Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search


NIWA scientists survey blue cod fishery

NIWA scientists survey blue cod fishery

Scientists at the National Institute of Water and Atmospheric Research (NIWA) have recently completed a survey of blue cod in the Marlborough Sounds.

The survey, which took place from late September until early November, was carried out on behalf of the Ministry for Primary Industries (MPI) to assess the status of blue cod stocks in the region.

It included the Queen Charlotte Sound, Pelorus Sound, D’Urville Island and Point Underwood to the northern tip of Arapawa Island, including the Brothers Islands.

For the first time NIWA fishery scientists surveying blue cod used video cameras attached to the cod pots they use to catch the fish.

“We wanted to observe how the fish behave in and around the pots, as well as work out how effective the pots are at catching fish,” NIWA fisheries scientist Mike Beentjes said.

In another survey first, a multibeam echosounder was used to map the habitat in the cod pot sampling areas. The echosounder provides high resolution 3D maps of the seabed that differentiate reef systems, cobbles and rubble from sand and mud. These maps will help in understanding the relationship between blue cod abundance and the type of habitats they prefer.

The last survey in this area was undertaken three years ago when scientists found there was a marked increase in the average size, age and abundance of blue cod in the inner Queen Charlotte Sound and Pelorus Sounds after the areas had been closed to fishing in 2008.

New MPI management measures, implemented a year ago, include a seasonal fishery open from 20 December to 31 August, a daily bag limit of two fish per person and a size limit of between 30 and 35cm.

Over the next few months NIWA scientists will also analyse the survey data to investigate the effect of fishing pressure on local populations. In addition they will age the blue cod otoliths, or ear bones, by counting annual rings to determine their age. Survey data will enable assessment of stock abundance, size, sex ratios and reproductive condition of the fish.

All information will be presented to the MPI Southern Inshore Stock Assessment Working Group for peer review in March next year.


© Scoop Media

Business Headlines | Sci-Tech Headlines


Interest Rates: Wheeler Hikes OCR To 3% On Inflationary Pressures, Eyes Kiwi

Reserve Bank governor Graeme Wheeler lifted the official cash rate for the second time in as many months, saying non-tradable inflationary pressures were "becoming apparent" in an economy that’s picking up pace and he's watching the impact of a strong kiwi dollar on import prices. More>>


Scoop Business: Equity Crowd Funding Carries Risks, High Failure Rate

Equity crowd funding, which became legal in New Zealand this month, comes with a high risk of failure based on figures showing existing forays into social capital have a success rate of less than 50 percent, one new entrant says. More>>


Scoop Business: NZ Migration Rises To 11-Year High In March

The country gained a seasonally adjusted 3,800 net new migrants in March, the most since February 2003, said Statistics New Zealand. A net 400 people left for Australia in March, down from 600 in February, according to seasonally adjusted figures. More>>


Hugh Pavletich: New Zealand’s Bubble Economy Is Vulnerable

The recent Forbes e-edition article by Jesse Colombo assesses the New Zealand economy “ 12 Reasons Why New Zealand's Economic Bubble Will End In Disaster ”, seems to have created quite a stir, creating extensive media coverage in New Zealand. More>>


Thursday Market Close: Genesis Debut Sparks Energy Rally

New Zealand stock rose after shares in the partially privatised Genesis Energy soared as much as 18 percent in its debut listing on the NZX, buoying other listed energy companies in the process. Meridian Energy, MightyRiverPower, Contact Energy and TrustPower paced gains. More>>


Power Outages, Roads Close: Easter Storm Moving Down Country

The NZ Transport Agency says storm conditions at the start of the Easter break are making driving hazardous in Auckland and Northland and it advises people extreme care is needed on the regions’ state highways and roads... More>>


Get More From Scoop

Computer Power Plus
Search Scoop  
Powered by Vodafone
NZ independent news