RESUMO
Estuarine and coastal transformation is as old as civilization yet has dramatically accelerated over the past 150 to 300 years. Reconstructed time lines, causes, and consequences of change in 12 once diverse and productive estuaries and coastal seas worldwide show similar patterns: Human impacts have depleted >90% of formerly important species, destroyed >65% of seagrass and wetland habitat, degraded water quality, and accelerated species invasions. Twentieth-century conservation efforts achieved partial recovery of upper trophic levels but have so far failed to restore former ecosystem structure and function. Our results provide detailed historical baselines and quantitative targets for ecosystem-based management and marine conservation.
Assuntos
Biodiversidade , Conservação dos Recursos Naturais/história , Ecossistema , Invertebrados , Água do Mar , Vertebrados , Água , Animais , Meio Ambiente , Eutrofização , Geografia , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Atividades Humanas/história , Humanos , Plantas , Densidade Demográfica , Dinâmica Populacional , Poluição da ÁguaRESUMO
Degradation of coral reef ecosystems began centuries ago, but there is no global summary of the magnitude of change. We compiled records, extending back thousands of years, of the status and trends of seven major guilds of carnivores, herbivores, and architectural species from 14 regions. Large animals declined before small animals and architectural species, and Atlantic reefs declined before reefs in the Red Sea and Australia, but the trajectories of decline were markedly similar worldwide. All reefs were substantially degraded long before outbreaks of coral disease and bleaching. Regardless of these new threats, reefs will not survive without immediate protection from human exploitation over large spatial scales.
