The marine environment in Northland’s Whangārei Harbour is of distinctive quality, and two marine areas are set aside for protection: around Motukaroro (Passage) Island and at Waikaraka.
The area only became a reserve because students at nearby Kamo High School applied for it to be protected, using their own research and funds, and undertaking consultation with the community. The process took 16 years (1990–2006), with thousands of students contributing during that time.
This achievement may be unique in the world and is an outstanding example of community-driven conservation.
This reserve covers two sites. Waikaraka is one of New Zealand’s richest mangrove environments and attracts abundant birdlife. Motukaroro covers reef and sandy seabed habitats and is notable for its diverse sea sponge populations.
The 227.5ha marine area at Waikaraka is almost entirely mangrove forest with associated intertidal mudflats and a subtidal channel edge. Being one of nature’s most highly productive zones, the gentle flowing waters and mud surrounding mangrove roots are home and nursery to many organisms: fish and shellfish as well as crabs, worms and shrimps.
Fish like snapper, trevally, kahawai, kingfish and mackerel spend important parts of their lives among mangroves, so the protection of marine reserve status here supports the fish population throughout the harbour. The Waikaraka mangroves also provide habitat for over 80 species of birdlife, some very rare, like dotterels.
One of the special features of the 26.2ha reserve at Motukaroro is the abundance and diversity of the marine life in the waters around it. The combination of deeper water and swift current flows has produced a diverse assemblage of reef-fish quite unique in a harbour environment.
The surrounding seabed is rocky, with large areas of kelp providing a haven and feeding ground for an unusually high variety of fish. On the westward point of the island there is a large, fragile environment of filter feeders, including anemones and sponges, whose brilliant colours are stunning and provide a spectacular dive.