| 英文摘要: | The underlying causes of biodiversity loss can be numerous and difficult to identify. Now evidence suggests that disease outbreaks triggered by warming oceans are a primary cause of the disappearance of Caribbean coral reefs. Is a warmer world a sicker world? Disease is widely recognized as a primary cause of biodiversity loss and ecosystem degradation in aquatic and terrestrial ecosystems. Rapid, regional population declines in trees, amphibians, mammals and even sea-stars have all been linked to disease outbreaks. One explanation is global warming1. Higher than normal temperatures are thought to increase the occurrence and severity of disease outbreaks through several mechanisms, including increased pathogen virulence and weakened host immune systems owing to physiological stresses. Writing in Nature Climate Change, Randall and van Woesik2 report that seemingly subtle increases in ocean temperature have completely altered the seascape of Caribbean reefs by triggering disease outbreaks in crucial, habitat-forming coral species. Caribbean reefs are primarily built by two types of coral: massive, long-lived colonies of Orbicella species (formerly known as Montastraea) and fast-growing Acropora species, which form branching colonies (Fig. 1). Historically, these two taxa dominated Caribbean reefs, but populations of species from both genera have largely collapsed across the region. Their loss means flatter reefs that no longer provide hiding places for other organisms (including fishes that people eat), do not buffer coastal communities from storms, and cannot grow vertically in response to sea-level rise.
|
