The Global 200 : a representation Approach to Conserving the Earth’s Distinctive Ecoregions
Download 2.75 Mb.
|
- Navigate this page:
- North Temperate Indo-Pacific
- South Temperate Indo-Pacific
Temperate UpwellingTemperate Upwelling regions are continental margins characterized by the regular upwelling up of nutrient rich bottom waters to the surface. These regions are highly productive and are associated with large fisheries and correspondingly large populations of marine mammals and seabirds. Species diversity is variable and often includes species entrained from deep upwelled water. Upwelling is largely a result of the effect of prevailing and local winds on oceanic currents. Upwelling associated with eastern boundary currents, (e.g., the California Current in the North Pacific Ocean) is driven by the wind’s deflection of surface waters away from the continental margin, resulting in cooler bottom water rising to the surface. Cross circulation brings water rich in nutrients from lower in the water column to the subsurface layers, resulting in similarly high productivity. The reliance on currents and wind patterns for productivity causes these regions to be sensitive to the effects of large-scale climate oscillations associated with El Niño events. The breakdown of typical wind patterns results in an interruption of nutrient upwelling and consequent decline of fish and sea birds. North Temperate Indo-PacificC alifornian Current [208] – Canada, Mexico, United States Geographic Location: Northeastern temperate Pacific Ocean along the coast of temperate North America Biodiversity Features: The area off the coast of California and Oregon supports huge populations of marine mammals, seabirds, and fishes. The area is best known for its extensive kelp forests and associated sea otters (Enhydra lutris). There is some endemism in invertebrates and fishes within the region. Highly diverse and productive upwelling ecosystems of the northeastern Pacific Ocean Selected Species: Yellowfin tuna (Thunnus albacares), yellowfin sole (Limanda aspera), Pacific cod (Gadus macrocephalus), California skate (Raja inornata), shovelnose guitarfish (Rhinobatos productus), longfin gunnel (Pholis clemensi), and numerous species of anadromous salmon (Oncorhynchus spp.), as well as great white sharks (Carcharodon spp.) are found here. Giant kelp (Macrocystis pyrifera) provides important habitat for numerous other species. The burrowing starlet sea anemone (Nematostella vectensis) is just one of many important invertebrates. Numerous marine mammals are found here, including the sea otter (Enhydra lutris), northern elephant seal (Mirounga angustirostris), California sea lion (Zalophus californianus), northern fur seal (Callorhinus ursinus), Guadalupe fur seal (Arctocephalus townsendii), Steller’s sea lion (Eumetopias jubatus), grey whale (Eschrichtius robustus), and harbor seal (Phoca vitulina). Cetaceans include pilot whale (Globicephala maerorynchus), and killer whale (Orcinus orca), northern right whale (Eubalaena glacialis). Other species include Pacific green turtle (Chelonia agassizii), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta), leatherback turtle (Dermochelys coriacea), Townsend’s shearwater (Puffinus auricularis), ashy storm-petrel (Oceanodroma homochroa), Heerman’s gull (Larus heermanni), Xantu’s murrelet (Synthliboramphus hypoleucus),and brown pelican (Pelecanus occidentalis). General Threats: Regional coastal waters have become polluted, especially near major cities, leading to problems of contaminated seafood. A major threat to the region comes from oil shipping accidents . Overfishing poses a serious threat to the region. South Temperate Atlantic B enguela Current [209] – Namibia, South Africa Geographic Location: Southeastern Atlantic Ocean near the southwestern coast of Africa Biodiversity Features: The Benguela Current flows north along the west coast of South Africa and Namibia, where it is the site of productive cold upwellings. In the south it meets the warmer Aghulhas Current flowing east from the Indian Ocean and in the north it interacts with the warmer Angolan current flowing south. Abundant populations of fish, seabirds and marine mammals occur, as well as important migratory bird populations in coastal lagoons and bays. the most productive upwelling zone in the south EAST atlantic with abundant fish, seabird and marine mammal populations Selected Species: Species include Jackass penguin (Spheniscus demersus), disk lamp shell (Discinisca tenuis), rock lobster (Jasus lalandii), pilchard (Sardinops ocellatus), Cape horse mackerel (Trachurus capensis), hake (Merluccius capensis), Cape fur seal (Artocephalus pusillus), southern right whale (Eubalaena australis), and the rare Heaviside’s dolphin (Cephalorhynchus heavisidei). General Threats: Persistent overharvesting of many commercially valuable species and products (e.g., pilchard, anchovy, rock lobster, and seabird guano), as well as industrial harbor development, especially in Walvis Bay. South Temperate Indo-PacificH umboldt Current [210] – Chile, Ecuador, Peru Geographic Location: Eastern Pacific Ocean along the coast of South America Biodiversity Features: Winds that blow across the mountains of Ecuador, Peru, and Chile move surface water offshore and cause upwelling of deeper, nutrient rich waters. This is one of the world's most productive marine ecosystems. This marine ecoregion sustains extraordinary numbers of marine birds, mammals, and fish. One of the world’s most productive upwelling areas, the largest in the southeastern Pacific OCEAN Selected Species: Three species of fish occur in extreme abundance and are the basis for much of the food chain: anchoveta (Engraulis ringens), sardine (Sardinops sagax), and jurel (Trachurus symmetricus). Other species include Chilean dolphin (Cephalorynchus eutropia), Burmeister’s porpoise (Phocoena spinipinnis), marine otter (Lutra felina), southern sea lion (Otaria flavescens), and South American fur seal (Arctocephalus australis). Birds include Elliot’s storm-petrel (Oceanites gracilis), Humboldt penguin (Sphniscus humboldti), Guanay cormorant (Phalacrocorax bouganvilli), Peruvian tern (Sterna lorata), and Inca tern (Larosterna inca). General Threats: Periodic variation in productivity due to shifting wind patterns related to the El Niño phenomenon cause populations to collapse, making this ecosystem very vulnerable to conventional intensive fishery practices. Upland activities such as mining, urbanization, and the release of untreated wastes have impacted these marine waters. A gulhas Current [211] – Mozambique, South Africa Geographic Location: Southwestern Indian Ocean near the southeastern coast of Africa Biodiversity Features: The warm waters of the Aghulhas Current flow southward along the Indian Ocean on the southeast coast of Africa, allowing for a high species diversity, including both endemic and Indo-Pacific species. The coasts harbor a mix of mangroves, vast offshore coral reefs, and sea grass beds that provide food resources and habitat for seabird colonies, nesting sea turtles, and numerous fishes. The Bazaruto National Park, an archipelago off Vilanculos, is home to over 100 individual dugongs (Dugong dugon), and five species of nesting sea turtles. South Africa’s De Hoop Nature Reserve includes a marine reserve with several species of dolphins (Family, Delphinidae) and the southern right whale (Eubalaena australis). DIVERSE ASSEMBLAGE OF SPECIES, INCLUDING SOME ENDEMISM Selected Species: Fish include the shallow-water Cape hake (Merluccius capensis), blackhand sole (Solea bleekeri), yellowfin tuna (Thunnus albacares), and albacore (T. alalunga). Dugong (Dugong dugon), inhabits this region, as do several species of dolphins (Family, Delphinidae), porpoises (Family, Phocoenidae), and breeding southern right whale (Eubalaena australis). Five species of sea turtles, including leatherback (Dermochelys coriacea), loggerhead (Caretta caretta), and green (Chelonia mydas) breed in this region; the hawksbill (Eretmochelys imbricata) and olive ridley (Lepidochelys olivacea) also exist here. General Threats: Loss of mangrove forests, siltation of coral reefs, destructive fishing practices (e.g., use of fine mesh nets and dynamite), and overfishing pose threats to these habitats. Poor rural sewage treatment leads to contamination, while poor farming practices and deforestation contribute to sedimentation and degradation of seagrasses and coral reefs. High levels of sedimentation have significantly altered the ecology of Zambezi River delta—a major river that drains into these marine waters. High levels of traffic associated with crude oil transport from the Arabian Gulf have resulted in contamination from tankers spills and discharge of polluted ballast waters. Directory: downloads downloads -> Northern England’s set-jetting locations downloads -> Dynatest 3031 lwd light Weight Deflectometer downloads -> Forth coming competitive exams downloads -> Brush High School Morning Announcements Friday, September 05, 2014 all school downloads -> Year 9 The Arts — Music downloads -> Years 7 and 8 standard elaborations — Australian Curriculum: Music draft downloads -> Chris Young sets 2016 “I’m Comin’ Over” Tour headlining dates downloads -> Slavery and Abolition: the Plymouth Connection Introduction downloads -> Summer Assignment Download 2.75 Mb. Share with your friends:
|