Setting quotas using provisional data: a case study from the South Australian abalone fisheries

ABSTRACTStock assessments of quota or effort managed fisheriesin which the duration of the fishing season is 12 months are invariably delivered well into the subsequent fishing season. As a result, quotas are frequently based on year-old data. This delay is often unavoidable because it may take months to collect, collate and analyse data necessary to assess fisheryperformance. The South Australian fisheriesfor blacklip ( Haliotis rubraLeach, 1814) and greenlip abalone(H. laevigata Donovan, 1808) have addressed this issue by using provisional data on current stock status to inform application of the harvest strategy decision rules that set the quota for the next year. The primary index of relative abundance for these fisheriesis catch per unit effort(CPUE). Our study uses 25 years (1988–2012) of CPUE data to quantify the differences between the provisional and complete-season CPUE estimates at the spatial scales used to assess the fisheries. We demonstrate that, in most cases, there was a strong rela...