Exploring the effect of Marine Protected Areas on the dynamics of fish communities in the southern Benguela: an individual-based modelling approach

Authored by Yunne-Jai Shin, John G Field, Dawit Yemane

Date Published: 2009

DOI: 10.1093/icesjms/fsn171

Sponsors: South African National Research Foundation (NRF)

Platforms: Java OSMOSE

Model Documentation: Other Narrative Flow charts

Model Code URLs: Model code not found

Abstract

Marine Protected Areas (MPAs) have been suggested as a tool that can achieve some of the goals of an Ecosystem Approach to Fisheries (EAF), e.g. prevention of overexploitation, biodiversity conservation, recovery of overexploited population, but the consequences of their establishment on the dynamics of protected components are often unclear. Spatial and multispecies models can be used to investigate the effects of their introduction. An individual-based, spatially explicit, size-structured, multispecies model (known as OSMOSE) is used to investigate the likely consequences of the introduction of three MPAs off the coast of South Africa, individually or in combination. The simultaneous introduction of the MPAs affected varying proportions of the distribution of the modelled species (5-17\%) and 12\% of the distribution of the whole community. In general, the introduction of the MPAs in the different scenarios resulted in a relative increase in the biomass of large predatory fish and a decrease in the biomass of small pelagic fish. The simulation demonstrates that consideration of trophic interactions is necessary when introducing MPAs, with indirect effects that may be detrimental to some (mainly smaller prey) species.

Tags

Uncertainty Simulations Conservation Ecosystem Impacts Indicators Fisheries management Reserves Species interactions Size-spectra