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

Autotrophic and heterotrophic picoplankton play fundamental roles in marine food webs and biogeochemical cycles. However, their growth responses have seldom been jointly assessed, including many temperate regions such as the Bay of Biscay. There, previous studies have shown their relevance in carbon fluxes.

Identifying sustainability priorities among value chain actors in artisanal common octopus fisheries.

Unlabelled: The United Nations (UN) Decade of Ocean Science highlights a need to improve the way in which scientific results effectively inform action and policies regarding the ocean. Our research contributes to achieving this goal by identifying practical actions, barriers, stakeholder contributions and resources required to increase the sustainability of activities carried out in the context of artisanal fisheries to meet UN Sustainable Development Goals (SDG) and International Year of Artisanal Fisheries and Aquaculture (IYAFA) Global Action Plan (GAP) Pillar targets. We conducted a novel 'social value chain analysis' via a participatory workshop to elicit perspectives of value chain actors and fisheries stakeholders associated with two Spanish artisanal common octopus () fisheries (western Asturias-Marine Stewardship Council [MSC] certified, and Galicia-non-MSC certified) about their priorities regarding sustainable octopus production and commercialization.

Comparative genomics of mortal and immortal cnidarians unveils novel keys behind rejuvenation.

is the only metazoan able to rejuvenate repeatedly after its medusae reproduce, hinting at biological immortality and challenging our understanding of aging. We present and compare whole-genome assemblies of and the nonimmortal using automatic and manual annotations, together with the transcriptome of life cycle reversal (LCR) process of We have identified variants and expansions of genes associated with replication, DNA repair, telomere maintenance, redox environment, stem cell population, and intercellular communication. Moreover, we have found silencing of polycomb repressive complex 2 targets and activation of pluripotency targets during LCR, which points to these transcription factors as pluripotency inducers in .

Increase in mercury and methylmercury levels with depth in a fish assemblage.

Despite their remoteness, deep-sea species bioaccumulate mercury, mostly in the form of the neurotoxin methylmercury (MeHg). Although the concentration of MeHg in the water column is known to increase with depth down to a maximum found at the base of the permanent thermocline, the knowledge of the relationship between MeHg content in marine species and their depth of occurrence is limited. We analyzed total mercury (THg) and MeHg concentrations in 25 species of fish inhabiting the Avilés Submarine Canyon and its adjacent shelf (Cantabrian Sea, North-East Atlantic) between 50 and 1868 m depth.

Holothurian (Echinodermata) diversity and distribution in the central Cantabrian Sea and the Avilés Canyon System (Bay of Biscay).

Here we report on the holothurian fauna at the Avilés Canyon System (Natura 2000 Site of Community Importance), central Cantabrian Sea, northern Spain. The samples were collected during several cruises covering the shelf, the continental slope and the abyssal depth. We identified 174 specimens, belonging to 35 species of the seven orders of class Holothuroidea.

Social attributes can drive or deter the sustainability of bottom-up management systems.

Despite the growing popularity of bottom-up fishery management schemes not all socio-ecological systems respond well to this approach. Unfortunately, due to the heterogeneous nature of socio-ecological systems and lack of long-term, place-based studies we have yet to disentangle the impact of social attributes on their sustainability. The gooseneck barnacle fishery in Asturias, a fishery with a long-standing tradition of bottom-up management schemes and a plethora of spatially explicit data, provides a unique opportunity to test the effect of social attributes on 7, heterogeneous, co-managed, Territorial Use Rights for Fishing (TURFs) areas.

Large-scale ocean connectivity and planktonic body size.

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition.

Biomagnification of persistent organic pollutants in a deep-sea, temperate food web.

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) were measured in a temperate, deep-sea ecosystem, the Avilés submarine Canyon (AC; Cantabrian Sea, Southern Bay of Biscay). There was an increase of contaminant concentration with the trophic level of the organisms, as calculated from stable nitrogen isotope data (δN). Such biomagnification was only significant for the pelagic food web and its magnitude was highly dependent on the type of top predators included in the analysis.

Body size-based trophic structure of a deep marine ecosystem.

Nitrogen stable isotope ratios (δ15N) and body size were used to describe the size-based trophic structure of a deep-sea ecosystem, the Avilés submarine Canyon (Cantabrian Sea, Southern Bay of Biscay). We analyzed δ15N of specimens collected on a seasonal basis (March 2012, October 2012, and May 2013), from a variety of zones (benthic, pelagic), taxa (from zooplankton through invertebrates and fishes to giant squids and cetaceans), or depths (from surface to 4700 m) that spanned nine orders of magnitude in body mass. Our data reveal a strong linear dependence of trophic level on body size when data were considered either individually, aggregated into taxonomical categories, or binned into size classes.

Assessing the sustainability and adaptive capacity of the gooseneck barnacle co-management system in Asturias, N. Spain.

The gooseneck barnacle fishery in Asturias (N. Spain) has undergone three important changes: (1) the early implementation of a co-management system based on Territorial User Rights for Fishing, (2) a change in management measures (due to a decrease in landings), and (3) an economic crisis. This has allowed us to analyze the systems' sustainability in time through examining five critical variables: landings, effort, catch per unit effort (CPUE), mean market prices, and annual revenue.

Burst feeding of Pelagia noctiluca ephyrae on Atlantic bluefin tuna (Thunnus thynnus) eggs.

This study investigates the predation of P. noctiluca ephyrae on Atlantic Bluefin tuna (ABFT) eggs under different experimental conditions. The specific factors considered in the experimental design were: a) water mix conditions to explore predation under two-dimensional (2D) and three-dimensional (3D) prey distributions, b) prey density to investigate the ingestion rate capacity, and c) incubation time to inspect gut saturation.

Faking giants: the evolution of high prey clearance rates in jellyfishes.

Jellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction.