Mediterranean aquaculture in a changing climate

Abstract

The semi-enclosed Mediterranean Sea is the biggest marginal sea of the Earth, and it is at the centre of the life of several millions of people. Seafood is widely consumed in this region, with an average of 16.5 Kg/capita/year, and one fourth of the seafood supply comes from aquaculture activities. The Mediterranean aquaculture sector has expanded over the last decades. It increased 77 % over the last decade reaching circa 1.3 million tons in 2009. The value ranged around 3.700 millions US dollars, representing 3.4 % of the global aquaculture value. The growth of seafood demand in the Mediterranean is expected to increase in the future, especially in southern countries. Yet, during the 21st century, the Mediterranean basin is expected to observe: (i) an increase in air temperature between 2.2 °C to 5.1 °C, (ii) a significant decrease in rainfall (ranging between -4 and -27), (iii) an increase in drought periods related to high frequency of days during which the temperature would exceed 30 °C, (iv) an increase of the sea level (around 35 cm) and saline intrusion. Moreover, extreme events, such as heat waves, droughts or floods, are also likely to be more frequent and violent. Here, we review the present status of the Mediterranean aquaculture (e.g. production trends, main farmed species, production systems, major producing countries), the most relevant impacts of climate change to this sector (e.g. temperature, eutrophication, harmful algae blooms, water stress, sea level rise, acidification and diseases), and provide a wide range of adaptation and mitigation strategies that can be implemented to minimize such climatic effects.