Distribution of Lysianassidae amphipods Eurythenes gryllus in the North-East Atlantic

Eurythenes gryllus represent an important link in the deep-sea ecosystem. Based on mechanisms reported in the literature, a number of possible pathways for dumped radionuclides to return to man, which include Eurythenes gryllus, have been established. Many of these pathways remain hypothetical and will require further study to be invalidated or confirmed. Studies conducted at the NEA dump site suggest a great variability in the catch rates of these amphipods, whose abundances diminish markedly above 20-25 m. The amphipods have always been observed with baited cameras and captured with baited traps because they are too motile to be captured by classical fishing devices. These observational techniques make it difficult to estimate population densities. It is possible to apply dispersion models of the bait odor, but these depend on parameters that are difficult to estimate especially in the deep-sea environment. In the future, efforts will be made to estimate population densities using acoustic techniques or nets with large openings