Using krill length data from fishery-dependent and fishery-independent data sources to measure changes in the Antarctic krill population structure in the Bransfield Strait

Krill length data collected from fishery-dependent and fishery-independent data sources were analysed for trends in population structure. Krill length data collected by the Scheme of Scientific Observation (SISO) and the CCAMLR Ecosystem Monitoring Program (CEMP) from 2008 to 2019 in the Bransfield Strait were compared. Differences in mean lengths and length-frequencies were apparent, however both data sources appeared to be tracking similar processes. CEMP data revealed patterns in population structure consistent with previous studies, and may provide a more appropriate source for measuring shifts in population structure and recruitment. Analysis demonstrates the importance of using long-term data collected by different sources to gain a complete understanding of trends in krill population structure and dynamics for use in fisheries management.