Demersal finfish distribution, abundance and their biological characteristics in Statistical Subareas 48.1 (northern part) and 48.2 (2018–2020)

The Republic of Chile completely revised its initial plan for a three-year project to study the distribution, abundance and biological characteristics of Antarctic demersal fish communities after the first survey had been undertaken in 2016. The revised proposal is planned to run from 2018 to 2020. Based on the experience gained in the first phase of research and recommendations made by WG-SAM-16 and WF-FSA-16, a revised proposal for a random, stratified trawl survey to be undertaken in Subareas 48.1 and 48.2 in accordance with CM-24-01 is provided. The objective of this research survey is to determine the distribution, abundance, and size composition of demersal finfish in Subareas 48.1 and 48.2. In this revised proposal, the study area includes the continental shelf of Elephant Island and of South Orkney Islands, between 100 and 500 m depth (Depth strata: 101-200 m, 201-260 m; 261-320 m, 320-380 m, 381-440, and 441-500 m). Sampling will be conducted using bottom trawl nets, with stations in the same approximate geographic coordinates as those used by the R/V Polarstern around Elephant Island (Kock & Jones, 2012) and the R/V Yuzhmorgeologiya around the South Orkney Islands (Jones & Kock, 2009). This will provide valuable information that will allow a comparison with the data collected by these two previous surveys. With the data obtained in each Subarea, size composition, density and standing stock biomass of fish resources will be determined using the delta-lognormal maximum likelihood estimator. Also, demersal habitats and biological data will be collected routinely on each station: total length and weight, sex and maturity stage and biological samples (stomachs, gonads and otoliths), for the main species of demersal finfish captured during the survey.