MEPS - Vol. 575 - FEATURE ARTICLE

Unfished reefs in Hawaii can support large biomasses of herbivorous fishes, such as these surgeonfish at Kure Atoll, but environmental factors also have an important influence. Photo: Jason Helyer

Helyer J, Samhouri JF

 

Fishing and environmental influences on estimates of unfished herbivorous fish biomass across the Hawaiian Archipelago


Estimates of baseline states in ecological communities often rely upon observations from remote, uninhabited areas. Helyer and Samhouri describe associations between environmental factors and herbivorous fishes across a gradient of human population densities in the Hawaiian Archipelago. They show how failure to incorporate environmental factors into estimates of unfished biomass can reduce or exaggerate the apparent influence of fishing. Biomasses of 4 herbivorous fish groups across much of the Main Hawaiian Islands are near or above a commonly used sustainability reference point. However, on Oahu, the island with the largest human population, biomasses of 2 groups were <20% of unfished biomass. These findings highlight how embracing spatial variability can aid identification of conservation targets and assessment of reef fisheries.

 

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