With its great biological and cultural wealth, the Mediterranean region faces the challenge of protecting its biodiversity from the threats of the modern world: high population growth, habitat loss and fragmentation, and overexploitation of natural resources. The efforts made to conserve Mediterranean biodiversity over the last 40 years are reflected in numerous conventions and agreements between Mediterranean countries to identify priority areas for biodiversity and implement measures to protect and manage them. The challenge in the coming years will be to ensure comparable implementation of these conventions in all the region’s countries.
The Value of Biodiversity
Biodiversity, understood as the variability of all life forms in a given region, is a valuable resource, as the genomes of each species, and even each population, hold the accumulated information of millions of years of evolutionary adaptations. The current benefits provided by all the different species are relatively unknown, as is the future potential of such a vast wellspring of information.
The Mediterranean Basin is considered to be one of the most biodiverse regions in the world. The physiographical complexity resulting from its specific climate conditions and geological history has given rise to a high diversity of plant life based on an intricate combination of factors such as climate, geomorphology, soil, hydrology and land use. This situation enables the existence of one of the largest concentrations of endemic plants in the world. The region is home to an estimated 22,500 plant species, including some 11,500 found nowhere else. By way of comparison, non-Mediterranean Europe is home to about 6,000 species. Thus, symbolic and high-value tree species, such as the Lebanon cedar, the argan in southweastern Morocco, or the oriental sweet gum and Cretan date palm tree in Greece and Turkey, are found exclusively in the Mediterranean region.
However, plants are not the only highly diverse group in the region. Some 319 mammal species (89 of which are endemic); 489 bird species (25 endemic); 230 reptile species (77 endemic); 79 amphibian species (27 endemic); and 253 endemic species of freshwater fish have been recorded in the region to date. The situation is similar with regard to the region’s marine life. Although the Mediterranean Sea accounts for less than 1% of the global water surface, it is home to 7% of the world’s macroscopic marine species, of which between 25% and 30% are endemic (Table 1). Furthermore, most of the biodiversity figures mentioned so far include only the most well-known and studied groups of organisms; however, these account for only a fraction of the total number of species found in the Mediterranean. Indeed, the marine environment alone is home to an estimated 17,000 species (Coll et al., 2011).
TABLE 1 Biodiversity in the Mediterranean Region*
Estimated Total Species | Endemic Species | Endangered Species | Data-deficient Species | |
Plants | 25,000 | 11,700 | 1191 | 1 |
Aquatic Plants | 4732 | 150 | 73 | 12 |
Birds | 601 | 16 | 22 | 0 |
Mammals | 334 | 89 | 54 | 30 |
Whales & Dolphins | 8 | 0 | 5 | 3 |
Amphibians | 106 | 68 | 27 | 0 |
Reptiles | 355 | 170 | 46 | 19 |
Freshwater Fish | 2532 | 253 | 142 | 41 |
Saltwater Fish | 600 | 74 | 47 | 180 |
Freshwater Crabs | 12 | 5 | 1 | 0 |
Dragonflies & Damselflies | 165 | 23 | 31 | 6 |
Source: IUCN. *Estimated total number of species, endemic species and species included in any category (Critically Endangered, Endangered or Vulnerable) of the IUCN Red List of Threatened Species. The number of data-deficient species reflects the high degree to which certain groups in the region remain unknown. 1To date, 50 plant species have been assessed on 12 Mediterranean islands. 2The figure refers to the number of species assessed to date for the Mediterranean Red List.
TABLE 2 Key Figures for the Mediterranean Region
Area (km2) | 2,085,292 | |
Remaining vegetation (km2) | 98,009 | |
Species assessed at the regional level on the Red List | 2,948 | |
Endangered species | 368 | |
Extinct species† | 16 | |
Human population (inhabitants) | 452,000,000 | |
Protected areas (km2) in categories I-IV* | 316,739 |
Source: IUCN, IUCN and UNEP, Conservation International. †Extinctions registered since the year 1500. *IUCN categories I-IV correspond to the highest levels of protection.
A Biodiversity ‘Hotspot’
Changes in the landscape and land ecosystems have increased in recent decades, especially in the Mediterranean. The main pressures on these ecosystems and their biodiversity come from tourism, urban development in coastal areas, overfishing, intensive farming and irrigation, and the abandonment of traditional agricultural practices. Some of the effects of these activities, such as the changes in the vegetation cover, can be easily estimated. For example, only 5% of the region’s original vegetation is thought to remain relatively intact. However, the effects of the contamination generated by these activities on biodiversity and the way ecosystems function are harder to identify and quantify.
Because of the fast rate at which its ecosystems are being destroyed, the Mediterranean region, so rich in exclusive species, is considered a biodiversity hotspot. This term is used to designate regions with a high number of endemic species, that is, species unique to the region, and with a habitat that has been gradually degraded in recent years, making its conservation a priority in order to prevent irreparable harm to global biodiversity.
Given this rapid loss of biodiversity, measurement tools must be used to somehow assess the magnitude and evolution of the process. In order to measure the likelihood of species’ extinction, the International Union for Conservation of Nature (IUCN) has developed the “Red List Categories and Criteria,” designed to make it possible to measure the extent to which any living species is threatened using precise and quantifiable criteria. The results of the Red List for the Mediterranean confirm the environmental problems plaguing the region and the threats to its traditionally high biodiversity: 54 mammal species, some endemic, such as the Mediterranean monk seal, the Barbary macaque or the Iberian lynx, are critically endangered. Likewise, more than 142 endemic freshwater fish and, more broadly, a total of 442 animal and plant species have been classified as endangered. The real figure is no doubt higher, but to date only around 3,000 species from certain groups of organisms, mainly vertebrates and terrestrial species, have been assessed. There are very significant gaps in the knowledge of the region’s species, including with regard to well-studied groups, such as mammals.
Threat Factors
Much of the Mediterranean’s diversity is linked to human activity. There is probably no other region in the world where the development of ecosystems has been so closely associated with humans for so long. For, in addition to thousands of plant and animal species, the Mediterranean is inhabited by a broad diversity of cultures. Today, the region has an estimated population of about 452 million inhabitants, not counting the 170 million tourists who visit each year. This figure is expected to burgeon to 523 million by 2025. In the coastal zones, the population will jump from 143 million inhabitants in 2000 to 174 million in 2025 (UNEP/MAP-Plan Bleu, 2009). However, the impact of human activity has been different in the north and south of the region, due to differences in aridity, land use, socioeconomic conditions and, above all, demographic pressure. At present, the GDP of the countries of Mediterranean Europe is about five times higher than the GDP of Southern and Eastern Mediterranean countries (UNEP/MAP-Plan Bleu, 2009). The current model of economic development increases the pressure on the environment, whilst poverty increases dependence on natural resources. The resulting loss of biodiversity affects economic growth potential, reducing the welfare of the human populations (health, food, ecosystem services) and limiting their options. The challenges and possibilities for biodiversity conservation are therefore largely influenced by economic inequity.
The Answer: Set Common Goals
The need to minimise and reverse the loss of biodiversity calls for a collective response from international institutions, governments and the body public. To this end, governance, understood as management of social or environmental policy, makes it possible to tackle this situation by allowing social and institutional stakeholders to share their experience and knowledge and is the basis for meeting the challenges of biodiversity conservation. One sign of progress on this issue is the large number of multilateral agreements signed and ratified in the last 40 years to protect the region’s biodiversity (see Chart 1).
CHART 1 Number of Declarations of Protected Areas in Mediterranean Countries (IUCN Categories I-IV)*
The design and implementation of natural resource management policies requires the development and measurement of indicators of the status of biodiversity. For example, the assessment of the risk of extinction of species at the Mediterranean level is a relevant indicator for regional political initiatives such as the Barcelona Convention. To this end, the Red List gives an idea of the status of biodiversity and offers scientific data for the development of natural resource conservation and management policies. These data make it possible to determine whether or not a country has met its commitments and objectives under different international agreements, such as the objective of stopping the loss of biodiversity by 2020 agreed in the Convention on Biological Diversity (see Table 3).
Table 3 Relevant International Conventions for Biodiversity Conservation in Mediterranean Countries
MAP 1 Distribution of Protected Area in the Mediterranean*
Protected areas lie at the core of the efforts to protect the world’s endangered species, and their pivotal role not only as essential providers of ecosystem services and biological resources but also as key components in strategies to mitigate climate change is increasingly recognised. Moreover, at times they have proven to be crucial to protecting certain threatened human communities and places of great cultural and spiritual value. However, conservation activities have not been equally implemented in the countries of the Mediterranean Basin. Despite being home to a considerable diversity and wealth of species, some countries suffer from structural deficiencies and a lack of work methodologies that weaken their ability to protect sensitive or important areas for biodiversity. This notwithstanding, the number of protected areas in the Mediterranean has increased considerably in the last 20 years. More than 4,200 such areas, subject to varying degrees of protection, have been declared throughout the region. The brunt of these areas is found in Northern Mediterranean countries, which are home to 95% of the areas with the highest categories of protection (I-IV). Nevertheless, the number of areas under some form of regulated management has steadily increased in the Southern Mediterranean, too, and some 200 areas in the region have been accorded one of the highest levels of protection (categories I-IV) (see Map 1).
References
Coll M, Piroddi C, Steenbeek J, Kaschner K, Ben Rais Lasram F, et al. 2010. “The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats.” PLoS ONE 5(8): e11842. doi:10.1371/journal.pone.0011842
Conservation International. Biodiversity Hotspots. www.biodiversityhotspots.org/xp/hotspots/mediterranean/Pages/default.aspx.
Cuttelod, A., García, N., Abdul Malak, D., Temple, H. and Katariya, V. “The Mediterranean: a biodiversity hotspot under threat.” In: Vié, J.-C., Hilton-Taylor, C. and Stuart, S. N. (eds.). The 2008 Review of The IUCN Red List of Threatened Species. IUCN Gland, Switzerland, 2001.
Dudley, N. (ed.). Guidelines for Applying Protected Area Management Categories. Gland, Switzerland: IUCN, 2008.
International Union for the Conservation of Nature (IUCN). Lista Roja. www.iucn.org/es/sobre/union/secretaria/oficinas/sudamerica/sur_trabajo/sur_especies/sur_listaroja/
International Union for the Conservation of Nature (IUCN). Mediterranean Red List. www.iucnredlist.org/initiatives/mediterranean
International Union for the Conservation of Nature (IUCN) and United Nations Environmental Programme (UNEP). The World Database on Protected Areas (WDPA). UNEP-WCMC. Cambridge, UK, 2010. www.protectedplanet.net.
UNEP/MAP-Plan Bleu. 2009. State of the Environment and Development in the Mediterranean, UNEP/MAP-Plan Bleu, Athens, 2009.