Genetic description and remote sensing techniques as management tools for zostera noltii seagrass populations along the Atlantic Moroccan coast

Abstract

Genetic description and remote sensing techniques as management tools for Zostera noltii seagrass populations along the Atlantic Moroccan coast. Seagrass meadows provide an essential ecological service in coastal ecosystems worldwide, although they are sensitive to many human factors, as a serious global regression has been documented. During sampling along the Atlantic Moroccan coast, five coastal lagoons were found characterized by the presence of intertidal monospecific seagrass Zostera noltii meadows (from south to north, Nayla, Oualidia, Sidi Moussa, Moulay Bousselham, and Larache). Two descriptive methods used to characterize Z. noltii populations could be used as management tools for future monitoring implementations: (1) the estimation of surface area covered by Z. noltii meadows using remote sensing techniques and in situ field surveys, and (2) the genetic characterisation of Z. noltii populations using simple sequence repeats (microsatellites) as molecular markers. Results revealed that the Nayla lagoon showed the largest area covered by Z. noltii (269,868 m2) and the highest coverage rate (5.19%), while presenting the lowest genetic/genotypic diversity values (T = 36, Â = 3.58, G = 50; R = 0.544; He = 0.43). On the other hand, northern populations displayed lower rates of seagrass coverage (∼1%) and higher values of genetic/genotypic diversity. Further genetic characterization also revealed that Z. noltii populations seem to be highly isolated in three geographically independent regions: northern Morocco (R1, Larache and Moulay Bousselham), central Morocco (R2, Oualidia and Sidi Moussa), and southern Morocco (R3, Nayla), which should be considered independent management units. Both seagrass coverage rate and the genetic description of seagrass populations along the Atlantic Moroccan coast seem to be useful management tools that could be used to evaluate changes in seagrass meadows over time to further establish appropriate conservation strategies.