Sub21-0052

To address concerns that observer sampling for catch composition in the JMA 7 trawl fishery may be biased if samples are gathered only at the start of processing, observers took up to four sub-samples of jack mackerel during the processing of catches and recorded additional information about the sub-sampling process. Differences in species proportions and the mean size of fish were not related to the time during processing at which the sub-samples were taken.