The verdict is in: marine reserves really do work.
New Zealand’s conservation agency, the Department of Conservation, has been collating information on scientific monitoring at 12 marine reserves around the islands of New Zealand.
“Marine reserves were set up to establish examples of New Zealand’s marine environment, to create an undersea equivalent of national parks and to allow benchmarked scientific research. That science now says that they are doing the job at they were set up to do,” says Felicity Wong of DOC’s Marine Conservation Unit.
For example, at one reserve in the north of New Zealand much of the sea floor two decades ago was barren but between 1978 and 2000 these barren areas all become coated in kelp forest or shallow mixed seaweeds. Now snapper is more abundant and bigger within the 518-hectare marine reserve at Leigh than immediately outside this area. The number of lobster within the marine reserve is also up, while kina have as decreased, allowing seaweed forests to regenerate.
In the Coromandel on the east coast of the north island, a similar story is told. The Te Whanganui-a-Hei (Cathedral Cove) marine reserve now has an estimated three times more algae within the marine reserve than outside the reserve. In the Marlborough Sounds, blue cod and rock lobsters are bigger and twice as common inside the marine reserve than outside. In Fiordland’s marine reserve, lobsters are seven times more abundant within the marine reserve than outside.
Wong said that results like these backed up extensive experience with marine reserves overseas, and confirmed scientific predictions at home.
The New Zealand government plans to do more. Its Biodiversity Strategy, released in 2000, specified a goal of protecting a full range of natural marine habitats and ecosystems by 2010. That would represent all New Zealand waters out to the limits of the 200-mile limit Exclusive Economic Zone. (This area won’t necessarily be all marine reserves – there are other protection mechanisms that may contribute to this target such as fisheries management areas.)
However, there is still some way to go.
“The area protected around mainland New Zealand is equivalent in area to only two thirds of New Zealand’s smallest national park on land (Abel Tasman),” Ms. Wong said. And at present, two marine reserves, around the Auckland and Kermadec Islands, are a significant proportion of that protection and are very inaccessible.
With the announcement of a marine reserve at the furthest south of New Zealand’s main islands, Rakiura/Stewart Island, earlier this year, the government has come closer to its 10-oper cent goal.
According to the Department of Conservation, marine reserves are about facilitating changes towards a more natural marine environment by removing targeted human pressures, and not necessarily about greater abundances of each species. Over time, numbers of different species may go up or down with natural variation.
Each marine reserve offers unique opportunities for scientific research and each one will yield different results because the environment in each is different, Ms. Wong said.
She cautioned that changes did not occur overnight, but added that the long-term goal was important: “We have an obligation to protect our marine environment for future generations.”