C.M 1q9~! L:51Biolog. Oceanogr. Commt.

Ibllot

DIEL VARIATONS IN VERTICAL DISTRIBUTION OF COPEPODSIN ~HE NORTH JBERIAN COAST

M.L. FERN~~DEZ-PUELLES (1)"L. VALDES (2)M. VARELA (3)

M.T. ALVAREZ-OSSORIO (3)

Instituto Espanol de Oceanografia

(1) Centro Oceanografico de BalearesApdo. 291 07080 Palma. Spain

(2) Centro Oceanografico de SantanderApdo. 240 39080 Santander. Spain

(3) Centro Oceanografico de La CorunaApdo. 130 15080 La Coruna. Spain

ABSTRACT

Included in the framework of the S~~P project (Sardine and AnchovyRecruitment Program), a study of copepods vertical distribution hasbeen carried out.

Zooplankton sampIes were taken at three different stations during a24 h. period, in the proximity of a drogue buoy using a LHPRsampling net, so that, it is assumed the same water mass wascontinuously sampled.

Copepods were counted and classified into seven categories accordingto their size. Development stages and copepodites formed the bulkof copepods population. The vertical distribution of zooplankton inthe water column seems to be related to that of chlorophyll. In allthe stations the pattern of sardine larvae densities is mainlyrelated to the abundance of nauplii and smaller fractions ofcopepodites. In general, the three areas reflected differences in-the plankton distribution which is discussed.

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. . . .I NTRODUCTION

7he Sardine Anchovy Recruitmcnt Project (SARP) form part of acooperativc European programme between Spain~ Portugal and Germanyon larvae. of sprat (Spratus spratus" L.) in the German. Bight,sardine (Sardina pilchardus, Walbaurn) off the North Coast of Spainand anchovy (Engraulis encrasicholus, L~) along the coast ofPortugal. As a contribution towards the SARP project, from April 17to May 121991, a pilot survey along,the North Coast of Spain ,wascarried out with the main purpose of Knowing the spawriing sardinedrea, the hydrographie structure and the rnicrozooplankton aburidanceto idcntify representativc sites for more detailed studies on larvalfcedirig. In this frarnework, a study on copepods, verticaldlstrib~tion (frcictionated in eg~s, natiplii, and five body ,.sizeclasscs) was ,included. (SARP), from April 17 to May 12, 1991 apilot survey along the North Coast of Spain was carried out~

According to prevlous observations, unfavorable oceanographicconditions are,arnong theprincipal determinants of larval survival;and these conditions.are reflccted in the plankton distribtition. Onthe otherharid~ food availabitility is considered tobe orie of themain links betweenoceanography and larval survival (Hunter, 1976;Bailay arid Houde, 1989; Turner, 1984). In this sense, the goal oflhis paper is to describe the aburidance and distribution of thecopcpods (from eggs to adults) arid the diel vertical variationpattern inthree sites sarnpled alongthe Ncirth Coast cif Spainwherethe aburidance of the sardine larvaewas important and likewise,their main biotic and abiotic parameters in relationship.

As part of the same cruise, studies of the particulate assemblages,distribution of thc sardine eggs/larvae, and larval feeding havebeen published elsewhere (Garcia-Soto, et al.; 1991; Robins et al.;1991; Lopez-Jarnar et a1., 1991;. Conway et ~:il., 1991 ~ )

Thc sarnpling to determirie the diel vertical distribution of themicrozooplankton was carried out using a modified version of ,thcLonghurst Hardy Plankton Recorder (LHPR; Williarns et al.; 1983),The double LHPR, used in the present study, consisted ofa fine net(53 ~ mesh aperture) for themicrozooplänkton and a coarse net (200

J..Uri mesh aperture) for thc sardirie.larvae.Each net was attached to acod~end unit which takes aseries of sequential. sarnples with aresolution bctter thari 5 m. SampIes were collected in oblique tows

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dt 2-3 Knots. During thc haul thc sample depth~ and flow rate ofthe . fine net systemwcre monitored and logged to an on-board PCcomrnunicating via corcd cablc separate to the towing cablc.

In ,order to ailow sampling tofollow the same water mass; a drogucddrifting buoy wasreleased at the initial station position~ Thisbuoy was then followed,for subsequent samplirig over the 24 hperiOd.At uifferent times LHPR hauls were taken to give a day/night seriesat each' site (Table I). Valid sampIes wereobtained on all haulswith the cxccption 'of, thc fine mesh sarnplcsin the 3rd haul inAsturias which was invalidated due to, a split filtering net. . Onboard , the plankton sarnples were preserved ,in 4% bufferedformaldehyde solution for subsequerit analysis in the laboratorY.

The zooplankton >53 lJ.IYl was classified ill 3 maingroups: thecopepods, the, nauplii and the eggs. Then the copepods wereclassified, into 5 differents sizes according to the cephalotoraxlerigth «0;45; 0;45-0.70; 0.70-0.95; 0.95-1.20 and >1.20 mm forclasses ,Cl; C2, C3, C4 and.C5 respectively)~ The size of naupliiwas <0.45 mm, and the size of cggs <0.14rnm•. Results were convertedto staridardised plots of vertical distribution profiles~

The sca. water temperature and salinity, values were taken with ,thehigh speed tow net at the same time as the rnicrozooplankton samples.The chlorophyll a and particlesize distribution was samples atthree standard depths with a 3 1 Niskin bottle;, Additionallyphysical and other biological parameters were monitored by CTDprofiles and vertical UNDULATOR dips for temperature, salinity andchlorophyll a~

Univariatestatistic included ANOVA were performed in order toidentify any differences in abundance among stations, time, sizesand depths. For delimiting individual groups of faunal similaritiesclustering was rcalized at the three sites takirig into account thecompleted 24 h hauls using thc Bray-curtis sLmilarity index.Finally a no-metric multidimensional scaling (MDS) was employed fordelimiting time and depth distribution as described by Field et ale(1982) and Clarke arid Green (1988). Thc statistical" calculationswere performed ,using the software package, STATGRAPHIC 1 forunivariate arialysis arid the software package PRIMER 2 forciultivariate analysis;

RESULTS

Hydrography and chlorophyll distribution

Duririg thc, first part cif the cruise (from April i7to. April 23)winds blowing fram NE resulted in'drifting of the buoys in St-1(Asturias) and St-2 (La Coruna) to the W (Fig.1). From April 24 toMay 12 the windsshifted to S, SW resulted in the drifting of thebuoy in St-3 (Santander) to the E~ ,In Santander, as the winds blewstrong thc displacement of the buoy in the 24 h period was of 14' inlongitude while in Asturias and La Coruna the winds were moderate

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~rid the dlsplacecieht of the buoyswere only of 6' and 2;8' oflongitudc rcspectivcly (Tablc I). The sca water tcmpcrature wasriniform in thc threc.,24 h. stations rangcd from mean~values of 11.95oe . (Asturias 19;00 am) abnd 12;27 ~C (La eoruiia,4.08 a;m.) for , thewhole water column thc warmer tcmperature was fourid in Santander,the minimum values were found in La eoruiia being 11.3 oe at thesurfacc, the maximUm water temperature ,in Santander went to 13;2 °C.Salinity was higher ,in La CORUNA (USP=35;70) than in Asturias(USP=35;65) and Santander (USP=35.20); Neverthcless sincediffcrences ware so samll, we assUme that the. physicalcharacteristics of,. thc water mass were the same at the three 24 hstations sampled. elorophyll distributions,weresimilar in Asturiasand La eoruiia (Fig.2) showing a stratification pattern with littlevariations throughout the 24 period of study, howevcr concentrationswere slighty higher in La eorufia than in Asturias. In Santander thechlorophyll values were below 0.5 mg ehla/m3 and the distributionswas very uniform not showing any sign of stratificatiori.

A·-'-'.

__ Zooplankton abundance arid composition

Copepod eggs, nauplii,copepodites arid copepod account for more than90 % of ciicrozooplnakton (>53 um) .cormriunity; TWenty~one species ofadult copepods were identified. Paracalanus Earvus, Pseudocalanuselongatus and Clausocalarius,sPP. made 41-65% of total abundance.Acartia claussi account for 8-31% .and· Oithona plumifera, O~

helgolandica and o. nana made 7~30% oftotal abundance. Accordingto the cephalotorax length, the group e5 (>1.20 ~m) include somecopepodites and adults of bigger, copepods such as calanushelgolandicus" Euchaeta.hebes, Metridia lucens, Candancia,armata andCentropages typicus. The group e4 (0.95-1;20 mm) includecopepodites of the former species arid adults of P. elongatus;

Group e3 (O.70-0;95)inciude adults of P. parvus; Clausocalanusspp., and A. clausi, copepodites of these species and adults ofOithona sp~.- and adults of the smaller species such as Microsetella.norvegica, Macrosetella. rosea, Oncaea,media, etc.

Copepods. assemblage and their relative abundance are almost the samein the three 24,h stations. However, in term of numbers, abundancesof adult copepods and copepodites were.similar only between St-1 andSt-3 (mean values of 3805 and, ,4451 ind;m/. 3, 37 and 59%respectively( whilc in,St-2 mena abundance only made 1945 ind.m/ 3

(46%). Eggs abundance in St-1 was tenfold the abundance en St-2 andSt-3 with mean valucs of 967, 96,and 85 eggs m/ 3 in each station.Nauplii abundance in St-1 was twofold,the abundance of St-2 and St-3with mean abundance of 5564, 2145 and.2958 ind. m/ 3, in Asturias;La Corufia and Santarider; 54, 51 and 39% respectively (Fig.3)~

Microzooplankton vertical distribution

To ascertain theAsturias (Stationwere carried out

vertical ,distribution of the zooplankton in1), 4 different hauls from April 24 to April 25at 10:00 am, 17:30; 22:20 and 3:30 am. sirice

1 STATGRAPHICS 1s registered trademark of Stratistical Graphicseorporation; ,2 PRIMER is statistical software package developed in PlymouthMarine Laboratory.

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sunrlse on that day was a~ 5h~30' an~ suns6~ ~t 19h.21', we canconsiderer 2 day/hauls and 2 night/hauls.

Thc , ver~icai distribution of, the 7 groups analyscd has been shoWnin Fig.4 at threc different ,hours sampled.

In thc morning haul: thc average nUIDber of the copepods was 4009ind/m3 , 5575 nauplii/m3 and 834 eggs/m3~, Thc maximum of theorganismes was at. 10 m depth where the smallcr nauplii and thesmallcr copcpods, at 20 m depth, were the more ~bUndant. Althoughother peack appeared ,at 40 m depth, it was lcss. The biggercopepods showed 2 maximum values at 20 and 45 m depth; as weIl astbe eggs. Thc smaller nauplii and copepods formed the 79% of thetotal copcpods.

In the afternoon haul ~he average of tbe copepods decreased with2560 ind/m3 , 3286 nauplii/m3 and 768 ind/m3. The copcpodsdistribution, at that,rrioment, seems to oe concentrated about15 ;.;. 30m and again thc smallcr copepods and nauplii formed the bulk of thezooplankton being 75%.

During the night haul ~he nUmber of organismes lncreasedwith 4847copepod/m3 , 7830 nauplii/m3 and 1299 eggs/m3 •. On this ocassiononly the maximum was found between 15-25 m depth where the naupliiwere very concentrated at 20 m,depth and the copepods around them,cven thc, bigger copcpods; The smaller organismes (nauplii +copcpodites) formed 74% of the total;

In, general'we'could see that during the day th~y were dispersed inwider layer of water from 10 to 40 m,depth, and not so conceritratedas in the other hauls. In the afternoon, the orgariismes moveupward, especiallY,the bigger sizes ,and at night the'bigger copepods wich didnot move up earlier wentto theupper laycrs, while the nauplii and the smaller copepoditesconcentrate thcmselves close to the 20 m layer;

At Station 2 (Coruna Coast) arid from April 28 to April 29- 4different LHPR haulswere carried out from the bottom, ( 100 m depth)to the surfacc , now 20 layers were considered. Inthe analysis"cxcept the 4:00 am haul the copepods fractions were only two (copepods< 0.7 mm and copepods >0.7 mm). The vertical distributionis shown in Fig 5.

At the 8:00 haul we found the maximum abundarice; thc average valuewas 6942 ind/m 3 whcrc the copepods formed 45%and thc.nauplii 53% ~On this occasion tbenauplii and the copepodites;<0~7rnm, formedtbc bulk being 86% of the total; In general the maximum nuIDbcr ofindividuals were at 20 to 40 mdepth , all of theffi, at the samelayer~ Bivalve larvac were also concentrated (2425 ind/rn 3) irideaper layer (55 m depth) where the riggs were very abundant.

At ~he, 18:00 haul the average nUmher decreased with 3052 ind/m 3

with 51%, of copcpods and 49% of nauplii~ .In this occasion thebivalvc larvae also decreased beirig 1146 ind/m 3 All of them wentupward to thc surfacc cxcept thc Cgg5.

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at 75 m depth off Santanderbeen carried out~ On tbisThe vertical distribution is

At the 24:00 haul the organismcs valuc reach thc minimum with 1920indim 3 whcre neithcr thc copepods, >0.7 mm, northe nauplii went tothc surface and only the smaller copepods a slightly increased innumbers in' the first 5 meters.

At 4:00 am the average was 4848 ind/m 3 with a clear increase at thesurface, of the nauplii, as weIl as the copepods.

Dur.i..ng the afternoon ,all the groups went upward close to thc 20-25m layers~ Except at midnight, in the complete darkness , all, themarine microzooplankton went to the surface incresing theirabunddnce.

At Station, 3 , From May 10 to May 11Coait, 6 different LHPR hauls haveuccdsion 15 layers were considered.show in Fig 6.

The maximun values were found at the 14:40 pm baul with 11470 irid/m~, 51% of nduplii and 23 % of smaller copepodites (Cl). Copepodsfrom 0.45-0.70 mm were, also abundant (19%). The distributionobserved was very irregular witb a lot of peacks as in thc surface,30 m, 60 m and 75 m deptb.

The minimum values were observed just after the sunset (19:40 hauI),thus the sunset bappened at 19:20 haul, the average layerwas 3314ind/m3, 31% of nauplii,41 % of smaller copepods (Cl) and 20 % of0.45-0.70 copepods (C2). The surface layer aS.well as tbe 40-45 m deptb were the most concentrated.

At ,20:40 pm haul tbe average layer increased slightly with 5656ind/m3, tbe O. 45 - 0 •7 ,nUll copepods" were more important than in thcother hauls. Again tbc nauplii (24%) and thc smaller copepods (37%)formed the bulk of thc copepods. ,Irregular distributed peacksappeared with the maximum about the 45 and 55 m depth.

At, the 2:05 am haul 7804 ind/m 3 were counted witb 30% of naupliiand 32% of smaller copepods. The nauplii and tbe copepods seems tobe eoneentrated about 15-20 mdpeth; The peaek about the 55 m depthhas still present at this time.

Very early in the morriing, 5:55 am baul (5:20 am sunrise time), tbeaverage number of zooplankters was 9347 ind/m3 , thc bulk of tbecopepods (NI-Cl and C2) were elose to thc surfaee' (39, 23 and 27%respectively). The other peacks about 30 and 50 m depth were stillt.here.

At 10:40 am haul the organismes number decreased at 7376 ind/m3,eacb layer; All the groups went down to medium layers around 30 to50 m depth.

Tbe nauplii seems to do important diel variation and cspecially, atmidday they went to tbe surfaee~ Thc Cl do not seemto do anyvertical migration and always keep themselves at medium layers. Tbc

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Inedium size copepods (C2 and C3) wcnt upward to the surface at nightand cvcn during the sunrise. The biggcr copepods (C4 and C5) movcdthemselvesvery irregularly, firiding them closc to thc surfaceduririg thc day.

Vertical distribution of microzooplankton follows a similar patternto that of chlorophyll. In Asturias and La Corufia,microzooplanktorl, irrespcctivc of thc hour or day, concentrated intbe upper layers of the water column, where chlorophyllvalues arehigher~ Nevertheless, in Santander wheretbe chlorophYll is evenlydistributed vertically, the microzooplankton does not show a clearvertical distribution as it does in Asturias and Sandander.

One way arialysis of varianc~ on log (x + 1) trarisformed abundancesfor all the stations revealed significant differences between thesizes and orgariismes but no thc depth~

Cluster analysis based on zooplankton abundances at each levelsamplcd show high affinities between groups at thc three 24.hstations (Fig.7). Each linkage include size classes that representeconsecutive developmental stages, sbowing that the cluster has aclear biologicla meaning. At a similarity level of.75% thc three 24statioris are divides,in twogroups, in the first, classes Cl, C2 (inCorufia) and C3 (in Asutiras and in Santander) appear together withthe nauplii (N1); in the second group, the association include bigcopepods and copepodites of the classes C4 and CS •. Copepod eggs donot show a high affinity for ariy of the groups and their appear withC2, C3 in Asturias but with C4, C5 in La Corufia.arid Santander~

These results suggest that the classes with a smaller body size,sich as N1, Cl, C2 and C3 exibit a similar behavior patrern withrespect to their position and movements in the water column. Thesesame trend is observed bewtween C2 and CS, but the behaviour betweenthe sarnller and the biggers may be disimilar.

The depth clustering analysis (riot represented) reveals theconcentration of the' bulk, ofcopepods in the upper 50 m.Differences in depth aburidances, are also evidenced by otherordinatio ntechniques as MDS (Fif.8, 9, 10)~ When. depth-tiIDeabundarices are plotted over sardine abundances, it is noted thatmicrozooplankton abundances and sardine abundance,are related inboth, depth and day/night distribution. .Nevertheless, maximu,numbers of organisrn appear during night in layers 35, 30 and 25 mdepth. This relationshipis particularly evident in Asturias whenmultiple correlatiori between the sardine larvae and nauplli was0.8539 and with thc copepods 0.6573 (both at the depth of maXimumabundances, 30 m).

DISCUSSION

Although one of the purposes of this paper was to know the behaviorpattern.of the microzooplankton common ,to thethree areas studied,the greater diversity of ecological factor involved in thc stations

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sampled does not allow us to explain eompletely thc diff~rerieesbetwcen thciir diel vertielä variation. During, deeades ofinvestigationson, zooplankton migration have found a,lot of eauseswhieh ean explain together the plankton movement, ineluding verticalas weIl as horizontal migration, ehanbes,in feeding behavior andalgernating reproduetive states (Haney, 1988)~

On the basis of luetuations in envlronmentäi faetors, zooplanktonexhibit a variety of daily eyeles and äny region has peeuliarfeatures where the plankton respond th,these differenees (Bayly,1986). Moreover therc are many meehanismes controlling the dielvertiela movement asO light, temperature, food arid predatoravoidanee. Many authors considerer that the food base for thesardine larvae are the samller developmental stage eopepods andtheir egss (Last, 1980; Conway et al., 1991)~ On this sense thebulk of the cornmunity studied was forme by the nauplii and the'smallercopepods size (Cl) never below 70%;

If we considerer the three stations studled were, different, in theirhydrographie eonditions (Cabanas etal~, 1991; Lavin et ale 1992)we ean understand that thc diel vertical variaiton will bedifferente.

Observing ,those diel variäitons between Asturias and La Corufia ,ispossible to appreeiate elear vertical migrations at night in thcmore aburidnat groups, exeept thc smaller eopepods,.but in Santanderthcy werc very irregularly distributed throughout the period, wherethe maximu, nUIDber of individual appared during mdday, insteadofdurign the night. Neverthriless thiseciuld be understood by thestudy cf the vertieal eomposition structure; beeause differentspeeies show different behavior with noeturrial or reversalmigrations going to thc upper layers (Harris, 1988)~

This migrations, is very confused speeially for smaller size ranges(lower thari 250 ~),:thus depending of,the period cif time, theirmovement to the surfaee ean riont be elear, althougt ,the biggereopepods always seems'togo upward (Magnessen, 1989)~ ,In our stUdythe, size elaseed analysed were ccnsidering thc sardine larvaefeeding objetive, so that it was not in smaller sizes.

In Norway (Lie et al, 1983) during May was observed a elearmigration for bigger eopepods, >250~, but ,not during June,likewise it oecured in Santander. Probably the period of timesampled among the three stations ean be other faetor of variabilityvery important.

If we considerer appart of the temporal arid spatialvariationbetween the; thelong buoy desplacement, in the ease of Santnader;should be eonsidered as other faetors involved (as water massesmovement, adveetion) to understand that irregular distribution. Itis very eomplex to'study thediel vertiela migration in one fixloeation but in a movement systems seems to be really impossible tounderstand (Margalef; 1980).

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Even when lhe drogge was followed continuosly in any station doesnot seem to be the same water masse from surface to bottom.Although the abundance was very different between day and nighthauls in La Coruna and in Asturias, the proportion of their~omponents was similar, but in the case of Santander was moredifferent (Fig.ll).

In Asturias we found a relation between the sardine and themicrozooplankton, the copepods as weIl as the nauplii in the upper30 m depth. The vertical migration for the sardine larvae seems tostart in the late afternoon earlier than the bigger copepods,keepirig their maximum during night.

In La Coruna the night vertical migration to the upper layer wasalso clear for the microzooplankton, . even when their maximum

.abundance was early in the morning at 30 m depth during the day.The sardine larvae appeared in deeper water, and again in lateafternoon they went up presenting their maximum abundance. The eggsdistribution was maximum at deeper layers specially during the day.Seems to be that the development of the eggs took place below 60 mdepth as other places in the Celtic Sea (williams et al, 1987).These eggs distribution does not appear·in the other stations. Samecorrelation among the plankton and the sardine was found in theupper layers.

In Santander the microzooplankton distribution was very irregularalong the water coltimn. The maxiumum microzooplankton abundance wasfound in the afternoon for all the size classes, thus seems to be inrelation to tbe chlorophyll and to the sardine larvae distribution.Nevcrtheless no correlations were found. Only some nocturnalmigration in upper layers was found to the bigger sizes of the~opepods.

The simultaneous use of univariatepermitted the interpretation· andobserved.

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and multivariate techniquesconfirmation of the results

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REFERENCES

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BAILY, I;A;E. (1986);- Aspects of died vertical migration and itsenigma variations in Limnology in Australia. Monographiaebiologieal. Vol. 61: 349-368.

BAILEY, K~M. and HOUDE, E~D. (1989).- Predation as eggs and larvaeof marine fishes and the recruitment problem. Adv. Mar.BioI., 25. 1-83.

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CABANAS, J.M., G. DIAZ DEL RIO, A•. LAVIN and T.NUMS, 1992.-Hydorgraphic conditions off the galician coast NW of Spain,during an upwelling event. Bol. Inst. Esp~ Oceanogr;8/1) : 27-40. ==....;;....--==...;:;...;;,.--==~_.....::..:==~

CT.AFKE, K.R. and GREEN, B.H. (1988).- Statistical desing andanalysis for a biological effects study. mare Ecol. Prog~.Sero 46:213-226.

CONWAY,& ••

D.V.P., TRANTER, P.R.G.~ FERNANDEZ DE PUELLES,S.H. COOMBS, 1991.- Feeding of larval spratsprattus L.) and sardine (Sardina pilcharduslCES, 1991/L:76.

M.L. and(SprattusWalbaum) •

FIELD, J.G., K.R.strategy forMarine Ecol.

CLARKE and R.M. WARWICK. (1982).- Aanalyzing multispeies distribution

Progr; Ser~ 8:37-52.

practicalpatterns.

LAST,

GARCIA SOTO, C., N.I.H. HALLIDAY, S.B. GROOM, A. LAVIN and S.H~COOMBS (1991).- Slope current and upwelling off the NW coastof Spain, .satellite imaginery and plankton distributionECOSARP pr6ject. ICES 91 C:17.

. .

HANEY, J. (1988).- Diel patterns of zooplankton behavior;. Bull.of marine Science 43(3) 583~603.

HUNTER, J.R. 1976~- Report of a colloquium on larval fish mortalitystudies and their relation to fisheries research, january1975. NOAA Tech; rep. NMFS Circ. 395: 5pp.

J.M. (1980).- Tbe food of twenty species of fish larvae inthe west-central North Sea. FishRes. Trieh. Rep. MAFFDireet. Fish Res. Lowestoft, 60 44 pp.

LAVIN~ A., 1991.- Condieiones '. hidrograficas de la zonaGalieia-Cantabrieo. Abril~Mayo 1990. Inf. Teen. Inst.Esp. Occanogr. nQ 109, 57 pp.

LAVIN, A. G. ,DIAZ DEL RIO, J.M. CABANAS and R. CARBALLO, 1992~­

SARP-AREA ·cruise. Hydrography and nutrients. Bol. Inst.Esp. Oeeariogr. 8(1);7-26.

LIE, V., T. MEGNESEN, B. TUNBERG and D.L. AKSNESS (1983).­preliminary studies an the vertical distribution of, sizefraetions in the zooplankton eommunities in Western NorwaySasia 68,65-80.

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LOPEZ-JAMAR, S.H. COOMBS, F. ALEMANY, J.BANET (1991).- A Sarp pilot studypilchardus) off north and northwestlCES C.M. 1991/L:69.

ALONSO, F. ALVAREZ,for sardine (Sardina

Spain in April-May 1991

MAGNESEN, T. (1980).- Vertical distribution of size fractions inthe zooplankton community in Lindaspollene. Western Norway2. Diel variations. Sarsia 74:69-77. Bergen lSSN 4827.

MARGALEF, R. (1980).- Perspectivas de la teoria ecologica. Blume,Barcelona: 110 pp.

ROBlNS, D. B. , M. VARELA, B. CASAS, N. C.H.Characterization to natural particulatethe northern coast of Spain in relationsardine spawning lCES, C.H. 1991/L.81.

HALLlDAY (1991).­assernblages aroundto a SARP study of

TURNER, J.T. (1984).- The feeding ecology of some zooplankters thatare importante prey items of larval fish. NOAA Tech. Rep.NMFS 7, 28 pp.

WlLLlAMS, R., D.V.P. CONWAY and N. COLLINS (1987).- verticaldistribution of eggs, nauplii and copepodits of Calanushelgolandieus in the Celtie Sea. Marine Biology 96,2'17-252.

WILLIAMS, R., N. COLLINS and D.V.P. CONWAY (1983).- The doubleLHPR system, a hilgh spedd miero and maeroplankton sampIer.Deep Sec. Res. 30, 331-342.

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Fig.l.-

Table.I.-

Fig.2.-

Fig.3.-

Fig.4.-

Fig.6a.-

24 h Stations position and microzooplankton biomass (>53 um) during April 1991 in the North Coast of Spain.

LHPR hauls information in the three Stations sampled inthe North Coast of Spain.

Chlorophyll a distribution in the three 24 h stations.

Copepods spatial variation (abundance) in the NorthCoast of Spain.

Microzooplankton vertical distribution at Station 1.

Microzooplankton vertical distribution at Station 2.

Microzooplankton vertical distribution at Station 3.

Fig.6b.- (Cont.) Microzooplankton verticalStation 3.

distribution at

Fig.7.-

Fig.8.-

4tJ.9.-

Fig.10.-

Fig.ll.-

Clustering size-classes at the three stations analysed.

MDS plot's resulting from the microzooplankton data inStation 1 and the superimposed sardine larvaeabundance.

MDS plot's resulting from the microzooplankton data inStation 2 and the superimposed sardine larvaeabundance.

MDS plot's resulting from the microzooplankton data inStation 3 and superimposed sardine larvae abundance.

Microzooplankton temporal variation during 24 h periodin the North of Spain.

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9°

ECOSARP APRIL 1991• >80

• 40-80

• 20-40

~ 10- 20

0<10

Fig, 1

ZOOPLANKTON (>53 ~M)

~RY WEIGHT (mg m-3 )I

2nd 2"" BUOT POSITIONS

STAAT

OB"

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lI',B'w

43' 311.0'N

43' 36,a'N6'47' W

,oe •• ", BOOT /'OSIT1OHS

ASTURIASSTAAT-

lI'39'W

43'24' N3'24'W 3'

Depth 53 pa Itean/std MeaD/ltdStation Date Tille Start Latitude Longitude Salpled Sallples lIater colUll vater colua

• Ho• 'elII'Itratore 'C S41inity t.

ISTlJRIAS '1.2/4/9J 10.00 43 38.0 06 39.6 89 25 11.95/0.14 35.63/0.OC22/4/91 17.30 n 37.2 06 41.4 79 21 12.08/0.33 35.66/0.0322/4/91 22.39 43 37.2 06 n.1 92 U.06/0.20 35.64/0.042314/91 03.30 43 37.2 06 45.0 86 22 12.02/0.20 35.64/0.03

LA COROIA 28/4/91 08.00 43 41.2 08 18.1 109 35 12.14/0.~ 35.10/0.0128/4/91 18.00 43 41.7 08 19.8 108 31 12.15/0.07 35.69/0.0228/4/91 23.57 43 41.7 08 20.0 131 21 l2.16/0.14 35.71/0.0229/4/91 04.08 C3 42.3 08 20.9 115 24 12.27/0.18 35.7110.02

SAN'I'AIfDIR 10/5/91 10.40 43 28.5 03 20.8 7. 16 U.17/0.03 35.33/0.1110/5/91 15.00 43 28.2 03 14 •• 75 18 12.27/0.07 35.42/0.0510/5/91 19.40 43 27.6 03 13.2 88 18 12.18/0.01 35.30/0.2010/5/91 23.0{) Cl 26.5 03 10.5 79 18 12.27/0.06 35.26/0.1811/5/91 02.30 43 25.5 03 08.0 69 17 12.22/0.02 35.25/0.1311/5/91 06.15 43 25.1 03 06.3 65 17 12.22/0.02 35.17/0.10

Table I

Total Chlorophyll (111 Chi • • - 3 )

GIJON 22-4-CJ1

80 <0, , <0, ,

Time Etl 15h 1711 21h 23,3(11 2,45h 5h EIl

• Depth (m) 24 h STATION LA CORUNA 2B-4-CJ1

:::::;:::::::::::::::::::::::::::::~::::::::::::::::::::::::::~::::::::::::::::::::::::::::::.::::::::::::: .)·1·::::::::~:::::::::::::::::::;:::::::·:::::::::;:::

: ."::1!:::.:·:·:·:....:·..,.1 ~I' j' j' !···!Ii·::::~:::!:::i:::i:i:::::i::·i:i:Ii·i···i·:r~~:~:::::i:;I;;i:I!mt:l:i:i;:~:;:::;::;:

bO ........•.. . . . . . . . ::::::::::' . : : : : : : :.................. <0,5 '.:.' .. . .. .. .. .. .. . . .. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . .

80..................................•............ . . . . . . . . . . . . . ... . . . . . . .. . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. . .. .. .. . .. .. .. ..

~ :.: : : : ::: :~ ::::::~ :::: : :.: : : : : :.: : : : :~ :~.. ;::::~::=H~20 ,; :::)(), 5 ::::

: :.: : : : : : : : : : : : : : :~ : : : : : : : : : : : :e: : : : :, : ':~:::::::::~/

40 ~:j:::::::~:::::: i: :::::~ ::::~: ::::~: ::::: ::~bO ~::::::::::::::::::::::::::::::::::::::::::::..

~ : : : : : : : : : : : : : : : : : : : <0,5: : : : : : : : : : : : : : : : : : : : :­80 ~::::: : : : : : : : : : : : : : : : ... : : : : : : : : : : : : : : : : : : : : :­

~ : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :...

Depth (m) 24 h 51All ON•Time 5h Hll

SANTANDER

22,3(11 2,3(J,

10-5-91

Time 8,3Ctl 12,3C1l 17h

Fig. 2

21h Ctl 5h

Copepods abundance in the North of SpainLHPR) 53 um

Ind No 1m3 (Thouaande)

6

5" .....• /

...... ,/0

.•.•- ,r'4 .........,."..

.,.'3

2

1

oJL.~~~L---r----L~==~-~_.L.:.~=~

SI. 1 SI. 2

Different stationsSt.3

_ Egge ~ Nauplli b~rIr~J Copepode

Aaturi..,Corufta and 8antander

Fig o. 3

•

DE~TH ~e

?5

oe UMe)

<LHPA-lezee ..",)

lee .

e ..

2~

DEPTH ~e<LHPR-l?13e p"')

?~ - - - ..

lee .

e - ..

•J)EPTH ~e . . .

<LHPR-3:3e ""')

......................................................................................

lee - .

•••~•• III ••,f

, , J

~ ~ =, I I, IJ ,

• • •• T I VE"T 1C-.L Ja 1.,.,.1 MIT ION (>a JUA)

Fig. 4

IND. Ho.....;S (>< leee)

•20

40

DEPTH

6e

ee

lee

e

• 2e

4e

DEPTH

68

se

lee

<l-HPR - .:ee •• )

.................................................. " .

..................................................................

DEPTH

•2.

6.••

1••

. - .

. -.- .

<Lt-FR - 4: •••",). .

. .

•••• Im •••, , , , , , , I

C ! i i C C C C

Fig. 5

ST 2

oe lee0)

o ..

(LHPA - 10:40 a.).....................................................................................

<LHPA - lS:0e ~m)

S0 ..

60

20

ae

60

20

DEPTH

DEPTH

•DEPTH

e

2e

40

60

ee

...........................................

..............................................................

<LHPft - 19:48 ~.)......................•..........................................

••••mI •••, , , , , , , ,f t i i C ~ c e

8T 3 ~TICAL DI8Tftl.uTION <>53 ~)

Fig. 6a

•

•

DEPTH .8

68

(U'PR-22:.8 ~.).8

•

28

~TH ••

CL)oP"-2118 )- .. .. .

DEPTH ••

CL""-SISB ... )- ._ .

•••l1•••••".", , ..·e I I I I I lee

Fig. 6b

SO

60 ~TURI~

70

80

80>-t-

100 CS-c:::: C3 H1 C2 C1 N1

e «.....J so

L~COR~60

Vl

70

N1C1

~TAN~

C2C3C4CS

I

-

r

I

I I

H1

Vl- 80t-c::::::::> 90

UI 100

>-«a:: 50

• CO60

70

80

90

100H1 CS C4 C3 C2 Cl Nl

FRACTIONS

Fig. 7

DEPTH-TIME MICROZOOPLANKTON IN ASTURIAS

55D

leT

Fig. 8

....on

D:18 AM

T: 18 PM

N:4 AM

SARDINE ABUNDANCE

0 00

o 0

°9 D

0 8 00-

00 o·0 e

-DEPTH-TIME MICROZOOPLAHKTOH IH LA CORUHA

SI>

,ec:

.... ,_.'8" '.D 15. 2'11.

2fU'

S~.. -

..,­

.'I~

C124P'f'.,-

SARDIHE ABUHDAHCE

o

o

o o °00 00 0

.. ~o

o00 •

• o

o

°o•

00

-----------------------------

Fig. 9

DEPTH-TIME MICROZOOPLAHKTOH IN SAHTAHDER

-.......-.­c-__2_a-_~--

-

_D_D

-

••

---- ...-

--._­-

-_.

-

Fig. 10

SARDINE ABUNDAHCE IN SAHTAHDER

00 0°0 _ a

0

(j) 0 • 0 0'

0

0 0 0.0

°0

Diel variation 01 Copepods abundanceGijon (St.1)

• ~ ~ w ~ • ~ u ~ 2 4 •

Time (houra)

_ copep.•O.46mr4IIIIIIII 0.46-0.70 IIlIll _ 0.7-0.16 _ EI 0.15-1.20_

• • 1.20 111. _ nauplll'O.tI m_ 0"0'0.46".

Diel variation 01 Copepods abundanceLa Corul\a (St. 2)

100"

ISO,.

25"

0"

1-------. ---

• 10 12 M 11 18 20 22 24 2 4 •

Time (houra)

_ Cop.pod.oO.7 ••

CI Nauplll·0.46m1ll

_ .0.7_

_ EI'. cO.46n111l

Santander (SI. 3) .

• ~ ~ M 11 • 20 UNI 4 •

Time (hourl)

• C""KoO"'~ O.4I~U_ CJ 0.7-0..... • O.e-UOlIlII- ·uo_ CJ .................. E........ _

Fig. 11