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.