Benthic habitat β-diversity modeling and landscape metrics for the selection of priority conservation areas using a systematic approach: Magdalena Bay, Mexico, as a case study

Albeit the need and importance of protected areas worldwide, there is no best practice methodology for their placement and design as this depends on several factors such as resource availability, data disponibility, and technical capacity. In this study, we show a novel approach on the use of β-diversity modeling and landscape metrics for the selection of priority conservation areas to assist the management of Magdalena Bay, one of the most important bays of Mexico. Quantitative estimates on the percentage of cover of benthic substrates from 60 ground truthed sites were used to perform a cluster analysis using the Bray-Curtis similarity index. Seven habitats were recognized, with habitats characterized by an inter-mix of sand, seagrass, macroalgae and rock substrates. A thematic map of benthic habitats was produced utilizing a supervised classification with the maximum likelihood rule on a natural color mosaic of high resolution satellite scenes (overall accuracy 80%, Kappa=0.69). Matlab was used to calculate β-diversity values based on the nature and distribution of habitats. A weighted overlay analysis considering habitat type, patch area/perimeter² ratio and β-diversity was performed to prioritize areas for conservation. Three areas, which constitute ~20% of the shallow benthic landscape, are proposed to be considered within aMarine Protected Area scheme. By selecting sites with these landscape characteristics we developed a cost-effective systematic approach to protect the natural processes responsible for maintaining diversity and the livelihoods of the local communities.