Investigation of krill transport factors in the Scotia Sea for the fisheries and management application

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

Data from acoustic surveys and oceanographic observations were used to estimate characteristics of krill transport across different polygons in the Scotia Sea. Krill flux over the study polygons was considered to be a passive transport by water masses and assessed by the geostrophic transport. Estimates of water velocity and krill biomass transported across the boundaries (outflow and inflow) of these polygons were made. Variabilities of the spatial–temporal distributions of krill biomass and aggregations characteristics associated with multiple processes of krill inflow–outflow over the study areas were traced. It was revealed that krill transport across fishing grounds affects the operational indices of commercial vessels (mean catch per haul, mean catch per hour). The authors discuss the characteristics of krill transport as important information for krill stock management in the Scotia Sea. It was shown that the annual krill biomass transported across traditional fishing grounds could exceed the precautionary catch limit based on the results of a multi-ship acoustic survey and adopted by the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) for the Scotia Sea.