Mokohīnau Islands

Size: 153 hectares

Area description

The Mokohīnau Islands are an isolated cluster of small pest-free islands, islets and rock stacks. The islands are approximately 22km north-east of Aotea / Great Barrier Island and administered by the Department of Conservation. 

Pokohinu / Burgess Island, the northernmost island, is 50 hectares in size. Most of the island is a scenic reserve and open to the public. The rest of the islands and small rock stacks, including Fanal, Flax and Trig islands, are nature reserves and protected wildlife sanctuaries requiring a permit from the Department of Conservation to land.

Mokohīnau Island group with Te Hauturu-o-Toi / Little Barrier.
Mokohīnau Island group looking south. Te Hauturu-o-Toi / Little Barrier is in the near distance.
Photo credit: Jacinda Woolly 2012

Key ecosystems

Marine habitats around the islands are diverse. They include broken rock, boulder beaches, sandy bottoms, drop-offs and kelp forests. Fish diversity is high due to the influence of the east Auckland current.

The islands are an extremely important site for seabirds. Large numbers of several species of burrowing seabirds breed here. Vegetation in the seabird nesting areas, colloquially known as "petrel scrub" (SA7), is mostly low-growing native herbs, flax, vines and scrub. This vegetation is influenced by the physical disturbance created by seabirds and from their guano deposits. 

The Mokohīnau Islands have the best remaining Tāmaki Makaurau / Auckland examples of petrel scrub. This is an ecosystem with a regional threat classification of Critically Endangered. 

Elsewhere on the islands, there is pōhutukawa treeland/flaxland/rockland (CL1) on the cliffs and patches of regenerating coastal broadleaved forest (WF4) on the larger islands. There are small wetland areas in hollows and valleys on Pokohinu / Burgess Island.

Key species

The islands provide safe refuge for some of New Zealand’s smallest endangered species including a stag beetle and a lizard endemic to the Mokohīnau Islands, as well as several threatened plant species.

The islands are a hotspot for seabird diversity with at least seven species of burrowing seabirds nesting here. The seabirds nesting on Pokohinu / Burgess Island include:

  • ōi (grey-faced petrel)
  • pakahā (fluttering shearwater)
  • tītī (sooty shearwater)
  • kuaka (common diving petrel)
  • little shearwater
  • takahikare-moana (white-faced storm petrel)
  • black-winged petrel.

Kororā (little penguin) and tarāpunga (red-billed gull) also breed here. The vegetation also supports a range of forest birds including kākāriki, tūī and korimako (bellbird).

Mokohīnau gecko in a shrub.
Mokohinau gecko.
Photo credit: Jacinda Woolly 2012

History

In 1883, a lighthouse was established on Pokohinu / Burgess Island. Lighthouse keepers grazed livestock on the island group until the lighthouse was automated in the 1970s. During this time, much of the native vegetation was cleared.

In 1973, goats were removed from Pokohinu / Burgess Island. In 1990, kiore (Pacific rats) were removed, making the island pest-free. Native vegetation continues to regenerate naturally following these events. 

Since becoming rodent-free, the islands have transformed into a seabird hotspot.

Related ecosystems

Cliff ecosystem

Pōhutukawa treeland, flaxland and rockland ecosystem (CL1)

This ecosystem occurs on coastal rock faces and eroding hill-slopes around the Auckland coastline and on offshore islands. It contains a mosaic of different plant communities including herbs, flax, shrubs and trees.

Threat status
Vulnerable

Coastal saline ecosystem

Iceplant, glasswort herbfield or loamfield ecosystem (SA7)

This coastal ecosystem is also known as petrel scrub. It occurs in association with burrowing seabird colonies and surface nesting seabirds in exposed locations. In Auckland, it is restricted to predator free offshore islands and rock stacks.

Threat status
Critically endangered

Warm forest ecosystem

Pōhutukawa, pūriri, broadleaved forest ecosystem (WF4)

Scattered along Auckland's coastlines, this broadleaved forest ecosystem provides an important source of food for kererū. They are also important seed dispersers for many species in this ecosystem.

Threat status
Endangered
 
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