273 NEAtlantic YesTodarodes pacific us 548365 504408 513407 NW Pacific YesNototodarus sloanii 35060 65019 71967 New Zealand NoMartialia hyadesi 1252 392 23868 Falklands YesSquid nei 736507 759638 857 188 All (Falklands - 30

NW Pacific - 45) YesCephalopods nei 74539 98376 108411 All (mainly India 85) No

All cephalopods 272] 639 2776233 2841060 All - 30 not discussedduring workshop

nei = FAO indication for groupings not indicated to lower taxon

THE WORKSHOP

Structure

The first day of the workshop was devoted to pre-sentations of various examples of cephalopod exploit-ation worldwide and to approaches to their manage-ment The different fisheries considered are listed inTable 1

The second day was devoted to two major discussionsessions Taking stock of finfish fisheries wisdom(Chair D Pauly) and Taking stock a different per-spective (Chair R K QDor) The discussions high-lighted the relevant similarities and differences betweenfish and cephalopods with respect to resource man-agement

After the two sessions discussions continued withina small selected panel finishing only the followingday During the last day workshop participants wererequested to answer a questionnaire in which six priorityproblems in each of three key topics in fisheries sciencepertaining to cephalopod management had to be iden-tifie~ from lists prepared during earlier plenary dis-CUSSIons

Selective summary of talks and discussions

Presentations of examples of various cephalopod

fisheries during the workshop encompassed severaldifferent approaches to management (see below) Allbut two suggested that the measures adopted had beensuccessful as far as sustainable utilization of theresources was concerned Moreover the two widelyknown squid fisheries failures involving Todarodespacificus (NW Pacific) in the 1970s and Illex illece-brosus (NW Atlantic) in the 1980s appeared to haveoccurred mainly as a consequence of life-cycleresponses to environmental changes probably aggra-vated by heavy fishing pressure (Dawe and Warren1993) Proof of this has been in the recovery of theT pacificus resource achieved naturally and not as aresult of a long-term change in fishing pressure manage-ment or demand (Sakurai et al 1997 pers comm)

Nevertheless even if the stability in many of thefisheries suggests a sustainable level of utilization itdoes not follow that the fishery is necessarily wellmanaged because for example the resources in ques-tion could be substantially underutilized Sound fish-eries management requires an appropriate balancebetween the conflicting objectives of maximizingcatch and minimizing the risk of unintended severedepletion of the resource Exactly where the besttrade-offs between these two concerns lie for cephalopodfisheries is regrettably not yet clear However areasonable balance between the two in the USAsmanagement strategy for two squid species in the NWAtlantic was noted Such management is based on alevel of total allowable catch that cannot be exceeded

464 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

Table I FAO catch statistics 1993-1995 and an evaluation of whether a taxon was covered during the Cape Town workshop

Catch (tons) RepresentativeTaxon Region coverage1993 1994 1995

Sepioidea 229662 239001 242079 All NoOctopus spp 4799 8397 4191 Senegal YesOctopoda 318200 287721 317706 All except Senegal NoLoligo gahi 5305 5859 22325 Falklands YesLoligo pealei 22200 22502 18926 NW Atlantic YesLoligo vulgaris reynaudii 6271 5814 7047 South Africa YesLoligo spp 253533 236928 219827 All (Thailands share -30) YesIllex illecebrosus 26353 31327 19072 NW Atlantic YesIllex argentinus 330300 310075 310000 SW Atlantic YesDosidicus gigas 122431 194631 99773 E Pacific NoTodarodes sagittatus 6862 6145 5273 NEAtlantic YesTodarodes pacificus 548365 504408 513407 NW Pacific YesNototodarus sloanii 35060 65019 71967 New Zealand NoMartialia hyadesi 1252 392 23868 Falklands YesSquid nei 736507 759638 857 188 All (Falklands - 30

NW Pacific - 45) YesCephalopods nei 74539 98376 108411 All (mainly India 85) No

All cephalopods 2721 639 2776233 2841060 All - 30 not discussedduring workshop

nei = FAO indication for groupings not indicated to lower taxon

THE WORKSHOP

Structure

The first day of the workshop was devoted to preshysentations of various examples of cephalopod exploitshyation worldwide and to approaches to their manageshyment The different fisheries considered are listed inTable 1

The second day was devoted to two major discussionsessions Taking stock of finfish fisheries wisdom(Chair D Pauly) and Taking stock a different pershyspective (Chair R K GDor) The discussions highshylighted the relevant similarities and differences betweenfish and cephalopods with respect to resource manshyagement

After the two sessions discussions continued withina small selected panel finishing only the followingday During the last day workshop participants wererequested to answer a questionnaire in which six priorityproblems in each of three key topics in fisheries sciencepertaining to cephalopod management had to be idenshytified from lists prepared during earlier plenary disshycussions

Selective summary of talks and discussions

Presentations of examples of various cephalopod

fisheries during the workshop encompassed severaldifferent approaches to management (see below) Allbut two suggested that the measures adopted had beensuccessful as far as sustainable utilization of theresources was concerned Moreover the two widelyknown squid fisheries failures involving Todarodespacificus (NW Pacific) in the 1970s and Illex illeceshybrosus (NW Atlantic) in the 1980s appeared to haveoccurred mainly as a consequence of life-cycleresponses to environmental changes probably aggrashyvated by heavy fishing pressure (Dawe and Warren1993) Proof of this has been in the recovery of theT pacificus resource achieved naturally and not as aresult of a long-term change in fishing pressure manageshyment or demand (Sakurai et al 1997 pers comm)

Nevertheless even if the stability in many of thefisheries suggests a sustainable level of utilization itdoes not follow that the fishery is necessarily wellmanaged because for example the resources in quesshytion could be substantially underutilized Sound fishshyeries management requires an appropriate balancebetween the conflicting objectives of maximizingcatch and minimizing the risk of unintended severedepletion of the resource Exactly where the besttrade-offs between these two concerns lie for cephalopodfisheries is regrettably not yet clear However areasonable balance between the two in the USAsmanagement strategy for two squid species in the NWAtlantic was noted Such management is based on alevel of total allowable catch that cannot be exceeded

i998 Lipinski et al international Cephalopod Fisheries Workshop Results 465

and on an overfishing definition that has been charac-terized as risky (Brodziak and Macy 1996)

The Falkland Islands Governments managementof cephalopod resources appears to be an effectiveorthodox approach to large-scale squid fisheriesinvolving a substantial fleet of large vessels (Beddingtonet at 1990 Basson et al 1996) A proportionalescapement strategy is applied and the basic manage-ment tool is control of effort The control mechanismsused are 1) limitation on the number of vessels at thebeginning of the season 2) limiting the length of thefishing season (Basson et al 1996) As part of thefishing licence requirement there each vessel suppliesdaily all the necessary information required for thisapproach to be effective However such requirementscould not easily be set for small-scale fisheries forwhich real-time monitoring is impossible

The management of the chokka squid Loiigovulgaris reynaudii fishery in South African waters is anexample of the gradual development of some practicalvariants of effort control in line with an accumulationof knowledge about the species life cycle (Augustynet ai 1994) It is a small-business fishery involvingabout 240 boats ranging between 4 and 15 m longAlthough the number of permits issued has been keptconstant effort has been increasing over timeAttempts to limit effort include the imposition of aclosed season of variable duration (3-5 weeks) duringthe peak spawning season and by the establishmentof a marine protected area where fishing is banned

The primary objective in the management of theJapanese squid fisheries is to obtain good within-seasonpredictions of recruitment as an aid to conductingindustrial operations This is done by early monitoringof environmental conditions as well as by conductingsurveys of paralarvae and pre-recruits (eg Murata1989)

With regard to general problems relevant to allcephalopod fisheries the applicability of data andideas from the fields of genetics physiology ecologyand physical oceanography were discussed Duringthe discussions possible differences and similaritiesbetween fish and cephalopods were emphasized

Genetics may be valuable in at least five spheres offisheries biology

bull taxonomic problemsbull stock structurebull migration patternsbull behavioural patterns during spawningbull monitoring of the level of genetic variability

While the benefits and application of the first threeaspects are fairly obvious the last two require moreclarification Behavioural patterns during spawningsuggest that sperm of at least two categories of males is

used for fertilization Solution to this paternity problem(Shaw and Boyle 1997) may help to discriminatebetween demes andor stocks From a short-termmanagement perspective monitoring of the level ofgenetic variability is probably of little relevance Inthe long-term however it may affect the ability of themetapopulation (sensu McQuinn 1997) to maintainits abundance or its capability to recover after a crashSpecially interesting is the role of genetic studies inassessing the effectiveness of the safety valves - theparts of the metapopulation (such as that in reserves)sheltered by fishing regulations from exploitation Dothey have the potential to rebuild local populations inthe event of a crash This is not a question that can beaddressed solely by stock identity and distributionstudies

Physiology often appears to be a theoretical subjectsomewhat removed from fisheries science Discussionat the workshop indicated arguments to the contraryIf an approach based on detailed models of all stagesof the life cycle is to become the basis for the manage-ment of resource exploitation within the foreseeablefuture basic physiological research will be necessaryto ascertain the key mechanisms governing the extentand variation of the surplus production capability ofthe resource each year (eg Murphy et at 1994 Wellsand Clarke 1996) Energy-transmission modes incephalopods differ from those of fish in that they aremuch more oxygen-limited To overcome this problemthey absorb oxygen through their skin furthermoretheir anaerobic metabolism goes through the octopine(and not lactate) chain Therefore growth and longevityof squid cannot be understood without basic physio-logical reviews and research (Jackson 1994 Pauly1998) During the workshop discussions consensuswas reached on certain points

bull Models required to describe growth of squid maybe complex it is impossible at present to proposea unitary growth model for all cephalopods It isdefinitely hazardous to base conclusions aboutsquid growth and longevity only upon unverifiedfield length or mass frequencies Models fitted onthe basis of such data were shown to be question-able when verified with validated statolith age data

bull Schnutes growth model (Schnute 1981) may beuseful if the issue is to distinguish between asymp-totic and non-asymptotic growth many if notmost cephalopods stop growing or at least slowdown during the spawning period Furthermorethe development of a model which allows forin-season fluctuations in size of cephalopods is ahigh priority

bull There is a need to revisit the longevity issue for largespecies of squid aquarium- and field-validation

i998 Lipinski et al international Cephalopod Fisheries Workshop Results 465

and on an overfishing definition that has been characshyterized as risky (Brodziak and Macy 1996)

The Falkland Islands Governments managementof cephalopod resources appears to be an effectiveorthodox approach to large-scale squid fisheriesinvolving a substantial fleet of large vessels (Beddingtonet at 1990 Basson et al 1996) A proportionalescapement strategy is applied and the basic manageshyment tool is control of effort The control mechanismsused are 1) limitation on the number of vessels at thebeginning of the season 2) limiting the length of thefishing season (Basson et al 1996) As part of thefishing licence requirement there each vessel suppliesdaily all the necessary information required for thisapproach to be effective However such requirementscould not easily be set for small-scale fisheries forwhich real-time monitoring is impossible

The management of the chokka squid Loiigovulgaris reynaudii fishery in South African waters is anexample of the gradual development of some practicalvariants of effort control in line with an accumulationof knowledge about the species life cycle (Augustynet ai 1994) It is a small-business fishery involvingabout 240 boats ranging between 4 and 15 m longAlthough the number of permits issued has been keptconstant effort has been increasing over timeAttempts to limit effort include the imposition of aclosed season of variable duration (3-5 weeks) duringthe peak spawning season and by the establishmentof a marine protected area where fishing is banned

The primary objective in the management of theJapanese squid fisheries is to obtain good within-seasonpredictions of recruitment as an aid to conductingindustrial operations This is done by early monitoringof environmental conditions as well as by conductingsurveys of paralarvae and pre-recruits (eg Murata1989)

With regard to general problems relevant to allcephalopod fisheries the applicability of data andideas from the fields of genetics physiology ecologyand physical oceanography were discussed Duringthe discussions possible differences and similaritiesbetween fish and cephalopods were emphasized

Genetics may be valuable in at least five spheres offisheries biology

bull taxonomic problemsbull stock structurebull migration patternsbull behavioural patterns during spawningbull monitoring of the level of genetic variability

While the benefits and application of the first threeaspects are fairly obvious the last two require moreclarification Behavioural patterns during spawningsuggest that sperm of at least two categories of males is

used for fertilization Solution to this paternity problem(Shaw and Boyle 1997) may help to discriminatebetween demes andor stocks From a short-termmanagement perspective monitoring of the level ofgenetic variability is probably of little relevance Inthe long-term however it may affect the ability of themetapopulation (sensu McQuinn 1997) to maintainits abundance or its capability to recover after a crashSpecially interesting is the role of genetic studies inassessing the effectiveness of the safety valves - theparts of the metapopulation (such as that in reserves)sheltered by fishing regulations from exploitation Dothey have the potential to rebuild local populations inthe event of a crash This is not a question that can beaddressed solely by stock identity and distributionstudies

Physiology often appears to be a theoretical subjectsomewhat removed from fisheries science Discussionat the workshop indicated arguments to the contraryIf an approach based on detailed models of all stagesof the life cycle is to become the basis for the manageshyment of resource exploitation within the foreseeablefuture basic physiological research will be necessaryto ascertain the key mechanisms governing the extentand variation of the surplus production capability ofthe resource each year (eg Murphy et at 1994 Wellsand Clarke 1996) Energy-transmission modes incephalopods differ from those of fish in that they aremuch more oxygen-limited To overcome this problemthey absorb oxygen through their skin furthermoretheir anaerobic metabolism goes through the octopine(and not lactate) chain Therefore growth and longevityof squid cannot be understood without basic physioshylogical reviews and research (Jackson 1994 Pauly1998) During the workshop discussions consensuswas reached on certain points

bull Models required to describe growth of squid maybe complex it is impossible at present to proposea unitary growth model for all cephalopods It isdefinitely hazardous to base conclusions aboutsquid growth and longevity only upon unverifiedfield length or mass frequencies Models fitted onthe basis of such data were shown to be questionshyable when verified with validated statolith age data

bull Schnutes growth model (Schnute 1981) may beuseful if the issue is to distinguish between asympshytotic and non-asymptotic growth many if notmost cephalopods stop growing or at least slowdown during the spawning period Furthermorethe development of a model which allows forin-season fluctuations in size of cephalopods is ahigh priority

bull There is a need to revisit the longevity issue for largespecies of squid aquarium- and field-validation

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consump-tion growth) and population ecology (behaviour-related ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one year-class spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manage-ment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruit-ment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manage-ment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg temper-ature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of impor-tance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consumpshytion growth) and population ecology (behaviourshyrelated ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one yearshyclass spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manageshyment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruitshyment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manageshyment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg tempershyature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of imporshytance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

]998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the rankingTopics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relation-ships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fish-eries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

1998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the ranking

Topics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relationshyships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fishshyeries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommend-ations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should con-centrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial vari-ations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fish-eries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994- Chokka squidon the Agu]has Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996- Assess-ment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the pro-vision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of ]ong-finned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of short-finned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roe]eveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997- Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessme-nt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994-Modelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998- Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997- The spatialdimension in population fluctuations Science 278(5343)162]-]623

ROBERTS C M 1997 - Ecological advice for the global fish-eries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 ]998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggrega-tions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Air J mar Sci 20 267- 284

ROSE G A 1997- The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommendshyations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should conshycentrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial varishyations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fishshyeries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994 - Chokka squidon the Agulhas Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996 - Assessshyment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the proshyvision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of longshyfinned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of shortshyfinned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roeleveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997 - Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessmeshynt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994shyModelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998 - Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997 - The spatialdimension in population fluctuations Science 278(5343)1621-1623

ROBERTS C M 1997 - Ecological advice for the global fishshyeries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 1998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggregashytions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 267 - 284

ROSE G A 1997 - The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

i998 Lipinski et al international Cephalopod Fisheries Workshop Results 465

and on an overfishing definition that has been charac-terized as risky (Brodziak and Macy 1996)

The Falkland Islands Governments managementof cephalopod resources appears to be an effectiveorthodox approach to large-scale squid fisheriesinvolving a substantial fleet of large vessels (Beddingtonet at 1990 Basson et al 1996) A proportionalescapement strategy is applied and the basic manage-ment tool is control of effort The control mechanismsused are 1) limitation on the number of vessels at thebeginning of the season 2) limiting the length of thefishing season (Basson et al 1996) As part of thefishing licence requirement there each vessel suppliesdaily all the necessary information required for thisapproach to be effective However such requirementscould not easily be set for small-scale fisheries forwhich real-time monitoring is impossible

The management of the chokka squid Loiigovulgaris reynaudii fishery in South African waters is anexample of the gradual development of some practicalvariants of effort control in line with an accumulationof knowledge about the species life cycle (Augustynet ai 1994) It is a small-business fishery involvingabout 240 boats ranging between 4 and 15 m longAlthough the number of permits issued has been keptconstant effort has been increasing over timeAttempts to limit effort include the imposition of aclosed season of variable duration (3-5 weeks) duringthe peak spawning season and by the establishmentof a marine protected area where fishing is banned

The primary objective in the management of theJapanese squid fisheries is to obtain good within-seasonpredictions of recruitment as an aid to conductingindustrial operations This is done by early monitoringof environmental conditions as well as by conductingsurveys of paralarvae and pre-recruits (eg Murata1989)

With regard to general problems relevant to allcephalopod fisheries the applicability of data andideas from the fields of genetics physiology ecologyand physical oceanography were discussed Duringthe discussions possible differences and similaritiesbetween fish and cephalopods were emphasized

Genetics may be valuable in at least five spheres offisheries biology

bull taxonomic problemsbull stock structurebull migration patternsbull behavioural patterns during spawningbull monitoring of the level of genetic variability

While the benefits and application of the first threeaspects are fairly obvious the last two require moreclarification Behavioural patterns during spawningsuggest that sperm of at least two categories of males is

used for fertilization Solution to this paternity problem(Shaw and Boyle 1997) may help to discriminatebetween demes andor stocks From a short-termmanagement perspective monitoring of the level ofgenetic variability is probably of little relevance Inthe long-term however it may affect the ability of themetapopulation (sensu McQuinn 1997) to maintainits abundance or its capability to recover after a crashSpecially interesting is the role of genetic studies inassessing the effectiveness of the safety valves - theparts of the metapopulation (such as that in reserves)sheltered by fishing regulations from exploitation Dothey have the potential to rebuild local populations inthe event of a crash This is not a question that can beaddressed solely by stock identity and distributionstudies

Physiology often appears to be a theoretical subjectsomewhat removed from fisheries science Discussionat the workshop indicated arguments to the contraryIf an approach based on detailed models of all stagesof the life cycle is to become the basis for the manage-ment of resource exploitation within the foreseeablefuture basic physiological research will be necessaryto ascertain the key mechanisms governing the extentand variation of the surplus production capability ofthe resource each year (eg Murphy et at 1994 Wellsand Clarke 1996) Energy-transmission modes incephalopods differ from those of fish in that they aremuch more oxygen-limited To overcome this problemthey absorb oxygen through their skin furthermoretheir anaerobic metabolism goes through the octopine(and not lactate) chain Therefore growth and longevityof squid cannot be understood without basic physio-logical reviews and research (Jackson 1994 Pauly1998) During the workshop discussions consensuswas reached on certain points

bull Models required to describe growth of squid maybe complex it is impossible at present to proposea unitary growth model for all cephalopods It isdefinitely hazardous to base conclusions aboutsquid growth and longevity only upon unverifiedfield length or mass frequencies Models fitted onthe basis of such data were shown to be question-able when verified with validated statolith age data

bull Schnutes growth model (Schnute 1981) may beuseful if the issue is to distinguish between asymp-totic and non-asymptotic growth many if notmost cephalopods stop growing or at least slowdown during the spawning period Furthermorethe development of a model which allows forin-season fluctuations in size of cephalopods is ahigh priority

bull There is a need to revisit the longevity issue for largespecies of squid aquarium- and field-validation

i998 Lipinski et al international Cephalopod Fisheries Workshop Results 465

and on an overfishing definition that has been characshyterized as risky (Brodziak and Macy 1996)

The Falkland Islands Governments managementof cephalopod resources appears to be an effectiveorthodox approach to large-scale squid fisheriesinvolving a substantial fleet of large vessels (Beddingtonet at 1990 Basson et al 1996) A proportionalescapement strategy is applied and the basic manageshyment tool is control of effort The control mechanismsused are 1) limitation on the number of vessels at thebeginning of the season 2) limiting the length of thefishing season (Basson et al 1996) As part of thefishing licence requirement there each vessel suppliesdaily all the necessary information required for thisapproach to be effective However such requirementscould not easily be set for small-scale fisheries forwhich real-time monitoring is impossible

The management of the chokka squid Loiigovulgaris reynaudii fishery in South African waters is anexample of the gradual development of some practicalvariants of effort control in line with an accumulationof knowledge about the species life cycle (Augustynet ai 1994) It is a small-business fishery involvingabout 240 boats ranging between 4 and 15 m longAlthough the number of permits issued has been keptconstant effort has been increasing over timeAttempts to limit effort include the imposition of aclosed season of variable duration (3-5 weeks) duringthe peak spawning season and by the establishmentof a marine protected area where fishing is banned

The primary objective in the management of theJapanese squid fisheries is to obtain good within-seasonpredictions of recruitment as an aid to conductingindustrial operations This is done by early monitoringof environmental conditions as well as by conductingsurveys of paralarvae and pre-recruits (eg Murata1989)

With regard to general problems relevant to allcephalopod fisheries the applicability of data andideas from the fields of genetics physiology ecologyand physical oceanography were discussed Duringthe discussions possible differences and similaritiesbetween fish and cephalopods were emphasized

Genetics may be valuable in at least five spheres offisheries biology

bull taxonomic problemsbull stock structurebull migration patternsbull behavioural patterns during spawningbull monitoring of the level of genetic variability

While the benefits and application of the first threeaspects are fairly obvious the last two require moreclarification Behavioural patterns during spawningsuggest that sperm of at least two categories of males is

used for fertilization Solution to this paternity problem(Shaw and Boyle 1997) may help to discriminatebetween demes andor stocks From a short-termmanagement perspective monitoring of the level ofgenetic variability is probably of little relevance Inthe long-term however it may affect the ability of themetapopulation (sensu McQuinn 1997) to maintainits abundance or its capability to recover after a crashSpecially interesting is the role of genetic studies inassessing the effectiveness of the safety valves - theparts of the metapopulation (such as that in reserves)sheltered by fishing regulations from exploitation Dothey have the potential to rebuild local populations inthe event of a crash This is not a question that can beaddressed solely by stock identity and distributionstudies

Physiology often appears to be a theoretical subjectsomewhat removed from fisheries science Discussionat the workshop indicated arguments to the contraryIf an approach based on detailed models of all stagesof the life cycle is to become the basis for the manageshyment of resource exploitation within the foreseeablefuture basic physiological research will be necessaryto ascertain the key mechanisms governing the extentand variation of the surplus production capability ofthe resource each year (eg Murphy et at 1994 Wellsand Clarke 1996) Energy-transmission modes incephalopods differ from those of fish in that they aremuch more oxygen-limited To overcome this problemthey absorb oxygen through their skin furthermoretheir anaerobic metabolism goes through the octopine(and not lactate) chain Therefore growth and longevityof squid cannot be understood without basic physioshylogical reviews and research (Jackson 1994 Pauly1998) During the workshop discussions consensuswas reached on certain points

bull Models required to describe growth of squid maybe complex it is impossible at present to proposea unitary growth model for all cephalopods It isdefinitely hazardous to base conclusions aboutsquid growth and longevity only upon unverifiedfield length or mass frequencies Models fitted onthe basis of such data were shown to be questionshyable when verified with validated statolith age data

bull Schnutes growth model (Schnute 1981) may beuseful if the issue is to distinguish between asympshytotic and non-asymptotic growth many if notmost cephalopods stop growing or at least slowdown during the spawning period Furthermorethe development of a model which allows forin-season fluctuations in size of cephalopods is ahigh priority

bull There is a need to revisit the longevity issue for largespecies of squid aquarium- and field-validation

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consump-tion growth) and population ecology (behaviour-related ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one year-class spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manage-ment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruit-ment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manage-ment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg temper-ature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of impor-tance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consumpshytion growth) and population ecology (behaviourshyrelated ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one yearshyclass spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manageshyment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruitshyment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manageshyment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg tempershyature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of imporshytance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

]998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the rankingTopics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relation-ships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fish-eries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

1998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the ranking

Topics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relationshyships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fishshyeries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommend-ations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should con-centrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial vari-ations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fish-eries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994- Chokka squidon the Agu]has Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996- Assess-ment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the pro-vision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of ]ong-finned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of short-finned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roe]eveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997- Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessme-nt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994-Modelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998- Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997- The spatialdimension in population fluctuations Science 278(5343)162]-]623

ROBERTS C M 1997 - Ecological advice for the global fish-eries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 ]998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggrega-tions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Air J mar Sci 20 267- 284

ROSE G A 1997- The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommendshyations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should conshycentrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial varishyations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fishshyeries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994 - Chokka squidon the Agulhas Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996 - Assessshyment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the proshyvision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of longshyfinned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of shortshyfinned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roeleveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997 - Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessmeshynt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994shyModelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998 - Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997 - The spatialdimension in population fluctuations Science 278(5343)1621-1623

ROBERTS C M 1997 - Ecological advice for the global fishshyeries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 1998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggregashytions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 267 - 284

ROSE G A 1997 - The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consump-tion growth) and population ecology (behaviour-related ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one year-class spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manage-ment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruit-ment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manage-ment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg temper-ature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of impor-tance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

466 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

experiments on adults of these species should beattempted where possible

bull Small species of squid reach maturityadulthoodwithin a year or less because of this they cangenerally withstand more intensive fishing pressureA cautious approach to the exploitation of largerspecies of squid is advised until fundamentalquestions relating to growth age and longevity areresolved

Theoretical ecology also has a contribution to makein the future management of cephalopod resources Inthis regard the following points were made during theworkshop

bull Cephalopods are highly individualistic both withregard to biological parameters (eg food consumpshytion growth) and population ecology (behaviourshyrelated ranking within a local population [deme]demes forming one metapopulation etc) The factthat growth rates and their variability may differbetween demes means that unless a random sampleof the whole metapopulation can be achieved agesampling and analyses should be stratified by demeswhen estimating the metapopulation age structureThe same applies to results of abundance surveysand fisheries statistics as measures of abundance

bull Fish populations have a buffer against interannualrecruitment fluctuations provided by the presenceof a number of year-classes in the spawning biomassIn contrast cephalopods often have only one yearshyclass spawning and hence make extensive use ofspatial distribution strategies to enhance survivaland so to provide an alternative form of buffer (seeRanta et al ]997 for a theoretical background andLipinski 1998 and ODor 1998 for cephalopodapplications) Spatial and temporal differences insurvival of paralarvae and individual somatic growthas well as distribution increase variability in theage and size of individuals and in the numbers inthe metapopulation from year to year

bull Because of this spatial aspect of survival carefullyplanned and flexible sets of closed areas and timesmay be used effectively as management tools inmost cephalopod fisheries They should howeverbe based on a thorough understanding of the lifecycle of the species and if possible good biomassestimates

bull A long paralarvaljuvenile phase exponentialgrowth until adulthood one-year life cycle (inmost cases) semelparity spatial survival strategymagnitude of differences between individuals etcmake cephalopods different from fish These factorsare likely to influence the practical aspects of fish-

eries research Examples are design and interpretationof the results of monitoring programmes design ofassessment models and choice between manageshyment strategies

In terms of environmental research the results ofwhich were presented at the workshop mainly byJapanese and South African scientists the mainemphasis was placed on prediction of recruitment Itwas pointed out that T pacificus recruitment wasrelated mainly to the area of the spawning groundsduring the 1970s cooling of the waters above thosegrounds resulted in decreased spawning activity andlessened recruitment The recent increase in recruitshyment is related to warming of the waters north of thetraditional spawning grounds In the case of theSouth African chokka jig fishery the large monthlyand annual catch fluctuations experienced led touncertainty and impacted upon resource manageshyment fishery economics and fishers livelihoods In1994 a specific multi-disciplinary research programmewas initiated by Sea Fisheries Cape Town (SouthAfrica) The primary purpose of the initiative was todevelop a predictive capability for both chokkarecruitment and availability to the fishery Research atpresent is focusing on the spawning grounds where thefishery operates and it is attempting to link regionalclimatic variability with regional oceanography andglobal phenomena such as El Nino Southern Oscillation(ENSO) events The work has led to the formulation ofmodels which attempt to couple physical (eg tempershyature and turbidity) and biological (eg spawningbiology) parameters (Roberts 1998)

Results of the questionnaire

During the third day the participants of the workshopwere requested to define select and prioritize any sixkey problems (ie simply list them in order of imporshytance) within each of three topics in fisheries scienceas applied to cephalopods The three topics were

bull Most important features of cephalopod fisheriesbiology as outlined by the Workshop (a list of 10problems had been compiled from which tochoose)

bull Key areas of research with regard to cephalopodsin fisheries science (a list of 29 problems hadbeen compiled)

bull Main conclusions (of the Workshop) regarding themanagement of cephalopod utilization (a list of 15problems had been compiled)

More than 70 questionnaires were distributed and

]998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the rankingTopics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relation-ships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fish-eries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

1998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the ranking

Topics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relationshyships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fishshyeries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommend-ations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should con-centrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial vari-ations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fish-eries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994- Chokka squidon the Agu]has Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996- Assess-ment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the pro-vision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of ]ong-finned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of short-finned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roe]eveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997- Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessme-nt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994-Modelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998- Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997- The spatialdimension in population fluctuations Science 278(5343)162]-]623

ROBERTS C M 1997 - Ecological advice for the global fish-eries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 ]998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggrega-tions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Air J mar Sci 20 267- 284

ROSE G A 1997- The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommendshyations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should conshycentrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial varishyations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fishshyeries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994 - Chokka squidon the Agulhas Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996 - Assessshyment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the proshyvision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of longshyfinned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of shortshyfinned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roeleveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997 - Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessmeshynt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994shyModelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998 - Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997 - The spatialdimension in population fluctuations Science 278(5343)1621-1623

ROBERTS C M 1997 - Ecological advice for the global fishshyeries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 1998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggregashytions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 267 - 284

ROSE G A 1997 - The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

]998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the rankingTopics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relation-ships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fish-eries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

1998 Lipinski et al International Cephalopod Fisheries Workshop Results

Table II Results of the questionnaire on the final day of the Cape Town workshop

467

Number of respondents assigning the ranking

Topics and problems of importance below to the problem listed

I 2 3 4 5 6

Key features of fisheries biology

I Most exploited squid species have a very short lifespan (annual or sub-annual) 19 5 2 I 0 0therefore the only manner by which catch levels in one ycar affect abundance inthe next is through the stock-recruit relationship

2 Because of the annual nature of squid species and their high level of interannual 2 8 6 5 2 0recruitment variability constant TAC harvesting strategies involve a relativelylow level of resource utilization although the lack of utilization of good recruit-ment in certain years of a mid-trophic level species may have ecosystem advan-tage

3 High within-season variability linked to pulse recmitment 2 4 2 5 4 34 Improved management measures would likely result from real-time monitoring 2 2 5 0 4 35 Short duration of adult phase in relation to total lifespan I 2 6 6 2 2

Key areas of rcsearch

I Clarify the life cycle in space and time (eg duration of different stages location 13 6 4 2 2 0of spawning nursery feeding grounds)

2 Identify links between the environment and resource recruitment 4 5 I 4 3 I3 Systematics (including paralarvae) 3 I 0 I I I4 Stock structure (genetics) good idea of stock differentiation for management 2 4 2 0 2 I

Kcy conclusions regarding management

I Account needs to be taken in assessments that squid recruitment at the fishing 5 5 3 4 2 Igrounds occurs as a series rather than as a single pulse

2 The optimal approach to management depends upon objectives which may vary 5 2 2 2 0 2for different fisheries one cannot maximize catches and minimize catch variability- there is a need for trade-offs (risk policy)

3 Because information on cephalopod fisheries is relatively sparse relative to the 4 I I 0 I 3situation in finfish more benefit can be expected of research in this area

4 Effort control is a cheaper alternative than TAC but account needs to be taken of 3 2 5 2 I 0the possibilities that cpue is not proportional to overall abundance and ofincreased efficiency

TAC = Total Allowable Catch

33 were returned the collective results of which aregiven in Table II It is apparent that although strongand varying views were expressed a fairly high levelof consensus was reached regarding key features ofcephalopod fisheries biology and research The keyconclusions regarding management of cephalopodswere less clear

In terms of the key features of cephalopod fisheriesbiology the most commonly endorsed view was thatmost exploited squid species have a very short lifespan(annual or sub-annual) therefore the only manner bywhich catch levels in one year affect abundance in thenext is through the stock-recruit relationship Thisopinion underlines the importance of what are currentlythe most crucial problems in cephalopod assessmentnamely longevity growth and stock-recruit relationshyships

For the key areas of cephalopod research the mostcommonly accepted need was to clarify the life cyclein space and time (eg duration of different stageslocation of spawning nursery feeding grounds) Ofsecond importance was to identify links between theenvironment and resource recruitment

In the key conclusions regarding management ofcephalopods the most frequently chosen statementwas that account needs to be taken in assessments thatsquid recruitment at the fishing grounds can occur asa series rather than a single pulse Other importantpoints were respectively

bull the optimal approach to management dependsupon objectives which may vary for different fishshyeries one cannot maximize catches and minimizecatch variability - there is a need for trade-offs

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommend-ations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should con-centrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial vari-ations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fish-eries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994- Chokka squidon the Agu]has Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996- Assess-ment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the pro-vision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of ]ong-finned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of short-finned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roe]eveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997- Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessme-nt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994-Modelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998- Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997- The spatialdimension in population fluctuations Science 278(5343)162]-]623

ROBERTS C M 1997 - Ecological advice for the global fish-eries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 ]998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggrega-tions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Air J mar Sci 20 267- 284

ROSE G A 1997- The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommendshyations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should conshycentrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial varishyations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fishshyeries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994 - Chokka squidon the Agulhas Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996 - Assessshyment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the proshyvision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of longshyfinned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of shortshyfinned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roeleveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997 - Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessmeshynt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994shyModelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998 - Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997 - The spatialdimension in population fluctuations Science 278(5343)1621-1623

ROBERTS C M 1997 - Ecological advice for the global fishshyeries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 1998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggregashytions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 267 - 284

ROSE G A 1997 - The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal of Marine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommend-ations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should con-centrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial vari-ations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fish-eries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994- Chokka squidon the Agu]has Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996- Assess-ment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the pro-vision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of ]ong-finned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of short-finned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roe]eveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997- Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessme-nt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994-Modelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998- Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997- The spatialdimension in population fluctuations Science 278(5343)162]-]623

ROBERTS C M 1997 - Ecological advice for the global fish-eries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 ]998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggrega-tions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld(Eds) S Air J mar Sci 20 267- 284

ROSE G A 1997- The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

468 Cephalopod Biodiversity Ecology and EvolutionSouth African Journal ofMarine Science 20

1998

bull because information on cephalopod fisheries isrelatively sparse relative to the situation in finfishmore benefit can be expected from research in thisarea

bull effort control is a cheaper alternative than [TotalAllowable Catch] TAC but account needs to betaken of the possibilities that [catch per unit effort]cpue is not proportional to overall abundance andof increased efficiency

In this prioritization of important issues in cephalopodmanagement there is an emergent dualism betweenfinfish-derived cautious observations and recommendshyations specific to the squid life cycle The value ofresearch in correctly shaping cephalopod fisheriesand their management also scored highly

HOW TO AVOID MISTAKES OF THE PASTCONCLUSIONS

It became abundantly clear that the views of mostparticipants were that current research should conshycentrate on improving understanding of the biologyof cephalopods in a life-cycle approach Spatial varishyations of cephalopod survival should be taken intoaccount particularly when extrapolating abundancesurvey results and fisheries statistics Spatial variabilityis also a key factor to consider when selecting areasfor andor timing of closures in effort-regulated fishshyeries The implementation of a management regimethrough a limited entry programme needs reasonablygood estimates of biomass which are seldom availableIn the absence of such data a cautious trial-and-erroradaptive management approach is required whichdemands that effort levels are reviewed periodicallyFurther effort has to be reduced immediately after asubstantial decrease in catch rates

Differences between fish and squid are likely to beimportant at the following stages

bull design of monitoring programmes (eg temporaland spatial scale of catch and effort data)

bull design of assessment modelsbull choice of management strategies

It is therefore of great importance to research toestablish these differences However cephalopod andfinfish fisheries are similar in that both require stablelong-term monitoring in order to understand thedynamics of the resources and the associated fleetsThere is no panacea for a lack of long-term monitoringWhere environmental forcing or community-leveldynamics have strong effects on resource productivitythey need to be monitored and understood as well

LITERATURE CITED

AUGUSTYN C J LIPINSKI M R SAUER W H H ROBERTSM J and B A MITCHELL-INNES 1994 - Chokka squidon the Agulhas Bank life history and ecology S Afr J Sci90(3) 143-154

BASSON M BEDDINGTON J R CROMBIE 1 A HOLDENS 1 PURCHASE L Y and G A TINGLEY 1996 - Assessshyment and management techniques for migratory annualsquid stocks the Illex argentinus fishery in the SouthwestAtlantic as an example Fish Res 28(1) 3-27

BEDDINGTON J R ROSENBERG A A CROMBIE J A andG P KIRKWOOD 1990 - Stock assessment and the proshyvision of management advice for the short fin squid fisheryin Falkland Islands waters Fish Res 8 351-365

BRODZIAK J K T and W K MACY 1996 - Growth of longshyfinned squid Loligo pealei in the northwest AtlanticFishery Bull Wash 94(2) 212-236

DAWE E G and W G WARREN 1993 - Recruitment of shortshyfinned squid in the Northwest Atlantic Ocean and someenvironmental relationships J Cephalopod BioI 2(2) 1-21

JACKSON G D 1994 - Application and future potential of statolithincrement analysis in squids and sepioids Can J Fish

aquat Sci 51(11) 2612-2625LIPINSKI M R 1998 - Cephalopod life cycles patterns and

exceptions In Cephalopod Biodiversity Ecology andEvolution Payne A 1 L Lipinski M R Clarke M R andM A C Roeleveld (Eds) S Afr J mar Sci 20 439-447

McQUINN I H 1997 - Metapopulations and the Atlantic herringRevs Fish Bioi Fish 7(3) 297-329

MURATA M 1989 - Population assessment management andfishery forecasting for the Japanese common squid Todnrodespacificus In Marine Invertebrate Fisheries their Assessmeshynt and Management Caddy 1 F (Ed) New York Wiley613-636

MURPHY E 1 RODHOUSE P G and C P NOLAN 1994shyModelling the selective effects of fishing on reproductivepotential and population structure of squid ICES J marSci 51(3) 299-313

ODOR R K 1998 - Can understanding squid life history strategiesand recruitment improve management In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 193-206

PAULY D 1998 - Why squid though not fish may be betterunderstood by pretending they are In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M R and M A C Roeleveld (Eds)S Afr J mar Sci 20 47-58

PAULY D CHRISTENSEN Y DALSGAARD J FROESE Rand F TORRES 1998 - Fishing down marine food websScience 279(5352) 860-863

RANTA E KAITALA V and P LUNDBERG 1997 - The spatialdimension in population fluctuations Science 278(5343)1621-1623

ROBERTS C M 1997 - Ecological advice for the global fishshyeries crisis Trends Ecol Evo 12(1) 35-38

ROBERTS M 1 1998 - The influence of the environment onchokka squid Loligo vulgaris reynaudii spawning aggregashytions steps towards a quantified model In CephalopodBiodiversity Ecology and Evolution Payne A I LLipinski M R Clarke M Rand M A C Roeleveld(Eds) S Afr J mar Sci 20 267 - 284

ROSE G A 1997 - The trouble with fisheries science Revs FishBioi Fish 7(3) 365-370

SAKURAI Y KIYOFUn H and S SAITOH 1997 - The effect

1998 Lipinski et at International Cephalopod Fisheries Workshop Results 469

of changing environmental regimes on Todarodes pacificuspopulations a possible scenario In Programmes andAbstracts of CIAC 97 Cephalopod Biodiversity Ecologyand Evolution Cape Town AugustSeptember 1997 80-81

SCHNUTE J [T] 1981 - A versatile growth model with statisti-cally stable parameters Can J Fish aquat Sci 38(9)1128-1l40

SHAW P W and P R BOYLE 1997 - Multiple paternity withinthe brood of single females of Loligo forbesi (CephalopodaLoliginidae) demonstrated with microsateJlite DNA markersMar Ecol Prog Ser 160 279-282

WELLS M J and A CLARKE 1996 - Energetics the costs ofliving and reproducing for an individual cephalopod PhiTrans R Soc Lond 3518 1083-] 104

1998 Lipinski et at International Cephalopod Fisheries Workshop Results 469

of changing environmentalregimes on Todarodes pacificuspopulations a possible scenario In Programmes andAbstracts of CIAC 97 Cephalopod Biodiversity Ecologyand Evolution Cape Town AugustSeptember 1997 80-81

SCHNUTE J [T] 1981 - A versatile growth model with statistishycally stable parameters Can J Fish aquat Sci 38(9)1128-1l40

SHAW P W and P R BOYLE 1997 - Multiple paternity withinthe brood of single females of Loligo forbesi (CephalopodaLoliginidae) demonstrated with microsarellite DNA markersMar poundCol Prog Ser 160 279-282

WELLS M J and A CLARKE 1996 - Energetics the costs ofliving and reproducing for an individual cephalopod PhiTrans R Soc Lond 3518 1083-1104