The Mediterranean sea, a hotspot for marine biodiversity

The Mediterranean is a semi-enclosed sea whose waters bathe the coasts of 21 countries of a region that has for centuries been the cradle of great civilisations. Its geological and human history has given the Mediterranean region its richness in terms of biodiversity, but also in terms of social, cultural and political diversity.

Known as one of the planet’s key areas for marine biodiversity, the Mediterranean Sea hosts habitats, species and assemblages of particular ecological importance. Its richness and quality contribute to the populations’ well being and to the development of coastal areas.

Although there are still significant gaps in information and reliable data on the biodiversity of many Mediterranean zones, a recent scientific assessment coordinated by the SPA/RAC identified 10 unprotected pelagic areas that conform to the criteria1 set out under the CBD for Ecologically or Biologically Significant Areas (EBSAs).

Other regional initiatives have contributed to identifying some key areas to be protected: WWF identified 13 key areas to protect (2001), Greenpeace identified 33 marine reserves (2004), ACCOBAMS identified 15 areas to protect (2007). More recently, Oceana, in the MedNet report, proposed 100 sites for a network of MPA (2011, 2012), CIESM identified 8 zones for future transnational Marine Peace Parks (2011).

Pressures

Mediterranean marine ecosystems are under significant pressure. The risks are linked to the intrinsic value of ecosystems, but also to the loss of biodiversity and natural habitats which play a major role in human health, lifestyle, food production and availability of natural resources for the economic development and the well-being of coastal populations.

The Mediterranean Sea is subjected to anthropogenic disturbances especially along the coasts and new potential or actual pressures are emerging in the open sea. It is also faced by a transformation of its environmental characteristics due to global changes.

The impacts of coastal development (agricultural, industrial…) and urbanisation are among its main threats and these have intensified over the last few years. Four hundred fifty million people live in the Mediterranean basin, 40% of whom live on the coast. This significant coastal demographic growth contributes to degraded landscapes, soil erosion, increased waste discharges into the sea, loss and fragmentation of natural habitats as well as a deterioration of the state of vulnerable or endangered species. The development of activities in coastal areas (fishing industry, aquaculture, tourism, urbanisation …) has created economic opportunities, but has also affected the local people’s standard of living.

The Mediterranean region is one of the world’s most important tourism destinations, attracting about 30% of international tourism. While generating benefits to the countries’ economy, this popularity generates significant negative impacts on the marine environment through uncontrolled coastal zone development and its impact on the degradation of seagrass meadows, through the increased use of water resources and the production of solid wastes and sewage.

Maritime transport is another important economic activity for the region: it represents about 30% of the international shipping trade and 25% of maritime oil transport. The associated risks of accidental or deliberate pollution, transport of exotic species are still poorly controlled.

Fishing is also an important activity in the Mediterranean in terms of employment, income and food security. Recreational fishing is an important sector for certain territories. Its continual development is poorly controlled. The uncontrolled rise in fishing efforts registered over the last decades in a number of Mediterranean countries has led to the decline of many fish stocks. According to recent evaluations made within the framework of the General Fisheries Commission for the Mediterranean (GFCM), 90% of the assessed fish stocks were overexploited.

The Mediterranean Sea is also considered to be one of the seas where the consequences of climate change will be the most visible in the years to come. Many areas are already affected by these impacts, coastal erosion being one of the most obvious. Many scientists and sea users have observed the arrival and spatio-temporal evolution of new marine species, some of which being invasive.

Aquaculture puts a localised and relatively strong pressure depending on the site and its development, which is backed by many public policies, raises questions in terms of its impact especially on the environment, fisheries and the associated stocks of raw material required to feed the fish.

Ongoing changes in the availability of resources and the cost of energy has led to a growing variety of pressures and makes spatial planning more difficult for stakeholders interested in the area (desalination, wind/tidal turbines… ) or in the deep sea resources (aggregates, oil, gas, rare minerals, biotechnology). This reduces the surface area available for MPAs or traditional stakeholders (artisanal fishing) and affects the required connectivity or representativity of the network of MPAs.

It is essential to take into consideration the vulnerability of coastal and marine ecosystems and to balance the socio-economic and cultural aspects of traditional stakeholders in such a pressured context, to ensure the resilience of these ecosystems and to promote sustainable exploitation practices of renewable resources.