Farmers help restore pa¯ua after quakes
The pa¯ua population along Kaiko¯ ura’s coastline, decimated by the 7.8-magnitude earthquake in November 2016, is slowly recovering thanks in part to the efforts of passionate pa¯ ua farmers on Arapawa Island in the Marlborough Sounds.
The earthquake forced the closure of the Kaiko¯ ura fishery as larvae and juvenile pa¯ua numbers were threatened. Sections of the seabed along the coast had risen by five metres and drastically altered intertidal zones after the quake. Arapawa Sea Farms Ltd owners Mike and Antonia Radon have been working alongside PAUAMAC3, the representative body for professional pa¯ ua divers. They hope to release thousands of baby pa¯ ua along the coast to help replenish the numbers.
PAUAMAC3 chairman Jason Ruawai said Mike Radon was helping educate his members by creating their own pa¯ua hatchery, ultimately benefiting the restoration of the population.
‘‘One of the functions of the education project that we are doing is to have a local hatchery in Kaiko¯ ura. Mike has a lot of input in terms of IP [intellectual property] and he’s taught a couple of our members the methodology of spawning and fertilisation.
‘‘There are areas in Kaiko¯ ura now which have been entirely decimated by the earthquake which means pretty much empty paddocks - so the nature of replenishing that is a very long process,’’ he said.
Ruawai said in order to restore the pa¯ ua population to pre-quake numbers, establishing hatcheries was important.
‘‘In terms of recovery of these empty paddocks, we think that enhancement is the right fit for these areas,’’ he said.
It took seven to eight months to grow the pa¯ ua in tanks before they were released into their natural habitat, Mike Radon said.
The Radons had been farming pa¯ua for about 15 years on Arapawa Island.
About 10,000 baby pa¯ ua would be released along the Kaiko¯ura coast and although not all would survive, it would help make a difference to numbers.
‘‘Of those, about 30 per cent will probably survive to harvest, so you’re down to 3000,’’ he said.
The process of growing the pa¯ ua was lengthy and not always successful, Radon said.
Male and female pa¯ua were induced into spawning, the sperm and eggs came together and hatched into larvae after about 30 hours.
The larvae was then raised in a tank, described as a sieve, for nine days and then kept in large tanks for seven to eight months before being released into the wild when they grew to a length of about 10 millimetres.
The Ministry for Primary Industries had funded a three-year education project which involved educating Kaiko¯ ura High School science students about pa¯ ua.
On Friday, 26 science students ventured out to learn about how pa¯ua was grown on Arapawa Island. Year 13 science student and Head Girl Claire Booker said it was ‘‘so cool’’ to see all the work that goes on behind the scenes to sustain the pa¯ ua farms.
‘‘You don’t think that a species that just lives in the ocean and goes about its day-to-day business is going to have so much technology and so much innovation behind what happens,’’ she said.