Schindler David W, Smol John P
University of Alberta, Department of Biological Sciences, Edmonton, Alberta, Canada.
Ambio. 2006 Jun;35(4):160-8. doi: 10.1579/0044-7447(2006)35[160:ceocwa]2.0.co;2.
Despite their generally isolated geographic locations, the freshwaters of the north are subjected to a wide spectrum of environmental stressors. High-latitude regions are especially sensitive to the effects of recent climatic warming, which have already resulted in marked regime shifts in the biological communities of many Arctic lakes and ponds. Important drivers of these limnological changes have included changes in the amount and duration of snow and ice cover, and, for rivers and lakes in their deltas, the frequency and extent of spring floods. Other important climate-related shifts include alterations in evaporation and precipitation ratios, marked changes in the quality and quantity of lake and river water inflows due to accelerated glacier and permafrost melting, and declining percentages of precipitation that falls as snow. The depletion of stratospheric ozone over the north, together with the clarity of many Arctic lakes, renders them especially susceptible to damage from ultraviolet radiation. In addition, the long-range atmospheric transport of pollutants, coupled with the focusing effects of contaminant transport from biological vectors to some local ecosystems (e.g., salmon nursery lakes, ponds draining seabird colonies) and biomagnification in long food chains, have led to elevated concentrations of many persistent organic pollutants (e.g., insecticides, which have never been used in Arctic regions) and other pollutants (e.g., mercury). Rapid development of gas and oil pipelines, mining for diamonds and metals, increases in human populations, and the development of all-season roads, seaports, and hydroelectric dams will stress northern aquatic ecosystems. The cumulative effects of these stresses will be far more serious than those caused by changing climate alone.
尽管北方的淡水区域地理位置通常较为孤立，但仍受到各种各样的环境压力因素影响。高纬度地区对近期气候变暖的影响尤为敏感，这已经导致许多北极湖泊和池塘的生物群落发生显著的状态转变。这些湖泊学变化的重要驱动因素包括冰雪覆盖量和持续时间的变化，以及对于三角洲地区的河流和湖泊而言，春季洪水的频率和范围。其他与气候相关的重要变化包括蒸发和降水比率的改变、由于冰川加速融化和永久冻土融化导致的湖泊和河流入水水质和水量的显著变化，以及降雪形式的降水百分比下降。北方平流层臭氧的消耗，加上许多北极湖泊的清澈度，使它们特别容易受到紫外线辐射的损害。此外，污染物的远距离大气传输，再加上从生物载体到一些当地生态系统（如鲑鱼育苗湖、排泄海鸟聚居地的池塘）的污染物传输的聚焦效应以及长食物链中的生物放大作用，导致许多持久性有机污染物（如从未在北极地区使用过的杀虫剂）和其他污染物（如汞）的浓度升高。天然气和石油管道的快速发展、钻石和金属开采、人口增长以及全年道路、海港和水电大坝的建设将给北方水生生态系统带来压力。这些压力的累积影响将比仅由气候变化造成的影响严重得多。
