NZ
Biodiversity Strategy
Theme
Three - Coastal and Marine Biodiversity
Part
Three
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Strategy go to the Biodiversity website
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Scope
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.
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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.
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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.
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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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