18. Kaikoura shallow water
Map ID Number: 18
Location: Northeast coast of South Island
Approximate area: 2,022km2
Description of area:
Limestone base rock.
Biological attributes:
Kaikoura’s shallow water environment has high algal diversity, some of which have cultural uses. It is a locality for the relict red seaweed of the order Bangiales. Between the coastal siltstone reefs there are localised areas of seagrasses. Kaikoura shelf and subtidal reefs are highly productive areas subject to periodic upwelling of deep nutrient-rich water. Steep reef walls, varied topography and high currents offshore support diverse communities of sessile filter feeders, including ascidians and sponges. The area has rich ascidian diversity (43 recorded species) and represents the southern limit of at least eight, and the northern limit of at least three described endemic species.
Criteria applied:
Species richness; extremities of range; habitat complexity/diversity.
Status and management:
Some commercial trawling for sea perch (Heliocolenus percoides) occurs from 40-100m on the shelf approximately 1km southeast of Kaikoura Peninsula. Trawling is localised to sea floor areas between scattered low reef outcrops. This activity impacts ascidians and sponges growing on shell and cobble substrata.
State of information:
Ecology of subtidal sessile benthic invertebrates is not well studied. A large amount of unpublished data exists from extensive subtidal collections of ascidians and sponges made by the University of Canterbury Marine Chemistry Group between 1992 and 1997 in the Kaikoura region. This information should be published in a biogeographic context. However, there is need for taxonomic revision and more extensive collections to interpret with certainty faunistic relationships in the New Zealand ascidiacea.
References and further reading:
Broom et al. (2004), Chiswell and Schiel (2001), Millar (1982), Nelson et al. (1990), Page (1993), Stocker (1985), Woods and Page (1999), Schiel and Hickford (2001).