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3.4 Benthic invertebrates, algae, and plants

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Click on a section of the map to dive under the sea and discover what lies beneath New Zealand's waters

Key areas for benthic invertebrate, algal, and plant biodiversity in the New Zealand marine ecoregion

Farewell Spit region Rocky coast of the northeast North Island Hauraki Gulf/Bay of Plenty estuaries Kaikoura shallow water Bryozoan coral beds Rocky coast seagrass habitats Convergent margin cold seeps Bryozoan coral beds Deep sea wood habitats West coast harbours of the North Island Macquarie Ridge Southeastern continental margin/Deep Western Boundary Current Southeastern continental margin/Deep Western Boundary Current Southeastern continental margin/Deep Western Boundary Current Subantarctic plateaus and islands Foveaux Strait/Stewart Island/Snares plateau shelf Chatham Islands Fiordland Chatham Rise Kaikoura shallow water Bryozoan coral beds Bryozoan coral beds Farewell Spit region Bryozoan coral beds Bryozoan coral beds Cook Strait Marlborough Sounds Rocky coast seagrass habitats Rocky coast seagrass habitats Deep sea wood habitats Deep sea wood habitats Convergent margin cold seeps Ranfurly Bank Hauraki Gulf/Bay of Plenty estuaries Active submarine volcanoes and hydrothermal vents Rocky coast of the northeast North Island West coast harbours of the North Island West coast harbours of the North Island West coast harbours of the North Island coast harbours of the North Island coast harbours of the North Island West coast harbours of the North Island West coast harbours of the North Island Cavalli seamounts The Three Kings Islands and shelf, Spirits Bay, and Pandora Bank South Norfolk Ridge and the Three Kings Rise Trench Environments Trench Environments Kermadec Ridge

The workshop group with expertise in marine invertebrates, algae, and plants arguably faced the greatest challenge in trying to summarise and highlight the biodiversity of New Zealand’s oceans. The challenge stems from the fact that invertebrates make up 33 of the world’s 34 animal phyla and have more species than all other domains and kingdoms combined (Ministry for the Environment 1997). There are an estimated 15,300-16,400 marine invertebrates in New Zealand, of which 7,462 have been described (D. Gordon, personal communication, March 2004).

For protista, algae, fungi, and plants, there are estimated to be 17,900-32,900 species, of which 2,700 have been described (D. Gordon, personal communication, March 2004). Many marine invertebrates, algae and plants are so small, or live in such obscure or isolated habitats that their existence has so far gone unnoticed. Sampling efforts are regularly uncovering new species. At the current rate of new species descriptions, it will take at least 90 years to complete an inventory of the New Zealand marine biota6, not including unicellular organisms (D. Gordon, personal communication, March 2004).

Marine invertebrates, algae, and plants occupy all marine habitats, from the sea floor to the sea surface, with the photosynthetic organisms restricted to the euphotic zone. The marine scientists at the workshop concentrated on benthic invertebrates and plants that dwell on, near, or are attached to the sea floor because their expertise centred on the benthic environment. During several work sessions the participants identified 24 important areas for marine biodiversity in New Zealand. While the group was able to delineate certain locations that are known to host special invertebrate, and algal, or plant communities, other important features of the marine environment were more difficult to represent geographically. These features include habitats such as kelp forests, mangrove forests, and rock wall suspension feeding assemblages, which are critical places for marine biodiversity, but have patchy distributions around the country. Participants decided to include these features as a list of “special habitats”, which are represented in the last nine entries of this section, although all known locations for such habitats are not depicted on the map.

Contributors: Peter Batson, Dennis Gordon, Ken Grange, Michelle Kelly, Daphne Lee, Alison MacDiarmid, Patricia Mather, Wendy Nelson, Mike Page, and Stephanie Turner.

6 Including the Protozoa (and prokaryotes) the task of inventorying New Zealand’s marine biota could take up to 400 years (D. Gordon, personal communication, March 2004).