The consequences of different inshore/offshore splits of the WCRL TAC

Abstract

Coarse estimates are provided of relative inshore (<30m depth) and offshore (30m+ depth) biomasses for each of the five super-areas using two methods – one being based on rough estimates provided by van Zyl of the hoop/trap catchability ratio, and the other on using the FIMS relative inshore/density results. Results indicate that the proportion of the biomass inshore in A34 is between 28-42% and between 5-25% for A8+. Constant catch projections for the inshore A34 and A8+ areas are also provided for a range (10%-40% or 10%-30% respectively) of assumptions regarding the inshore biomass as % of total biomass, and indicate that increases in the current inshore allocations in these two super-areas will lead to a rapid and substantial decrease in inshore abundance.