Science Centres: Fisheries

Local people from Ohope interview recreational fishers and measure their catch. (Photo: Les Morgan, Ohope)

Recreational fishers continue to contribute valuable data by taking part in ramp surveys at the end of their day’s fishing. NIWA have been coordinating surveys of kahawai catches in Northland, the Hauraki Gulf, and the East Cape since 2001, and these look set to continue.

NIWA scientists have developed a kahawai population model which uses the survey information to determine the current state of the kahawai stock off the northeastern coast of the North Island.

"Collecting data over continuous years allows us to track weak and strong age classes through time. This in turn determines the number of fish in the total population," says fisheries biologist Nicola Rush.

The evidence for kahawai in the area is encouraging, indicating a good spread of age classes along the coast. As suspected by many recreational fishers, the Hauraki Gulf appears to be a juvenile nursery for kahawai, as is also the case for snapper. The young fish tend to migrate out into open water after three to four years.

The surveys are funded by the Ministry of Fisheries.