Southern Bay Of Biscay Research Articles

Strengthening the evidence for seasonal intertidal exploitation in Mesolithic Europe and new insights into Early Holocene environmental conditions in the Bay of Biscay from the oxygen isotope composition of Phorcus lineatus (da Costa, 1778) shells

Strengthening the evidence for seasonal intertidal exploitation in Mesolithic Europe and new insights into Early Holocene environmental conditions in the Bay of Biscay from the oxygen isotope composition of Phorcus lineatus (da Costa, 1778) shells

Genomic analysis of NE Atlantic sardine (Sardina pilchardus) reveals reduced variation in a recently established North Sea population and directs reconsideration of management units.

The European sardine (Sardina pilchardus) is under intense fishing pressure and exhibits distributional/abundance shifts linked to environmental change. The current understanding of population demographics needed for sustainable management is uncertain due to concerns that previous genetic studies lacked resolution and limited sampling of sardine north of the Bay of Biscay. To address these issues, we performed mtDNA sequencing and genome wide SNP analysis of samples collected across the Bay of Biscay, Celtic Sea, English Channel and North Sea. The complete SNP data reported a lack of structure throughout the sampled area compatible with high gene flow. A consensus suite of positive outlier SNPs was identified which reported a significant correlation with geographical distance with the largest differentiation between the southern Bay of Biscay and North Sea samples which also reported a significant mtDNA ΦST. While the roles of dispersal limitation and environmental heterogeneity underpinning this require further study, this adds to growing evidence that selection is influencing sardine population structure against a background of high gene flow. The results indicate that while there may be a level of demographic independence between North Sea and South Biscay sardine, the current delimitation of central (Biscay) and northern (Channel and Celtic Sea) operational stocks may misrepresent connectivity between the Biscay and Channel. The North Sea sample exhibited markedly lower mtDNA and nuclear variation than other samples. As sardine have only recently invaded the North Sea such reduced genetic variation is compatible with predictions for peripheral leading-edge populations but contrasts with patterns for other small pelagic species and emphasises the need to consider species-specific genetic structure in ecosystem-based management. Nascent management of the North Sea sardine fishery must ensure that current low levels of genetic diversity are not eroded further as this may decrease the species adaptive potential and inhibit its expansion.

Thermal refugia reinforce macroalgal resilience against climate change in the southeastern Bay of Biscay.

Rising global temperatures present unprecedented challenges to marine ecosystems, demanding a profound understanding of their ecological dynamics for effective conservation strategies. Over a comprehensive macroalgal assessment spanning three decades, we investigated the spatiotemporal evolution of shallow-water benthic communities in the southern Bay of Biscay, uncovering climate-resilient areas amidst the ongoing phase shift in the region. Our investigation identified seven locations serving as potential climate refugia, where cold-affinity, canopy-forming macroalgal species persisted and community structure was similar to that observed in 1991. We unveiled a clear association between the emergence of these refugia, sea surface temperature (SST), and the Community Temperature Index, positioning SST as a significant driver of the observed phase shift in the region. Warming processes, defined as tropicalization (increase of warm-affinity species) and deborealization (decrease of cold-affinity species), were prominent outside refugia. In contrast, cooling processes, defined as borealization (increase of cold-affinity species) and detropicalization (decrease of warm-affinity species), prevailed inside refugia. Refugia exhibited approximately 35% lower warming processes compared to non-refuge areas. This resulted in a dominance of warm-affinity species outside refugia, contrasting with the stability observed within refugia. The persistence of canopy-forming species in refuge areas significantly contributed to maintaining ecosystem diversity and stability. These findings underscored the pivotal role of climate refugia in mitigating climate-driven impacts. Prioritizing the protection and restoration of these refugia can foster resilience and ensure the preservation of biodiversity for future generations. Our study illustrates the importance of refining our understanding of how marine ecosystems respond to climate change, offering actionable insights essential for informed conservation strategies and sustainable environmental management.

Deep-Sea Ophiuroids (Echinodermata; Ophiuroidea) from the Avilés Canyon System: Seven New Records for the Spanish North Atlantic Marine Subdivision

The Avilés Canyon System (ACS) is located in the southern Bay of Biscay (northern Spain, Cantabrian Sea). It has been declared a Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network and recognized as a Vulnerable Marine Ecosystem (VME). This area is included in the North Atlantic Marine Subdivision (NAMD). The present study reviews ophiuroid fauna collected during the INDEMARES–ACS project and compares the new findings with previous studies using the Official Spanish Checklist (“Inventario Español de Especies Marinas”) to update our knowledge on the diversity and distribution of these species. During the surveys carried out within the LIFE + INDEMARES–Avilés Canyon System project (2010–2012), a total of 7413 specimens belonging to 45 ophiuroid species were collected from 50 stations in a depth range between 266 and 2291 m. The most frequent species was Ophiactis abyssicola (M. Sars, 1861). Comparing the identified species with public datasets, seven species should be considered as new records for NAMD: Ophiocten centobi Paterson, Tyler & Gage, 1982, Amphiura borealis (G.O. Sars, 1872), Amphiura fragilis Verrill, 1885, Ophiochondrus armatus (Koehler, 1907), Ophiosabine parcita (Koehler, 1906), Ophiophrixus spinosus (Storm, 1881), Ophiotreta valenciennesi (Lyman, 1879). Furthermore, one species has expanded its bathymetric range: Ophiosabine parcita (Koehler, 1906).

Spatial and seasonal variability of picoplankton abundance and growth rates in the southern Bay of Biscay

Spatial and seasonal variability of picoplankton abundance and growth rates in the southern Bay of Biscay

Last Glacial – Holocene variability of the European Slope Current, NE Atlantic

Last Glacial – Holocene variability of the European Slope Current, NE Atlantic

Temperature and salinity trends in the northern limit of the Canary Current Upwelling System

Temperature and salinity trends in the northern limit of the Canary Current Upwelling System

Otolith shape and elemental signatures provide insights into the connectivity of euryhaline Chelon labrosus inhabiting two close estuaries with different burdens of xenoestrogens in the Southern Bay of Biscay

Otolith shape and elemental signatures provide insights into the connectivity of euryhaline Chelon labrosus inhabiting two close estuaries with different burdens of xenoestrogens in the Southern Bay of Biscay

Distribution of recent planktonic foraminifera in surface sediments of the Basque shelf (S Bay of Biscay): Oceanographic implications

Distribution of recent planktonic foraminifera in surface sediments of the Basque shelf (S Bay of Biscay): Oceanographic implications

Faunal behavior in response to near bottom water dynamics in a marine protected area (Cantabrian Sea, southern Bay of Biscay)

Faunal behavior in response to near bottom water dynamics in a marine protected area (Cantabrian Sea, southern Bay of Biscay)

Deep sea starfishes (Echinodermata: Asteroidea) from the Avilés Canyon System (Bay of Biscay), including two new records

Deep sea starfishes (Echinodermata: Asteroidea) from the Avilés Canyon System (Bay of Biscay), including two new records

Seamounts, canyons and slope: The preference of a new stilipedid amphipod (Crustacea: Amphipoda) for the Bay of Biscay

Seamounts, canyons and slope: The preference of a new stilipedid amphipod (Crustacea: Amphipoda) for the Bay of Biscay

Improving the efficiency of wide-angle seismic data inversion through a nonlinear algorithm: case study of the MARCONI-3 profile

Wide-angle seismic reflection/refraction (WA) surveys provide data that can be modeled to obtain lithospheric-scale P-wave velocity (VP) models. The interpretation of these datasets is often performed as a laborious and time-consuming trial-and-error procedure, in which the relevant model parameters (layer thickness and VP) are manually adjusted until the forward modeling matches the observed travel-times. In this work, we present a fully automatic iterative nonlinear approach to invert WA datasets based on the simulated annealing technique. We test our proposed approach with data from the MARCONI-3 WA profile (southern Bay of Biscay) and compare the outcome with an existing detailed interpretation, discussing the similarities between the two models and the agreement between our model and the observed travel-times.

Avilés Canyon System: Increasing the benthic biodiversity knowledge

Avilés Canyon System: Increasing the benthic biodiversity knowledge

Alongshore upwelling modulates the intensity of marine heatwaves in a temperate coastal sea

Alongshore upwelling modulates the intensity of marine heatwaves in a temperate coastal sea

Contrasted spatio-temporal changes in the demersal fish assemblages and the dominance of the environment vs fishing pressure, in the Bay of Biscay and Celtic Sea

Climate change and resource exploitation represent strong selection pressure affecting the spatio-temporal dynamics of marine assemblages that ensure food provision for humans. However, such dynamics remain poorly documented, and their drivers unclear. Here, we investigate changes in fish assemblages of two key European fishing areas, the Bay of Biscay (BoB) and the Celtic Sea (CS), during the last two decades. We quantify the relative contribution of change in energy (i.e. temperature and trophic resources), habitat (depth, substrate, oxygen) and fishing pressure to explaining observed spatial and temporal variations in fish diversity. We used long-term scientific surveys to evaluate the spatio-temporal changes in species richness (SR), abundance and composition of demersal fish (Actinopterygii) assemblages at different spatial scales combined with a range of regression models and variance partitioning. Diversity patterns showed greater variability in space than in time: SR weakly changed over time, while compositional dissimilarity showed local patterns of taxonomic homogenization in the CS and differentiation in the southern BoB, where local assemblages were becoming more similar and dissimilar over time, respectively. Energy funnelled through small pelagic species as a potential trophic link affecting the dynamics of demersal assemblages was the most important driver, while habitat and fishing pressure had limited importance. Our study revealed contrasted dynamics of demersal fish assemblages at a regional scale that were best explained by the dynamics of small pelagic species. Direct effects of environmental forcing and fishing pressure were limited in both regions which have a long history of fishing and still remain relatively buffered from global warming effects. This research paved the way to combine methods inspired by biogeography with scientific monitoring surveys to detect spatio-temporal dynamics of fish assemblages and their drivers in marine ecosystems under multiple pressures.

Response of Food-Webs Indicators to Human Pressures, in the Scope of the Marine Strategy Framework Directive

Understanding food webs environmental condition is a challenging task since evaluations are limited by data on key ecosystem elements, by the availability of indicators that incorporate relevant guilds and by the difficulty in establishing cause-effect relations between pressures and health status, as multiple overlapping pressures can affect taxonomic elements differently. The present work aims to investigate food webs assessment under the Marine Strategy Framework Directive (MSFD), revealing gaps and future research needs in the North Eastern Atlantic. To understand reporting patterns, information on the criteria employed and the resulting assessment trends of Descriptor 4—Food webs were surveyed from the MSFD reports. A multivariate analysis was applied to food webs assessment status and spatially overlapping anthropogenic pressures to understand if the assessment was detecting pressures, considering fish elements. Results revealed that reporting strategies varied between Member States. High reporting effort was exhibited by the United Kingdom in opposition to Ireland or France. Reporting of other groups other than fish and plankton was limited to the United Kingdom due to the availability of monitoring programs and data. The analysis applied to criteria considering fish elements reinforced that reporting strategies and trends differed between countries, although some similarities were found for the Bay of Biscay and Iberian coast and the Celtic Seas. Food webs assessment trends for fish were variable in Spain and were stable or increased in Portugal and the United Kingdom. Anthropogenic drivers significantly influencing food web trends for fish elements were fishing, and climate anomalies in the southern Bay of Biscay and Iberian coast, while eutrophication and chemical contamination had effects on trends in the Celtic Sea and the North Sea. Results allowed to establish a relation between anthropogenic effects and food web patterns, however, these were limited since food webs assessment is incongruent in terms of criteria used and data is still limited at relevant scales. This study reinforced the necessity to increase Member States harmonization and calibration to improve our understanding of food webs environmental status.

First recording of a bathypelagic deep scattering layer in the Bay of Biscay

First recording of a bathypelagic deep scattering layer in the Bay of Biscay

The future of marine citizenship is now: Cetacean conservation in the eyes of young Spanish citizens

Abstract The number of young conservationist movements is increasing worldwide, as new generations become more aware of the environmental problems that are having an impact on the planet. Consequently, young people appear to play a fundamental role in developing successful conservation strategies. This research examines young citizens’ knowledge, attitudes and engagement in cetacean conservation in coastal and non‐coastal regions of Spain, and assesses the influence of whaling tradition. A total of 902 anonymous surveys were conducted with students between 14 and 16 years old at 10 high schools located in nine different study areas, six located along the Cantabrian coast (Southern Bay of Biscay) and three located in inland regions of Spain. In general, results showed low levels of knowledge about cetaceans and whaling among young people, but high concern about cetacean conservation. As it was expected, knowledge about the history of whaling was higher in participants from areas with than without a whaling tradition. However, no statistically significant differences were found regarding attitudes towards cetaceans between these two groups. Significant differences were detected between genders with respect to cetacean conservation and engagement. Females showed more positive attitudes towards cetaceans when compared with their male counterparts. A correlation between knowledge and positive attitudes regarding whales and dolphins was found in areas located along the Cantabrian coast, and a correlation between positive attitudes and engagement in cetacean conservation was observed in all study areas. Although the majority of participants showed strong support for the protection of whales and dolphins, less than two‐thirds stated that they were willing to engage in cetacean conservation. The results of this study may contribute to the implementation of improved marine education programmes. These programmes should not only raise awareness of the marine environment, but also promote pro‐environmental behaviour and engagement in the protection of the ocean.

Evidence of Atlantic bluefin tuna spawning in the Bay of Biscay, north-eastern Atlantic.

The spawning grounds of the Atlantic bluefin tuna (Thunnus thynnus) are traditionally considered to be the Gulf of Mexico (Gulf of Mexico) and the Mediterranean Sea (Mediterranean Sea). However, for the western Atlantic, unequivocal evidence of bluefin spawning outside the Gulf of Mexico has been shown. In this study we present the first records of genetically confirmed bluefin larvae in the southern Bay of Biscay (eastern Atlantic). These findings provide evidence of bluefin spawning activity outside the Mediterranean Sea, in the north-eastern Atlantic. However, our results suggest that the bluefin spawning in the Bay of Biscay is a sporadic phenomenon.