The effect of marine protected areas on an exploited population of sex-changing temperate reef fish: an individual-based model

Authored by C G Attwood, W H H Sauer, S E Kerwath, A Goetz

Date Published: 2008

DOI: 10.2989/ajms.2008.30.2.10.560

Sponsors: United States National Science Foundation (NSF)

Platforms: No platforms listed

Model Documentation: Other Narrative Flow charts Mathematical description

Model Code URLs: Model code not found

Abstract

The effect of two marine protected areas (MPAs) on roman Chrysoblephus laticeps (Sparidae), an exploited reef-fish species inhabiting the South African temperate south coast, was simulated with a spatially explicit, individual-based model based on geographically correct habitat distribution. The model domains were small compared with the dispersal range of pre-recruits, and recruitment was held constant. Adult fish movement rules were based on the results of high-resolution mark-and-recapture and telemetry studies. Fish densities, age-structure and life-history parameters were derived from comprehensive underwater surveys and biological analyses. The model included the effect of fishing on size-at-sex change. The results indicate a recovery of fish abundance-per-recruit, size frequency and sex ratio to, or close to, pre-exploitation levels within the protected areas 10 years after the implementation of both MPAs. Results suggest that, for resident species such as roman, even small MPAs (6 km(2)) can offer protection. The small exchange of post-recruit fish into the adjacent areas results in negligible improvement (1\%) of catches. The MPAs support more and larger spawning fish, which may improve recruitment into adjacent fished areas

Tags

South-africa Home-range Activity patterns Life-history Fisheries management Plectropomus leopardus serranidae Chrysoblephus-laticeps sparidae Argyrozona-argyrozona pisces Protogynous hermaphroditism Adult movement