Selectivity and YPR in the South East Fishery

Evaluation of selectivity in the South-East fishery to determine its sustainable yield

Fisheries assessments are typically performed species by species, and gear by gear, as though the species or fisheries existed in a vacuum. But fishing gears catch a variety of commercial and bycatch species and different industry sectors compete for some of the same species. Multi-species assessments hold out the promise of injecting some of the reality of a fishery into the vacuum of single species assessments.

Unfortunately, multi-species assessments are data hungry. Of the two principal multi-species approaches, biological multi-species interactions are the hardest to define and the most data hungry. Despite intensive sampling programs extending over decades in the US and Europe, there are only a few instances where results from biological multi-species assessments are used in fisheries management. Technical multi-species interactions - interactions due to fishing gears catching more than one species at a time - are easier to define and the data requirements are less. The primary approach used for estimating technical multi-species interactions is multi-species yield per recruit (MSYPR) and this is the approach used in this report. However, even the data requirements for MSYPR proved onerous for a complex multi-species, multigear fishery like the South East Fishery (SEF), where many species are not quantitatively assessed.