Distribution of mercury species in different tissues and trophic levels of commonly consumed fish species from the south Bay of Biscay (France).

Mercury (Hg) is a contaminant of global concern in marine ecosystems, notably due to its ability to accumulate and concentrate in food webs. Concentrations of total mercury (THg), methylmercury (MeHg) and inorganic mercury (IHg) were assessed and compared in different tissues (liver, muscle, and gonads) of three common fish species (hake Merluccius merluccius, red mullet Mullus surmuletus, and sole Solea solea) from the continental shelf from the southern part of the Bay of Biscay. Several studies investigated Hg concentration in fish muscle, but few assessed concentrations in other organs, despite the importance of such data to understand contaminant organotropism and metabolization.

Differential micropollutants bioaccumulation in European hake and their parasites Anisakis sp.

Organisms are exposed to various stressors including parasites and micropollutants. Their combined effects are hard to predict. This study assessed the trophic relationship, micropollutants bioaccumulation and infection degree in a host-parasite couple.

Absence of spatial genetic structure in common dentex (Dentex dentex Linnaeus, 1758) in the Mediterranean Sea as evidenced by nuclear and mitochondrial molecular markers.

The common dentex, Dentex dentex, is a fish species which inhabits marine environments in the Mediterranean and Northeast Atlantic regions. This is an important species from an ecological, economic and conservation perspective, however critical information on its population genetic structure is lacking. Most samples were obtained from the Mediterranean Sea (17 sites) with an emphasis around Corsica (5 sites), plus one Atlantic Ocean site.

Spatio-temporal patterns of perkinsosis in the Manila clam Ruditapes philippinarum from Arcachon Bay (SW France).

Pathogens belonging to the genus Perkinsus infect many bivalve molluscan species around the world, including the Manila clam Ruditapes philippinarum. We investigated the spatial distribution of this parasite at 34 stations throughout Arcachon Bay (SW France). Prevalence of perkinsosis was 93% and mean infection abundance was 96 x 10(3) cells g(-1) wet gill.

Brown muscle disease (BMD), an emergent pathology affecting Manila clam Ruditapes philippinarum in Arcachon Bay (SW France).

We describe an emerging pathology, brown muscle disease (BMD), which specifically affects the Manila clam Ruditapes philippinarum in Arcachon Bay (France). BMD induces a transformation of the posterior adductor muscle, which becomes infused by conchiolin and calcified, reducing the ability of clams to bury. The disease affects both types of muscular tissue, with striated muscle becoming affected to a higher degree than smooth muscle.