Snapper tag mortality study (SNA2002/04)
During the first week of March NIWA will be conducting experimental work to assess survivorship amongst snapper tagged with its newly developed electronic tag. Snapper will be caught using commercial trawl and long-line vessels from waters close to Kawau Island. The snapper will then be tagged, placed into a large sea cage and monitored for two weeks.
3 March 2003
The Ministry of Fisheries uses the results from large-scale tagging programmes, such as the one conducted last year on the west coast of the North Island, to assess the sustainability of New Zealand snapper stocks. It is critical to know how many fish survive the tagging process as this has a major bearing on the final result. The work NIWA will undertake in the Kawau region is specifically intended to address this.
NIWA tags are electronic; because these are inserted cleanly into the gut cavity it is usually not possible to determine if a fish has been tagged except by use of specialised equipment.
NIWA expects to tag 2000 snapper for release into the sea cage; these will be taken from a range of depths and, in the case of trawl, from a range of different tow durations.
