Publication Abstract

Threatened fishes of the world: Bolbometopon muricatum (Valenciennes, 1840) (Scaridae)

T.J. Donaldson and N.K. Dulvy

Predation plays an important role in the dynamics of prey fishes at local scales, but there is little evidence that predation is important at larger spatial scales. We test for an increase in smaller prey fish species as an indirect consequence of the removal of predatory coral reef fishes. Three community size metrics are described along a 13-island gradient of subsistence-level exploitation. The steepness of size spectra slopes increased with increasing fishing intensity. This could result from either the removal of larger fishes or increases (prey release) of smaller fishes. Declines in the densities of the largest size classes were apparent, but there were no significant increases in the densities of smaller size classes. The mean weight of individuals and the mean maximum length of the community declined by 45% and 25% respectively with increasing fishing intensity. The declines in all three size metrics coupled with no clear increases in the densities of small size classes suggests predator-prey coupling of fish communities is weak or absent at large spatial scales on Fijian coral reefs.

Reference:

T.J. Donaldson and N.K. Dulvy (2004) Threatened fishes of the world: Bolbometopon muricatum (Valenciennes, 1840) (Scaridae). Environmental Biology of Fishes, 70(3): 373.