Data from: Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities

An understanding of the indirect effects of fishing on predator-prey relationships is required for the development of valid multispecies yield models for reef fisheries and for determining the factors governing fish community structure at larger scales. We used an underwater visual census technique to examine the indirect effects of fishing on the biomass and diversity (species richness) of reef fishes in a series of ten traditional Fijian fishing grounds (qoliqoli) subject to a range of fishing intensities. All members of the families Chaetodontidae (butterflyfishes), Labridae (wrasses), Lutjanidae (snappers), Mullidae (goatfishes), Scaridae (parrotfishes) and the sub-family Epinephelinae (groupers and coral trout) which could be reliably identified were censused. Each species censused was assigned to one of three trophic groups: herbivore, invertebrate feeder or piscivore. The biomass of all piscivorous fishes and of large (>30 cm) piscivorous fishes differed significantly between qoliqoli and was significantly correlated with fishing intensity. However, the biomass of piscivorous fishes was not correlated with the biomass or diversity of their potential prey (which were not targeted by the fishery). This suggested that the indirect effects of fishing did not have an important bearing on fish diversity or biomass and that predation by the target species did not play an important role in structuring these Fijian reef fish communities. The results contrast with those from a number of studies at smaller scales and provided further indications that the structure of reef fish communities is not governed by a single dominant process, but by a range of processes which operate on different scales in different circumstances.Reef fish size and abundance data from underwater visual census surveys in FijiThe data file comprises 25536 length estimates for 144 species of reef fishes recorded by underwater visual census in 10 adjoining coral reef areas spanning the western coast of Kadavu Island, Fiji. These data were collected during one phase of a larger study of reef fish community structure, fisheries and fishing impacts in Fiji. Habitat cover data were collected at the same time as the fish census data and are provided as a separate file. Data collection is described in detail in Jennings, S. and Polunin, N.V.C. (1997) "Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities" (Coral Reefs, 16, 71-82). Additional descriptions of the data structure and data collection process are provided in the accompanying "readme" file.Fiji_reef_fish_Jennings_Polunin_1997.csvHabitat data from underwater visual census surveys in FijiThe data file comprises mean habitat descriptors for 7 sites in each of 10 adjoining coral reef areas spanning the western coast coast of Kadavu Island, Fiji. The habitat descriptors are percentage cover of living corals, rock, sand and rubble, a measure of habitat complexity and depth. These data were collected during one phase of a larger study of reef fish community structure, fisheries and fishing impacts in Fiji. Fish census data were collected at the same time as the habitat data and are provided as a separate file. Data collection is described in detail by Jennings, S. and Polunin, N.V.C. (1997) "Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities" (Coral Reefs, 16, 71-82). Additional descriptions of the data structure and data collection process are provided in the accompanying "readme" file.Fiji_habitat_Jennings_Polunin_1997.cs