Birds are an integral part of most freshwater ecosystems (lakes, rivers, wetlands) but their role in the trophic dynamics of these water bodies has often been overlooked. As a conspicuous part of the biota of water bodies, aquatic birds are indicators of their trophic state both in terms of species composition (quality) as well as occupancy and breeding (quantity). Birds may also influence the trophic state of a water body by importing nutrients (.e.g. resident or migrating birds feeding on adjacent watersheds or the sea). Because of anthropogenic activities, predation or their mobility, birds may not utilize otherwise suitable aquatic habitat. These factors complicate the relationship between aquatic bird production and the trophic status of habitats. As a consequence, the role of aquatic birds in freshwater ecosystems has usually been ignored.
This volume contains a wide range of papers selected from those presented at the symposium and reviewed.

Zusammenfassung
Proceedings of a symposium held in Sackville, New Brunswick, Canada in August 1991

Inhalt
Preface. I: Bird Populations in Lake Ecosystems. II: Nutrient Import and Export by Bird. III: Bird Response to Nutrient Levels and Acidification. IV: Food Choices and Habitat Selection. V: Bird Fish Interactions. VI: The Status of Loons. VII: Management of Aquatic Bird Populations.