Modelling the Mediterranean marine ecosystem as a whole: addressing the challenge of complexity

An ecosystem modelling approach was used to understand and assess the whole 16 Mediterranean marine ecosystem structure and functioning. In particular, two food web 17 models for the 1950s and 2000s periods were built to investigate: 1) the main structural and 18 functional characteristics of the Mediterranean food-web during these time periods; 2) the key 19 species/functional groups and interactions; 3) the role of fisheries and its impact; and 4) the 20 ecosystem properties of the Mediterranean Sea in comparison with other European Regional 21 Seas. Results show that among all functional groups the highest trophic levels were observed 22 for marine mammals and large predatory fish. The ecosystem flows were mainly dominated by 23 lower trophic level organisms, as benthic invertebrates, zooplankton and phytoplankton while 24 small pelagic fish, mainly European sardines and anchovies, prevailed in terms of biomasses and 25 catches. Large pelagic fish, sharks and medium pelagic fish seemed to play a key role in the past 26 ecosystem, replaced in more recent year by large pelagic fish, benthopelagic and benthic 27 cephalopods. Fisheries showed large impacts on most living groups of the ecosystem in both 28 time periods. Also, when comparing the Mediterranean to the other European Regional Seas, 29 the Mediterranean stood alone in relation to the type of flows driving the system and the 30 cycling indices, suggesting higher levels of community stress induced by intensive fishing 31 activities. In the near future, effort should be dedicated to implement spatial and temporal 32 dynamic simulations to evaluate the exploitation status of the Mediterranean Sea and explore 33 different management policies and future scenarios.

PIRODDI Chiara;  COLL Marta;  STEENBEEK Jeroen;  MACIAS MOY Diego;  CHRISTENSEN Villy; 

2015-08-12

INTER-RESEARCH

JRC90427

0171-8630,   

http://www.int-res.com/abstracts/meps/v533/p47-65/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC90427,   

10.3354/meps11387,