ABSTRACT
In June 2015, an individual of Diretmichthys parini (Post and Quero, 1981) was trawled at 530m depth, in the North Sea off Norway and donated to research. This capture, the first for this species in the North Sea was the northernmost recorded so far, and provided an opportunity to document some aspects of the biology and ecology of this data-poor species. This individual was a female, 331mm total length of 33years old, with low mercury content in muscle and liver (~0.2µgg-1 wet mass). Stable isotope ratios (C and N) in muscle and liver were consistent with the planktonic diet expected for this species. The capture of this fish at the northern latitude known so far would be consistent with the extension of the home range and the latitudinal shift hypothesized for this species in the 1990's.
Subject(s)
Fishes , Animals , Female , Mercury , Muscles/chemistry , North SeaABSTRACT
Despite being generally located far from contamination sources, deep marine ecosystems are impacted by chemicals like PCB. The PCB contamination in five fish and shark species collected in the continental slope of the Gulf of Lions (NW Mediterranean Sea) was measured, with a special focus on intra- and interspecific variability and on the driving factors. Significant differences occurred between species. Higher values were measured in Scyliorhinus canicula, Galeus melastomus and Helicolenus dactylopterus and lower values in Phycis blennoides and Lepidorhombus boscii. These differences might be explained by specific abilities to accumulate and eliminate contaminant, mostly through cytochrome P450 pathway. Interindividual variation was also high and no correlation was observed between contamination and length, age or trophic level. Despite its major importance, actual bioaccumulation of PCB in deep fish is not as documented as in other marine ecosystems, calling for a better assessment of the factors driving individual bioaccumulation mechanisms and originating high variability in PCB contamination.
