Element concentrations and fatty acid profiles in American lobster (Homarus americanus) from the Bay of Fundy and Gulf of St. Lawrence

Recent investigations suggested a northward and eastward habitat shift of American lobster (Homarus americanus) from the Bay of Fundy (BoF) to waters of the Gulf of St Lawrence (GSL). In this context, we conducted comparative analyses of fatty acids (FA) and 16 elements of physiological measures across lobster tissues (hepatopancreas, muscle, shell) through multivariate statistical methods High levels of n-3 polyunsaturated FA (PUFA): EPA (C20:5n3) and DHA (C22:6n3) and planktonic based diet for GSL lobsters suggests higher quality in addition to anti-inflammatory markers (FA ratios). In contrast, BoF lobsters recorded higher concentrations of C18:1n9, C20:3n6, and C18:2n6 indicators of inflammation, carnivorous diet and oxidative stress. Similarly, Principal Component Analyses (PCA) displayed strong clustering of toxic elements (Hg, Cd) with pro-inflammatory FA in BoF. This pattern could be related to environmental conditions and altered food sources differences in the two ecosystems of GSL and BoF. Furthermore, inflammatory signs in BoF are always associated with shell disease in lobsters. Finally, abundance invasive species, particularly green crab (Carcinus maenas) in BoF act as both a physiological stressor and an ecological competitor for lobsters in BoF that are not present in GSL. Control of the invasive organism could enhance lobster abundance, health and habitat stability. Our findings reinforce the idea that local environmental stressors and biotic interactions with lobster influence abundance and health and drive the lobster distributional habitat shift toward less desirable southeastern Atlantic areas to more balanced ecosystems currently existent in the more northwest Atlantic areas.