Connections between northern Iberia and western France around the Bay of Biscay during the Chalcolithic, Early Bronze Age, and Middle Bronze Age are addressed in this article through a multivariate cluster analysis of a dataset of 1273 metal finds, comprising 4554 metal artefacts grouped into five multiregional clusters with distinctive distributions, chronologies, content, and contexts. Changes in distribution and chronology show that metalwork from faraway regions was deposited in similar ways, reflecting changing patterns of interregional connectivity. Changes in context and content suggest social transformations. The clustering method known as Latent Class Analysis is presented here in the hope that it will be applicable to other datasets elsewhere in the world.

We present the distribution of the parthenopid crab species Distolambrus maltzami from the North-east Atlantic with a first record from UK seas. The distribution of D. maltzami in the Celtic-Biscay area in the eastern Atlantic, is both described based on recent records from survey data and estimated from modelling its environmental niche. The predicted probability of occurrence is greatest in areas with fluctuating tidal currents and water masses that are rich in chlorophyll-a, cold (minimum bottom temperature lower than 10°C) and oxygen-rich. We include a simple key to distinguish the two parthenopid crab species previously encountered in the region and highlight the importance of a multidisciplinary approach to fisheries data collection.

Rhamphobrachium (Rhamphobrachium) agassizii is reported from the Cantabrian Sea, Spain, from depths of 925–1207 m. This is its first record off the Iberian Peninsula and in European waters, representing its northernmost distribution in the North Atlantic Ocean to date. Previous reports of R. (R.) agassizii from the eastern and western North Atlantic demonstrate its apparent amphi-Atlantic distribution, which appears consistent with the distribution of the main Atlantic currents. It is a typical deep-water species with its deepest record at 2165 m from the Azores archipelago. The specimens were collected singly at two stations, attesting to the rarity of the species in contrast to its congener R. (Spinigerium) brevibrachiatum which was the most dominant polychaete species in a previous study.

This project studies the early Roman non-wheel-thrown Aquitania-Tarraconensis-type (AQTA) pottery from the Bay of Biscay region. The ‘ollae’-type AQTA ceramics display clear evidence of specialised production, consumption and interregional exchange by both terrestrial and maritime routes throughout the region.

Trawling activities are considered to be one of the main sources of disturbance to the seabed worldwide. We aimed to disentangle the dominance of environmental variations and trawling intensity in order to explain the distribution of diversity patterns over 152 sampling sites in the French trawl fishing-ground, the Grande Vasière. Using a towed underwater video device, we identified 39 taxa to the finest taxonomic level possible, which were clustered according to their vulnerability to trawling disturbance based on functional traits. Using generalized linear models, we investigated whether the density distribution of each vulnerability group was sensitive to trawling intensity and habitat characteristics. Our analyses revealed a structuring effect of depth and substratum on community structure. The distribution of the more vulnerable group was a negative function of trawling intensity, while the distributions of the less vulnerable groups were independent of trawling intensity. Video monitoring coupled with trait-based vulnerability assessment of macro-epibenthic communities might be more relevant than the traditional taxonomic approach to identifying the areas that are most vulnerable to fishing activities in conservation planning.

Weight–Body Length relationships (WLR) of 45 fish species (37 Actinopterygii and eight Elasmobranchii) were investigated. A total of 31,167 individuals were caught and their biological parameters measured during the four quarters from 2013 to 2015, on five scientific surveys sampling the North-eastern Atlantic Ocean from the North Sea to the Bay of Biscay (ICES Divisions IVb, IVc, VIId, VIIe, VIIg, VIIh, VIIj, VIIIa and VIIIb). Among 45 tested species, all showed a significant correlation between total length (L) and total weight (W). The influence of sex on WLR was estimated for 39 species and presented a significant sexual dimorphism for 18 species. Condition factor (K) of females was always higher than for males. Moreover, a spatial effect on the WLR according to five ecoregions (the Bay of Biscay, the Celtic Sea, the Western English Channel, the Eastern English Channel and the North Sea), was significant for 18 species among 38 tested species. The temporal effect was tested according to components (year and quarter/season). The seasonality effect on WLR is more frequently significant than the year especially for the Elasmobranchii species, and can be related to the spawning season. Finally, depressiform species (skates, sharks and flatfish) are characterized by positive allometric growth, whereas there is no such clear pattern regarding roundfishes growth, whatever their body shape is.

A new species of Ampharetidae, Anobothrus amourouxi sp. nov., has been identified from bathyal depths of the Capbreton Canyon, Bay of Biscay (NE Atlantic Ocean). This new species is characterized by inner branchiae with transversal ciliated ridges, notochaetae from modified eighth thoracic unciniger with hirsute tips, uncini from thoracic unciniger with 6–7 teeth in lateral view arranged in two vertical rows in frontal view, fused segments II + III with paleae from SII and reduced notopodia without chaetae from SIII. An identification key for all hitherto described species of the genus Anobothrus is provided.

During the Capbreton cruises (1987–1990), samples of bathyal benthic macrofauna were taken at 37 stations situated along the continental slope (480–1113 m depth) of the Capbreton Canyon (Bay of Biscay, north-east Atlantic). Ten species of polychaetes belonging to six genera (Melinna, Eclysippe, Amphicteis, Anobothrus, Glyphanostomum and Tanseimaruana) of the family Ampharetidae Malmgren, 1866 were collected at 13 of these stations. Most of these species are reported for the first time in the area. Amphicteis aff. wesenbergae is reported for the first time after its recent description and a new species belonging to the genus Glyphanostomum is here described. Moreover, the finding of Melinna monoceroides represents the northernmost record of the species; Tanseimaruana vestis is recorded for the second time from the East Atlantic after its recent finding in Icelandic waters; Anobothrus aff. gracilis is reported for the second time from the Iberian Peninsula, representing, the southernmost record of the species in the Atlantic Ocean. The potential identification of two fragments of an Ampharetinae indet as Anobothrus laubieri, a deep water Arctic species, is discussed.

The diet of young Atlantic bluefin tuna (Thunnus thynnus) in the Bay of Biscay foraging ground was assessed using stomach-content analysis (SCA) and stable-isotope analysis coupled with isotope mixing model. Whereas SCA showed that the young tuna fed mainly on horse mackerel (Trachurus trachurus), the estimation of liver and muscle mixing model analyses indicated that northern krill (Meganyctiphanes norvegica) was the most important food resource. These contrasting observations are probably due to the different time scales spanned by the different methods. The present results suggest that young bluefin tuna prey at different trophic levels of the Bay of Biscay pelagic food web, thus behaving as an opportunist and generalist predator.

Deepwater fish are characterized by long lifespans, late maturity and low productivity. This implies slow recovery from low biomass levels and it is, therefore, important to manage these stocks correctly to avoid overfishing. However, these stocks are generally data poor, which it makes difficult to apply quantitative assessment models on which to base their management. The management strategy evaluation (MSE) approach consists in evaluating the performance of management strategies by simulation before their implementation. In the evaluation, the main sources of uncertainty in a fishery system and its management process should be taken into account in order to find robust management strategies. Thus, the MSE approach is relevant to the management of data-poor stocks. We used the FLBEIA software, an FLR library coded in the R statistical language, to conduct a bio-economic impact assessment of fisheries management strategies. We evaluated the performance of several management strategies in three different deepwater case studies using the MSE approach: beaked redfish (Sebastes mentella) in the Norwegian Sea, blackspot seabream (Pagellus bogaraveo) in the Strait of Gibraltar, and French mixed deepwater fisheries in the North East Atlantic. In conclusion, we found that the S. mentella stock is very sensitive to the stock recruitment relationship chosen. For P. bogaraveo, simulations showed that the present constant catch management is as good as more sophisticated strategies. Finally, in mixed fisheries, case study fleet dynamics were key for the success of management strategies

A one-year study of the reproductive biology of a population of Diopatra marocensis at the Villaviciosa estuary, northern Spain, was undertaken with emphasis on brooding behaviour, larval development and gametogenesis. Field observations together with a histological study of monthly collected individuals revealed that the population was iteroparous, reproducing annually during a short breeding season extending from March to June. The study demonstrated that all individuals of the population at Villaviciosa estuary were producing at the same time eggs and sperm providing for the first time evidence for the occurrence of simultaneous hermaphroditism in D. marocensis. Mature sperm was of the ent-aquasperm type and was stored in modified nephridial chambers in brooding individuals. In the latter, eggs in advanced cleavage phases were also observed inside the coelom suggesting that fertilization was internal. Eggs in late vitellogenesis presented micronucleoli in the periphery of the nucleus, a phenomenon reported previously for few polychaete species. Pure males and females were never found. It is here suggested that in D. marocensis population size may influence sex allocation and that under conditions of low population densities simultaneous hermaphrodites may be favoured. The study of the larval development confirmed the direct development reported previously for populations of Morocco and Portugal. Further results suggest consumption of nurse eggs and adelphophagy by developing larvae.

An integrated research program was initiated to evaluate if the European shagPhalacrocorax aristotelis can be used as a robust indicator of themarine environment in Mor Braz, Brittany, France. This program focuses on aspects of theecology of the shag including its abundance, demography, diet and at-sea distributionmeasured at three breeding colonies. The annual population growth rate was estimated at1.01 for the period 1987–2009. The number of breeding pairs (mean: 565) was highlyvariable from year to year. Part of this interannual variation was explained by variationsin sea surface temperature and sea surface height in winter and spring: the number ofbreeding pairs was negatively related to sea surface temperature and sea surface height.First year, second year and adult survival probabilities were 0.44, 0.76 and 0.81,respectively. Juvenile survival rate varied between colonies, despite the short distancesseparating these islets. Average productivity was one young fledged per nest, but itvaried between years and islets. Density of individuals at sea varied between 1.40ind.km-2 during the breeding season and 3.08 ind.km-2 after thebreeding season had ended. Individuals foraged up to 7 km from the nest and performed onaverage 2.7 foraging trips per day. The average number of dives deeper than 5 m variedfrom 126 to 400 per day. Mean diving depth, dive duration and time spent at bottom were 13m, 28 s, and 19 s respectively. Regurgitated pellets were collected regularly. Four fishfamilies (Gadidae, Gobiidae, Atherinidae and Labridae) represented more than 65% of thepreys throughout the year, a percentage reaching more than 95% of the prey from May toOctober. The other fish in the diet were Cottidae, Ammodytidae, and Clupeidae. The diet ofthe European shag consisted of benthic fish throughout the year, and also included pelagicfish more frequently between June and October. The synchronous variations of productivitybetween colonies suggest that some common environmental factors affect this demographicparameter at the regional scale. Thus, the European shag has a good potential for being areliable ecological indicator of the state of this marine environment. Finally, improvedknowledge on the foraging ecology of shags will be useful in the process of designingMarine Protected Areas in the Mor Braz to help ensure sustainable management of marineresources and biodiversity conservation.

A new suprabenthic mysid, Mysidopsis cachuchoensis sp. nov., is described from specimens sampled with a suprabenthic sled at the ‘Le Danois' Bank (the ‘El Cachucho' Marine Protected Area; southern Bay of Biscay). The main distinguishing features of this new species are the structure of its eyestalk and antennal scale as well as the armature of its telson and uropodal endopods. Inferred from the present unique record (828 m depth, inner basin between the bank and the Cantabrian shelf), it seems to be a rare endemic species of the bank, living on muddy bottoms of the upper bathyal.

The nannastacid cumacean Campylaspis laevigata is reported for the first time in the Mediterranean Sea from specimens collected on the Israeli continental slope. This species is redescribed, based on specimens from the Bay of Biscay and the Mediterranean, and distinguished from the closely allied congeners Campylaspis glabra and Campylaspis nitens, both recorded from the Mediterranean. The three species have a smooth carapace, but may be distinguished by the structure and setation of the uropods: the inner margin of the peduncle is serrated in C. laevigata and C. nitens (not serrated in C. glabra), but the latter has more setae (6) on the endopodal inner margin and a rudimentary eyelobe. The known bathymetric distribution of C. laevigata ranges from 280 to 2000 m, and its highest abundances in the southern Bay of Biscay were found between 500 and 800 m, possibly related to food availability in the near-bottom environment.

A new bathyal leucothoid amphipod, Leucothoe cathalaa sp. nov., is described and illustrated based on specimens collected at the Le Danois Bank (‘El Cachucho’ Marine Protected Area), southern Bay of Biscay. This species can be distinguished from the other species of the genus Leucothoe by the hardly visible eyes (translucent ocelli, in preserved specimens); antenna 1 with minute accessory flagellum; coxae 1–3 with 2 serrations on posterodistal margin; epimeron 3 posterodistal corner produced, bifid, with one seta between blunt lobes and telson apex pointed without accessory teeth. In live specimens, the eyes are easily visible, each represented as a rounded whitish-pigmented spot. The new species has been found living on fine sandy soft-bottoms between 486 and 574 m depth at the top of the bank. An identification key to the deep Atlantic European species of Leucothoe is provided, as well as ecological and biological comments.

We describe Dysponetus joeli sp. nov. from shallow maerl habitats in the north-east Atlantic (English Channel and Bay of Biscay). Dysponetus joeli differs from congeneric species by a unique combination of characters, including a large syllid-like pharynx, 2–4 simple serrated neurochaetae (closely similar to notochaetae, but much smaller and more delicate), D-shaped chaetal spines and ventral cirri on the third segment. A phylogenetic parsimony analysis based on morphological traits suggests that Dysponetus is not monophyletic unless it includes the closely related genera Vigtorniella and Pseudodysponetus, which are well delineated inside the dysponetid clade. Chaetal spines seem to be secondarily derived from paleae and to have originated in infaunal dysponetid forms. They should not be considered as plesiomorphic, but as evidence to support the clade made up by Dysponetus–Vigtorniella and Pseudodysponetus as delineated by a phylogenetic analysis.

The sea surface temperature (SST) variability of the Bay of Biscay and adjacent regions (1854–2010) has been examined in relation to the evolution of the Atlantic Multidecadal Oscillation (AMO), a major climate mode. The AMO index explains ~25% of the interannual variability of the annual SST during the last 150 years, while different indices of the North Atlantic Oscillation (NAO) explain ≤1% of the long-term record. NAO is a high frequency climate mode while AMO can modulate low frequency changes. Sixty per cent of the AMO variability is contained in periods longer than a decade. The basin-scale influence of NAO on SST over specific years (1995 to 1998) is presented and the SST anomalies explained. The period analysed represents an abrupt change in NAO and the North Atlantic circulation state as shown with altimetry and SST data. Additional atmospheric climate data over a shorter ~60 year period (1950–2008) show the influence on the Bay of Biscay SST of the East Atlantic (EA) pattern and the Scandinavia (SCA) pattern. These atmospheric teleconnections explain respectively ~25% and ~20% of the SST variability. The winter SST in the shelf-break/slope or poleward current region is analysed in relation to AMO. The poleward current shows a trend towards increasing SSTs during the last three decades as a result of the combined positive phase of AMO and global warming. The seasonality of this winter warm flow in the Iberian region is related to the autumn/winter seasonality of south-westerly (SW) winds. The SW winds are strengthened along the European shelf-break by the development of low pressure conditions in the region to the north of the Azores and therefore a negative NAO. AMO overall modulates multidecadal changes (~60% of the AMO variance). The long-term time-series of SST and SST anomalies in the Bay of Biscay show AMO-like cycles with maxima near 1870 and 1950 and minima near 1900 and 1980 indicating a period of 60–80 years during the last century and a half. Similar AMO-like variability is found in the Russell cycle of the Western English Channel (1924–1972). AMO relates at least to four mesozooplankton components of the Russell cycle: the abundance of the chaetognaths Parasagitta elegans and Parasagitta setosa (AMO −), the amount of the species Calanus helgolandicus (AMO −), the amount of the larvae of decapod crustaceans (AMO −) and the number of pilchard eggs (Sardine pilchardus; AMO +). In addition to AMO, the decadal to multidecadal (D2M) variability in the number of sunspots is analysed for the last 300 years. Several periodicities and a multi-secular linear increase are presented. There are secular minima near 1710, 1810, 1910 and 2010. The long term variability (>11 years) of the solar sunspot activity explains ~50% of the variance of the SST of the Bay of Biscay with periods longer than 11 years. AMO is finally compared with the Pacific Decadal Oscillation, the leading principal component of North Pacific SST anomalies.

The temperature evolution over the past 40 years in the Bay of Biscay (North-East Atlantic) is investigated from an in situ data analysis, completed with a satellite SST (Sea Surface Temperature) analysis over the last 20 years. The in situ dataset is an interannual version of the BoByClim climatology, covering the Bay of Biscay area with a 10-km horizontal resolution and a 5-m vertical step. The satellite dataset is the European COastral Sea Operational Observing and Forcast System Program (ECOOP) daily analysis, covering the IBIROOS (Iberian-Biscay-Irish Sea) area with a 4-km resolution. The study area (43°N-50°N/12°W-1°W) extends over the intersection of the domains covered by these two analyses. In the 0–200 m layer of this domain, a heat budget has been computed from an ocean circulation model over the period 1965-2004. Heat is essentially imported from the west by the North Atlantic Drift, then exported southward and northward, or transferred downward into deeper layers. The annual average of air-sea flux is weak, with a zero isoline crossing the domain from the northwest to the southeast. Ocean and atmosphere, forming a coupled system, have comparable contributions and may both result in a heat sink or source. At the interannual scale, variability is mainly controlled by the air-sea flux, with a secondary contribution from oceanic transport. A strong warming of $\sim $ 0.2 °C/decade for the period 1965-2004 is apparent from the surface down to the 200-m depth. The decadal evolution is consistent with several analyses over the North Atlantic. Meanwhile, warming is approximately twice faster than in the whole basin. This trend is not steady, as a cooling period occurred until the early 1970's, and the temperature increase has been significantly stronger during the last 20 years ( $\sim $ 0.3 °C/decade between 0 and 100 m, from 1986 to 2005). The trend and the interannual variability are maximal over the northern part of the shelf. The typical duration of interannual anomalies is two years and their penetration depth is ~100 m, although they occasionally exceed 200 m. The interseasonal anomalies are also stronger within the mixed layer (root-mean-square, RMS = 0.6 °C at the surface) than below (RMS = 0.3 °C at 100 m). Their geographic distribution is radically different between the surface and the deep levels. A seasonal dependence of the warming rate is evident in the upper layer, as the temperature trend is stronger in summer than in winter (by a factor of 2 at the surface). Some of the potential implications for the ecosystem are discussed, particularly in terms of species distribution and dynamics of species exploited by fisheries.

The Asian date mussel Musculista senhousia, previously recorded from the Pacific coast of North America, Australasia and the Mediterranean, is reported for the first time from the Atlantic coast of Europe in Arcachon Bay, where it occurs intertidally and to depths of 5 m. It has been present in Arcachon Bay since 2002 and has since been found in 2006 within two further inlets of the Bay of Biscay, Hossegor Lake and the Bidasoa estuary. Their appearance is probably associated with oyster transfer from Thau lagoon in the Mediterranean Sea to Arcachon Bay.

Regular monitoring of the status of cetacean populations is essential for conservation, policy and management. By using a passenger ferry as a scientific research platform, this study provides information on seasonal, annual and longer-term changes in the occurrence of three cetacean species along a relatively fixed transect through the English Channel and the Bay of Biscay. Data were collected over an 11 year period through the Biscay Dolphin Research Programme (BDRP). Surveys were conducted every month from 1996–2006 between Portsmouth, England and Bilbao, Spain by a team of experienced observers using standard techniques. From a 0.125° by 0.125° grid, cells were surveyed in each year and where each species was recorded they were identified using a geographical information system (GIS). A rapid analytical method—species occupancy (defined as the proportion of surveyed cells that a species was detected in)—was used to assess whether there were any trends in occurrence over time for three cetacean species. From this analysis, a significant trend to increasing occurrence of harbour porpoises in summer months in the English Channel was identified. There were also increases in the occurrence of common dolphins in the English Channel in winter months and striped dolphins in the Bay of Biscay in winter months corresponding with a decrease in summer occurrence, across the study period. However, while consistent, these trends were not significant.