Biomass-based targets and the management of multispecies coral reef fisheries

Published source details McClanahan T.R., Graham N.A.J., MacNeil M.A. & Cinner J.E. (2015) Biomass-based targets and the management of multispecies coral reef fisheries. Conservation Biology, 29, 409-417.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Cease or prohibit all types of fishing in a marine protected area Action Link

Cease or prohibit all types of fishing in a marine protected area

A replicated, site comparison study in 2005–2012 of 233 coral reef sites across the western Indian Ocean (multiple countries) (McClanhan et al. 2015) found that the biomass of the fishable portion of reef fish communities (standing stock biomass) increased across a gradient of decreasing fishing intensity resulting from six different management regimes, and was highest in protected areas closed to fishing and with enforcement. Data were not statistically tested. Average fishable biomass was greatest in large, remote marine protected areas (2,189 kg/ha, 36 sites) and areas closed to fishing with high compliance (957 kg/ha, 114 sites), whereas young areas closed to fishing with low compliance had 489 kg/ha (66 sites). Areas where all (line and traps only) or most (spear and gill nets also used) destructive gears were restricted had 390 and 382 kg/ha of fishable biomass, respectively. The lowest biomass was in areas with no gear restrictions (269 kg/ha, 50 sites, seines and explosives used). In addition, many of the individual sites, even in areas with closures and high compliance, had a fishable biomass below 1,150 kg/ha (estimated by the authors as the target standing stock biomass needed for the recovery of exploited reef fish), and were thus failing to achieve conservation targets. Coral reef fish assemblages were surveyed at 233 individual sites across the Indian Ocean (off Comoros, Kenya, Madagascar, Mayotte, Mozambique, the Maldives, Seychelles, the Chagos archipelago and Tanzania) between 2005–2012. Fish were surveyed at each site by underwater visual census (3 to 5 belt transects of 50 or 100 m, or 8 point counts – see original paper for sampling methods by country). Sites were classified by the six dominant management categories.

(Summarised by: Natasha Taylor)