Download AEBR 358 A shallow water benthic habitat survey and trial kina removals in the Whāngai Mokopuna Rohe Moana

Tangata Whenua of Tutukaka, Ngunguru and Hora Hora seek to protect and enhance ecosystem health in their rohe. In February 2024, the Rehuotane Ki Tai 186a temporary closure was established within three nautical miles of the coast. The harvest for rock lobster, cockle, crab, garfish, mussel, octopus, pāua, pipi, rock oyster, sea cucumber, sea horse, sea snail, starfish and tuatua was prohibited and no fishing with nets was allowed in Tutukaka Harbour or the Ngunguru and Hora Hora estuaries.

The Whāngai Mokopuna Rohe Moana management group initiated this research project in conjunction with appointed Tangata Kaitiaki to identify areas of healthy kelp forest and the extent of kina barrens and to trial kina removals at two sites. A cost effective and repeatable “rapid assessment” survey method was developed using readily available mapping software and in-water observations.

A simple habitat classification system was used by two experienced freedivers who reported what they saw to the crew on the support boat. We surveyed 17 km of coastline in three days, recording the location of each observation. There were extensive mature or active kina barrens observed in water depths of 10 metres or less. These areas had low biodiversity and few reef fish.

Two areas were selected for clearance of kina using free divers. Most kina collected in August and during follow up clearance in November had edible roe. Most kina were culled in situ because dive time was limited and kina density was high but some kina were harvested and distributed to hapū members. The project demonstrated the effectiveness of the rapid assessment method and provided valuable insights for future community led surveys and restoration initiatives.