title: Global assessment of the status of coral reef herbivorous fishes: evidence for fishing effects.
abstract: On coral reefs, herbivorous fishes consume benthic primary producers and regulate competition between fleshy algae and reef-building corals. Many of these species are also important fishery targets, yet little is known about their global status. Using a large-scale synthesis of peer-reviewed and unpublished data, we examine variability in abundance and biomass of herbivorous reef fishes and explore evidence for fishing impacts globally and within regions. We show that biomass is more than twice as high in locations not accessible to fisheries relative to fisheries-accessible locations. Although there are large biogeographic differences in total biomass, the effects of fishing are consistent in nearly all regions. We also show that exposure to fishing alters the structure of the herbivore community by disproportionately reducing biomass of large-bodied functional groups (scraper/excavators, browsers, grazer/detritivores), while increasing biomass and abundance of territorial algal-farming damselfishes (Pomacentridae). The browser functional group that consumes macroalgae and can help to prevent coral-macroalgal phase shifts appears to be most susceptible to fishing. This fishing down the herbivore guild probably alters the effectiveness of these fishes in regulating algal abundance on reefs. Finally, data from remote and unfished locations provide important baselines for setting management and conservation targets for this important group of fishes.
authors.affiliation: Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, , San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA, U.S. Geological Survey, Hawaii Cooperative Fishery Research Unit, University of Hawaii at Manoa, , Honolulu, HI 96822, USA, The Nature Conservancy, , Brisbane, Queensland 4101, Australia, OceanInk, , Kamuela, HI 96743, USA, National Geographic Society, , Washington, DC 20090, USA, Australian Institute of Marine Science, TMC, , Townsville, Queensland 4810, Australia, Pacific Islands Fisheries Science Center, Coral Reef Ecosystem Division, National Oceanic and Atmospheric Administration (NOAA), , Honolulu, HI 96822, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Edwards
authors.forename: A M
authors.initials: AM
authors.lastname: Friedlander
authors.forename: A G
authors.initials: AG
authors.lastname: Green
authors.forename: M J
authors.initials: MJ
authors.lastname: Hardt
authors.forename: E
authors.initials: E
authors.lastname: Sala
authors.forename: H P
authors.initials: HP
authors.lastname: Sweatman
authors.forename: I D
authors.initials: ID
authors.lastname: Williams
authors.forename: B
authors.initials: B
authors.lastname: Zgliczynski
authors.forename: S A
authors.initials: SA
authors.lastname: Sandin
authors.forename: J E
authors.initials: JE
authors.lastname: Smith
mesh_terms: D000818:Animals; D044822:Biodiversity; D018533:Biomass; D003247:Conservation of Natural Resources; D057894:Coral Reefs; D005398:Fisheries; D005399:Fishes / Q000502:physiology*; D005843:Geography; D060434:Herbivory; D011156:Population Density; D011157:Population Dynamics
keywords: fishing; herbivory; macroalgae and turf algae; phase shift; reef-fish; resilience