Science Centres: Fisheries

NIWA has produced this chart of New Zealand Fisheries Management Areas. Contact posters@niwa.co.nz to order one ($30.00 including p&p and GST for New Zealand).

New Zealand vessels fishing for Antarctic toothfish in the Ross Sea last summer have had their best season ever, with the total value of the catch exceeding $20 million.

NIWA continues to lead the scientific research in this fishery. We are analysing commercial catch and biological data, supervising the tag-recapture programme, developing new approaches to stock assessment and an ‘effects of fishing’ model, and presenting the results to the Commission for the Conservation of Antarctic Marine Living Resources. Funding for this research comes from the Ministry of Fisheries (MFish).

Antarctic toothfish have been tagged since 2001. Initially, the aim was to determine movement and growth rates, but more recently the focus has shifted to estimating abundance. NIWA manages the tag-return programme for the Ross Sea on behalf of MFish. To date, over 4400 fish have been tagged and almost 80 recaptured from the Ross Sea. We have been analysing the results of the 2005 season tagging programme so that these data can be used to update the stock assessment model of Antarctic toothfish. Because it’s a relatively new, exploratory fishery, results suggest that so far fishing has caused little reduction in stock size.

NIWA is also in the process of developing a trophic model to evaluate the flow of carbon through the Ross Sea ecosystem. This model will ultimately allow us to understand the effects of fishing on ecosystems in the Ross Sea. To help understand other indirect effects of the toothfish fishery, NIWA continues to look at bycatch (other fish, seabirds, and marine mammals).