Deep scattering layer over Reykjanes Ridge and in the Irminger Sea

No abstracts are to be cited without prior reference to the author.

In recent years, Iceland has conducted several trawl-acoustic surveys in the Irminger Sea and adjacent waters. The target species for the investigations has been pelagic redfish (Sebastes mentella), but all specimens caught in the “Gloria type” trawl used (40 mm codend) have been measured and/or counted. In addition to the redfish, the catch has consisted of numerous species of fishes with a modal length between 10 and 20 cm. In all the surveys, an extensive deep-scattering layer has been observed, mostly in depth between 300-800 m from the surface. In this paper, we show distribution and composition of the deep-scattering layer, based on combined information since 1996. Excluding the redfish, Myctophidae are the most common family of fish that are caught, most common species are Lampanyctus macdonaldi, Notoscopelus kroeyeri, Lampadena speculigera, Benthosema glaciale and Myctophum punctatum. Other common families (most common species in parenthesis) are Bathylagidae (Bathylagus euryops), Stomiidae (Chauliodus sloani, Stomias boa ferox, Borostomias antarcticus), Serrivomeridae (Serrivomer beani), Melamphaeidae (Scopelogadus beanii, Poromitra crassiceps), Platytroctidae (Normichthys operosus, Holtbyrnia macrops, Holtbyrnia anomala, Searsia koefoedi).