Source: NIWA – National Institute of Water and Atmospheric Research
People along the Kapiti and Wanganui coast may spot NIWA’s research vessel Kaharoa operating close to shore in the next few weeks as scientists carry out a survey of snapper, tarakihi, red gunard and John Dory.
The trawl survey is the third and final in a series to establish how many fish there are, their ages and where they are situated within the fishery known as SNA8 – second largest snapper fishery in New Zealand.
Voyage leader and NIWA fisheries scientist Dr Emma Jones says the survey provides independent data that will be used to compare to similar historic surveys to help determine how the fishery may have changed.
“The surveys provide data completely independent of that collected from the commercial fishery. Because we use the same vessel, same net design and same protocols, our results are comparable with results from surveys carried out 20 years ago.”
“This provides us with an independent picture of how fish abundance and communities have changed over the time.”
Dr Jones says the data feeds into stock assessments that determine whether a fish stock is at a sustainable level. “The most important one for this survey is the stock assessment for snapper off the west coast of the North Island.”
Kaharoa leaves from Wellington on Friday and will be coming in and out of New Plymouth port during the survey. At some points in the South Taranaki Bight it will be in waters as shallow as 10m and close to shore along the Kapiti coast. Scientists will be collecting otoliths, or ear bones, from the fish that enables them to determine their age.
Stringent processes are in place to minimise the risk of encountering any Maui dolphins. The survey is taking place outside the West Coast Marine Mammal Sanctuary and is only sampling where the commercial fishing boats are allowed to fish.
A marine mammal observer will be on board to keep watch for dolphins before and during trawl activity. If any Maui dolphins are seen, fishing operations will stop in that location.
Fisheries New Zealand’s Team Manager Inshore Fisheries North, Jacob Hore says the snapper stock on the North Island’s west coast is an important shared fishery that is of high value to customary, recreational, and commercial fishers.
“Snapper in this fishery has been steadily rebuilding over the past 15 years, and we’re confident about its future. Information from this survey will support discussions on a management review of this fishery, which is planned for 2021.”