Structure and functioning of the Moroccan Mediterranean marine ecosystem: a trophic perspective

The Moroccan Mediterranean region has experienced significant development in various sectors, including tourism, fishing, industry, agriculture, and construction. However, the trophic functioning of its ecosystem and its vulnerability to these developments remain largely unexplored. To address this gap, an in-depth examination of the Moroccan Mediterranean Sea ecosystem was conducted using the Ecopath with Ecosim modelling approach from 2000 to 2003. This study aimed to describe the structure, functioning and state of the system. The model incorporated 40 functional groups, including 21 fish, 12 invertebrates, 2 primary producers, and 2 detritus groups, as well as individual groups for marine mammals, seabirds, and turtles. Analysis revealed that the functional groups were organized into five trophic levels, with swordfish and bluefin tuna occupying the highest level. Results also indicated that the ecosystem structure relies heavily on high flows into detritus and exports. Transfer efficiencies values are within the typical range for aquatic environments. The model’s pedigree scored of 0.49 indicates that it was built from data of generally acceptable quality- a notable achievement given the limited availability of data for the Mediterranean Sea in Morocco. Across the entire study area, the total biomass of the modeled ecosystem (excluding detritus) was estimated at 93 t · km− 2. Indicators of omnivory showed low values across most groups. Pelagic sharks, large pelagic fish, and hake were identified as ecologically important groups within the ecosystem.