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The biodiversity of the Mediterranean Sea: estimates, patterns, and threats.

Coll M, Piroddi C, Steenbeek J, Kaschner K, Ben Rais Lasram F, Aguzzi J, Ballesteros E, Bianchi CN, Corbera J, Dailianis T, Danovaro R, Estrada M, Froglia C, Galil BS, Gasol JM, Gertwagen R, Gil J, Guilhaumon F, Kesner-Reyes K, Kitsos MS, Koukouras A, Lampadariou N, Laxamana E, López-Fé de la Cuadra CM, Lotze HK, Martin D, Mouillot D, Oro D, Raicevich S, Rius-Barile J, Saiz-Salinas JI, San Vicente C, Somot S, Templado J, Turon X, Vafidis D, Villanueva R, Voultsiadou E - PLoS ONE (2010)

Bottom Line: Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea.Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth.This abstract has been translated to other languages (File S1).

View Article: PubMed Central - PubMed

Affiliation: Institut de Ciències del Mar, Scientific Spanish Council (ICM-CSIC), Barcelona, Spain. mcoll@icm.csic.es

ABSTRACT
The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet-undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well. This abstract has been translated to other languages (File S1).

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Distribution of monk seals and nesting sites of marine turtles in the Mediterranean.Present (red areas) and historical (yellow areas) distribution of the Mediterranean monk seal [22], [23], [101], [106], [117]–[119], and nesting sites for loggerhead turtle and green turtle [modified from 22]. Green and red triangles, respectively, are the former nesting sites for loggerhead turtle and green turtle; green and red dots are the present sites. Question marks represent sites where one or a few Mediterranean monk seals have been recently seen.
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pone-0011842-g009: Distribution of monk seals and nesting sites of marine turtles in the Mediterranean.Present (red areas) and historical (yellow areas) distribution of the Mediterranean monk seal [22], [23], [101], [106], [117]–[119], and nesting sites for loggerhead turtle and green turtle [modified from 22]. Green and red triangles, respectively, are the former nesting sites for loggerhead turtle and green turtle; green and red dots are the present sites. Question marks represent sites where one or a few Mediterranean monk seals have been recently seen.

Mentions: Population declines have also been noted among marine mammals throughout the Mediterranean. These species include sperm whales, which have been declining since the end of the 1980s [274]; short-beaked common dolphins, which began to decline around the 1970s [93], [275]; common bottlenose dolphins, which have decreased by at least 30% over the past 60 years [97], [276]; and striped dolphins, which have been in decline since the early 1990s [277]. The Mediterranean monk seal, in particular, was deliberately hunted during the Roman period [278], and it disappeared in the greatest part of the Mediterranean basin during the early 1900s [279], [280]. Currently, it mainly occurs in small, isolated areas of the Greek and Turkish coasts, and northwest African coastal waters (Figure 9), but the presence of Mediterranean monk seal in some of these areas is uncertain. There are fewer loggerhead and green turtles throughout the Mediterranean, although historical records were available to determine the severity of their population decline [22], [95]. Known nesting sites especially for the loggerhead turtle disappeared in several areas of the basin [22] (Figure 9).


The biodiversity of the Mediterranean Sea: estimates, patterns, and threats.

Coll M, Piroddi C, Steenbeek J, Kaschner K, Ben Rais Lasram F, Aguzzi J, Ballesteros E, Bianchi CN, Corbera J, Dailianis T, Danovaro R, Estrada M, Froglia C, Galil BS, Gasol JM, Gertwagen R, Gil J, Guilhaumon F, Kesner-Reyes K, Kitsos MS, Koukouras A, Lampadariou N, Laxamana E, López-Fé de la Cuadra CM, Lotze HK, Martin D, Mouillot D, Oro D, Raicevich S, Rius-Barile J, Saiz-Salinas JI, San Vicente C, Somot S, Templado J, Turon X, Vafidis D, Villanueva R, Voultsiadou E - PLoS ONE (2010)

Distribution of monk seals and nesting sites of marine turtles in the Mediterranean.Present (red areas) and historical (yellow areas) distribution of the Mediterranean monk seal [22], [23], [101], [106], [117]–[119], and nesting sites for loggerhead turtle and green turtle [modified from 22]. Green and red triangles, respectively, are the former nesting sites for loggerhead turtle and green turtle; green and red dots are the present sites. Question marks represent sites where one or a few Mediterranean monk seals have been recently seen.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2914016&req=5

pone-0011842-g009: Distribution of monk seals and nesting sites of marine turtles in the Mediterranean.Present (red areas) and historical (yellow areas) distribution of the Mediterranean monk seal [22], [23], [101], [106], [117]–[119], and nesting sites for loggerhead turtle and green turtle [modified from 22]. Green and red triangles, respectively, are the former nesting sites for loggerhead turtle and green turtle; green and red dots are the present sites. Question marks represent sites where one or a few Mediterranean monk seals have been recently seen.
Mentions: Population declines have also been noted among marine mammals throughout the Mediterranean. These species include sperm whales, which have been declining since the end of the 1980s [274]; short-beaked common dolphins, which began to decline around the 1970s [93], [275]; common bottlenose dolphins, which have decreased by at least 30% over the past 60 years [97], [276]; and striped dolphins, which have been in decline since the early 1990s [277]. The Mediterranean monk seal, in particular, was deliberately hunted during the Roman period [278], and it disappeared in the greatest part of the Mediterranean basin during the early 1900s [279], [280]. Currently, it mainly occurs in small, isolated areas of the Greek and Turkish coasts, and northwest African coastal waters (Figure 9), but the presence of Mediterranean monk seal in some of these areas is uncertain. There are fewer loggerhead and green turtles throughout the Mediterranean, although historical records were available to determine the severity of their population decline [22], [95]. Known nesting sites especially for the loggerhead turtle disappeared in several areas of the basin [22] (Figure 9).

Bottom Line: Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea.Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth.This abstract has been translated to other languages (File S1).

View Article: PubMed Central - PubMed

Affiliation: Institut de Ciències del Mar, Scientific Spanish Council (ICM-CSIC), Barcelona, Spain. mcoll@icm.csic.es

ABSTRACT
The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet-undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well. This abstract has been translated to other languages (File S1).

Show MeSH
Related in: MedlinePlus