Press Release 07 May 2007

Plastic baleage wrap is used as a deadly weapon against an invasive marine sea squirt, by the supreme prize winners in this year's Marlborough Environment Awards.

The Didemnum Working Group was last Friday <> awarded the supreme and habitat enhancement prize, for its industry-led vendetta against Didemnum vexillum. The prize is $2000 from the Marlborough Research Centre Trust and HortResearch, plus a $1000 category prize for habitat enhancement from Grove Mill Winery, owned by the New Zealand Wine Company.

Didemnum was first found in the Marlborough Sounds in 2001, on a steel logging barge originally from the Philippines. It thrives on underwater surfaces like wharf piles, boat bottoms, mussel lines, salmon cages and submerged trees.

Covering undersea objects like poured yellow wax, the sea squirt is a serious threat to the $180 million marine farming industry, says Aaron Pannell who is managing a Didemnum clean-up for the Group. It covers mussel lines, eventually dragging shellfish off the ropes and onto the seafloor.

Mr Pannell predicts that left unchecked, Didemnum will become an ecological problem, spreading onto pebbly seashore and slow-moving species like crabs and crayfish. It has already been found on seaweed and rocks.

Last summer a $90,000 control operation in Shakespeare Bay, near Picton, involved wrapping 12 jetties, 46 moorings and 190 wharf piles with plastic baleage wrap and covering 11,396 square metres of seabed. Thirty nine mussel lines were also treated (wrapped in plastic sleeves) and two infested trees removed from the water. Follow-up will cost $15,000-$20,000.

The plastic wrap stops the Didemnum from both feeding and breeding, Mr Pannell explains. Control is carried out during the sea squirt's relatively short reproductive stage, over the summer months.

Members of the working group are the New Zealand Marine Farming Association, Aquaculture New Zealand, Port Marlborough, the Marlborough District Council and the Cawthron Institute.

The aquaculture industry has so far spent $250,000 in cash and kind on Didemnum control. Partly because the pest was discovered just before Biosecurity New Zealand was formed, there has been relatively little Government funding as like gorse and rabbits, it was not regarded as a new threat. Also, there has been debate over whether Didemnum is a native or introduced species; an argument which Mr Pannell sees as largely irrelevant due to the economic and ecological threat it poses.

Grove Mill wins winegrowing prize
Grove Mill Wines, owned by the New Zealand Wine Company, was the winner of the winegrowing/horticulture prize, sponsored by Rapaura Vintners. The award chiefly recognises the company's achievement in becoming carboNZero, under Landcare Research's Emissions and Biodiversity Exchange (EBEX) programme.

Carbon emissions produced during winemaking and distribution are monitored and minimised, then any carbon debits paid back by buying credits from Ron Marriott at Cape Jackson in the Marlborough Sounds, where native regeneration is encouraged.

The winners of this year's farming prize - sponsored by Marlborough Federated Farmers and Fonterra - are dairyfarmers Geoff and Alison Millar of Dalton's Bridge.

The Millars are pioneers of the dairying industry's clean streams movement, fencing off and bridging streams on their 300 hectare Rutlandvale property long before there was pressure to do so. As well as aiming to manage their herd and dairy shed in an environmentally sustainable manner, they are starting to protect native bush, scattered native trees and a wetland on the property.

Conrass Forest, near Canvastown, is the winner of the forestry category sponsored by the Marlborough Forest Industry Association. Conrass has been owned by the Hughes family for 130 years. The forest was established in 1964 and is now into its second cycle, managed by family member and forestry consultant, Bert Hughes.

The judges were impressed that the Hughes are incorporating lessons learned during harvesting, into the planning and planting of the next cycle.

Soil and sun heats home
There's been plenty of talk about energy efficient housing for Marlborough and now there's also action, from Gary Smith, winner of the innovation award sponsored by Cuddon Limited. Gary has designed and built vineyard accommodation in Seddon, which harnesses heat from the sun and soil with the aim of achieving a 75% electricity saving.

Sealord Marine Farms Ltd claimed the efficiency award, sponsored by the Prenzel Distilling Company. Sealord operates 54 marine farms in the Marlborough Sounds. Research and development into optimum seeding of lines to minimise effects on the environment while maximising production have resulted in more efficient use of fuel, labour and time.

Other pluses were the breaking down and rebuilding of mussel floats and knitting of stocking nets used to hold seeding stock, at Sealord's Elaine Bay site.

A landscape award was offered for the first time this year, supported by the Marlborough Landscape Working Groups with sponsorship picked up by long-time sponsor Batty's Road Nursery. Spy Valley Wines has married the winery building, its surrounds and the vineyard with the surrounding landscape.

Each category prize is worth $1000 plus Cuddon presents a trophy to the innovation award winner.

Field days will be held on all the winning properties beginning with Conrass Forest and the Millars' dairy farm on Wednesday, May 23 then Gary Smith's vineyard worker accommodation, Spy Valley Wines and Grove Mill Winery on Wednesday, May 30. On Wednesday, June 6, a presentation will be given on Didemnum at Havelock, followed by a field trip to Elaine Bay hosted by Sealord Marine Farms (numbers limited).