Zucchetta, M., Venier, C., Taji, M. A., Mangin, A., & Pastres, R. (2016). Modelling the spatial distribution of the seagrass Posidonia oceanica along the North African coast: Implications for the assessment of Good Environmental Status. [Article]. Ecological Indicators, 61, 1011-1023.
DOI:10.1016/j.ecolind.2015.10.059
Anthropogenic use of marine habitats has the potential to degrade these environments. Identifying regions that are either heavily degraded or relatively pristine is critical to establishing conservation priorities. Ecological indicators, including abiotic and biotic factors, offer methods for determining the health of the ecosystem. While measurements for abiotic factors may be readily available across a large region through remote sensing, biotic data can be scarce. This paper explores the use of a species distribution model for an indicator species as a method for identifying regions of relatively low impact along the North African coast. A bionomial generalized linear model was fit using presences/absence data for P. oceanica, a seagrass, and a collection of environmental variables. The models identified coastal regions as having high probability of suitable habitat, particularly along the Tunisian and Libyan coasts. In order to assess impact in an area the potential distribution indicator was developed. This indicator is the ratio of predicted distribution of the species to actual observations of the species in the area. Areas where the ratio of actual presence to predicted presence is close to one may be considered to have low impact, where areas with ratios much lower than one may be experiencing sever human impacts. This study demonstrates a method for the use of remote sensing data to assessing regions of low and high anthropogenic impact. These methods appear particularly applicable for those that wish to assess ecosystem health across a large extent, but due to assumptions made regarding the development of the indicator derived from the species distribution model, local ground truthing of environmental health may still be required at the local scale.