The Mediterranean Sea – Primary Productivity

Primary production, the production of organic carbon molecules from carbon dioxide and water by converting sunlight energy to chemical energy through the process of photosynthesis, is the basis of our biosphere. The total Mediterranean Sea primary productivity is 1 % of the global primary productivity (Uitz et al. 2010 ). The entire Mediterranean Sea as a large marine ecosystem (LME) is characterized as a low-productivity ecosystem, <150 gC m �2 year �1 and, as such, is considered a Class III ecosystem (Aquarone et al. 2009 ). Based on Nixon’s ( 1995 ) defi nition, it is a mesotrophic sea, yet many parts of this LME are oligotrophic, and the Levantine Basin (eastern Mediterranean) is even ultraoligotrophic. Global and local abiotic fl uctuations cause variation in the primaryproducer communities and their ability to photosynthesize, thus leading to modifi cation of the food web.