Corals in Fiordland

Red corals (Errina novaezelandiae) can be found at shallower depths in Fiordland than anywhere else in New Zealand.

Image (47.64K)

None of the corals found in Fiordland are of the reef building kind. Corals in Fiordland fall into four major types: the solitary stony corals, the red hydrozoan corals, the black corals and various gorgonian seafans.

Some of the red coral colonies can grow quite large. Chris and I have seen colonies over a metre in length. The black corals grow considerably larger and there are reports of 5m high giants which must be several hundred years old.

There are an estimated 7.5 million black coral colonies in Fiordland, some of which grow to within 5m of the surface. Globally, black corals are becoming increasingly threatened by the black coral trade. In New Zealand it is illegal to take black coral so this amazing assemblage should remain intact apart from occasional diver, crayfish pot or anchor damage.

Black coral colonies may be decades old. The commensal snakestars steal food but keep the colony free from silt.

Black corals live in close association with a snakestar Asterobrachion constrictum. While the snakestar steals food from the black coral colony it also keeps the colony free from silt. Most black corals host several snakestars and it is obvious that they do better than similar colonies without snakestars. Colonies lacking snakestars are often brown and discoloured with the occasional dead patch ... it is truly a mutualistic arrangement.

A tightly coiled snakestar. Snakestars feed by extending their tentacles over the host colony and removing trapped material. They feed more frequently at night or under low light conditions. (53.13K)

Chris Paulin examines a black coral colony in Fiordland. Worldwide black corals are threatened because of their use in jewelry. (34.82K)

Black coral research

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Last modified on Monday, September 04, 2000