The effects of jellyfish on the social-ecological coastal systems in Catalonia, Spain

2nd International Ocean Research Conference, One planet one ocean, 17-21 November 2014, Barcelona, SpainAlthough there is uncertainty whether the increase is real or just a natural long term fluctuation, there is concern regarding the possible effects of increasing numbers of Jellyfish in the coastal waters and strandings on the beachs of Catalonia, Spain. Beach managers are concerned with the effects of strandings on the recreational appeal of beaches and the large tourist industry which relies on these ecosystem services. There is also evidence of jellyfish feeding on fish larvae which could impact on fish populations and the fisheries which rely on them. This study attempts to quantify the possible impacts of future increases in jellyfish (Pelagia noctiluca) regarding the effects on regional small pelagic fisheries (Engraulis encrasicolus & Sardina pilchardus) and the tourist industry using an innovative holistic modelling approach. The Systems Approach Framework methodology was followed in order to construct a model encapsulating the relevant social, economic and ecological dynamics. A pre-existing age-class fisheries model (MEFISTO) was adapted together with a jellyfish population matrix model, a strandings model, an economic impact-output matrix and a recent study regarding the valuation of beach ecosystem services based on the user perception of jellyfish strandings. This study concludes that the possible overall impact on the regional economy is relatively low when analysing the effect of pelagia noctiluca on the small pelagic fisheries and beach-user tourist industryPeer Reviewe