of the projects would be managed by the participating agencies.
Research and development are needed in several areas of applied limnology, and these programs should take an experimental approach (one that emphasizes manipulation of whole-lake systems or large in-lake enclosures in controlled fashion).
Improved techniques for littoral zone and aquatic macrophyte management need to be developed. Research should go beyond the removal of nuisance macrophytes to address the restoration of native species that are essential for waterfowl and fish habitat. Basic research is necessary to improve understanding of fundamental limnological processes in littoral zones and the interactions between littoral and pelagic zones of lakes.
Biomanipulation (food web management) has great potential for low-cost and long-term management of lakes, and research in this emerging field must be stimulated.
Innovative and low-cost approaches to contaminant cleanup in lakes need to be developed, especially for such widespread problems as contamination by mercury and PCBs.
The relationships between loadings of stress-causing substances and responses of lakes need to be understood more precisely. This is true even for such well-studied phenomena as phosphorus and algal bloom problems. Research should be undertaken to improve predictions of trophic state from nutrient loading relationships. In particular, phosphorus loading should be evaluated in terms of both its biological availability, which can be estimated chemically, and its effects on plant communities in receiving waters.
Improved assessment programs are needed to determine the severity and extent of damage in lakes and their change in status over time. Innovative basic research is required to improve the science of assessment and monitoring. There is a great need for cost-effective, reliable indicators of ecosystem function, including those that will reflect long-term change and response to stress. Research on indicators should include traditional community and ecosystem measurements, paleoecological trend assessments, and remote sensing.
Procedures such as food web manipulation, introduction of phytophagous insects and fish, liming, and reintroduction of native species show promise for effective and long-lasting results when used alone or in combination with other restoration measures. Further research and development should be undertaken on these techniques.
Paleolimnological approaches should be used to infer the past trophic history of lakes and to decide whether lakes should