16 páginas, 5 figuras, 9 tablas.-- Scientific Council Meeting ; The cod stock on Flemish Cap, NAFO Division 3M, remains collapsed. The situation was originally attributed to the severe overfishing of last abundant year-classes, but the recruitment failed since 1995 and the stock did not recovered. Commercial catches are insignificant and two surveys in the area in 2001 did not observed good recruitment. The situation remains steady at a very low level, and it is unlikely a recovery of the stock in a short o medium term ; This study was supported by the European Commission (DG XIV, Study 00-028), CSIC, IEO, IPIMAR, and the Basque Government. ; Peer reviewed
13 páginas, 6 figuras, 6 tablas.-- Scientific Council Meeting ; The analysis of the cod stock made last year indicated a collapse of the population, originally produced by a severe overfishing of some past abundant year-classes, that became heavier by the failure of the recruitment since 1995. New information from the fishery and from the July survey, both in 2000, coincides to indicate that the situation remains steady at a very low level without some sign that could foretell good recruitment. ; This study was supported by the European Commission (DG XIV, Study 98-048), CSIC, IEO, IPIMAR, and the Basque Government. ; Peer reviewed
13 páginas, 8 figuras, 8 tablas.-- Scientific Council Meeting. ; Since 1974, when a TAC was established for the first time, catches ranged from 48 000 tons in 1989 to a minimum of 353 tons estimated for 1999. In recent years most of the catches were taken by non-Contracting Parties. In 1999 the TAC was zero and there was not directed fishery on Div. 3M cod, however catches were estimated in 353 tons, with 350 tons from non-Contracting Parties. In the 1999 assessment, the status of the stock was qualified as collapse, attributed to three possible factors: a stock decline due to overfishing, an increase in catchability at low abundance levels and a very poor recruitment since. The EU bottom trawl survey on Flemish Cap has been carried out since 1988. The survey covered all the area where cod occurs. Total biomass was estimated by swept area method showed a peak of 104 000 tons in 1989 and fell since then to the present minimum with 2 596 tons. Abundance indices at age between 1988 and 1999 are shown in Table 2. Ages ranged from 1 to 12, but the ages older than 7 were rare. Recruitment indices at age 1 in the last four years were at the lowest level since the beginning of the series. The low abundance of those year-classes was confirmed in more recent years, being also scarce in 1999, at ages 1 to 4. A trend in growth at age along the EU-survey data series was seen. Ages 1 to 4 have been increasing its size all the time. This is probably a population reaction against the decline of the stock. Older ages seldom reacted in the same way. ; This study was supported by the European Commission (DG XIV, Study 96-030), CSIC, IEO, IPIMAR, and the Basque Government. ; Peer reviewed
13 páginas, 8 figuras.-- Scientific Council Meeting ; On July 1996 a fishing research survey was carried out over the Flemish Cap area (Northwest Atlantic) aboard the RN 'Comide de Saavedra". It was the ninth of a series of surveys conducted by the European Union since 1983 During this survey, salinity and temperature data were collected using a CTD sound. This report analyzes hydrographic conditions on the bank, as well as it describes three different water masses. First there Is the water around the bank, showing the typical features of Labrador Current's waters; secondly, the central water, originated by solar heat input on Labrador waters; and, finally, an unusual type of water which appears between 200 and 300 m and seems to be mixed with North Atlantic Current waters. ; Peer reviewed
11 páginas, 8 figuras, 3 tablas ; Spawning stock biomass (SSB) is one of the most common measures of stock status. However recent research on reproductive potential has shown that alternative variables may be an improvement over SSB. In the case of European hake (Merluccius merluccius), it is known that large individuals produce more eggs by unit of body weight, and their quality is better than those of small individuals. Under these circumstances, application of reproductive potential may be pertinent in the implementation of the Johannesburg agreement, since it is not only the spawning biomass but also its age or length structure that defines stock productivity and its ability to achieve maximum sustainable yield (MSY). In this contribution we used an age-length structured population model to assess the impact of different reproductive indices (total spawning biomass, female spawning biomass and egg production) on MSY reference points. First, we analyzed how these different indices alter our perception about per recruit productivity. Second, we analyzed the quality of these alternative reproductive indices to explain and predict recruitment using different model structures (Ricker and Beverton–Holt) and Bayesian inference. Third, we combined per recruit models and stochastic stock–recruitment relationships to estimate the probability distributions of MSY biological reference points (MSY, Fmsy, Stockmsy, and Fcrash). Our results show that, for hake stocks where larger fish have a strong contribution to stock reproductive potential, use of alternative reproductive indices will affect estimations of stock sustainability. The change in perception of relative contribution of each length class is exhibited in two opposite ways: reproductive potential per recruit and the shape of the stock–recruitment relationship defined with steepness. In our case, the change from SSB to egg production, resulted in an increase in steepness which counteracted the depletion per recruit resulting in a larger Fmsy. ; Funding for this research was received from the European Union's Seventh Framework Programme (FP7/2007–2013) under grant agreement n◦ 244706/ECOKNOWS project. ; Peer reviewed
17 páginas, 6 figuras, 5 tablas ; The incidence of cetacean strandings is expected to depend on a combination of factors, including the distribution and abundance of the cetaceans, their prey, and causes of mortality (e.g. natural, fishery bycatch), as well as currents and winds which affect whether carcasses reach the shore. We investigated spatiotemporal patterns and trends in the numbers of strandings of three species of small cetacean in Galicia (NW Spain) and their relationships with meteorological, oceanographic, prey abundance and fishing-related variables, aiming to disentangle the relationship that may exist between these factors, cetacean abundance and mortality off the coast. Strandings of 1166 common dolphins (Delphinus delphis), 118 bottlenose dolphins (Tursiops truncatus) and 90 harbour porpoises (Phocoena phocoena) during 2000–2013 were analysed. Generalised additive and generalised additive-mixed model results showed that the variables which best explained the pattern of strandings of the three cetacean species were those related with local ocean meteorology (strength and direction of the North–South component of the winds and the number of days with South-West winds) and the winter North Atlantic Oscillation Index. There were no significant relationships with indices of fishing effort or landings. Only bottlenose dolphin showed possible fluctuations in local abundance over the study period. There was no evidence of long-term trends in number of strandings in any of the species and their abundances were, therefore, considered to have been relatively stable during the study period ; The standing network was partially funded by the "Dirección Xeral de Conservación da Natureza da Xunta de Galicia" in Spain and by the "Fundação para a Ciência e Tecnologia" in Portugal. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007–2013) under Grant Agreement No 613571— MareFrame. The main author (C.S.) received a pre-doctoral grant from the Spanish Institute of Oceanography (BOE-A-2011-2541) ; Peer reviewed
14 pages, 9 figures, 3 tables.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) ; The protection of fish nurseries has been recognized as a useful tool to efficiently manage fisheries given that protected areas enhance the recruitment of target species. To identify and locate potential nursery areas, a solid understanding of species-environment relationships and their spatio-temporal dynamics is needed. Within this context, in this study we assess where European hake (Merluccius merluccius) recruits persistently aggregate in the northern continental shelf of the Iberian Peninsula. Hake recruit data collected during scientific trawl surveys between 2005 and 2016 were analyzed using Bayesian hurdle hierarchical spatio-temporal models, considering the environmental variables bathymetry, sea bottom temperature and salinity. Additionally, three different spatio-temporal structures (i.e., persistent, progressive, or opportunistic) were compared to assess the temporal persistence of nurseries over time. Among all the environmental variables analyzed, bathymetry was the most important. The preferential habitat of recruits was found to be within a bathymetric range of 120–200 m. Our findings clearly show that there is a temporally persistent main nursery located along the continental shelf of the Artabrian gulf (off La Coruña) in addition to several areas with high aggregations of hake recruits but with strong inter-annual variability. We argue that the analytical framework applied in this study allowed us to identify European hake nurseries in the northern continental shelf of the Iberian Peninsula, as well as their spatio-temporal fluctuations throughout the study period (2005–2016), and to assess which environmental factors, among bathymetry, sea bottom temperature and salinity, influence the occurrence and abundance of recruits in the study area. Results of our models also produce a new abundance index that could be useful for improving traditional stock assessment models ; DEMERSALES surveys were co-funded by the EU within the Spanish national program for the collection, management, and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy. This study was a contribution to the project IMPRESS (RTI2018-099868-B-I00), European Regional Development Fund (ERDF), Ministry of Science, Innovation and Universities—State Research Agency ; Peer reviewed
