摘要
尽管受到保护,班夫国家公园的水生生态系统仍面临许多人类活动带来的压力。大部分是20世纪早期放养计划造成的恶果。现在在公园内有10种非本地品种的鱼,而有一种本地鱼的亚种已经绝迹,有两种鱼受到威胁。在温泉和洞穴内出现了许多稀有的无脊椎动物,包括一种濒危软体动物。许多原来无鱼的湖泊中主要的无脊椎动物在放养了鱼类后绝迹了,即使某些湖内放养的鱼没有存活,它们也没有重新出现。本文叙述了在两个高山小湖为恢复生态所作的努力。营养物质的输入和路上撒盐去冰改变了鲍河及其支流的化学特性,在某些地段覆盖了底栖藻类。围垦和改道使园区内鲍河水系面积的40%以上受到了影响。空气中的有机污染物集中在冰川和高海拔积雪场,它们足以威胁渔业,在某些情况下,污染物的量接近了为人类消费制定的标准限值。
Despite their protected status, aquatic ecosystems of Banff National Park have been subjected to a number of human stresses. Largely as the result of stocking programs earlier in the century, 10 species of nonnative fishes now occur in the Park, while one endemic subspecies of fish have been extirpated, and 2 other species are threatened. A number of rare invertebrates occur in hot springs and caves, including one mollusk that is endangered. Key invertebrates were extirpated from a number of fishless lakes by stocked fish, and in some cases have not returned, even though fishes did not survive. Restoration efforts in 2 small alpine lakes are described. Addition of nutrients and road salt have changed the chemical nature of the Bow River and its tributaries, and caused incidence of benthic algal mats to form in some sections. Impoundment and diversions affect over 40% of the Bow River catchment within the Park. Airborne organic contaminants concentrate in glaciers and high elevation snowpacks, yielding amounts high enough to contaminate fisheries to levels that in some cases approach guidelines for human consumption.
