Researchers used long-term monitored reefs off the coast of north-western Australia to understand how fishing changed shark communities in coral reef ecosystems. Two uninhabitated areas with atoll-like reefs with differing management regimes, closed marine protected area and open to shark fishing, were studied. Researchers found evidence that the loss of sharks due to fishing can have a cascading effect on the food chain with effects on mesopredators and primary consumers. Both habitat and shark fishing, individually and interactively, affected reef fish community composition and trophic structure across sites. Bottom-up processes such as bleaching and cyclones appear to affect herbivores, planktivores, and corallivores, but do not affect carnivores. Healthy reef shark populations should be a target of management of coral reefs, since the presence of sharks may promote the abundance of herbivores.
Author: Ruppert, J.L.W., M.J. Travers, L.L. Smith, M-J Fortin, and M.G. Meekan
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PLoS ONE 8(9): e74648. doi:10.1371/journal.pone.0074648.