The principal aim of the Pelagic Biomass Surveys is to obtain estimates of the total biomass of anchovy, sardine and west coast round herring and to obtain data on their population length frequency compositions, for input to the operational management procedure (OMP) for making Total Allowable Catch (TAC) recommendations for the following year. The surveys also obtain information on the environment and food regime impacting anchovy, sardine and west coast round herring around the coast, although recent surveys (~2009 onwards) have included much less environmental sampling than earlier years. The survey uses hydro-acoustics to estimate fish density and abundance, and midwater trawling to identify acoustic targets and to obtain length frequency and other biological data, and ichthyoplankton and environmental sampling are also conducted. The abundance and biomass estimates from these surveys are an essential input into the management process and serve as a scientific basis for the...