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Foveaux Strait/
Stewart Island/
Snares plateau shelf
Map ID number:
21
Location: South of the
South Island
Approximate area: 52,014km 2
Description of area:
The area encompassing Foveaux Strait/
Stewart Island/Snares plateau shelf is rich in
biogenic carbonate (shell gravel). There is
low sedimentation from Stewart Island rivers
and the area includes “pristine estuaries”.
Biological attributes:
The shell gravel biogenic carbonate is
produced by abundant Stewart Island rock
wall suspension feeders, especially by
bryozoans and molluscs, along with serpulid
polychaetes and brachiopods on the shelf.
The three-dimensionality of the habitat is
created by bryozoans, sponges, ascidians,
and cnidarians. In shallow water some
macroalgal species are habitat formers. A
high diversity of fish is associated with such
three-dimensional habitats.
There are high levels of local endemnicity
across many taxa. There is high algal
diversity, productivity, and biomass, with
significant endemics. The area has some
major estuaries with extensive seagrass beds.
Criteria applied:
Species diversity; species richness;
endemism; trophic/functional diversity;
representation; unusual proportion/degree of
biomass; habitat complexity/diversity.
Status and management:
The Foveaux Strait oyster fishery and Snares
Plateau fishery are managed in terms of
“stock” but not yet from a holistic ecosystem
perspective.
State of information:
See references below.
References and further reading:
Cranfield et al. (1999, 2001, 2003), Head
(1985), Willan (1981)
Anenomes, Stewart Island
©Sean Cooper
Subantarctic
plateaus
and islands
Map ID number:
22
Location: South of
New Zealand land mass
Approximate area: 342,544km 2
Description of area:
The subantarctic plateaus and islands have
extensive areas of deep continental shelf. In
places it is rich in biogenic shell gravel.
Biological attributes:
The area has high algal productivity and
biomass with significant endemics. There are
rock wall faunas associated with emergent
islands, deep canyons, and seamounts.
Criteria applied:
Endemism; trophic/functional diversity.
Status and management:
The Southern Plateau supports commercial
fisheries for a considerable number of
species, each of which is controlled by the
Quota Management System. Fishing is
banned within the 4,840km 2 of the Auckland
Islands Marine Reserve.
State of information:
There are large areas in which the benthos
has not been adequately sampled or
documented.
References and further reading:
Anderson et al. (1998), Bradford-Grieve
et al. (2003), Hay et al. (1985), Nelson
(1999b).
Paua
©Sean Cooper
62 ■ BIODIVERSITY – NEW ZEALAND’S MARINE ECOREGION