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Aim Deep-diving cetaceans are oceanic species exposed to multiple anthropogenic pressures including high intensity underwater noise, and knowledge of their distribution is crucial to manage their conservation. Due to intrinsic low densities, wide distribution ranges and limited presence at the sea surface, these species are rarely sighted. Pooling data from multiple visual surveys sharing a common line-transect methodology can increase sightings but requires accounting for heterogeneity in protocols and platforms. Location North Atlantic Ocean and Mediterranean Sea. Time period 1998 to 2015. Major taxa Ziphiidae; Physeteriidae; Kogiidae. Methods About 1,240,000 km of pooled effort provided 630 sightings of ziphiids, 836 of physeteriids and 106 of kogiids. For each taxon, we built a hierarchical model to estimate the effective strip width depending on observation conditions and survey types. We then modelled relative densities in a generalized additive modelling framework. Geographical predictions were limited to interpolations identified with a gap analysis of environmental space coverage. Results Deeper areas of the North Atlantic gyre were mostly environmental extrapolation in the predictions, thereby highlighting gaps in sampling across the different surveys. For the three species groups, the highest relative densities were predicted along continental slopes, particularly in the western North Atlantic Ocean where the Gulf Stream creates dynamic frontal zones and eddies. Main conclusions Pooling a large number of surveys provided the first basin-wide models of distribution for deep-diving cetaceans, including several data-deficient taxa, across the North Atlantic Ocean and the Mediterranean Sea. These models can help the conservation of elusive and poorly known marine megafauna.

A detailed study on skate and ray discards survivability based on sampling trials by observers on board commercial vessels and onshore survival experiments has been carried out by IEO. Our objective was to obtain the composition of species, size and sex of the species caught in fisheries in the Cantabrian‐Northwest fishing ground using the information provided by observers onboard commercial vessels and to analyze the percentage of mixture of species retained on board or discarded and also to obtain survival estimates from dedicated experiments.

The increasing frequency of sperm whale (Physeter macrocephalus) strandings during the winter in the North Sea has resulted in many theories about why this phenomenon occurs. Using a newly updated catalogue of North Sea sperm whale strandings, the possible roles of environmental drivers, which might affect the entry of migrating sperm whales into the North Sea and/or their stranding, were investigated using generalised additive mixed models. Little or no evidence was found of effects of sunspot activity, the North Atlantic Oscillation (NAO) Index or sea surface pressure around Iceland (a component of the NAO) on the occurrence of strandings. Several sea and land surface temperature indices were positively correlated with the occurrence of strandings. There is evidence of changing relationships between strandings and environmental variables during the last three decades and, given the absence of an obvious mechanism by which the temperature-strandings link might operate, it is important to recognise that several different processes may contribute to the strandings, including the recovery of the sperm whale population following the cessation of commercial whaling in the late 20th century. In addition, and since temperature could also be affecting the whales´ prey and changes in prey distribution could explain whale stranding patterns, this paper updates previous studies of diet, confirming the continued dominance of the Boreoatlantic armhook squid Gonatus fabricii in stomach contents of sperm whales stranded on North Sea coasts, although remains of small numbers of North Sea species were also found, suggesting some feeding within the North Sea

Scientific fishing survey DESCARSEL0917 took place on board the research vessel "Miguel Oliver" in the NW Cantabrian national fishing ground (ICES areas 8c and 9a), during September 2017, under similar conditions to those of the commercial fleet. Survival experiments were carried out during the DESCARSEL0917 along the continental shelf and upper slope of Galicia. The objective was to determine survival rates of sea cucumbers Parastichopus tremulus and P. regalis to the processes of discarding and handling in trawl fishing. Both species are by caught by the Spanish otter bottom trawl fleet at the area. Most of the catches are discarded although in recent years there has been an increase in the number of landings due to the economic value of the species, which are exported to Asian markets

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In addition to crustaceans, remains from 17 individual squid were found in the stomach of a 58 cm slender sunfish Ranzania laevis from Australia, adding a new prey item to their little studied diet. Taken together with existing data from the literature, crustaceans appear to be a common prey item, with larger R. laevis (26–65 cm) also taking small fish and squid. Along with new documentation on breaching, the unexpected finding of squid in the stomach confirms that these fish are fast and agile predators., SI

We provide an example on how to merge large-scale datasets into a single one and how to determine where geographical extrapolation can be made while still within environmental interpolation.

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Study Project 99/016 “Data collection for stock assessment of two hakes (Merluccius hubbsi and M. australis) in international and Falkland waters of the SW Atlantic” ran from January 2000 to December 2001. The main objective of the project was the collection and collation of already existing and newly acquired fishery and biological data needed for preliminary assessment of two hake species occurring in the study area. In addition to this basic remit, additional objectives included the creation of a common database, study of spawning seasons and areas, discard pattern and length-frequency composition of target and non-target species, estimation of annual by-catch rates, analysis of trophic relationships, marine mammals by-catch and sightings, morphometric analysis for stock differentiation, and developing GIS applications for analysis of the data collected. Historical fishery and biological data series available from IEO and FIGFD (since 1988 and 1987 respectively) were provided to the project. New fishery and biological data were collected by scientific observers provided by IEO, ANAMER and FIGFD, and placed on board Spanish fishing vessels operating in the study area during the project period. Data on fishing activity included effort, catches and discards of target and non-target species on a haul-by-haul basis. Biological information (size, sex, maturity stage, etc) of target and non-target species was recorded on a daily basis. Data on landings and effort were provided by ANAMER to its subcontractor (MG OTERO) for processing and estimation of total catch and effort of the whole Spanish fishing fleet in the area; MG OTERO was also responsible for organisation of observers in collaboration with ANAMER staff in Vigo and Port Stanley. Ancillary data on location, time of fishing, depth, SST, SBT, sea roughness, wind, etc, was recorded on a haul-by-haul basis. This type of information was essential for development of GIS at AU to relate the species distribution to physical and environmental factors. Other information collected was about by-catches and sightings of small cetaceans and seabirds, and biological samples such as otoliths, stomachs and whole specimens of hakes for subsequent studies on growth (IEO, FIGFD), diet and morphometrics (AU). All the historical and new data collected during the project were collated and integrated into a common database designed by all participants and built at IEO. The information was used for preliminary assessment of two hake populations co-ordinated by RRAG during a workshop held in London in July 2001. All these data will be analysed and written up for future publications. Discard rates of target species were generally low in all areas and seasons with the highest discard rate for Notothen sp. (around 100% of the catch). Illex squid was found to be the major by-catch for hake fishery in the 46 S area. IEO observers reported data on incidental catches of marine mammals and sea birds since 1993 and the analysis of this information was made by AU. The observed mortality in the fishing gears comprised small numbers of black-browed albatross, gentoo penguin and the hourglass dolphin. The species most frequently sighted was the Peale’s dolphin, although this species did not appear in by-catches, followed by the hourglass dolphin. The project provided an opportunity to collect and integrate for the first time at European level the necessary fishery and biological data for the development of partial stock assessment for the future rational management of the fisheries in the area. Such management is needed for the sustainability of the commercial fisheries, the conservation of the onshore and offshore jobs and the supply of fish to the most important markets worldwide., EUROPEAN COMMISSION DIRECTORATE GENERAL FISHERIES – DG XIV

The genus Patagonotothen is the most common Nototheniid on the Patagonian Shelf and slope and is part of the by-catch species in the bottom trawl fisheries. This paper presents preliminary results from the EC CRAFT project “Promoting higher added value to a finfish species rejected to sea”, aiming to develop the research and the technology necessary to promote higher added value to fishing activity by taking profit from a finfish species (Rockcod, Patagonotothen spp.) not known to consumers and currently discarded by the EU fishing fleet operating in the South West Atlantic in order to supply the EU seafood industry with a good quality raw material for human food manufacturing. Historical fishery data series (26 168 commercial hauls of which 12 745 were positive), including effort, catches and discards, as well as biological and environmental information, from 1988 onwards was used to describe and quantify patterns and spatio-temporal changes in the rockcod fishery. These data was collected by scientific observers on board commercial vessels.GIS analysis was carried out in order to study the seasonal geographical changes in the distribution of abundance, SST and densities calculated from CPUE. Fishery and environmental data as well as SST data derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR), were analysed in order to find monthly variations in spatial and depth distribution of Patagonotothen spp. Preliminary results demonstrated that, within areas of occurrence, there are significant correlations between fish abundance (CPUE), the oceanographic conditions of the area (SST gradients) and depth in certain months

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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.