Population and standing crop estimates for rocky reef fishes of North‐Eastern New Zealand

Abstract

Estimates of the population and standing crop of fishes were made in 6 selected transect areas around Goat Island, a typical rocky reef area on the coast of northeastern New Zealand. There were considerable differences in the numbers of species and individuals between the sampling areas. Chance encounters with schools of transient fish was a major source of variation between replicate censuses. Among the resident species, variation in numbers could be attributed to habitat differences. Bottom topography and algal cover are important factors affecting the distribution and abundance of reef fishes. Standing crop estimates of resident fishes ranged from < 0.001 kg.cntdot.m-2 (low relief bottom, sparse algal cover) to 0.103 kg.cntdot.m-2 (high relief bottom, extensive algal cover). These figures are similar to those for California [USA] kelp beds and for coral reefs. Reef fish populations are susceptible to exploitation and the scarcity of larger fish in 2 of the study areas could be attributed to spearfishing. Resident species are most vulnerable to spearfishing and legal protection for these fish is suggested.