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Published: 2001-08-20 00:00:00

The Waikato Region is at risk from the introduction of exotic marine organisms which can threaten natural marine ecosystems, commercial interests, recreational, cultural and amenity values and public health, Environment Waikato’s Policy Committee heard this week.

The Region had, already been infested with the deliberate introduction of spartina, originally introduced to in the 1940s to reclaim tidal land for grazing stock. A variation has been proposed to the Regional Coastal Plan on the use and discharge of hazardous substances which will enable resource consents to be applied for to use herbicides to control the weed.

The Committee heard that numerous exotic marine species had already arrived and become established in New Zealand and could have serious effects. The main risk was from shipping ballast water and hull defouling, which can introduce unwanted species from overseas and other parts of the country. Another risk was from deliberate or accidental release of organisms such as aquatic plant species from the foreshore.

Environmental planner Rosalind Wilton said an international shipping lane ran close to the Coromandel Peninsula en route to the Port of Auckland and there was an international and intranational route up the west coast. The Region was at risk from ships that exchange ballast water in the Region’s coastal waters rather than oceanic waters, which sometimes occurs at Colville channel, and at Taharoa.

Regulations made under the Biosecurity Act require ships to exchange their ballast water in mid-ocean waters, but rough seas can mean this is sometimes too dangerous.

“For many New Zealanders, the use of harbours and coastlines for fishing, boating, water sports or simply being in the outdoors is a key part of their lifestyle. Introduced organisms may produce calcareous reefs or slimy growths that alter beaches, cover structures and block pipelines, turn lagoons eutrophic and cause noxious smells.”

The Ministry of Fisheries was the main government agency responsible for managing marine biosecurity, and $9.8 million was allocated last year out of funding for the marine environment under the New Zealand Biosecurity Strategy. This is to be used for research, risk assessment, surveillance, ballast water monitoring and development of rapid response measures.

Other agencies such as Ministry of Agriculture and Forestry, Environmental Risk Management Authority, Department of Conservation and Regional Councils also had responsibilities. Regional Councils had responsibility for biosecurity, and could develop Regional Pest Management Strategies to identify organisms that have become established in the Region and declare them pests in a particular region.

Environment Waikato had a role in promoting sustainability of natural and physical resources and controlling activities in the Coastal Marine Area. The Regional Coastal Plan contained policies to protect natural character and habitat and maintain or enhance water quality, she said.
The plan also controls through rules the introduction of exotic plant species and discharges from boat maintenance areas.

Environment Waikato’s role was on-going liaison with the Ministry of Fisheries, and respond to any need for a multi agency approach to deal with any significant marine incursion to protect the marine environment for the Region.

Cr David Peart said Environment Waikato needed to make submissions to the Government’s Oceans Policy to clarify any holes in the system where central Government responsibilities ended and councils began.