title: [Coral reefs in the face of ecological threats of XXI century].
abstract: To date, more than a quarter of tropical coral reefs of the World Ocean are believed to be totally de- stroyed. Given the present rates of reefs degradation, this value may be doubled in the nearest 30 years. For the essential part of coastal community, the destruction of coral ecosystems implies the loss of the major food sources, natural protection from storms, and significant (if not the only) revenue from exploi- tation of reefs especially in tourism industry. Finally, the disappearance of low-laying coral islands may threat the local communities by deprivation of living space. Global negative effects include temperature anomalies of sea surface waters and an increase of atmospheric CO2 concentration leading to ocean acidification. Local negative effects are related to in- crease of sedimentation and eutrophication, cyclone and storm passes, coral diseases, chemical pollution, mechanical destruction of corals by humans, anthropogenic depletion of functional groups of fish and invertebrates. An entire set of responses of coral ecosystems to stressful factors on the levels of both separate taxa and ecosystem is discussed. An analysis of published data suggests that with high probability the tropical coral communities will come to collapse stage by the middle of the current century at more than 50% of the area of their biogeographic range, especially in the regions of dense human population. At the most optimistic scenario, complex effect of reviewed negative factors will result in coral ecosystems main- taining in some areas. However, after global transformations, these ecosystems will be dominated by the most resistant taxa, mainly massive and encrusting forms of long-lived species with low growth rates and high competitive ability. Among such taxa, Poritidae demonstrates the highest adaptive capability. At the most pessimistic scenario, scleractinian communities will be replaced by alternative communities of macroalgae and non-calcareous anthozoans.
authors.forename: K S
authors.initials: KS
authors.lastname: Tkachenko
mesh_terms: D000818:Animals; D037421:Anthozoa; D057231:Climate Change; D057894:Coral Reefs; D006801:Humans