Carey C
Department of Environmental, Population, and Organismic Biology, University of Colorado, Boulder, Colorado 80309-0334, USA.
Environ Health Perspect. 2000 Mar;108 Suppl 1(Suppl 1):143-50. doi: 10.1289/ehp.00108s1143.
Many populations of amphibians are declining on all six continents on which they occur. Some causes of amphibian declines, such as habitat destruction, direct application of xenobiotics, and introduction of predators or competitors, are clearly attributable to human activities. Infectious disease appears to be the direct cause of mass amphibian die-offs in relatively undisturbed areas of the world where anthropomorphic environmental disruption is minimal. In these cases, it is not yet clear whether these epizootics result from the natural evolution of new pathogens or from environmental changes that promote the emergence of pathogenic forms and/or that weaken the immune defenses of amphibians. Because some aspects of pathogen-related amphibian mass mortalities are similar to outbreaks of new diseases in humans and coral reef organisms, amphibian declines may be part of a much larger pattern than previously appreciated.
两栖动物分布于六大洲，其许多种群数量都在下降。两栖动物数量下降的一些原因，如栖息地破坏、外源化合物的直接应用以及引入捕食者或竞争者，显然都可归因于人类活动。在世界上相对未受干扰、人为环境破坏最小的地区，传染病似乎是两栖动物大量死亡的直接原因。在这些情况下，目前尚不清楚这些动物流行病是由新病原体的自然进化引起的，还是由促进致病形式出现和/或削弱两栖动物免疫防御的环境变化引起的。由于与病原体相关的两栖动物大量死亡的某些方面与人类和珊瑚礁生物中新型疾病的爆发相似，两栖动物数量下降可能是一个比以前认识到的更大模式的一部分。
