Theme Session on the Recent Advances in the Oceanography and Biology of the Iberian Waters and Adjacent Shelf Seas: Results from Integrated Multidisciplinary Projects (Q)

ICES CM 2004/Q:01 Historical fluctuation of spawning area of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in the bay of Biscay from 1967 to 2004 Edwige Bellier, Benjamin Planque, and Pierre Petitgas Fluctuations in spatial spawning dynamics of small pelagic fish influence recruitement sucess and interannual variabil-ity in population abundance. Hence it is necessary to describe interannual variability of spawning habitats and to char-acterize long term changes in the spatial distribution of eggs of small pelagic fish. This study describes the evolution of spatial distribution of eggs of two commercial species in the Bay of Biscay: anchovy (Engraulis encrasicolus) and sar-dine (Sardina pilchardus). Fish eggs data were collected in the Bay of Biscay from 1967 to 1972, and from 2000 to 2004. Using geostatistical analyses, spatial distribution of anchovy and sardine eggs are analysed for each survey. Maps of probability of egg presence, and maps of egg abundance are generated. This allows to determine realised spawning habitats for the two periods of study, and to define persistent spawning areas, occasional spawning areas, and non-spawning areas The interannual and interdecadal variability of the spatial distribution of anchovy and sardine eggs is characterised. This study will permit the investigation of the potential impact of oceanographic conditions in the bay of Biscay and of future climate change on the spatial spawning dynamics of anchovy and sardine. Keywords: anchovy, sardine, eggs, spatial distribution, interannual variability corresponding author: Benjamin Planque Edwige Bellier, Pierre Petitgas: Ifremer, Laboratoire d’Ecologie Halieutique, Centre de Nantes, rue de l’île d’ Yeu, BP 21105, 44311 Nantes Cedex3, France [tél: 33 2 40 37 41 17, fax : 33 2 40 37 40 75, e-mail: benja-min.planque@ifremer.fr] ICES CM 2004/Q:02 Effects of environmental factors on potential spawning habitat of small pelagic fish in the bay of Biscay Benjamin Planque, Edwige Bellier, and Pascal Lazure Large amplitude variations in the recruitment in small pelagic fish results from interaction between a fluctuating envi-ronment and population dynamics processes such as spawning. The spatial extent and location of spawning, which is critical to the fate of eggs and larvae, can vary strongly from year-to-year, as a result of changing population structure and environmental conditions. Spawning habitat can be divided in "potential spawning habitat", defined as habitat where the hydrological conditions are suitable for spawning, "realised spawning habitat', defined as habitat where spawning actually occurs, and successful spawning habitat", defined as habitat where fish have spawned and from where successful recruitment has resulted. Using biological data collected during the periods 1967–1972 and 2000-2003, as well as hydrological data and hydrological hindcasts, we investigate the role of environmental parameters in controlling the "potential" spawning habitat of anchovy and sardine in the bay of Biscay. The results are discussed in the context of possible future environmental changes and their potential impacts on sardine and anchovy reproductive strategy in the north-east Atlantic. Keywords: small pelagic fish, bay of Biscay, potential spawning habitat, environmental impact. Benjamin Planque and E. Bellier: IFREMER, Laboratoire écologie halieutique, rue de l'île d'Yeu, BP21105, 44311 Nantes Cedex 3, France [tel: +33 (0)240 37 41 17, fax: +33 (0)240 37 40 75, e-mail: benjamin.planque@ifremer.fr], Pascal Lazure: IFREMER, DEL/AO. BP 70. 29280, Plouzané. France

ICES CM 2004/Q:03

Primary production rates along the northwest Iberian coastal transition zone derived from fast repetition rate fluorometry (FRRF)

Patricia Estévez-Blanco, Emilio Fernández, Antonio Bode, Francisco Castiñeira, Jorge Lorenzo, and Manuel Varela

1

A series of 25 vertical profiles conducted with a Fast Repetition Rate Fluorometer (FRRF) during the oceanographic cruise PELACUS-0303 (March-April 2003) allowed to determine the photochemical efficiency of phytoplankton pho-tosystem II from variable fluorescence measurements (Fv/Fm) and to further relate these results with the thermohaline variability of the NW Iberian coastal transition zone during the sampling period. Fv/Fm values were always higher than 0.45 thus indicating that by the time sampling was carried out the photochemical efficiency of phytoplankton PSII were close to their maximum potential values. FRRF data were used to derive continuous vertical profiles of primary produc-tion rates from theoretical bio-optical formulations. The highest depth-averaged primary production rates per unit of chlorophyll-a was found in the central Cantabrian Sea, whereas the lowest productivity values were characteristic of the easternmost region of the southern Bay of Biscay. This spatial pattern resulted from marked geographical differences in the vertical distribution of thermohaline properties which determined the distribution of phytoplankton biomass in the water column. FRRF-derived primary production estimates were contrasted with parallel carbon incorporation rates obtained from 14C based photosynthesis versus irradiance (P-E) curves. A statistically significant linear relationship was found between both set of estimates. As expected, FRRF-derived production rates were c.a. 1.8 times higher than 14C-derived rates due to the fact that FRRF-derived rates provide in situ estimates of gross primary production whereas es-timates based on the 14C technique lie between gross and net phytoplankton photosynthesis.

Keywords: Primary production, FRRF, shelf waters, NW Iberian Peninsula

Patricia Estévez-Blanco and Emilio Fernández: Laboratorio de Ecología Marina, Departamento de Ecología y Biología Animal, Facultad de Ciencias del Mar, Universidad de Vigo, Ctra. Colegio Universitario s/n 36310 Vigo, Spain [tel: +34 986 81 40 87, fax: +34 986 81 25 56, e-mail:pestevez@uvigo.es, esuarez@uvigo.es]. Antonio Bode, Francisco Castiñeira, Jorge Lorenzo and Manuel Varela: Instituto Español de Oceanografía. Centro Oceanográfico de A Coruña. Apdo. 130. 15080 A Coruña. Spain. [tel: +34 981 205362, fax: +34 981 229077, e-mail: anto-nio.bode@co.ieo.es , fran.castiñeira@co.ieo.es, jorge.lorenzo@co.ieo.es, manuel.varela@co.ieo.es].

ICES CM 2004/Q:04

Allometric deviation of phytoplankton metabolism and the energy flow through a coastal ecosystem

Pedro Cermeño, E. Marañón, J. Rodríguez, E. Fernández, F. Jiménez, and L. Zabala

The ‘energetic equivalence hypothesis’ states that total energy flow per unit area within the ecosystem is independent of organism size. This hypothesis stems from a large body of evidence which relates metabolic rates and organism abun-dance to their body size through the so called ¾ power allometric rule. However, this view contrasts with the typical observation that in productive coastal ecosystems, large sized phytoplankton (>20µm of equivalent spherical diameter) account for most of the total primary production. In this work, we test the ‘energetic equivalence hypothesis’ for phyto-plankton living in a coastal ecosystem affected by upwelling. We obtained a total of 50 abundance and cell-specific photosynthesis size spectra during a full annual cycle from July 2001 to July 2002 in the Ría de Vigo (NW of Spain). On average, the slope of the size abundance spectrum was –0.77±0.01. The size spectrum of cell-specific photosynthe-sis showed an average slope of 1.13±0.03 which is significantly higher than 0.75 predicted by the size scaling theory. Assuming that phytoplankton respiration is independent of cell size, our results indicate that larger microalgae have higher growth rates than smaller cells do. The combination of abundance and cell-specific photosynthesis size spectra suggests that larger phytoplankton utilize a disproportionately large share of the resources within the ecosystem. The implication is that an allometric deviation of the phytoplankton metabolism from overall allometric rules, rather than biomass accumulation is major responsible for a higher contribution of large sized phytoplankton to the total primary production.

Keywords: Phytoplankton, Allometry, Energy flow.

Pedro Cermeño, Emilio Marañón and Emilio Fernández: Laboratorio de Ecología Marina, Departamento de Ecología y Biología Animal, Facultad de Ciencias del Mar, Ctra. Colegio Universitario, 36310 Vigo, Spain [tel: +34 986 81 40 87, fax: +34 986 81 25 56, e-mail: pca@uvigo.es, em@uvigo.es, esuraez@uvigo.es]. Jaime Rodríguez, Francisco Jiménez and Laura Zabala: Departamento de Ecología y Geología, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain. [tel: +34 952 13 18 44, fax: +34 852 13 20 00, e-mail: jaime@uvigo.es]

2

ICES CM 2004/Q:05 Release of dissolved organic nitrogen (DON) by microbial populations in the NW Iberian Peninsula shelf and adjacent open-ocean Atlantic waters Marta M. Varela and Antonio Bode Dissolved organic nitrogen (DON) release rates by the microplankton community were measured in the surface layer of the Atlantic Ocean in a wide range of productivity regimes, in order to quantify the fraction of recently incorporated nitrogen flowing to the dissolved organic pool. We determined the percentage of DON release relative to the gross up-take of ammonium (PERNH4+) and total nitrogen uptake (PERtotal). The experiments were conducted during 5 oceanographic cruises from August 1998 to October 2000, covering 3 regions: the upwelling region of the NW Iberian Peninsula, the Bay of Biscay and a latitudinal transect in the Central Atlantic Ocean between 50ºN and 35ºS. PERNH4+ ranged from 3 to 46% while PERtotal varied between 21 and 82 %. Highest values for both PERNH4+ and PERtotal were found in oligotrophic oceanic waters (< 0.25 mg chlorophyll a). In oceanic environments, a positive linear rela-tionship between nitrogen uptake rates and DON release, with alog-log linear regression slope significantly <1, indi-cated that PER was inversely related to total nitrogen uptake. In contrast, in more productive areas, such as the conti-nental shelf of the NW Iberian Peninsula, the slope of the relationship found between nitrogen uptake and DON release rates was not significantly <1. These results suggest that different processes could be controlling the release of DON in these contrasting environments. Whereas in open-ocean Atlantic waters, microbial processes could be the cause of the enhanced DON release, in neritic Iberian Peninsula areas DON release would depend mainly on the phytoplankton biomass. Keywords: microbial community, nitrogen uptake, DON release, Atlantic waters. Marta M. Varela and Antonio Bode: Instituto Español de Oceanografía. Centro Oceanográfico de A Coruña. Apdo. 130. 15080, A Coruña, Spain [tel: + 34 981207033, fax: + 34 981229077, e-mail: marta.varela@co.ieo.es; anto-nio.bode@co.ieo.es]. ICES CM 2004/Q:06 Characterization of the anchovy (Engraulis encrasicholus) and sardine (Sardinia pilchardus) spawning habitats in the Bay of Biscay from the routine application of the annual DEPM surveys in the Southeast Bay of Biscay Y. Sagarminaga, X Irigoien1, A. Uriarte, M. Santos, L. Ibaibarriaga, P.Alvarez, and V. Valencia The purpose of this paper is to analyze the spatial distribution of anchovy (Engraulis encrasicholus) and sardine (Sar-dinia pilchardus) spring spawning and its relationship with the environmental parameters and processes affecting the Bay of Biscay in that period. To do this, egg abundances and environmental data acquired during the Bay of Biscay DEPM survey series, held in May from 1999 to 2002, have been used. The main spawning grounds for each species were identified and the coincidences and dissimilarities in their spatial distribution were analyzed, revealing a spatial segregation of the main spawning grounds and a coexistence in secondary spawning grounds. Regarding the relationship of the spawning distribution with the environmental parameters analyzed (Sea surface tem-perature, sea surface salinity, and sub-surface chlorophyll-a concentration),it was observed that sardine may be more strongly influenced by sea surface temperature than anchovy because it is in an edge of its spawning period and this could have a limiting effect. Nevertheless anchovy, which is at the peak spawning period, benefits from the optimal temperature conditions and its distribution may be more strongly affected by the distribution of the main primary pro-duction areas. Anyway, the temperature has an important role in defining the kick off of the anchovy spawning period which starts when the steep increase of sea surface temperatures begins during spring in the area of study. Keywords: Spawning, Bay of Biscay, small pelagics, Anchovy, Sardine, spatial distribution, environment. AZTI, Food and Fish Technological Institute, Marine Research Unit. Herrera Kaia Portualdea z/g. 20110 PASAIA(Gipuzkoa) Basque Country. Spain. (Ph: + 34 943 00 48 00, fax: + 34 943 00 48 01). ysagarminaga@pas.azti.es

3

ICES CM 2004/Q:07 Natural abundance of stable nitrogen isotopes reflect changes in pelagic food webs and mobility of size classes of the north Iberian sardine (Sardina pilchardus) Antonio Bode, Pablo Carrera, Jorge Lorenzo, Carmela Porteiro, and M. Begoña Santos The natural abundance of stable nitrogen isotopes (d15N) in sardine (Sardina pilchardus) and plankton was determined from samples collected between 1998 and 2003 in the north-western shelf of the Iberian Peninsula with the purpose of studying the variability in the trophic position of sardine. Sardines were grouped in 3 size-length classes (small: <16 cm; medium: 16-20 cm; large: >20 cm). Plankton samples were size-fractionated between ca. 0.7 and 2000 mm of indi-vidual length. The plankton at the base of the pelagic food web in the western shelf region (Galicia) was more enriched in d15N than plankton in the northern and eastern region (Mar Cantábrico), likely as a consequence of upwelling. Vari-ability in d15N in sardine was related both to changes in feeding strategies during growth and to the mobility of size classes between adjacent shelf regions. Large sardines showed regional differences in d15N similar to those of small plankton, suggesting that old specimens remained for long periods in the same region. In contrast, small and medium-sized sardines have similar d15N values in all regions. We hypothesize that interannual differences in d15N of sardine are caused mainly by variations in the mobility of large size classes, as the isotopic signature of the small sardines was relatively less variable and suggest low variability in the plankton food web. In turn, such variations would be related to changes in the size of the sardine population in the north Iberian shelf. Keywords: sardine, plankton, feeding, stable isotopes, migration, NW Iberian Peninsula Antonio Bode and Jorge Lorenzo: Instituto Español de Oceanografía. Centro Oceanográfico de A Coruña. Apdo. 130. 15080 A Coruña. Spain. [tel: +34 981 205362, fax: +34 981 229077, e-mail: antonio.bode@co.ieo.es, Pablo Carrera: Museo do Mar de Galicia. Avda. Atlántida 160, 36208 Alcabre, Vigo. Spain.[tel: +34 986 247750, e-mail: pablo.carrera@museodomar.com]. Carmela Porteiro and M.B. Santos: Instituto Español de Oceanografía. Centro Oceanográfico de Vigo. Apdo. 1552. 36280 Vigo. Spain. [tel: +34 986 492111, fax: +34 986 492351, e-mail: car-mela.porteiro@vi.ieo.es, m.b.santos@vi.ieo.es] ICES CM 2004/Q:08 Low enrichment in stable isotopes of mesozooplankton suggest predominance of microbial food webs in the Mar Cantábrico (S Bay of Biscay) Antonio Bode, Jorge Lorenzo, Marco Amez, Luis Valdés, and Manuel Varela Trophic variability of the mesozooplankton community (>200 mm) and of selected copepod taxa in the Mar Cantábrico (S Bay of Biscay) was studied through the determination of the natural abundance of stable carbon (d13C) and nitrogen isotopes (d15N) in samples collected monthly between March 2001 and October 2003 at 3 coastal and shelf stations off Gijón. Due to the large variability in d13C and d15N values there were non significant differences between stations or seasons, despite significant differences in dissolved nutrients, and the biomass of phyto- and mesozooplankton. Only mesozooplankton d13C was significantly lower near the coast when compared with open shelf stations. Both d13C and d15N were positively correlated in the season of low phytoplankton biomass (May-December), but not in the winter-spring season (January-April). In contrast, isotopic abundances and mean nitrate concentrations were negatively corre-lated during winter-spring while no significant relationships for other seasons were found. In addition, chlorophyll con-centrations were not correlated to either d13C or d15N. Large overlap in isotopic abundances between individuals of Acartia, Centropages and Calanus were also found, despite significant differences in C:N ratios. Average estimates of the trophic position of mesozooplankton, computed as the d15N enrichment relative to <200 mm plankton collected during the spring, varied between 1.0? (total mesozooplankton comunity) and 2.2? (Calanus). Such low enrichment val-ues, along with the lack of correlation with phytoplankton biomass and the large variability in isotopic composition, suggest that mesozooplankton in the Mar Cantábrico largely depends on microbial preys for most of the year. Keywords: mesozooplankton, stable isotopes, food webs, shelf waters, NW Iberian Peninsula Antonio Bode, Jorge Lorenzo and Manuel Varela: Instituto Español de Oceanografía. Centro Oceanográfico de A Coruña. Apdo. 130. 15080 A Coruña. Spain. [tel: +34 981 205362, fax: +34 981 229077, e-mail: anto-nio.bode@co.ieo.es, jorge.lorenzo@co.ieo.es, manuel.varela@co.ieo.es]. Marco Amez and Luis Valdés: Instituto Español de Oceanografía. Centro Oceanográfico de Gijón. Avda. Príncipe de Asturias 70 bis, 33212 Gijón. Spain. [tel. +34 985 308672, fax: +34 985 326277, e-mail:amez@st.ieo.es, luis.valdes@gi.ieo.es]

4

ICES CM 2004/Q:09 Variability in the diet of common dolphins (Delphinus delphis) in Galician waters 1991–2003 and relationship with prey abundance M.B. Santos, G.J. Pierce, A. López, J.A. Martínez, M.T. Fernández, E. Ieno, C. Porteiro, P. Carrera, and M. Meixide Analyses of marine mammal diets in Galician waters have been carried out over the last 13 years as part of four con-secutive European funded projects. The species that is best represented in samples from stranded animals is the com-mon dolphin Delphinus delphis, for which 322 non-empty stomachs were analysed during 1991–2003. We quantified interannual and seasonal variation in the diet, as well as differences between the diets of male/female and juvenile/adult dolphins. Although sampling is based on stranded dolphins, the majority showed evidence of having died as a conse-quence of interactions with fisheries (by-catch). The influence of cause of death on stomach contents was examined. The most important prey species were (small) blue whiting (Micromesistius poutassou), sardine (Sardina pilchardus) and scad (Trachurus sp.), all of high commercial importance in Galician waters, and (in the first quarter of the year), sand smelt Atherina sp. Interannual trends in the importance of sardine and blue whiting in the diet of common dolphins appear to track trends in spawning stock biomass and recruitment strength respectively. Preliminary estimates are also made for the amount of fish removed by the common dolphin population in Galician waters. Keywords: sardine, common dolphin, diet, fisheries. M.B. Santos, C. Porteiro and M. Meixide: Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, P.O. Box 1552, 36200, Vigo, Spain [tel: +34 986 492111, fax: +34 986 492351, e-mail: m.b.santos@vi.ieo.es, car-mela.porteiro@vi.ieo.es, manolo.meixide@vi.ieo.es]. M.B. Santos, G.J. Pierce, E. Ieno: Department of Zoology, School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, Aberdeen, Scotland [tel: +44 1224 272459, fax: +44 1224 272396, e-mail: m.b.santos@abdn.ac.uk, g.j.pierce@abdn.ac.uk, en_ieno@yahoo.co.uk]. A. López and J.A. Martínez: CEMMA, Ap. 15, 36380 Gondomar, Spain [tel: +34 686989008, cemma@arrakis.es]. P. Carrera, Museo del Mar de Galicia, Avda. Atlántida, 160, 36208 Vigo, Spain [tel. +34 986 247750, e-mail: pablo.carrera@museodomar.com]. M.T. Fernández, ECOBIOMAR, Instituto de Investigacións Mariñas (CSIC), Edu-ardo Cabello 6, 36208 Vigo, Spain [tel. +34 986 214458, fax: +34 986 292762, e-mail: mariateresa@iim.csic.es] ICES CM 2004/Q:10 Application of generalised additive models to the daily egg production method for the Bay of Biscay anchovy (Engraulis Encrasicolous L.) L. Ibaibarriaga, M. Santos, A. Uriarte, D. Borchers, C. Dixon, and S. Wood The traditional Daily Egg Production Method (DEPM) has been applied since 1987 for the Bay of Biscay anchovy (En-graulis encrasicolus L.). Recently new methodology and software for the estimation of the daily egg production and mortality rates has been developed as part as the EU project (Study 99/080). Staged egg frequencies are first trans-formed into daily cohort densities by using a new ageing method based on a multinomial model fitted to incubation ex-periment data and on a prior probability density function of spawning time. Daily cohort egg numbers are fitted by means of a generalised additive model (GAM) with over dispersed Poisson error distribution and log link, in which the daily egg production and mortality rates are fitted as smooth functions of spatial and environmental variables. Total daily egg production is computed as the sum of the predicted values over the survey area. Variance is estimated by non parametric bootstrap from the original incubation experiment and survey data, so that the variability due to the ageing process can also be quantified. This paper applies this methodology for the Bay of Biscay anchovy in years 1996 to 1999 and compares the results with those obtained in the traditional method. L Ibaibarriaga, M. Santos, and A. Uriarte: AZTI Foundation, Fisheries and Food Technological Institute, Herrera Kaia Portualdea z/g, 20110 Pasaia, Basque Country, Spain,[tel: +34 943004800, contacting e-mail: libaibar-riaga@pas.azti.es]. D. Borchers, and C. Dixon: CREEM, University of St. Andrews, The Observatory, Buchanan Gar-dens, St. Andrews, Fife, KY16 9LZ, Scotland, UK. S. Wood: Department of Statistics, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.

5

ICES CM 2004/Q:11 Comparison between the performance in detecting fish from airborne (lidar) and ship (echosounder) devices. a study case in SW Europe (the Bay of Biscay and Atlantic waters of the Iberian Peninsula) Andrés Uriarte, Pablo Carrera, Guillermo Boyra, Jim Churnside, Carla Scalabrin, and Vitor Marques The feasibility in using airborne devices to assess the early juvenile fractions of the main pelagic fish species occurred in SW Europe (The Bay of Biscay and the western part of the Iberian Peninsula) was studied by comparison with the traditional acoustic method. The basic principle for LIDAR (Light Detecting and Range) is the same as radar and as the acoustic echosounder. Field comparison were undertook in summer 1998 and 1999 during the recruitment period of sardine and anchovy in selected areas of the Bay of Biscay (i.e. the inner part and around the Garonne River mouth), North-western part of the Spanish area and the North of Portugal. These areas presented different oceanographic fea-tures, being important the turbulence events in the western part, (i.e. upwelling) and the horizontal stratification in the Bay of Biscay. Both devices, echosounder and LIDAR were compared on account the received backscattered energy for the whole area and the shape of the targets seen for the same transect steamed at the same time, (but not necessarily the same day). Visual observation of targets revealed a great coincidence between devices. Nevertheless, optical properties of the targets (i.e., fish and plankton) are different from the acoustic ones, and therefore, differences in received back-scattering energy were found. This paper also evaluates the possibilities and problems for scientific direct surveying of the spatial distribution and relative abundance of early juveniles (of about 6 months old) of several pelagic species by means of Airborne systems for fish detecting. Andrés Uriarte1, Pablo Carrera2, Guillermo Boyra1, Jim Churnside3, Carla Scalabrin4, Vitor Marques5 Correspondance to: pablo.carrera@museodomar.com 1 Fundación AZTI Instituto Tecnológico Pesquero y Alimentario. Herrera Kaia Portualde, Z/G 20110 Pasaia Spain 2 Museo do Mar de Galicica. Avenida Atlántida 160 36208 Vigo, Spain 3 NOAA Environmental Technology Laboratory, 325 Broadway Boulder, CO 80303 4 IFREMER, Laboratoire de Sète, 1 Rue Jean Vilar, 34203 Sète Cedex France 5 IPIMAR, Avda de Brasilia, 1400 Lisboa, Portugal ICES CM 2004/Q:12 Analysis of the dynamics of the Atlanto-Iberian sardine using combined catch at age data and acoustic estimates by area: the effect of the recruitment strength on the distribution area of sardine Pablo Carrera, Manica, Dankert Skagen, José M. Bellido, Victor Marques, Alexandre Morais, Carmela Porteiro, and Yorgos Stratoudakis Most of the recruitment of the Atlanto-Iberian sardine occurs off the western coast of the Iberian Peninsula, while in the Cantabrian Sea the sardine population is dominated by fish older than 3 years, suggesting the existence of a migration movement from the Portuguese coast towards the inner areas. In order to analyse this sardine movement by ages across areas, a model that accounts for changes in fish abundance by cohorts between years and areas was constructed. Stock distribution by year, by area and by age was estimated using the proportions obtained in the spring acoustic surveys and the catch-at-age data. The influence of recruitment strength on the extension/range of sardine movement is examined. Results seem to indicate that sardine acts by pulses or waves which are denso-dependent. ICES CM 2004/Q:13 Withdrawn Using ichtyoplanckton datasets and environmental data from international surveys to analyse Sardine (Sardina pilchardus, Walb.) spawning areas off the Iberian Peninsula and adjacent waters Miguel Bernal, Maria Manuel Angelico, Paolo Oliveira, Marian Peña, Maria Santos ,Yolanda Sagarminaga, Enrique Nogueira, Ana Lago de Lanzós, Concha Franco, Paula Alvarez, Jacques Masse, Pierre Petitgas, Benjamin Planque, and Yorgos Stratoudakis. Sardina pilchardus is a small pelagic fish broadly distributed along the North-East Atlantic (NEA) and the Mediterra-nean waters. Sardine shows a protracted spawning period, with a latitudinal gradient in spawning peak and duration of spawning period. Here, a historical analysis of the spawning areas of sardine along the European Atlantic waters is per-formed, combining both bibliographic information and ichthyoplankton survey data analysis, complemented with satel-lite and survey environmental information. The most comprehensive ichthyoplankton database available for this analy-sis covers the Iberian Peninsula and starts in the late 80s. Ichthyoplankton data for the Iberian Peninsula and adjacent

6

waters have been gathered through several EU projects (e.g. INDICES study project 97 – 017,and PELASSES DGXIV 99-010), and have been collated in the context of the ongoing EU project SARDYN (“Sardine Dynamics in the North East Atlantic”). Data include surveys carried out with CalVET and Bongo nets, and, since 2000, surveys carried out with the Continuous Underway Fish Egg Sampler (CUFES). Environmental data from the surveys include depth, tem-perature and, in some cases, salinity, fluorescence and/or chlorophyll measurements, while for recent years satellite de-rived information on temperature and chlorophyll were also added to the analysis. Years with detailed environmental data are used to characterise the environmental conditions of the spawning habitat, while years without detailed envi-ronmental data are used to analyse changes in spawning areas. Keywords: sardine, spawning area, spawning habitat, ichthyoplancton. M. Bernal and M. Peña: INSTITUTO ESPAÑOL DE OCEANOGRAFÍA (IEO)-C.O. Málaga, Puerto Pesquero s/n, 29640 Fuengirola, Spain. [tel: +34 952 471907, Fax: +34 952463808, e-mail: miguel.bernal@ma.ieo.es] M.M. An-gelico, P. Oliveira and Y. Stratoudakis: INIAP/IPIMAR, Avenida de Brasília, 1449-006, Lisboa, Portugal. [tel: +351213027000, fax: +351213015948]. M. Santos, Y. Sagarminaga and P. Alvarez, AZTI, Food and Fish Technologi-cal Institute, Marine Research Unit. Herrera Kaia Portualdea z/g. 20110 PASAIA(Gipuzkoa) Basque Country. Spain .[tel: + 34 943 00 48 00, fax: + 34 943 00 48 01] E. Nogueira, IEO-GIjón, vda. Príncipe de Asturias, 70 bis, 33212 Gijón, Spain. [tel: +34 985308672, fax: +34 983326277] A. Lago de Lanzós and C. Franco: IEO-Madrid, Corazón de Maria 8, 28002 Madrid, Spain. [tel: +34 913473600, fax: +34914135597], Jacques Masse, P. Petitgas and B. Planque IFREMER BP 21105, 44311 Nantes, France [tel: + 33 240374043, fax: +33 240374001] ICES CM 2004/Q:14

The influence of spatio-temporal egg production variability on the modelled survival of the early life history stages of mackerel (Scomber scombrus) in the eastern North Atlantic

Joachim Bartsch

During the EU-funded SEAMAR (Shelf Edge Advection Mortality And Recruitment) programme, an Individual-Based Model (IBM) was developed for the simulation of year-to-year survival of the early life history stages of mackerel (Scomber scombrus) in the eastern North Atlantic, extending from the Iberian peninsula to the north of the British Isles. The model system consists of a circulation model to provide physical input data for an IBM, which simulates the trans-port, growth and mortality of mackerel eggs, larvae and post-larvae. Larval and post-larval growth is modelled as a function of length, temperature and food distribution; mortality is modelled as a function of length and absolute growth rate. Simulations have previously been carried out for the years 1998, 1999 and 2000, in all cases using the same 1998 initial egg distribution as the input field. In the present contribution, the effects of varying the input field are examined by comparing simulations for 1998 and 2001 using initial egg distributions for 1998 and 2001, respectively, and also for a 2001 simulation using the 1998 egg data as input. Results showed that, using corresponding years of egg distribution for inputs, modelled survival for the years 1998 and 2001, was very similar, although total egg production (i.e. the magnitude of the input field) in 2001 was only 70% of that during 1998. The higher relative survival in 2001 results from differences in the timing of peak production, which was 5 weeks later in 2001 than in 1998 and also from higher overall food availability in 2001. Modelled survival for 2001 using 1998 egg data as the initial input field, increases survival by 50% compared with using 2001 egg data for initialization. This is mainly a function of the increased egg production in 1998 compared with 2001. Implications for using this IBM as a management tool are discussed. Keywords: Individual-based model, mackerel larvae, growth, mortality, survival indices Joachim Bartsch: COMMSYS, Baumackerweg 9, 27607 Langen, Germany. [tel.: +49 4743 911058, Fax: +49 4743 911057, e-mail: jo.bartsch@commsys.cux.shuttle.de] ICES CM 2004/Q:15 Geographic variability in sardine maturity and growth within the Atlanto-Iberian stock area Alexandra Silva, M. Begoña Santos, Alexandre Morais, Pablo Carrera, Afonso Jorge, Eugenia Peleteiro, Bruno Caneco, and Carmela Porteiro A single sardine stock is considered in the European Atlantic waters within ICES Divisions VIIIc and IXa (Atlanto-Iberian sardine stock). A coordinated Portuguese-Spanish acoustic survey covering the entire stock area has been car-ried out annually in spring since 1996, to provide estimates of sardine abundance and biological parameters for the as-sessment of the stock. Up to now, biological parameters have been estimated by survey areas, which broadly correspond to the ICES Divisions. In this paper, we analyse sardine growth and maturation at a finer spatial scale. The stock area is

7

divided into eight zones and estimates of maturity ogives and growth patterns are provided for each zone. A Generalised Linear Model is applied to maturity data by individual fish to estimate the probability of being mature at length in each zone and year and to assess the significance of maturation differences in space and time. Estimates of the proportion of adult and spawning sardine populations are also provided. The analysis of sardine growth is based on the comparison of mean lengths-at-age among years and zones using a two-way ANOVA. Unbiased estimates of the mean lengths-at-age and corresponding variances are obtained from age-length-keys raised to the population abundance at-length. Sardine maturity and growth patterns for the overall stock area and by zone, as well as their variations in recent years are de-scribed. The implications of geographic differences in sardine biology to the definition of the stock are also discussed. Keywords: Sardine, stock identity, maturity, growth. Alexandra Silva, Alexandre Morais, Afonso Jorge and Bruno Caneco: INIAP-IPIMAR, Av. Brasilia, 1499-006 Lisboa, Portugal [tel: +351213027000, fax: +351213015948, e-mail: asilva@ipimar.pt, amorais@ipimar.pt, bcaneco@ipimar.pt], M.Begoña Santos, Eugenia Peleteiro and C. Porteiro: Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, P.O. Box 1552, 36200, Vigo, Spain [tel: +34 986 492111, fax: +34 986 492351, e-mail: m.b.santos@vi.ieo.es, quena.peleteiro@vi.ieo.es, carmela.porteiro@vi.ieo.es]. P. Carrera, Museo del Mar de Galicia, Avda. Atlántida, 160, 36208 Vigo, Spain [tel. +34 986 247750, e-mail: pablo.carrera@museodomar.com] ICES CM 2004/Q:16 Withdrawn

ICES CM 2004/Q:17

Critical review of the Spanish capability in marine research and its representation in research projects, scientific journals and marine councils

Luis Valdés and A. López-Urrutia

Marine research in Spain has experienced an important development in recent years what has resulted in a better mobi-lization and coordination of human resources, improvement of capabilities, participation in large integrated research projects and sustained increase in scientific productivity. However the success in the scientific production indices is not followed neither in the citation indices nor in the national presence in the top positions of marine research councils (e.g. ICES). A critical review of the Spanish capability in marine research is presented here and the results compared with the Spanish economical position, the priorities of inversion in other scientific research and other indices.

Keywords: Economic capability, ICES, marine science, publication rates, SCI, Spain.

Luis Valdés and A. López-Urrutia: IEO-C.O. Gijón, Avda Príncipe de Asturias 70, 33212 Gijón, Spain. [tel: +34 985 308672, fax: +34 985 326277, e-mail: luis.valdes@gi.ieo.es].

ICES CM 2004/Q:18 Consistency of the Spanish and Portuguese spring acoustic surveys off the Iberian Peninsula Victor Marques, Pablo Carrera, Alexandre Morais, Carmela Porteiro, Juan Miquel, and Yorgos Stratoudakis Annual acoustic surveys targeted at sardine have been routinely performed by both Spain and Portugal in Atlantic wa-ters of the Iberian Peninsula since 1983. To ensure comparability of the estimates, several meetings have taken place with the aim of coordinating the methods and analyses used. During the 1980s, both countries followed almost the same schedule to improve the abundance estimation. The whole distribution area of the Atlanto-Iberian sardine stock in spring has been covered since 1996 using two research vessels and, in order to compare the abundance estimates ob-tained from the two vessels, both vessels covered a common area located off North Portugal during three years. In addi-tion, another common area, the Gulf of Cadiz, was also covered with two research vessels but this time with a differ-ence of one month. This paper describes the results obtained during these exercises. The possibility of combining the estimates from the two national surveys in a single abundance index and its potential effect on the assessment of the sardine stock is discussed. Keywords: Acoustics, sardine, distribution and abundance, Iberian Peninsula.

8

V. Marques, A. Morais, Y. Stratoudakis: IPIMAR, Avenida de Brasilia, 1449-006, Lisboa, Portugal [tel: +351 213027000, fax: +351 213015948, e-mail:vmarques@ipimar.pt; amorais@ipimar.pt; yorgos@ipimar.pt]: P. Carrera:

Museo del Mar de Galicia, Avda. Atlántida, 160, 36208 Vigo, Spain [tel. +34 986 247750, e-mail: pablo.carrera@museodomar.com]. C. Porteiro: IEO, Centro Oceanográfico de Vigo, P.O. Box 1552, 36200, Vigo, Spain [tel: +34 986 492111, fax: +34 986 492351, e-mail: carmela.porteiro@vi.ieo.es]. J. Miquel: IEO, Centro Oceanográfico de Baleares, Apartado 291, 07080 Palma de Maiorca, Spain. ICES CM 2004/Q:19

Sardine (Sardina pilchardus) spawning season in the North East Atlantic and relationships with sea surface tem-perature

Yorgos Stratoudakis, Steve Coombs, Tim Smyth, Jerom Costas, Concha Franco, Ana Lago de Lanzós, Alexandra Silva, Maria Begoña Santos, Paula Alvarez, and Maria Santos

Sardine (Sardina pilchardus) spawning occurs along the North East Atlantic margin from the Celtic Sea to southern Mauritania and, considering all areas, in all months of the year. Literature information, survey (egg densities) and mar-ket (fish maturity stages) data are used to describe the duration and magnitude of spawning by area and to identify changes over time. This information is related to the seasonal patterns of temperature and upwelling by region from both in situ measurements and using satellite derived data on sea-surface temperature and ocean colour (chlorophyll a).

Keywords: Sardine, North East Atlantic, spawning period, environmental conditions. Y. Stratoudakis, A. Silva: INIAP/ IPIMAR, Avenida de Brasilia, 1449-006, Lisboa, Portugal [tel: +351 213027000, fax: +351 213015948 , e-mail: yorgos@ipimar.pt]. S. Coombs: MBA, The Laboratory, Citadel Hill, Plymouth, PL1 2 PB, UK [tel: +44 1752633275, fax: +44 1752633102, e-mail: shc@mba.ac.uk]. T. Smyth: PML, The Hoe Plymouth PL1 3DH [tel: +44 1752633417, fax: +44 1752 633101, e-mail: tjsm@pml.ac.uk]. J. Costas, C. Franco, A. Lago de Lanzós: IEO, Centro Oceanográfico de Madrid, Corazón de Maria 8, 28002 Madrid, Spain [tel: +34 913473600, fax: +34 914135597, e-mail: ana.lagodelanzos@md.ieo.es]. M.B. Santos: IEO, Centro Oceanográfico de Vigo, P.O. Box 1552, 36200, Vigo, Spain [tel: +34 986492111, fax: +34 986492351, e-mail: m.b.santos@vi.ieo.es]. P. Alvarez, M. Santos: AZTI, Food and Fish Technological Institute, Marine Research Unit, Herrera Kaia Portualdea z/g. 20110 PASAIA (Gipuzkoa) Basque Country, Spain [tel: + 34 943004800, fax: + 34 943004801, e-mail: palvarez@pas.azti.es].

ICES CM 2004/Q:20 Sardine tagging off the Iberian peninsula: laboratory experiments and operations at sea Benito Peleteiro, Ana Marçalo, Mercedes Olmedo, Pedro Pousão-Ferreira, Javier Sanchez, Susana Garrido, Carmela Porteiro, and Yorgos Stratoudakis

Within the EU project SARDYN, tagging laboratory experiments and operations at sea were designed to study the movements of sardine (Sardina pilchardus) off the Iberian peninsula. In the summer of 2003, around 2000 fish were caught and transferred alive to aquaculture tanks (IEO - Vigo and IPIMAR - Olhão). Mortality ranged between 10-30% in the first week, mainly due to stress and scale loss associated to fishing and handling. Feeding (dry pellets) and schooling was soon assumed in the tanks and subsequent mortality has been close to zero for almost a year. Three tags (T-bar in the dorsal fin, Streamer in the operculum and the tail and Fingerling in the tail) were tested in several trials. All tags produced low mortality (< 5%), and the final choice for tagging at sea (Streamer in the tail) was based on the rate of detachment, tag visibility, interference with swimming and feeding behaviour and easiness of operation. In the summer of 2004, up to 30000 sardine are aimed to be tagged off the Iberian Peninsula (southern and northwestern Por-tugal, western Galicia and central Cantabrian). A publicity strategy has been devised, aiming to enhance the probability of tag recoveries. Keywords: Acclimation, mortality, tag choice, operation at sea, recovery strategy.

B. Peleteiro, M. Olmedo, J. Sanchez, C. Porteiro: IEO, Centro Oceanorgafico de Vigo, [tel: +34 986492111, fax: +34 986492351, e-mail: tito.peleteiro@vi.ieo.es]. A. Marçalo, S. Garrido, Y. Stratoudakis: INIAP/IPIMAR, Avenida de Brasília, 1449-006, Lisboa, Portugal [tel: +351 21 3027000, fax: +351 213015948 , e-mail: Yorgos@ipimar.pt]. A. Marçalo, P. Pousão-Ferreira: INIAP/IPIMAR-CRIP Sul, PPO, Avenida 5 de Outubro, 8700, Olhão, Portugal. ICES CM 2004/Q:21 Stock discrimination and temporal and spatial genetic variation of sardine (Sardina pilchardus) in north eastern Atlantic, with a combined analysis of nuclear (microsatellites and allozymes) and mitochondrial DNA markers. Panagiotis Kasapidis, Serge Planes, Veronique Laurent, Ricardo Quinta, Ana Teia, Philippe Lenfant, Stelios Dariviana-kis, Vasso Terzoglou, Giorgos Kotoulas, and Antonios Magoulas

9

Within the context of EU project SARDYN, we assess genetic variability of sardine in north eastern Atlantic and com-pare it with the extremes of the species distribution. Three different types of genetic markers are used: allozymes, mi-crosatellites and mitochondrial DNA RFLP's. The spatial and temporal stability of genetic properties will be evaluated by comparing results from different adult samples from 2000 and 2003 spawning season, adult samples from 2003 fee-ding season, as well as egg and larvae samples from 2003 spawning season. Adult samples are currently scored for 27 allozyme loci (10 of them being highly polymorphic), and for a mtDNA part that includes the control region, using 3 restriction enzymes, while adult, egg and larvae samples are scored for 6 microsatellite loci. Preliminary results from microsatellite analysis of adult samples showed very high genetic variability within each sample and low genetic diffe-rentiation among samples, which indicate large effective population sizes and high levels of gene flow among local po-pulations. The allozyme analysis suggest low genetic differentiation among samples from the Bay of Biscay, Madeira and Cadiz, while they exhibit a strong barrier with samples from the south of Morocco. The combined analysis of the whole data set is expected to clarify whether north eastern Atlantic populations constitute a single stock. Keywords: Sardina pilchardus, Atlantic, allozymes, microsatellite DNA, mitochondrial DNA, molecular markers, stock structure, marine fisheries P. Kasapidis, S. Darivianakis, V. Terzoglou, G. Kotoulas, A. Magoulas: Hellenic Centre for Marine Research, Institute of Marine Biology and Genetics, Gournes Pediados, GR 71500 Heraklion, Greece [tel: +30 2810337854, fax: +30 2810337820, e-mail: kasapidi@imbc.gr, magoulas@imbc.gr]. S. Planes, V. Laurent, P. Lenfant: Ecole Pratique des Hautes Etudes - UMR CNRS 8046, Universite de Perpignan, Avenue de Villeneuve, 66860 Perpignan cedex, France [tel: +33 4 68 66 20 55, fax: +33 4 68 50 36 86, e-mail: planes@univ-perp.fr]. R. Quinta, A. Teia: Instituto de Investi-gacao Agraria e das Pescas (INIAP/IPIMAR), Avenida de Brasilia, s/n, Lisboa, 1449-006, Portugal [tel: +351 21 3027000, fax: +351 21 3015948, e-mail: rquinta@ipimar.pt]. ICES CM 2004/Q:22 Poster Zooplankton composition, distribution and abundance in the Bay of Biscay and adjacent Atlantic waters from a cetacean sighting survey Ana Miranda, G. Fernández, C. Eirín, and S. Lens In 1989 a Spanish shipboard sighting survey was carried out as part of a combined international cetacean's survey in the North Atlantic (NASS-89). The cruise had taken place during July-August covering the Bay of Biscay and adjacent Atlantic waters between 42º-52º N and 25º W. Zooplankton samples obtained during that cruise has recently being processed and analysed. Due to the relatively scarce information available about the zooplankton of the area surveyed it was considered useful to present now this information. Data about the composition, distribution and abundance of the zooplankton fraction between 200 mm and 2 mm were obtained. The dominant groups in the oceanic area were Acan-tharia, Radiolaria and Amphipoda. In some stations these groups represent more than 50 % of the plankton community. In the Bay of Biscay, apart from the groups found in the oceanic area, they also appeared Doliolida and the copepod Calanoides carinatus (Krøyer, 1848). Abundances have ranged between 2 and 27,785 ind/m3 accounting for the wide extension and different thermohaline characteristics of the area sampled. The groups with more than 500 ind/m3 were the Radiolaria, Acantharia, Chaetognatha and the copepod Calanoides carinatus. The last two groups were more abun-dant in the coastal zone. Keywords: Zooplankton, composition, distribution, abundance, North East Atlantic.

Ana Miranda: Instituto Español de Oceanografía, Centro Oceanográfico de Vigo. Apdo. 1552. ES-36200.Vigo. SPAIN. Tel: +34 986 492111. Fax: + 34 986 492351. E-mail: ana.miranda@vi.ieo.es

ICES CM 2004/Q:23 Poster Abnormal domination of Sardinella aurita in the ichthyoplankton community of the Gulf of Cádiz: related changes in the hydrologic and mesozooplanktonic structures J. P. Rubín and P. Mafalda Jr. During the yearly ‘Ictio.Alborán-Cádiz’ (1994–1997) multidisciplinary oceanographic surveys, the eggs and larvae of anchovy (Engraulis encrasicolus) are generally the dominant in the middle shelf ichthyoplankton community of the Gulf of Cádiz in summer. In the 1995 survey a notorious change have detected: the maximum localized abundance for

10

ichthyoplanktonic components of gilt sardine Sardinella aurita have multiplied x 10 (eggs) and x 20 (larvae) the an-chovy’s components. In this paper we discuss the observed changes in the northern Gulf hydrologic structure and in the larval fish and mesozooplankton assemblages (cluster analysis). Keywords: ichthyoplankton / mesozooplankton assemblages, Sardinella aurita, Engraulis encrasicolus, hydrologic structure, Gulf of Cádiz. Juan P. Rubín: Instituto Español de Oceanografía. Centro Oceanográfico de Málaga-Fuengirola. Muelle Pesquero s/n. 29640 Fuengirola (Málaga). Spain. [jprubin@ma.ieo.es]. Paulo Mafalda Jr: Universidade Federal da Bahia, Brazil (Visiting Scholar at Centro Oceanográfico de Málaga-Fuengirola, grant CAPES) [paulo.mafalda@ma.ieo.es]. ICES CM 2004/Q:24 Poster Spatial-temporal characterization of the Northern Hake landings and landings per unit effort of the Basque (Spanish) fleets, in the period 1992–2003 Paulino Lucio, Marina Santurtún, Iñaki Quincoces, and Ane Iriondo The annual distribution of the Northern Hake landings in the Basque Country (Spain) ports, are presented in relation to the ICES statistical rectangles, in the period 1992-2003. For the same time period, the Northern Hake annual landings per unit effort values (LPUEs) of the two main Basque trawler fleets (“Baka” otter trawl and Pair bottom trawl with very high vertical opening overture (VHVO)) are also of-fered per ICES statistical rectangle. Finally, the evolution of the relative importance of Hake and accompanying species catches (landings), since 1994 to 2003, by sea area (Sub-Area VI, VII and Divisions VIIIa,b,d), and fleet ("Baka" otter trawl and VHVO Pair bottom trawl) is also indicated. Keywords: Hake, North-east Atlantic, Spatial distribution, Statistical rectangle, Landings composition, Landings per unit effort, trawl. Paulino Lucio: Txatxarramendi ugartea z/g, 48395 Sukarrieta, Bizkaia, Basque Country, Spain [tel: +34 94 6029400, fax:+34 94 6870006, e-mail: plucio@suk.azti.es. Marina Santurtún: [e-mail: msanturtun@suk.azti.es]. Iñaki Quinco-ces: [e-mail: iquincoces@suk.azti.es]; Ane Iriondo: [e-mail: airiondo@suk.azti.es] ICES CM 2004/Q:25 Poster Close coupling between phytoplankton size structure and sardine (Sardina pilchardus) biomass in frontal systems of the west coast of the Iberian Peninsula Valesca Pérez, Emilio Fernández, Antonio Bode, Pablo Carrera, Begoña Castro, Elvira Ceballos, Jorge Lorenzo, Marian Peña, Manuel Varela, and Marta María Varela. The main goal of this investigation was to find out the relationships between the thermohaline characteristics of the wa-ter column, total phytoplankton biomass and size distribution, and the abundance of eggs, larvae and total biomass of sardine (Sardina pilchardus). This study, which was carried out during PELACUS 0401 cruise in March-April 2001, was inserted in a larger survey focused on the evaluation of pelagic resources and on the description of the oceano-graphic conditions in the northwest coast of the Iberian Peninsula. High sardine biomass was associated with frontal systems, where large cells (>40 µm) dominated phytoplankton biomass. In contrast, sardine was almost absent in areas with high vertical mixing and low biomass of large phytoplankton. Keywords: phytoplankton size and biomass, sardine, NW Iberian Peninsula. Valesca Pérez and Emilio Fernández: Dpto. Ecoloxia e Bioloxia Animal, Facultade de Ciencias do Mar, Universidade de Vigo, Ctra. Colexio Universitario s/n, 36310 Vigo, Spain [tel: +34 986 814087, fax: +34 986 812556, e-mail: vperez@uvigo.es, esuarez@uvigo.es]. Antonio Bode, Begoña Castro, Jorge Lorenzo, Manuel Varela and Marta María Varela: Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía, Muelle de Ánimas, Apdo.130, E-15080 A Coruña, Spain [tel: +34 981 205362, fax: +34 981 229077, e-mail: antonio.bode@co.ieo.es, be-gona.castro@co.ieo.es, jorge.lorenzo@co.ieo.es, manuel.varela@co.ieo.es, marta.varela@co.ieo.es]. Pablo Carrera:

11

Museo del Mar de Galicia, Avda. Atlántida 160, 36208 Vigo, Spain [tel. +34 986 247750, e-mail: pablo.carrera@museodomar.com]. Marian Peña: Centro Oceanográfico de Málaga, Instituto Español de Ocean-ografía, Apdo. 285, 29640 Málaga, Spain [tel. +34 952 582254, fax: +34 952 463808]. Elvira Ceballos: Centro Oceanográfico de Vigo, Instituto Español de Oceanografía, Cabo Estay, Canido, Apdo. 1552, E-36200, Vigo [tel.: +34 986 492111, fax +34 986 492351,e-mail: elvira.ceballos@vi.ieo.es]

12