21. Foveaux Strait/Stewart Island/Snares plateau shelf
Map ID Number: 21
Location: South of the South Island
Approximate area: 52,014km2
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)