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Te-Whanganui-A-Hei/Hahei (Cathedral Cove) Marine Reserve

When Te Whanganui-A-Hei (Cathedral Cove) Marine Reserve was gazetted in 1992 it became New Zealand’s sixth marine reserve and the first for the Coromandel. The reserve covers 9 square kilometres and is administered by the Department of Conservation in partnership with the Te Whanganui-A-Hei Marine Reserve Committee.

Te Whanganui-A-Hei became a marine reserve in 1992. As there is no recreational or commercial fishing allowed inside the Marine Reserve, the plants and animals are free to return to their natural balance. More sea life, and more varieties of sea life, live inside the Marine Reserve boundaries compared to outside the Reserve. Snapper, crayfish and many fish species are much larger, and there are far more of them. Areas where nothing grew except large numbers of kina (known as “kina barrens”) are quickly turning into large areas of kelp forest. A natural balance of species is evolving and recreating the ecosystems that would have existed prior to the arrival of man.

Te Whanganui-A-Hei Marine Reserve is special because many habitats normally found in much bigger areas on the eastern Coromandel Peninsula coast are found in this quite small area. The area around the snorkel trail (Gemstone Bay) is a prime example of this where four different habitats exist and support a diverse selection of seaweeds, fish, shellfish, sponges, anemones, corals and starfish.



Marine habitats are affected by exposure to waves and what lies on the sea floor (substrate). Te Whanganui-A-Hei Marine Reserve has many different substrates in a small area, from large areas of sand, through rocky reefs and flat hard rock bottom, to boulder and cobble fields. Each area has its own range of plants and animals.

The Experiencing Marine Reserves programme is active at this reserve.


Find out more on the DoC website, or visit the following link(s):

Wikipedia - Te Whanganui-A-Hei Marine Reserve.

Mercury Bay Online Page including photo gallery.

Victoria University Research - "Impacts of sedimentation on Rocky Reef Communities in the Hahei Marine Reserve." Sponsors