A project to refine methods for estimating egg production in application of the DEPM is needed because:
1) spawning biomass estimates obtained using the DEPM are the key biological performance indicators in the SASF and SPF;
2) the DEPM is recognized as being imprecise and the main source of this imprecision is associated with estimation of mean daily egg production;
3) a range of field and statistical methods are used to estimate total daily egg production but there is no consensus about which approach is most appropriate for the range of circumstances that are encountered, with different methods currently used in the Americas, Europe and Australia.
Uncertainty in the method used to estimate the spawning biomass of Jack Mackerel off the east coast of Australia was raised as an issue of particular concern in the recent public debate associated with the introduction of a large factory trawler into the SPF.
That debate undermined public confidence in the stock assessment and management of the SPF and has the potential to undermine other fisheries species of small pelagic fishes.