chapter  14
26 Pages

Heavy Metals, Trophic Levels, Food Chains, and Future Risks

In this book, we primarily examine levels of metals in eggs and feathers of colonial waterbirds. Although egg levels are thought to be the best predictor of mercury risk to avian reproduction (Wolfe et al. 1998), we suggest that eggs and feathers of prefledging young each provide different information. Eggs provide information on female exposure during egg formation (from circulating levels at the time of egg formation) and eggs represent exposure of the developing embryo. Feathers represent local exposure during the prefledging period because parents of our estuarine species bring back foods from the local area to feed chicks. Chapter 9 provides an overview of effects from metals. In the chapters for each species group (Chapters 10 through 13), we describe levels and discuss potential effects for each species.