Estimates of cetacean abundance in European Atlantic waters in summer

This report summarises design-based estimates of abundance for those cetacean species for which sufficient data were obtained during SCANS-III: harbour porpoise, bottlenose dolphin, Risso’s dolphin, white-beaked dolphin, white-sided dolphin, common dolphin, striped dolphin, pilot whale, all beaked whale species combined, sperm whale, minke whale and fin whale

Data on the distribution and feeding of fin whales off the Galician coasts

One ofthe aims of a next CODA (Cetacean Offshore Distribution and Abundance in the European Atlantic)-IEO survey, is to investigate the presence of fin whales and their prey off the Galician coast. As a preparation it was considered useful to look at the available historical information regarding fin whale presence off GaIicia. Some observations about fin whaIe feeding are aIso presented here. The catch statistics for 1952 - 1985 were analysed for pattems of seasonal distribution. Information about the geographic distribution of fin whaIes was obtained from positions in the catch statistics, from sightings made by the whaling boats and from severaI sighting surveys. These positions were represented in charts with bathymetric profiles to visualise the distribution of whales in relation with the sea bottom topography. The prey species found in the stomachs of 17 individuaIs caught during the 1983 season were identified and their degree of digestion and semi-quantitative abundance evaIuated. Throughout the historie series more than 70 % ofthe catches occur between July and September. Some temporal distributional pattems can be described along the time series and in relation with annual values ofNAO and Gulf Stream indices. Positions of catches and sightings data were plotted by months and compared to show the seasonal distribution and reIative movements of fin whaIes. Only 3 of the 17 stomachs were empty. The prey most commonly found (85.7 % of the stomachs with food) was the euphausiid Meganycthiphanes norvegica. One whale has only the gadoid fish Micromesistius poutassou and another whale a mixture of both items. The degree of digestion and the amount of food in the stomachs suggest a moming feeding periodo The position and dates of the catches of these specimens could also indicate areas where euphausiids and fish were locally abundant in that particular year

Informe de campaña PELACUS 0411

El Instituto Español de Oceanografía inició sus campañas acústicas de primavera para evaluar los recursos pesqueros en la plataforma norte y nordeste de la Península Ibérica en 1986. La serie anual de campañas ha sufrido variaciones metodológicas a lo largo de los años y un cambio en su enfoque. Durante los primeros años de la serie (hasta el 1996) el objetivo principal de las campañas (SARACUS, PELACUS) fue la determinación de la abundancia y distribución del stock de sardina que se realizaba mediante prospección acústica combinada con la información proveniente de arrastres pelágicos. El objetivo principal de los cambios que se han producido en la campaña en los últimos años ha sido el permitir su evolución hacia una plataforma de seguimiento del ecosistema pelágico de la plataforma norte y noroeste peninsular. Con esta evolución, se intenta dar respuesta a la necesidad planteada por la UE y otros organismos internacionales de obtener los datos e información necesarios para alimentar los modelos de ecosistema, concebidos como parte clave del Ecosystem Approach to Fisheries Management (EAFM) y posibilitar la monitorización integrada que pueda dar respuesta a los requerimientos de la Directiva Marco de la Estrategia Marina (2008/56/CE).PELACUS 0411 es la vigésimo octava campaña de la serie histórica cuya extensión permite el llevar a cabo estudios retrospectivos sobre las posibles causas de la variabilidad temporal en las propiedades físicas y biológicas y en los procesos observados en el ecosistema pelágico. Al mismo tiempo, constituye una fuente de datos importante para la calibración y validación de los modelos físicos, acoplados (físico-biológicos) y de hábitat y la recopilación de información necesaria para el cálculo de indicadores que permitan determinar el Buen Estado Medioambiental (GES en inglés) de las aguas de la plataforma del norte y noreste de la Península Ibérica dentro de los requerimientos de la Estrategia Marina. Las campañas PELACUS se engloban en el proyecto ECOPEL II: Estudio del ecosistema pelágico, la distribución de las especies y sus relaciones con el medio ambiente, cuyo objetivo principal es el estudio de la dinámica y funcionamiento del ecosistema pelágico de la plataforma Ibero Atlántica.UE- DCF Programa Nacional de Datos Básicos- Instituto Español de Oceanografí

Variación interanual en la presencia de cetáceos en la división 3L del área de regulación de la Northwest Atlantic Fisheries Organization (NAFO, Flemish pass)

Peer reviewe

The trophic relationships of several commercial finfish species from the southwest Atlantic.

This study aims to quantify the trophic relationships of seven commercially valuable predatory fish species (Argentine hake Merluccius hubbsi, southern hake Merluccius australis, Patagonian toothfish Dissostichus eleginoides, southern blue whiting Micromesistius australis australis, red cod Salilota australis, kingclip Genypterus blacodes and hoki Macruronus magellanicus) over a two-year period. A total of 1590 stomachs from these species was collected from the high seas of the southwest Atlantic and in the waters around the Falkland Islands. The percentage similarity index shows that all species except southern hake occupy very similar trophic positions, with a high percentage dietary overlap. Despite this, niche breadths were relatively narrow, with the majority of feeding occurring on locally abundant prey items (notothiniid fish and the squids Illex argentinus and Loligo gahi). In the two species for which sample size was largest, Argentine hake and kingclip, geographical differences in diet were found, which may be related to regional variation in prey abundance. The results are discussed in relation to the seasonal migrations of predators and prey and the hydroclimate regime

Morphometric and meristic variation in Argentine hake (Merluccius hubbsi) and southern hake (Merluccius australis) from the southwest Atlantic.

Samples of Merluccius hubbsi (N=147) were collected from the southwest Atlantic, in the high seas at 42o S and 46oS and from the waters around the Falkland Islands. A sample of M. australis (N=23) was also collected in Falkland Islands waters. Variation in the population structure was investigated using multivariate analysis of a total of external and skeletal morphometric data, counts of fin rays and teeth, and measurements on scales. All measurements were standardised to mean body size and each character set was analysed separately. Principle components analysis and discriminant analysis were used to identify differences between M. hubbsi from different areas and differences between the two species. The results indicate the presence of two groups of Merluccius hubbsi within the study area, one found on the high seas and one in the waters around the Falkland Islands. Results are discussed in relation to the reproductive and trophic migrations of M. hubbsi, the relative importance of genetic and environmental differences, and the results of similar studies from the southwest Atlantic

Fisheries interactions of Delphinus delphis in the north-east Atlantic with an emphasis on Galicia, north-west Spain.

Bycatch from interactions with fisherie s remains the biggest global threat to marine mammals. Galicia, north - west Spain, is one of the world’s main fishing regions and a high level of cetacean - fisheries interactions has been reported from on - board observers, interviews with fisheries stakeholde rs and analysis of stranded and by - caught carcasses. Delphinus delphis is the most abundant cetacean in the area and since 1990 necropsies of over 1800 stranded and by - caught Delphinus have been conducted. Life history data (age, maturity, and pregnancy ra te data) from stranded and by - caught cetaceans can be used to construct life tables and to estimate overall mortality and fisheries mortality rates. Age and maturity were determined from stranded and by - caught Delphinus between 1990 and 2009. Males and fem ales reach sexual maturity at 8.5 and 7.5 years of age, respectively, and no temporal difference in age at sexual maturity was observed. Results indicate 13% annual mortality in the Delphinus delphis north - east Atlantic population and necropsy data suggest s that 60% of mortality (i.e. 7.2% annual mortality) is attributable to fisheries interactions, predominantly from pair trawls and gillnets. By - caught Delphinus were found to die significantly younger than non - by - caught animals (p=<0.001) although no sex - r elated difference in bycatch rate was observed (p=0.051). The estimated annual mortality due to fisheries interactions greatly exceeds the 2% limit set by ASCOBANS and the IWC and high bycatch rates are also reported for other countries e.g. the UK, France and Portugal. Although Delphinus delphis in the north - east Atlantic is one continuous population, the high level of bycatch occurring in parts of the range is most likely unsustainable and will be discussed. There is a need to carry out on - board monitorin g, notably in the north - west Iberian Peninsula (Galicia and Portugal), to incorporate cetacean bycatch into fisheries advice and, above all, to start introducing mitigation measures

Are there climatic signals in fishery data for sardine (Sardina pilchardus) along the Iberian Atlantic coast?

The Iberian sardine (Sardina pilchardus) is distributed along the whole shelf of the Iberian Peninsula with the highest catches being taken from southern Galician waters and northern Portugal. The fishery is dependent on the strength of the recruitment in this area and recruitment processes seem to be driven by a combination of oceanographic (local) and climatic (global) events. In an exploratory analysis we examined whether the variability observed in landings from ICES areas VIIIc (northern) and IXa (western Iberia) from 1940 to 2005, and in estimated annual recruitment and spawning stock size for the whole stock could be related to environmental conditions at large and local scales, taking into account temporal autocorrelation in the response variables. Landings for areas VIIIc and IXa show differing trends and were most strongly related, respectively, to the multi-decadal Atlantic oscillation (AMO) and to SST (with an optimum around 15o C). Recruitment was negatively related to air temperature (AT). We stress the need for taking into account time lagged effects, non linear relationships, autocorrelation in response variables and collinearity between explanatory variables. We discuss possible mechanisms underlying these observed patterns and whether the apparent climatic relationships have any predictive value