Heard Island and McDonald Islands Random Stratified Trawl Survey (RSTS) strata

Brief description

A trawl survey is conducted each year at Heard Island and McDonald Islands (HIMI) to assess the abundance and biology of fish and invertebrate species. The survey provides information for input into the stock assessments for the two main fished species, Patagonian toothfish (Dissostichus eleginoides), and mackerel icefish (Champsocephalus gunnari). In addition, it provides information on biodiversity and bycatch species from the fishery.

Nine strata were defined as areas for sampling during the annual Random Stratified Trawl Survey (RSTS) conducted on board an industry vessel. The area of the plateau down to 1000 metres depth was divided into nine strata, each covering an area of similar depth and/or fish abundance. A number of randomly allocated stations (between 10 and 30) are sampled in each stratum during every survey to assess the abundance of juvenile and adult toothfish on the shallow and deep parts of the Heard Island Plateau (300 to 1000 metres depth) and to assess the abundance of mackerel icefish on the Heard Island Plateau.

Although the number and boundaries of strata have been adjusted over the years, they have been consistent since 2002 (Welsford et al. 2006).

This dataset consists of a polygon shapefile representing the strata and a map displaying the strata.

Lineage

Progress Code: completed

Notes

Purpose
To provide information for input into fish stock assessments.