tailieunhanh - Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen

Results from this laboratory can be used for a discussion of the biological consequences of pollution and will provide students with an appreciation for how dilution influences a chemical's biological effect. While endocrine disrupters are currently a 'hot topic,' other pollutants could also be tested. We tested some heavy metals (which are a perennial concern) and had some very interesting growth abnormalities show up. Chemical pollutants are not the only parameters that may influence sponge growth. The rate or success of gemmule could be tested as a function of temperature, light, food concentration, water. | About Issues in Ecology Issues in Ecology is designed to report in language understandable by non-scientists the consensus of a panel of scientific experts on issues relevant to the environment. Issues in Ecology is supported by the Pew Scholars in Conservation Biology program and by the Ecological Society of America. It is published at irregular intervals as reports are completed. All reports undergo peer review and must be approved by the Editorial Board before publication. Issues in Ecology is an official publication of the Ecological Society of America the nation s leading professional society of ecologists. Founded in 1915 ESA seeks to promote the responsible application of ecological principles to the solution of environmental problems. For more information contact the Ecological Society of America 2010 Massachusetts Avenue NW Suite 400 Washington DC 20036. IsSn 1092-8987 Issues in Ecology Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen Photo by Brett Johnson Issues in Ecology Number 3 Summer 1998 Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen SUMMARY Runoff from our farms and cities is a major source of phosphorus P and nitrogen N entering rivers lakes and coastal waters. Acid rain and airborne pollutants generated by human activities also supply N to surface waters. These nutrient sources are called nonpoint because they involve widely dispersed activities. Nonpoint inputs are difficult to measure and regulate because of their dispersed origins and because they vary with the seasons and the weather. Yet nonpoint inputs are the major source of water pollution in the United States today and their impacts are profound. In aquatic ecosystems overenrichment with P and N causes a wide range of problems including toxic algal blooms loss of oxygen fish kills loss of seagrass beds and other aquatic vegetation degradation of coral reefs and loss of biodiversity including species important to commercial and sport fisheries and .