Wellington Scoop

NIWA scientists will be counting snapper off the coast

News from NIWA
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.”

captain of NIWA ship

News from NIWA – October 5
After 75 nights at sea, all the temporary master of NIWA research vessel Kaharoa could think about today was getting off the ship and having a beer. John Brosnan and his six-strong crew returned to Wellington this morning after completing the longest trip ever undertaken by the 28-metre long ship.

Border closures in Australia and Mauritius due to COVID prevented the crew from disembarking during their two-and-a-half-month trip to deploy remote ocean monitoring Argo buoys in the Indian Ocean.

And even though they’re back in their home port, the crew still can’t leave the ship until they return a negative COVID test so the beer will have to go on ice for a little while longer.

It hasn’t been plain sailing for the ship with Mr Brosnan estimating they had “about one and a half days of good weather” the entire time they were away. “We were hit by storm after storm. The ship was rolling and rolling all the time.”

Asked how they managed to keep their spirits up for so long without getting off the ship, Mr Brosnan said it was a matter of taking things one day at a time. “When you’re on board you just concentrate on what needs to be done day by day.”

There were two stops in Fremantle for refuelling – one on the way there and one on the way back, but although land was tantalisingly close the crew was confined to the ship.

The team deployed more than 100 Argo buoys while they were away – adding these free-drifting scientific instruments to an international science network of more than 3800 buoys across the world’s oceans to measure the role the oceans play in our climate and weather systems.

Scientists say the data collected by the Argo project has revolutionised our knowledge of ocean dynamics.

However, this year Coronavirus delays have disrupted Argo voyages around the world making maintaining coverage an increasing challenge.

NIWA has deployed more than 1100 Argo floats in the Pacific, Indian and Southern Ocean over 22 voyages since 2004, more than any other individual vessel.

It will be tomorrow or Wednesday before the crew will finally set foot on land again – and Mr Brosnan gets his well-earned beer. As for Kaharoa, she sets sail again this week on a new scientific voyage up the west coast of the North Island.