%0 Journal Article
%T The Ecology of Coral Reef Top Predators in the Papah¨ˇnaumoku¨ˇkea Marine National Monument
%A Jonathan J. Dale
%A Carl G. Meyer
%A Christian E. Clark
%J Journal of Marine Biology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/725602
%X Coral reef habitats in the Papah¨ˇnaumoku¨ˇkea Marine National Monument (PMNM) are characterized by abundant top-level predators such as sharks and jacks. The predator assemblage is dominated both numerically and in biomass by giant trevally (Caranx ignobilis) and Galapagos sharks (Carcharhinus galapagensis). A lower diversity of predatory teleosts, particularly groupers and snappers, distinguishes the PMNM from other remote, unfished atolls in the Pacific. Most coral reef top predators are site attached to a ˇ°homeˇ± atoll, but move extensively within these atolls. Abundances of the most common sharks and jacks are highest in atoll fore reef habitats. Top predators within the PMNM forage on a diverse range of prey and exert top-down control over shallow-water reef fish assemblages. Ecological models suggest ecosystem processes may be most impacted by top predators through indirect effects of predation. Knowledge gaps are identified to guide future studies of top predators in the PMNM. 1. Introduction Large predators are becoming scarce on many coral reefs, with fishing thought to be a major factor in declines [1¨C7]. Coral reef top predators often command high market prices, providing strong economic incentives for commercial harvesting [8, 9]. Major contributors to commercial overharvesting of coral reef predators include the shark fin fishery [8, 10¨C12] and the live reef food fish trade [9, 13]. Consequently, intensive commercial exploitation has resulted in dramatic declines in reef predators in many locations [4, 13], and recent studies suggest even subsistence fishing can deplete reef predators [2, 5, 6]. Although less clear cut than in terrestrial systems (e.g., [14, 15]), there is growing evidence that removal of top predators from marine ecosystems may trigger trophic cascades resulting in phase shifts [2, 6, 16¨C19]. In coral reef ecosystems, these shifts appear to favor algal-dominated reefs populated by small planktivorous fishes and echinoderms, at the expense of reef-building scleractinian corals [2, 6, 16, 19]. Collectively these studies indicate that effective conservation of top level predators is important for coral reef ecosystem health. Science-based management and effective conservation of coral reef top predators requires a broad understanding of their ecology. We need to know which species are present, their abundance, spatial dynamics and habitat requirements, rates of growth, reproduction and mortality, diet, and ecological interactions with other species. Unfortunately, the natural ecology of top predators has already been
%U http://www.hindawi.com/journals/jmb/2011/725602/