Impact assessment of multiple pressures on ecosystem services with a state and transition model: Application to Posidonia oceanica seagrass meadows.

A significant challenge in the integration of ecosystem services into decision-making processes lies in effectively capturing the dynamics of marine socio-ecological systems, including their evolutionary pathways, equilibrium states, and tipping points. This paper explores the evolutionary trajectories of a vital marine ecosystem endemic to the Mediterranean Sea: the Posidonia oceanica seagrass meadows, in response to various drivers of change. A state-and-transition model is employed to assess the ecosystem services provided by P.

Global mercury concentrations in biota: their use as a basis for a global biomonitoring framework.

An important provision of the Minamata Convention on Mercury is to monitor and evaluate the effectiveness of the adopted measures and its implementation. Here, we describe for the first time currently available biotic mercury (Hg) data on a global scale to improve the understanding of global efforts to reduce the impact of Hg pollution on people and the environment. Data from the peer-reviewed literature were compiled in the Global Biotic Mercury Synthesis (GBMS) database (>550,000 data points).

Bioconcentration, bioaccumulation and biomagnification of mercury in plankton of the Mediterranean Sea.

Plankton plays a prominent role in the bioaccumulation of mercury (Hg). The MERITE-HIPPOCAMPE campaign was carried out in spring 2019 along a north-south transect including coastal and offshore areas of the Mediterranean Sea. Sampling of sea water and plankton by pumping and nets was carried out in the chlorophyll maximum layer.

Isotopic and biochemical trophic markers reveal the complexity of interactions at the base of pelagic food webs (Mediterranean sea).

To gain insight into the impact of bottom-up changes in the plankton community on planktivorous fish in the context of the decline of small pelagic fisheries in the Northwestern Mediterranean Sea, we have conducted an extensive year-long study. The investigation combined biochemical analyses (proteins, carbohydrates, and lipids) with C and N stable isotope analyses (SIA) to simultaneously study phytoplankton, zooplankton, and eight planktivorous fish species (Engraulis encrasicolus, Sardina pilchardus, Sardinella aurita, Sprattus sprattus, Cepola macrophthalma, Chromis chromis, Boops boops, and Spicara maena). This study is the first to analyze both stable isotope and biochemical compositions in coastal particulate organic matter (POM) size classes (0.

The Station Marine d'Endoume, Marseille: 150 years of natural history.

When marine natural sciences began to be the concern of most European scientists, in the middle of the 19th century, Marseille, in southern France, was no exception. The creation, ca. 150 years ago, of the first Zoology Laboratory of the Faculty of Sciences of Marseille took place in 1868.

Trace elements, dioxins and PCBs in different fish species and marine regions: Importance of the taxon and regional features.

Chemical contaminant concentrations in wild organisms are used to assess environmental status under the European Marine Strategy Framework Directive. However, this approach is challenged by the complex intra- and inter-species variability, and the different regional features. In this study, concentrations in trace elements (As, Cd, Hg and Pb), polychlorinated biphenyls (PCBs), polychlorodibenzo-para-dioxines (PCDDs) and polychlorodibenzofuranes (PCDFs) were monitored in 8 fish species sampled on the continental shelf of three French regions: the Eastern English Channel (EEC) and Bay of Biscay (BoB) in the Northeast Atlantic Ocean, and the Gulf of Lions (GoL) in Western Mediterranean Sea.

A study of trophic structure, physiological condition and mercury biomagnification in swordfish (Xiphias gladius): Evidence of unfavourable conditions for the swordfish population in the Western Mediterranean.

Studies integrating trophic ecology, physiological condition and accumulation of heavy metals in top predators, such as swordfish, are needed to better understand the links between them and the risk to humans associated with consumption of these fish. This research focuses on the swordfish of the Catalan Sea and follows a multi method approach that considers their diet, their liver lipid content, and mercury accumulation in their bodies as well as in their prey. The aim is to highlight the links between trophic ecology, physiology (fish condition), and eco-toxicology.

Dominance of Scorpaena maderensis among scorpaenids of littoral rocky reefs in Corsica (NW Mediterranean): Further evidence of Mediterranean Sea warming.

The population of Scorpaenidae was investigated in the Nature Reserve of Scàndula (Corsica, France, NW Mediterranean). While absent from Corsica a few decades ago, the Madeira rockfish Scorpaena maderensis is now the most abundant scorpaenid species in shallow rocky reef areas, far outnumbering Scorpaena notata and Scorpaena porcus. Considered as a subtropical species of Atlantic origin, the northward progression of the thermophilic S.

Congruent trophic pathways underpin global coral reef food webs.

Ecological interactions uphold ecosystem structure and functioning. However, as species richness increases, the number of possible interactions rises exponentially. More than 6,000 species of coral reef fishes exist across the world's tropical oceans, resulting in an almost innumerable array of possible trophic interactions.

All shallow coastal habitats matter as nurseries for Mediterranean juvenile fish.

Coastal zones are ecosystems of high economic value but exposed to numerous disturbances, while they represent nurseries for many fish species, raising the issue of the preservation of their functions and services. In this context, the juvenile fish assemblages of all types of habitats present in shallow coastal zones were studied on the south-east coast of France using underwater visual censuses in warm (June-July 2014) and cold (April 2015) periods. A total of fourteen habitat types were characterized, which could be grouped into three broad categories, rocky substrates (natural and artificial), sedimentary bottoms with all levels of granulometry, and seagrass beds including Cymodocea nodosa and Posidonia oceanica meadows; the ecotones or interfaces between the three broad habitat categories were individualized as particular habitat types.

Delineating reef fish trophic guilds with global gut content data synthesis and phylogeny.

Understanding species' roles in food webs requires an accurate assessment of their trophic niche. However, it is challenging to delineate potential trophic interactions across an ecosystem, and a paucity of empirical information often leads to inconsistent definitions of trophic guilds based on expert opinion, especially when applied to hyperdiverse ecosystems. Using coral reef fishes as a model group, we show that experts disagree on the assignment of broad trophic guilds for more than 20% of species, which hampers comparability across studies.

Patterns of trace metal bioaccumulation and trophic transfer in a phytoplankton-zooplankton-small pelagic fish marine food web.

Trace metal contamination in the European sardine and anchovy food web was investigated in the Gulf of Lions, NW Mediterranean Sea, including seawater and size fractions of plankton. The results highlighted: i) higher and more variable concentrations in the smaller plankton size classes for all metals except cadmium; ii) higher concentrations in anchovy versus sardine for all elements except lead; iii) different patterns of metal bioaccumulation through the food web: cobalt, nickel, copper, silver, lead and zinc displayed continuously decreasing concentrations (with the exception of increased zinc in fish only), while mercury concentrations dropped considerably in larger plankton size classes and rose significantly in fish. Lastly, cadmium concentrations were found to be highest in intermediate plankton size classes, with very low levels in fish.

Functional traits unravel temporal changes in fish biomass production on artificial reefs.

Artificial reefs (ARs) are deployed worldwide as they are expected to support fisheries management. While the underlying mechanisms remain widely debated, production was recently determined as the most probable cause of increases in fish biomass. Changes in fish biomass in a temperate AR system were investigated from December 2008 to November 2015 by considering seven distinct functional groups, and isotopic functional indices were used to identify how these changes may have affected organic matter (OM) fluxes.

Mercury in blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus) from north-eastern Atlantic: Implication for fishery management.

Pelagic sharks (blue shark Prionace glauca and shortfin mako Isurus oxyrinchus) caught by long-line Spanish and Portuguese fleets in the NE Atlantic, were sampled at Vigo fish market (Spain) for total mercury (Hg) analysis. Hg concentration in white muscle increased with size and weight in both species, but at a higher rate in shortfin mako than in the blue shark. No difference was found with sex, year and season.

Different transfer pathways of an organochlorine pesticide across marine tropical food webs assessed with stable isotope analysis.

Chlordecone is a persistent organochlorine pesticide used in the banana fields of the French West Indies from 1972 to 1993. Three marine habitats (mangroves, seagrass beds and coral reefs) of two study sites located downstream contaminated rivers were chosen to evaluate the level of contamination of marine food webs. On each habitat, the food chain collected included suspended organic matter, primary producers (macroalgae, algal turf, seagrass), zooplankton, symbiotic organisms (corals, sea anemones), primary consumers (herbivores, suspension feeders, biofilm feeders), omnivores and detritivores (lobsters, fish), secondary consumers (carnivores 1: invertebrate feeders, planktivores) and tertiary consumers (carnivores 2: invertebrate and fish feeders, piscivores).

An ecosystem-based approach to assess the status of Mediterranean algae-dominated shallow rocky reefs.

A conceptual model was constructed for the functioning the algae-dominated rocky reef ecosystem of the Mediterranean Sea. The Ecosystem-Based Quality Index (reef-EBQI) is based upon this model. This index meets the objectives of the EU Marine Strategy Framework Directive.

210Po and 210Pb trophic transfer within the phytoplankton-zooplankton-anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea).

The transfer of (210)Po and (210)Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of (210)Po and (210)Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on (210)Po, (210)Pb activity concentrations and (210)Po/(210)Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter.

Response of a seagrass fish assemblage to improved wastewater treatment.

We compared the structure of a seagrass fish assemblage near a sewage outlet before and after improvements to wastewater treatment. To determine whether responses by the fish assemblage were due to changes in water quality or to other factors, comparisons were made with the structure of a fish assemblage from a nearby site unaffected by sewage effluent. Total species richness, density and biomass of fish, decreased at both sites over the 30-year period.

PCB concentrations in plankton size classes, a temporal study in Marseille Bay, Western Mediterranean Sea.

PCB levels in plankton were investigated in the Bay of Marseille, Western Mediterranean Sea, between September 2010 and October 2011. Concentrations of PCB congeners (CB 18, CB 52, CB 101, CB 118, CB 138, CB 153, CB 180) were determined in three plankton size-classes (60-200, 200-500 and 500-1000μm) together with different parameters: chlorophyll content, plankton dry-weight biomass, carbon and nitrogen stable isotope ratios and plankton-community structure. The ∑PCB7 concentrations ranged between 14.

An ecosystem-based approach to assess the status of a Mediterranean ecosystem, the Posidonia oceanica seagrass meadow.

Biotic indices, which reflect the quality of the environment, are widely used in the marine realm. Sometimes, key species or ecosystem engineers are selected for this purpose. This is the case of the Mediterranean seagrass Posidonia oceanica, widely used as a biological quality element in the context of the European Union Water Framework Directive (WFD).

Response of rocky reef top predators (Serranidae: Epinephelinae) in and around marine protected areas in the Western Mediterranean Sea.

Groupers species are extremely vulnerable to overfishing and many species are threatened worldwide. In recent decades, Mediterranean groupers experienced dramatic population declines. Marine protected areas (MPAs) can protect populations inside their boundaries and provide individuals to adjacent fishing areas through the process of spillover and larval export.

The great melting pot. Common sole population connectivity assessed by otolith and water fingerprints.

Quantifying the scale and importance of individual dispersion between populations and life stages is a key challenge in marine ecology. The common sole (Solea solea), an important commercial flatfish in the North Sea, Atlantic Ocean and the Mediterranean Sea, has a marine pelagic larval stage, a benthic juvenile stage in coastal nurseries (lagoons, estuaries or shallow marine areas) and a benthic adult stage in deeper marine waters on the continental shelf. To date, the ecological connectivity among these life stages has been little assessed in the Mediterranean.

Rare species support vulnerable functions in high-diversity ecosystems.

Around the world, the human-induced collapses of populations and species have triggered a sixth mass extinction crisis, with rare species often being the first to disappear. Although the role of species diversity in the maintenance of ecosystem processes has been widely investigated, the role of rare species remains controversial. A critical issue is whether common species insure against the loss of functions supported by rare species.

Environmental determinants of coral reef fish diversity across several French Polynesian atolls.

The present study aimed at exploring the diversity of coral reef fishes in 10 French Polynesian atolls and sought to determine which environmental variables best explain diversity. A total of 136,614 fish belonging to 302 species were recorded in 1995 and 1996. The stepwise multiple regression analysis showed that the best model of variation in species richness (55% of total variation) incorporated three geomorphologic descriptors (atoll perimeter, submerged rim and abundance of pinnacles) and two habitat descriptors (percentage cover of dead coral and sand).