The effects of marine protected areas over time and species' dispersal
potential: a quantitative conservation conflict attempt

Aristides Moustakas

doi:10.5194/we-16-113-2016

Abstract

Abstract. Protected areas are an important conservation measure. However, there are controversial findings regarding whether closed areas are beneficial for species and habitat conservation as well as for harvesting. Species dispersal is acknowledged as a key factor for the design and impacts of protected areas. A series of agent-based models using random diffusion to model fish dispersal were run before and after habitat protection. All results were normalized without the protected habitat in each scenario to detect the relative difference after protecting an area, all else being equal. Model outputs were compared with published data regarding the impacts over time of MPAs on fish biomass. In addition, data on species' dispersal potential in terms of kilometres per year are compared with model outputs. Results show that fish landings of species with short dispersal rates will take longer to reach the levels from before the Marine Protected Areas (MPAs) were established than landings of species with long dispersal rates. Further, the establishment of an MPA generates a higher relative population source within the MPA for species with low dispersal abilities than for species with high dispersal abilities. Results derived here show that there exists a feasible win-win scenario that maximizes both fish biomass and fish catches.

Highlights

Habitat protection is a complex issue which has only recently achieved high public visibility (UN, 2010)
While there are cases where closed areas are beneficial for species and habitat conservation (Jones et al, 2011; Seytre and Francour, 2014), there are studies that question the benefits of closures from an economic perspective regarding fish landings (Gårdmark et al, 2006; Jones et al, 2011)
Model outputs showed that recovery of landings was faster for species with high dispersal rates than for those with low dispersal rates

Summary

Introduction

Habitat protection is a complex issue which has only recently achieved high public visibility (UN, 2010). While there are cases where closed areas are beneficial for species and habitat conservation (Jones et al, 2011; Seytre and Francour, 2014), there are studies that question the benefits of closures from an economic perspective regarding fish landings (Gårdmark et al, 2006; Jones et al, 2011). This in turn has implications for both food security (Pauly et al, 2005) and economic impacts on fisheries (Eide et al, 2003, 2011; Jentoft and Eide, 2011). A win-win scenario in terms of both increased fish biomass and increased fish landings after establishing an MPA is ideal (Rees et al, 2010a) but questionable

Methods

Results

Discussion

Conclusion