Search results
Results from the WOW.Com Content Network
Rare species are generally considered threatened because a small population size is less likely to recover from ecological disasters. Rare plants can be classified based on the size and distribution of their populations. Some species may be rare because they consist of only a few individuals, are confined to a limited geographic area, or both ...
For a species to be assessed as vulnerable to extinction the best available evidence must meet quantitative criteria set by the IUCN designed to reflect "a high risk of extinction in the wild". Endangered and critically endangered species also meet the quantitative criteria of vulnerable species, and are listed separately.
The species of rare biosphere can offer the gene pool that can be activated under changing conditions, thus keeping the ecosystem functional. [4] Members of the rare biosphere have been recognised as important drivers of many key ecosystem functions, for example providing bioavailable nitrogen in marine and soil environment. [5] [6]
The IUCN Red List of Threatened Species by the International Union for Conservation of Nature is the best known worldwide conservation status listing and ranking system. . Species are classified by the IUCN Red List into nine groups set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmenta
For a species to be considered endangered by the IUCN it must meet certain quantitative criteria which are designed to classify taxa facing "a very high risk of extinction". An even higher risk is faced by critically endangered species, which meet the quantitative criteria for endangered species. Critically endangered fishes are listed ...
They provide habitats and food for a diversity of marine life comparable to coral reefs. This includes invertebrates like shrimp and crabs, cod and flatfish, marine mammals and birds. They provide refuges for endangered species such as seahorses, turtles, and dugongs. They function as nursery habitats for shrimps, scallops and many commercial ...
Fish species diversity is roughly divided equally between marine (oceanic) and freshwater ecosystems. Coral reefs in the Indo-Pacific constitute the centre of diversity for marine fishes, whereas continental freshwater fishes are most diverse in large river basins of tropical rainforests, especially the Amazon, Congo, and Mekong basins.
General characteristics of a large marine ecosystem (Gulf of Alaska) Killer whales (orcas) are highly visible marine apex predators that hunt many large species. But most biological activity in the ocean takes place with microscopic marine organisms that cannot be seen individually with the naked eye, such as marine bacteria and phytoplankton.