Further work towards the assessment of the South African round herring (Etrumeus whiteheadi) resource using data from 1987 to 2010

Abstract

Round herring (Etrumeus whiteheadi), commonly referred to as Red Eye, is exploited by the South African pelagic fishery. The fishery has been managed with a Precautionary Upper Catch Limit of 100 000t for at least the past eight years. An assessment of this resource is required in order to inform on any future decisions to the management of the round herring. The assessment of round herring is complicated by the fact that the time series of hydroacoustic survey estimates of abundance have been obtained from surveys which were designed first for anchovy and secondly for sardine. However, Coetzee and Merkle (2009) recently proposed that the time series of survey estimates of abundance are comparable, paving the way for an assessment of this resource to be undertaken. de Moor and Butterworth (2010) presented some initial results from fitting a model to November survey estimates of total biomass, May survey estimates of recruitment numbers and commercial length frequency data. This document presents further advancements in the assessment of the round herring resource and some results for discussion.