Comments on the krill samples undertaken by observers to evaluate efficiency of SISO sampling protocols in the krill fishery

In this paper, the authors consider inter-vessel variability in the length composition of krill in catches from commercial vessels operated in local fishing grounds in Subarea 48.2 during March 2024. The authors obtained additional evidence that existing observation protocols   tend to under sample krill for different length groups especially recruitment groups, assuming homogeneity of krill length composition in the catch regardless of catch size and duration of fishing operation as well as not taking into account potential spatio-temporal heterogeity in krill distribution patterns within fishing grounds. The most vulnerable to the gear construction, fishing method and observer krill protocols is the keeping of recruitment group and adult krill in the catches. It seems the sample size would not be effective for accurate data on analyses of what the krill fishery is catching in term of krill length composition. Our data obtained in season 2024 are additional evidence of the need to revise the efficiency of observer krill samples in the context of Scientific Observer’s Manual with special atterntion to observer krill samples onboard vessel used continuous fishing method.