How Do Contaminants Move and Change
| In the early
1980s, waterfowl in marshy areas of California's San Joaquin Valley started
appearing with birth deformities. The birth rate among mallard ducks declined,
and a large portion of the black-crowned night heron population was wiped
out. Scientists traced the cause of this disaster to the element selenium
(chemical symbol Se).
How did the Se get there and what can we do to protect wildlife from contamination? Read on, starting with Clue #1, to find out how scientists studied this problem and what answers they found.