Marine reserves protect the marine environment – new report

Department of Conservation

1 October 2004

They are worth the wait - the science on New Zealand marine reserves shows that they enhance the marine environment.

During this year the Conservation Department has been collating information on scientific monitoring at 12 marine reserves around the country.

"The department's monitoring shows significant improvements in marine environmental values within our marine reserves," Felicity Wong of DOC's Marine Conservation Unit said today (release date.)

For example, at Cape Rodney-Okakari, (Leigh) snapper are now significantly more abundant and bigger within the 518 ha marine reserve than immediately outside this area. While lobster abundance within the marine reserve is also up, kina abundance has decreased, allowing depleted seaweed forests to regenerate.

Marine Conservation Unit manager Felicity Wong said that results like this backed up extensive experience with marine reserves overseas, and confirmed scientific predictions at home.

"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 that they were set up to do."

The Government's Biodiversity Strategy, released in 2000, specified a goal of protecting a full range of natural marine habitats and ecosystems by 2010. With the announcement of Te Wharawhara (Ulva Island) marine reserve at Rakiura/Stewart Island earlier this year a further step was taken towards meeting the goal of 10%. Two marine reserves, around the Auckland and Kermadec Islands however are a significant proportion of that protection and   are very inaccessible.

"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. "We have an obligation to protect our marine environment for future generations.

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.   Overtime, 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. Changes did not occur overnight. Even after 30 years environmental changes would still be expected to occur.

Media contact: Felicity Wong.

Manager Marine Conservation Unit, Department of Conservation. DDI (04) 471 3179, Mob 027 482 4652.

Summary results for each marine reserve (more detailed results can be found at https://wgnhoiis2/Conservation/Marine-and-Coastal/Marine-Reserves/Monitoring.asp):

Cape Rodney-Okakari Point (Leigh or Goat Island) , Auckland- monitoring since 1978:

In the Cape Rodney to Okakari Point marine reserve in 1978, much of the sea floor between five and nine metre depths was mostly rock flat barrens dominated and maintained by sea urchins. Between 1978 and 2000 these barrens all changed to habitats dominated by large brown seaweed-kelp forest or shallow mixed seaweeds. It is considered that these habitat changes were probably due to lobster and snapper preying on urchins, causing a decline in sea urchin densities, and thereby allowing seaweed regeneration (this is called a trophic cascade). The densities of a limpet and a gastropod species in the reserve have also changed, probably a response to the habitat changes, and therefore another indirect effect of the above trophic cascade. The change from barrens to seaweed habitat has been slow, as one urchin per square metre is sufficient to maintain a barren. The productivity of seaweed habitats in the reserve increased by 58% between 1978 and 1996 due to these habitat changes.

Contact: Kala Sivaguru: Ph 09 307 4876; e-mail ksivaguru@doc.govt.nz

Poor Knights Islands, Northland– monitoring since 1998:

Data collection for reef benthic flora and fauna was first done in 1998, and has been repeated annually to establish any trends of change. The monitoring program has provided a body of quantitative information, (replicated spatially and temporally), that demonstrated that no-take marine reserves in north-east New Zealand outperform partial protection strategies in the recovery of target exploited species, and lead to rapid and significant recovery of target species.

Contact: Keith Hawkins: Ph 09 437 4553; e-mail khawkins@doc.govt.nz

Kapiti Island , Wellington– study in 1999-2000, 2003-2004

Monitoring of Kapiti Marine Reserve to establish what differences existed in size and abundance of 34 key species (including algae, fish and invertebrates) between the reserve and control sites. Data was compared to that collected by NIWA study in 1992 prior to the establishment of the marine reserve to determine what changes had occurred over time. Sites inside the marine reserve supported a greater species abundance, and in some cases, larger size classes. There was some evidence for a general shift in the community structure particularly in algal plants. Evidence of greater species diversity at the northern end of the Island with decreasing diversity towards the south.

Contact: Ian Cooksley; Ph 0 4 296 1391; e-mail icooksley@doc.govt.nz

Te Whanganui-a-Hei (Cathedral Cove) , Coromandel Peninsula – monitoring since 1996:

Algal biomass within the marine reserve is estimated to be three times greater than outside the reserve.   Increased rock lobster numbers have led to fewer kina, and as a result more seaweed.   Significant increases in the size and numbers of fish

Contact: Jason Roxburgh: Ph 07 867 9185; e-mail jroxburgh@doc.govt.nz

Tuhua ( Mayor Island), Bay of Plenty – monitoring since 1993:

Recovery of reef fish to date has been very limited. The most likely explanations are that the size of the reserve is too small in relation to boundary overspill effects and possible continued fishing within the reserve.                                                        

Contact: Kim Young: Ph 0 7 349 7414; e-mail kyoung@doc.govt.nz

Long Island-Kokomohua , Marlborough Sounds – monitoring since 1992:

Blue cod and rock lobsters are significantly larger and more than twice as abundant in the marine reserve than outside e.g. by 2003 blue cod were more than twice as abundant from rubble habitats within the marine reserve compared to similar outside.

Contact: Andrew Baxter: Ph 03 546 3172; e-mail   abaxter@doc.govt.nz

Piopiotahi (Milford) , Fiordland – monitoring since 2000:

Lobsters are seven times more abundant within the marine reserve than outside. Fish are more abundant within the marine reserve than outside.

Contact: Sean Cooper: Ph 03 2147559; e-mail scooper@doc.govt.nz

Te Awaatu Channel (The Gut) , Fiordland – monitoring since 1999:

More fish within the marine reserve than outside. Lobsters are three times more abundant within the marine reserve than outside.

Contact: Sean Cooper: Ph 03 2147559 ; e-mail scooper@doc.govt.nz

Tonga Island, Nelson– monitoring since 1993:

Rock lobster are significantly larger and more abundant   within the marine reserve than outside. The lobster population increased on average by 4.4 per cent a

year in the reserve from 1993 to 2000, and declined by 2.9 per cent a year outside. Lobster egg production has been estimated to be nine times greater within the reserve.

Contact: Andrew Baxter: Ph 03 546 3172; e-mail   abaxter@doc.govt.nz

Te Angiangi, Hawkes Bay – monitoring since 1995:

Lobster numbers and size have significantly increased, but fish numbers and size have not. This may be because half of the reef where the fish live lies outside the reserve where continuous spill over effects occur.

Contact; Debbie Freeman: Ph 06 869 0473; e-mail   dfreeman@doc.govt.nz

Pohatu, Banks Peninsula – monitoring since 2000:

Blue cod abundance within the marine reserve is greater than outside.

Contact: Al Hutt: Ph 03 304 1000; e-mail ahutt@doc.govt.nz

Te Tapuwae o Rongokako , East Coast – monitoring since 1999:

Greater abundances of lobsters and large blue cod, snapper and tarakihi within the marine reserve than outside. Paua are larger and more abundant, and kina are larger, but there are fewer of them.

Contact: Debbie Freeman: Ph 06 869 0473; e-mail   dfreeman@doc.govt.nz

Questions and Answers

It is Government policy (New Zealand Biodiversity Strategy 2000) to protect 10% of New Zealand's marine environment by 2010 in a network of representative protected areas.   This includes all New Zealand waters out to the limits of the EEZ or 200-mile limit.   But 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.

The ocean risks losing its balance if too many fish, sea-weed, sand or rocks are removed or excessive sewage, chemical wastes and sediment runoff occurs. It is important to conserve the health and natural character and quality of the coastal and marine environment. One way to achieve this is through a representative network of marine protected areas of different marine ecosystems.

There is increasing evidence that ocean ecosystems are being altered beyond their range of natural variation by a combination of human activities, including fishing, pollution, and coastal development.   Marine reserves complement existing coastal and ocean management and provide the highest level of protection

MRs have been shown to aid the recovery of species populations and habitats from exploitation, and environmental stresses.

Firstly the main beneficiaries are the species within the marine reserve who will ultimately be able to exist in a natural and balanced ecosystem without external pressures. Secondly, enabling all New Zealanders, now and in the future, to experience a balanced ecosystem and thirdly, researchers who can develop a better marine scientific understanding.

Research is showing that organisms in reserves show differences in behaviour, size, abundance, and in some cases habitat organisation between reserve and non-reserve areas.    For the future marine protected areas will provide broad benefits as sites for reference in long term research to understand marine ecosystems and ecosystem services. In summary marine reserves:

•  Protect marine biodiversity

•  Provide a benchmark to measure the impacts of development elsewhere;

•  Help improve our knowledge of marine ecosystems and how they work;

•  Allow current and future generations to be assured of the protection of intrinsic values, including those of marine wilderness;

•  Can contribute to community economic development through eco-based tourism;

•  Maintain genetic diversity of marine species.

While changes to individual species in a reserve following protection are often rapid, it can take 15 - 30 years or longer to establish more stable and natural food webs.

6. Why aren't all the Marine Reserves monitored?

It is important to establish marine reserves in areas that have unique characteristics not necessarily for convenience. It is an issue of balancing remoteness against resource availability. The Department of Conservation aims to have a minimum baseline monitoring in all reserves, but in practice some reserves will have more active science programmes than others.

The surveys are usually carried out by scientists with expertise relevant to the habitat type or marine species in question.   The marine science community in New Zealand is small and individual scientists may work for government agencies,universities, CRI's or private research companies.

Frequency varies as surveys are designed with specific research objectives to monitor the variations in type of habitat and marine species in a particular area.

No. This is an often held misunderstanding.    The primary purpose of marine reserves is to conserve the total natural ecosystems and biodiversity of the coastal and marine environment, which in itself is justification, and also for New Zealanders to enjoy, and for research purposes. Fish, of course, are part of the mix.

Many estuarine habitats have been lost or damaged through land reclamation and development. Addressing these threats involves cooperating with other management authorities onshore.   The Department of Conservation is concerned about the impacts of the terrestrial runoff and pollution and actively intervenes on these issues at resource consent hearings under the Resource Management Act 1991.   There are also some excellent local community based initiatives for replanting coastal areas and waterways. These are demonstrating huge benefits for harbours (e.g. Whaingaroa (Raglan) Harbour).