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NZ Biodiversity Strategy

NZ Biodiversity Strategy

Theme Three - Coastal and Marine Biodiversity

Part Three


For the full Strategy go to the Biodiversity website here » »


State of coastal and marine biodiversity
Current management
Seamounts - jewels of the ocean
Information and awareness of marine biodiversity
Coordinated managment
Coastal and marine habitats
Coastal and marine species
Sustainable fisheries
Marine biosecurity
Marine protected areas and representativeness
Action plan


Coastal and marine environments including estuaries, inshore coastal and offshore areas within New Zealand's territory and other jurisdiction (including the Exclusive Economic Zone) and the resident and migratory marine species (plants, benthic organisms, fish, marine mammals, birds and other organisms) inhabiting these areas.  Desired outcome for 2020

New Zealand's natural marine habitats and ecosystems are maintained in a healthy functioning state. Degraded marine habitats are recovering. A full range of marine habitats and ecosystems representative of New Zealand's indigenous marine biodiversity is protected.

No human-induced extinctions of marine species within New Zealand's marine environment have occured. Rare or threatened marine species are adequately protected from harvesting and other human threats, enabling them to recover. 

Marine biodiversity is appreciated, and any harvesting or marine development is done in an informed, controlled and ecologically sustainable manner [26]

No new undesirable introduced species are established, and threats to indigenous biodiversity from established exotic organisms are being reduced and controlled.

[26] The Fisheries Act 1996 requires that any adverse effects of fishing on the aquatic environment be avoided, remedied or mitigated, and the biological diversity of the aquatic environment be maintained.


State of coastal and marine biodiversity 

New Zealand's Exclusive Economic Zone (EEZ) extends from the edge of the territorial sea (12 nautical miles from shore) to 200 nautical miles (370 km) from shore and covers 430 million hectares - more than 15 times New Zealand's land area. Figure 3.2 shows the extent of New Zealand's marine environment. 

New Zealand's coastal and marine ecosystems and species are highly diverse. This is due to a combination of factors - our geological history and isolation, the range and complexity of habitats, and the influence of some major ocean currents. The result is a wide variety, but patchy distribution, of coastal and marine plants and animals. 


Figure 3.2 New Zealand's Marine Environment and Protected Marine Areas


About 8000 marine species have been described in New Zealand waters, including 61 seabirds, 41 marine mammals, 964 fish (of which 108 are endemic), 2000 molluscs (snails, shellfish and squid), 350 sponges, 400 echinoderms (kina, starfish and so on), 900 species of seaweeds and 700 species of micro-algae. These make up almost one-third of New Zealand's total number of described indigenous species.

However, there are many more to be discovered, with seven new species being identified on average each fortnight. Marine scientists estimate that perhaps as much as 80 percent of New Zealand's indigenous biodiversity is found in the sea. While many of our marine fish are found in other countries' seas, many of our benthic (bottom dwelling) marine species are endemic to New Zealand. 

New Zealand is visited by a number of migratory species, and provides habitat that is critical to the long-term viability of some of these species, particularly for marine birds that breed in New Zealand. 

Evaluating the state of New Zealand's marine and coastal biodiversity is difficult due to our very limited information. 

Although our coastal waters and habitats are generally of high quality by international standards, they are under stress in some areas, particularly estuaries near towns and cities and the mouths of large rivers. Some 390 million tonnes of sediment are washed from the mainland into the sea each year, contributing to the decline of some estuarine and inshore habitats. Point source discharges and contaminated runoff also have impacts. Many estuarine ecosystems have been lost or damaged through land reclamation, encroachment from land development, and other human activities. 

Estuarine and other coastal ecosystems are also threatened by the invasion of exotic species such as the Asian date mussel and Undaria seaweed. These species are spread by vessels transporting ballast water, hull encrustations, and marine farming equipment from one marine area to another. 

Many coastal fish stocks were heavily reduced between 1965 and 1985 following deregulation of the industry. Since the introduction of the fisheries Quota Management System (QMS), most QMS stocks for which biomass and productivity data are known are thought to be above sustainable levels. However, for over half of the stocks managed under the QMS, too little is known to be able to assess whether harvesting levels are sustainable. It is known that for several species (including snapper and orange roughy) some stocks have been depleted below levels judged to produce maximum sustainable yields.

With hunting of marine mammals banned in New Zealand waters since 1978, most whale and dolphin species are recovering or at least holding their own. Fur seal and sea lion numbers appear to be recovering, although their populations are a fraction of their original size. Fisheries by-catch (capture of non-target species) remains a problem for some species, such as Hector's dolphin, New Zealand sea lion, and albatross, although programmes are underway to protect these species.

Shellfish and some other marine invertebrates remain vulnerable to overharvest and to habitat degradation, caused by sediment from rivers, pollution, changes in sea temperatures and fishing activities such as the dragging of heavy nets along the sea floor. 

Many of our marine species spend part of their lives in international waters, particularly in the southern ocean, so the state of these areas is of importance to New Zealand's marine biodiversity. New Zealand also has interests in resources in international waters, for example in the marine area around New Zealand's Antarctic territory - the Ross Dependency. 



Current management 

New Zealand's coastal and marine environment is managed by several different agencies, often for competing economic, social and environmental purposes. Responsibilities for managing coastal and marine biodiversity are shared between central and local government. MFish manages fisheries under the Fisheries Acts and is responsible for some aspects of marine biosecurity, DoC looks after protected areas and species, and DoC and regional councils together manage coastal resources (excluding fishing and many significant fishing impacts) under the RMA28. 

Local authorities manage land use impacts and discharges, which also impact on marine ecosystems and biodiversity. Discharges from shipping are managed by regulations under the RMA inside the territorial sea and through rules administered by the Maritime Safety Authority outside territorial waters. Mining is subject to the Crown Minerals Act 1991 in both the territorial waters and the larger EEZ. Within territorial waters, regional councils are responsible for managing the environmental effects of mining and other activities under regional coastal plans and the New Zealand Coastal Policy Statement. 

Management of the marine environment over the last century has largely focused on sustaining fisheries for use, rather than protecting marine biodiversity for its own sake. This differs from our approach on land where there has been a greater emphasis on protecting species and their habitats (see Theme One). Only a limited number of species are protected under law - our marine mammals (protected under the Marine Mammals Protection Act 1978), most seabirds and a small number of other species (spotted black groper, marine reptiles, black and red corals)(protected under the Wildlife Act 1953). Approximately 4 percent [29] of the territorial sea is protected in marine reserves that are established for scientific purposes under the Marine Reserves Act 1971. 

In response to increasing global pressure on marine resources, international management regimes are being developed. The United Nations Convention on the Law of the Sea (UNCLOS) was signed in 1982 and provides a standard international regime for ocean spaces including the territorial sea, the EEZ (which had previously been a global common), and the continental shelf. UNCLOS provides for a sustained yield fisheries regime, as well as the protection of the marine environment. New Zealand has until 2006 to delineate the outer limit of the continental shelf and define our jurisdiction over seabed resources in this area. 

Further agreements have added to New Zealand's marine responsibilities. New Zealand has recently signed the United Nations Fish Stocks Agreement, which provides a framework for managing fish stocks that are migratory or extend beyond the EEZ. The Convention on the Conservation of Migratory Species (Bonn Convention) will also provide mechanisms for New Zealand's involvement in managing biodiversity beyond our territorial limits. 

New Zealand is also party to treaties covering the protection of the Antarctic and its marine living resources. Legislation implementing these treaties is administered by the Ministry of Foreign Affairs and Trade. 

[29] The 735,000 hectare marine reserve around the Kermadec Islands is much larger than any other marine reserve in New Zealand to date. If excluded this percentage is reduced to about 0.1 percent.


Seamounts - jewels of the ocean  

Beneath the vast surface of New Zealand's EEZ, pinnacles and plateaux rise from the ocean depths. Known as seamounts, these undersea hills and mountains are home to diverse marine organisms.

New Zealand, with its complex undersea landforms, has many and varied seamounts scattered throughout the region. Many have only recently been discovered. The marine life inhabiting our seamounts is poorly known and many species have yet to be described. However, we do know that seamounts host many unusual and unique species and have rich biodiversity. Species include benthic (bottom dwelling) animals like bryozoans (small coral-like animals), corals (some growing in "trees" up to 15 metres tall), sea stars, sea cucumbers, sponges, molluscs, anemones and crabs. Seamounts also attract fish and so have become favoured sites for deep-sea fishing for species like orange roughy, oreo and cardinal fish. 

There is growing concern among marine scientists in New Zealand about the impact of deep sea fishing using bottom-dragging trawl nets on seamount communities, for example within the Chatham Rise fishery. Research on seamounts south of Tasmania has shown destructive effects in heavily trawled areas. Deep-sea benthic species are particularly vulnerable to disturbance because they are generally slow to grow and reproduce. Some of the coral trees, for example, are estimated to be centuries old. 

It is difficult to determine the impact of deep sea trawling on life on seamounts. Pieces of broken coral and assortments of other organisms caught in trawl nets suggest that fishing is having some impact, but we do not know how changes to seamount benthic communities caused by fishing may affect the sustainability of our deep-water fisheries. Growing information about such impacts highlights the need to be cautious about fishing seamounts - in the areas fished, the methods we use and the amount of fish taken.


Summary of issues

Information and awareness of marine biodiversity 

Our current knowledge of marine life and how marine ecosystems work is not adequate to show whether we are sustainably managing New Zealand's marine biodiversity. People have perceived the ocean to be uniform and limitless in its capacity to provide food and absorb waste. In general, New Zealanders do not appreciate the great levels of diversity found in marine ecosystems and the threats to this diversity. 

  • Many marine species remain undescribed and information on the distribution and lifecycle of others remains sparse.
  • We have not yet identified and classified New Zealand's marine habitats, the communities of marine life within them, the processes that drive marine ecosystems, or the full extent of threats to marine biodiversity from human activities and broader environmental changes.
  • The inter-relationships and dependencies between fishing activities, fisheries stocks and other components of marine biodiversity (that is, an ecosystem-based approach) are inadequately addressed in research and management actions. Some non-target species are being adversely affected by fishing, and others may be at risk.
  • Current levels of information are inadequate to determine whether or not harvesting levels are sustainable for over half the fish stocks managed under the QMS. As harvesting pressure on some of these stocks increases, additional information is vital to avoid the risk of these stocks collapsing.
  • We do not fully understand the scale of land use impacts, including sedimentation and pollution, on marine biodiversity.
  • We currently do not have the information needed to anticipate the nature and intensity of ecological changes that might be induced by climate change.


Coordinated management

New Zealand's coastal and marine environment is used by a variety of interest groups, and responsibilities for its management are shared between a range of central and local government agencies. This requires the management roles and accountabilities of each agency to be clearly defined and demands a high level of cooperation and coordination between agencies.

  • Some responsibilities for managing marine biodiversity are not clearly understood, resulting in a lack of accountability for actions and outcomes. There is a need to clarify the respective roles of regional councils, Department of Conservation, Ministry of Fisheries, Ministry for the Environment, the Maritime Safety Authority, Ministry of Foreign Affairs and Trade, Ministry of Transport, Ministry of Commerce, the fishing industry and other interest groups in managing marine biodiversity.
  • Beyond the territorial sea there is incomplete coverage of management issues, a lack of coordination of agency responsibilities, and the potential for practices to be inconsistent with those within the 12 mile limit.
  • Land use activities (such as nutrient enrichment and pollution from sewage, sedimentation from land runoff, and coastal development) and aquaculture activities can adversely affect habitats important to both fishery stocks and marine ecosystems, and they need to be managed accordingly.
  • The management of the coastal and marine environment and of impacts on that environment needs to be integrated within an ecosystem-based framework with explicit biodiversity objectives.


Coastal and marine habitats 

Although our coastal waters and habitats are generally of high quality by international standards they are under stress in some areas - in particular estuaries and the mouths of rivers near urban areas.

  • Land uses, such as agriculture and forestry, adversely affect the coastal environment through runoff containing eroded soils, nutrients and contaminants; and coastal land development has a major impact on some coastal ecosystems.
  • The discharge of wastes from industry and households, including sewage and pollutants in urban stormwater, has an adverse impact on marine and estuarine water quality and also marine biodiversity, although the extent of this is not known.
  • Some marine habitats, including seamount communities, and coral, bryozoan, sponge and other benthic communities, are being adversely affected by mechanical activities such as trawling, dredging, dumping and the extraction of oil, gas and minerals. 


Coastal and marine species  

Some of our coastal and marine species are at risk from human activities, in particular fishing and land-based activities. 

  • Commercial fishing, although managed through the QMS, has depleted stocks of some target species (for example, snapper, orange roughy and rock lobster) to below levels judged desirable by fisheries scientists and managers. Management should focus on rebuilding depleted stocks and avoiding, remedying or mitigating any negative effects of fishing on ecosystems.
  • Commercial fishing impacts include: the capture (by-catch) of non-target species, such as fish, marine mammals (dolphins, sea lions and fur seals), marine invertebrates and seabirds; genetic changes in response to fishing; effects on predator/prey relationships and damage to benthic communities.
  • Harvesting pressure in coastal environments from recreational and customary fishing has a significant impact on shellfish and inshore finfish stocks in some areas, and information needs, monitoring and management options for these need to be investigated further.
  • The effects of pollution, particularly persistent organic pollutants, and sediments on species and ecosystems are unknown.


Sustainable fisheries 

Wild fisheries are reaching their natural limits. The global fish catch - quadrupled in the last 40 years - is no longer rising, seemingly because the oceans cannot sustain a greater catch. The problem is worsened by marine ecosystems being damaged by pollution and habitats being damaged or destroyed. 

New Zealand's fisheries have a similar history. In the 1970s, open access to fishery resources and emphasis on increasing commercial harvest led to over-fishing which began to impact on fish stocks and returns to fishers. The extension of New Zealand control over the 200-mile EEZ, coupled with new technology, meant that our fishing industry could expand to fish new species and areas. 

The QMS was introduced in 1986 in part to address over-fishing. Under the Fisheries Act, harvest levels for fisheries are based on maximum sustainable yield (or biomass for maximum sustainable yield). Where the biomass falls below this, the harvest should be reduced to build the fishery back up to the level that will produce the maximum sustainable yield. Unfished populations are often fished at a higher level initially until the biomass is "fished down" to a maximum sustainable yield level. The allowable commercial catch is allocated to holders of quotas in proportion to their holding. 

Sustainability is still a concern. For over half of the fish stocks managed under the QMS, too little is known to be able to assess whether harvesting is maintaining stocks at or about the level that will produce the maximum sustainable yield. Information is best for important commercially harvested fish stocks, with about 70 percent of the commercial catch (in tonnage) being from fisheries where the stock status is known. Some stocks, including snapper and orange roughy, have been depleted to below the maximum sustainable yield level, although management strategies are in place to rebuild these stocks [30]

Approaches to fishery management continue to evolve as understanding of the marine environment increases and attitudes change. There is now recognition that fisheries are part of an ecosystem and should not be managed in isolation. The 1996 Fisheries Act (which deals only with the effects of fishing) requires that ecosystem inter-relationships be considered. "Changing Course - Towards Fisheries 2010", Mfish's Strategic Direction, reflects growing awareness of the need to maintain wider ecosystem viability and to encourage stakeholder initiatives. Some fisheries are managed on this basis. The scallop fishery in Nelson, for example, is managed to make sure that some areas are not damaged by dredging to protect other species (including brachiopods). 

Our improving understanding of ecosystem issues is moving us in the right direction and confirms that an integrated approach to fisheries and environmental management is needed to conserve marine biodiversity.

[30] The Fisheries Act 1996 Amendment Act 1999 allows for some approved by-catch species to be fished to a level below the maximum sustainable yield level, but only where the long-term viability of the fish stock is not impaired.

Marine biosecurity 

New Zealand's coastal and marine environment is vulnerable to the establishment and spread of introduced marine pest species and diseases. 

  • New marine organisms may arrive, and be transferred around New Zealand waters, in ballast water (used to stabilise ships) or attached to the hulls of visiting ships and fishing and recreational vessels.
  • Responsibility for surveillance of the marine environment and emergency response to the entry of new exotic species rests with Mfish. However, responsibilities for managing pests already in New Zealand waters need to be further defined (see Theme Five).
  • Mechanisms are needed to control the introduction and spread, within New Zealand waters, of new species, pathogens and toxic organisms that are potentially harmful to marine species and ecosystems.
  • Aquaculture poses some risks for marine biosecurity through the transfer of organisms into or around New Zealand waters on spat or equipment, escapes from containment, and the possible introduction of pathogens with imported stock. 

Marine protected areas and representativeness

New Zealand's marine reserves cover only a tiny area of New Zealand's marine environment and are not representative of the range of our distinctive coastal and marine habitats and ecosystems (see figure 3.2). Marine reserves and other no-take or restricted areas can also provide refuge areas from which degraded areas can be restocked. 

  • Under the Marine Reserves Act 1971, marine reserves can only be created within territorial waters, but not beyond, resulting in limited protection mechanisms for marine ecosystems outside the 12 mile limit, within the EEZ and areas under New Zealand's jurisdiction.
  • The purpose of marine reserves created under the Marine Reserves Act is to preserve a variety of marine habitats for scientific study, but not specifically to meet biodiversity conservation objectives, the achievement of which are incidental to this purpose.
  • Outside of marine reserves, measures to protect coastal and marine ecosystems are contained in the RMA (which deals with matters other than fisheries management and excludes the control of fisheries and many fishing impacts) [31] and the Fisheries Act 1996 (which deals with fishing and fishing impacts). However, improved integration and implementation of these measures are required.
  • There is a range of measures under the Fisheries Act which can be used to provide protection for fisheries purposes. These include area closures, seasonal area closures, restrictions on certain fishing techniques, partial closures to certain commercial fishing, taiapure and mataitai.
  • New Zealand has a role in protecting areas outside the EEZ, particulalry the Antarctic.

[31] Section 30(2) of the RMA excludes the control of harvesting or enhancement of fisheries from regional council functions, where the purpose of the control is to conserve, enhance, protect, allocate or manage any fishery. 


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