Krill biomass estimation: Sampling and measurement variability

Krill are the subject of growing commercial fisheries and therefore management is necessary to ensure long-term sustainability. catch limits, set by Commission for Conservation Antarctic Marine Living Resources, based on absolute krill biomass, estimated from acoustic-trawl surveys. In this work, we develop a method determining an error budget surveys which includes sampling measurement variability. We use our examine sensitivity biomass estimates parameters in acoustic target strength (TS) models, length frequency distribution wetmass relationships derived net data. determined that average coefficient variation ( CV ) was 17.7% due scaling observations density 5.3%. found large proportion variability orientation distribution, parameter TS model. Orientation distributions with narrow standard deviations were emphasise results nulls relationship, has potential lead biologically implausible results.