Marine ecoregion

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A marine ecoregion is an ecoregion, or ecological region, of the oceans and seas identified and defined based on biogeographic characteristics.

Contents

Introduction

A more complete definition describes them as “Areas of relatively homogeneous species composition, clearly distinct from adjacent systems” dominated by “a small number of ecosystems and/or a distinct suite of oceanographic or topographic features”. Ecologically they “are strongly cohesive units, sufficiently large to encompass ecological or life history processes for most sedentary species.” [1]

Marine Ecoregions of the World—MEOW

The global classification system Marine Ecoregions of the World—MEOW was devised by an international team, including major conservation organizations, academic institutions and intergovernmental organizations. [1] The system covers coastal and continental shelf waters of the world, and does not include deep ocean waters. The MEOW system integrated the biogeographic regionalization systems in use at national or continental scale, like Australia's Integrated Marine and Coastal Regionalisation of Australia and the Nature Conservancy’s system in the Americas, although it often uses different names for the subdivisions. [1]

This system has a strong biogeographic basis, but was designed to aid in conservation activities for marine ecosystems. Its subdivisions include both the seafloor (benthic) and shelf pelagic (neritic) biotas of each marine region. [1]

The digital ecoregions layer is available for download as an ArcGIS Shapefile. [2]

Subdivisions

Ecoregions

The Marine Ecoregions of the World classification defines 232 marine ecoregions (e.g. Adriatic Sea, Cortezian, Ningaloo, Ross Sea) for the coastal and shelf waters of the world.

Provinces

These marine ecoregions form part of a nested system and are grouped into 62 provinces (e.g. the South China Sea, Mediterranean Sea, Central Indian Ocean Islands).

Realms

The provinces in turn, are grouped into 12 major realms. The latter are considered analogous to the eight terrestrial ecozones, represent large regions of the ocean basins:

  1. Arctic
  2. Temperate Northern Atlantic
  3. Temperate Northern Pacific
  4. Tropical Atlantic
  5. Western Indo-Pacific
  6. Central Indo-Pacific
  7. Eastern Indo-Pacific
  8. Tropical Eastern Pacific
  9. Temperate South America
  10. Temperate Southern Africa
  11. Temperate Australasia
  12. Southern Ocean

Other marine ecoregion classifications

Other classifications of marine ecoregions or equivalent areas have been widely developed at national and regional levels, as well as a small number of global schemes.

Each of these systems, along with numerous regional biogeographic classifications, was used to inform the MEOW system. The WWF Global 200 work also identifies a number of major habitat types that correspond to the terrestrial biomes: polar, temperate shelves and seas, temperate upwelling, tropical upwelling, tropical coral, pelagic (trades and westerlies), abyssal, and hadal (ocean trench).

Briggs Coastal Provinces

One of the most comprehensive early classifications was the system of 53 coastal provinces developed by Briggs in 1974. [3] The near-global system of 64 large marine ecosystems has a partial biogeographic basis.

WWF Global 200

The World Wildlife Fund—WWF identified 43 priority marine ecoregions, as part of its Global 200 initiative. [4]

See also

Related Research Articles

Biome Community of organisms associated with an environment

A biome is a distinct biogeographical unit consisting of a biological community that has formed in response to a shared regional climate. Biomes may span more than one continent. Biome is a broader term than habitat and can comprise a variety of habitats.

Ecoregion Ecologically and geographically defined area that is smaller than a bioregion

An ecoregion or ecozone is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation.

Upwelling The replacement by deep water moving upwards of surface water driven offshore by wind

Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. Due to the biomass of phytoplankton and presence of cool water in these regions, upwelling zones can be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll-a.

Biogeographic realm Broadest biogeographic division of Earths land surface

A biogeographic realm or ecozone is the broadest biogeographic division of Earth's land surface, based on distributional patterns of terrestrial organisms. They are subdivided into ecoregions, which are classified based on their biomes or habitat types.

The Global 200 is the list of ecoregions identified by WWF, the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". So, for example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.

Tropical Atlantic Marine realm covering both sides of the Atlantic between the temperate realms

The Tropical Atlantic realm is one of twelve marine realms that cover the world's coastal seas and continental shelves.

Northwest Shelf Transition

The Northwest Shelf Transition, also known as Bonaparte Coast, is a biogeographic region of Australia's continental shelf. It adjoins the Kimberley region of Western Australia and the adjacent coast of the Northern Territory.

Western Indo-Pacific Biogeographic region of the Earths seas, comprising the tropical waters of the eastern and central Indian Ocean.

The Western Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the eastern and central Indian Ocean. It is part of the larger Indo-Pacific, which includes the tropical Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia. The Western Indo-Pacific may be classified as a marine realm, one of the great biogeographic divisions of the world's ocean basins, or as a subrealm of the Indo-Pacific.

Central Indo-Pacific A biogeographic region of Earths seas, comprising the tropical waters of the western Pacific Ocean, the eastern Indian Ocean, and the connecting seas.

The Central Indo-Pacific is a biogeographic region of Earth's seas, comprising the tropical waters of the western Pacific Ocean, the eastern Indian Ocean, and the connecting seas.

Temperate Northern Pacific Biogeographic region of the Earths seas, comprising the temperate waters of the northern Pacific Ocean

The Temperate Northern Pacific is a biogeographic region of the Earth's seas, comprising the temperate waters of the northern Pacific Ocean.

Marine habitats Habitat that supports marine life

Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea. A habitat is an ecological or environmental area inhabited by one or more living species. The marine environment supports many kinds of these habitats. Marine habitats can be divided into coastal and open ocean habitats. Coastal habitats are found in the area that extends from as far as the tide comes in on the shoreline out to the edge of the continental shelf. Most marine life is found in coastal habitats, even though the shelf area occupies only seven percent of the total ocean area. Open ocean habitats are found in the deep ocean beyond the edge of the continental shelf.

Temperate Southern Africa Biogeographic region of the Earths seas, comprising the temperate waters of southern Africa.

Temperate Southern Africa is a biogeographic region of the Earth's seas, comprising the temperate waters of southern Africa, where the Atlantic Ocean and Indian Ocean meet. It includes the coast of South Africa and Namibia, and reaches into southern Angola. It also includes the remote islands of Amsterdam and Saint-Paul, to the east in the southern Indian Ocean.

Temperate South America Biogeographic region of the Earths seas, comprising the temperate and subtropical ocean waters of South America

Temperate South America is a biogeographic region of the Earth's seas, comprising the temperate and subtropical waters of South America, including both the Pacific and Atlantic coasts of the continent and adjacent islands. It also includes the remote Gough Island and Tristan da Cunha in the South Atlantic Ocean.

Temperate Australasia Biogeographic region of the Earths seas, comprising the temperate and subtropical waters of Australia and New Zealand

Temperate Australasia is a biogeographic region of the Earth's seas, comprising the temperate and subtropical waters of Australia and New Zealand, including both the Indian Ocean and Pacific coasts of the continent and adjacent islands.

Eastern Indo-Pacific Biogeographic region of the Earths seas, comprising the ocean waters of tropical Polynesia

The Eastern Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters around island groups in the central Pacific Ocean. It includes most of Polynesia, except for New Zealand and the Kermadec Islands. It also includes the Marshall Islands and Kiribati from Micronesia. It adjoins the Central Indo-Pacific realm to the west, which encompasses Melanesia and the other island groups of Micronesia.

Temperate Northern Atlantic Biogeographic region of the Earths seas, comprising the temperate and subtropical waters of the North Atlantic Ocean and Mediterranean Sea

The Temperate Northern Atlantic is a biogeographic region of the Earth's seas, comprising the temperate and subtropical waters of the North Atlantic Ocean and connecting seas, including the Mediterranean Sea, Black Sea, and northern Gulf of Mexico.

The Magdalena Transition is a marine ecoregion in the eastern Pacific Ocean. It includes the coastal waters along the southwestern Baja California Peninsula, extending from Punta Abreojos in the north to Cabo San Lucas at the peninsula's southern tip.

References

  1. 1 2 3 4 Spalding, Mark D., Helen E. Fox, Gerald R. Allen, Nick Davidson et al. "Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas". Bioscience Vol. 57 No. 7, July/August 2007, pp. 573–583.
  2. ↑ "MEOW digital ecoregions layer: ArcGIS Shapefile download link". Archived from the original on 2012-07-19. Retrieved 2010-12-03.
  3. ↑ Briggs JC (1974) Marine Zoogeography. McGraw-Hill, New York, USA
  4. ↑ Olson DM, Dinerstein E. 2002; "The Global 200: priority ecoregions for conservation"; Annals of the Missouri Botanical Garden 89: 199-224
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