Interactions between fisheries and early life stages of skates in nursery areas of the eastern Bering Sea

From late 2014 through 2017, fishery observers in the North Pacific Observer Program, National Marine Fisheries Service, were trained in the identification and sampling of skate egg cases to investigate the interactions between fisheries and skate nursery areas in the eastern Bering Sea. Trained observers identified and assessed 2887 egg cases in a wide range of fisheries across all gear types, with the majority of egg cases being encountered on vessels targeting deepwater species, such as the arrowtooth flounder (Atheresthes stomias), Greenland halibut (Reinhardtius hippoglossoides), Pacific cod (Gadus macrocephalus), and sablefish (Anoplopoma fimbria). A large proportion of the egg cases identified were reported on boats using bottom trawling gear, but an even greater proportion were reported on longliners. Egg cases identified represent 10 skate taxa. Over half (67%) of them were identified as Alaska skate (Bathyraja parmifera), and 19% were identified as either Aleutian skate (B. aleutica) or Bering skate (B. interrupta). More than 42% of all the egg cases assessed were viable (contained a living skate); over 50% of egg cases of Alaska skate and of egg cases encountered on longliners were viable. The highest concentrations of egg cases generally were reported near known skate nursery areas, particularly in the Bering, Pribilof, and Pervenets Canyons.