DOI: 10.5061/dryad.pg440kd
title: Data from: Giant coral reef fishes display markedly different susceptibility to night spearfishing

description: The humphead wrasse (Cheilinus undulatus) and bumphead parrotfish
 (Bolbometopon muricatum) are two of the largest, most iconic fishes of
 Indo-Pacific coral reefs. Both species form prized components of
 subsistence and commercial fisheries and are vulnerable to overfishing. C.
 undulatus is listed as Endangered and B. muricatum as Vulnerable on the
 IUCN Red List of Threatened Species. We investigated how night
 spearfishing pressure and habitat associations affected both species in a
 relatively lightly exploited setting; the Kia fishing grounds, Isabel
 Province, Solomon Islands. We used fisheries-independent data from
 underwater visual census surveys and negative binomial models to estimate
 abundances of adult C. undulatus and B. muricatum as a function of
 spearfishing pressure and reef strata. Our results showed that, in Kia,
 night spearfishing pressure from free divers had no measurable effect on
 C. undulatus abundances, but abundances of B. muricatum were 3.6 times
 lower in areas of high spearfishing pressure, after accounting for natural
 variations due to habitat preferences. It is likely the species’ different
 nocturnal aggregation behaviours, combined with the fishers’ use of night
 spearfishing by spot-checking underpin these species’ varying
 susceptibility. Our study highlights that B. muricatum is extremely
 susceptible to night spearfishing; however, we do not intend to draw
 conservation attention away from C. undulatus. Our data relate only to the
 Kia fishing grounds, where human population density is low, the
 spot-checking strategy is effective for reliably spearing large numbers of
 fish, particularly B. muricatum, and fisheries have only recently begun to
 be commercialised; such conditions are increasingly rare. Instead, we
 recommend that regional managers assess the state of their fisheries and
 the dynamics affecting the vulnerability of the fishes to fishing pressure
 based on local-scale, fisheries-independent data, where resources permit.
description: The_Nature_Conservancy_Solomons_UVC_Fish_SurveyThe underwater visual census transect data from the dives conducted around the Kia fishery. This file contains a sheet with the data and a sheet with metadata which describes the meaning of each column in the data sheet along with any other critical information.Reef strata polygons for the coral reefs around Kia, Santa Isabel, Solomon IslandsThe shapefile (the .shp plus associated files) in this folder contains polygons for the five reef strata (back reef, fore reef, fringing reef, patch reef, and subtidal reef flats) that we used to represent different reef habitats for Bolbometopon muricatum and Cheilinus undulatus around Kia, Santa Isabel, Solomon Islands. These were derived from the Millenium Coral Reef Mapping data. We outline what each reef strata represents in Supplementary Information A of "Giant coral reef fishes display markedly different susceptibility to night spearfishing". Note: this shapefile has the coordinate reference system EPSG 4326.reefstrata.zipFishing zones around Kia, Santa Isabel, Solomon IslandsThe shapefile (the .shp plus associated files) in this folder contains the boundaries of nine fishing zones around Kia, Santa Isabel, Solomon Islands, as delineated by local expert fishermen. The nine fishing zones are 1A, 1B, 1C, 1D, 2A, 2B, 3A, 3B, 3C. All Zone 1 polygons represent areas of high historical fishing pressure. Polygons for Zones 2 and 3 represent areas of low historical fishing pressure. Note: this shapefile has the coordinate reference system EPSG 4326.fishingzones.zip