TitleFishing down a Caribbean food web relaxes trophic cascades
Publication TypeJournal Article
Year of Publication2012
AuthorsMumby PJ, Steneck RS, Edwards AJ, Ferrari R, Coleman R, Harborne AR, Gibson JP
Type of ArticleArticle
ISBN Number0171-8630
Accession NumberBIOSIS:PREV201200167310
Keywords(mature, immature)], (protected species)] [Cephalopholis fulvus], 00512, General biology - Conservation and resource management, 07002,, 07003, Behavioral, 07502, Ecology: environmental biology -, 07506, Ecology: environmental biology - Plant, 07508, Ecology: environmental biology - Animal, 07512, Ecology:, 07516, Ecology: environmental, 64008, Invertebrata:, Algae, Microorganisms, Nonvascular Plants, Plants, Algae, Plantae, Animals,, Animals, Chordates, Fish, Nonhuman Vertebrates,, Behavior, Behavioral biology - General and comparative behavior, biodiversity, biology - Animal behavior, biology - Wildlife management: aquatic, Chlorophyta [13300], Chordata, Animalia, Cnidaria, Cnidaria [41000], comparative, experimental morphology, physiology and pathology -, environmental biology - Oceanography, fish community structure shift, General and methods, guttatus] [grouper, Invertebrates, Management (Conservation), Marine Ecology (Ecology, Environmental Sciences), Osteichthyes [85206], species abundance, foraging behavior, fishing down, Caribbean food web,, Vertebrates, Wildlife, [Cephalopholis cruentatus] [Stegastes planifrons, [coral reef]/Pisces, Vertebrata,, [Halimeda tuna]/Invertebrata, Animalia, [Lutjanidae] [Serranidae], [parrotfish] [serranid] [snapper] [Sparisoma viride] [Epinephelus, [Stegastes partitus
AbstractThe fishing down of marine food webs has been described in pelagic and demersal systems but rarely documented in coral reef environments. We recorded a rapid shift in fish community structure in Belize that accompanied a marked decline in grouper and snapper abundance and a switch towards smaller, less desirable, herbivorous parrotfishes. In a 6 to 7 yr period (2002-2008/09), observations of large-bodied grouper (Serranidae) declined significantly from an encounter probability of 21% per 200 m(2) transect to just 2%. The biomass of carnivorous snappers (Lutjanidae) underwent a 7-fold decline, primarily in the species Ocyurus chrysurus. During this period, the inclusion of parrotfish in fish catches at nearby Glover's Atoll increased from a frequency of 6% in 2004 to similar to 20% of speared individuals by 2008. Parrotfish biomass declined by 41% between 2002 and 2008/09, with a major decline in the large and dominant herbivore Sparisoma viride. No changes in parrotfish biomass were detectable in nearby marine reserves during this time. Several important indirect effects of fishing were observed. The biomass of mesopredators including Cephalopholis fulvus, C. cruentatus, and Epinephelus guttatus increased dramatically by 880% as compared to the 2002 levels. We putatively attribute this response to a release from predation and constraints to foraging behaviour imposed by large serranids. Further, we find that the density of adult damselfish of the species Stegastes planifrons and S. partitus decreased by similar to 45%. We attribute this decline to elevated predation by the increased densities of mesopredators, which have been shown to prey upon juvenile damselfish. No change in damselfish densities was found at 2 control locations where fishing was prohibited. The decline in parrotfish in the central Mesoamerican barrier reef likely accounts for recent anecdotal observations of Halimeda tuna spreading to microhabitats that have previously been grazed intensively. While these results imply that the resilience of these reefs may be seriously impaired, the Belize Government has recently enacted new legislation to improve the management of grouper and outlaw harvesting of most herbivorous fish.