As the information on morbidity and mortality was presented, Mr. Wallace encouraged the students to brainstorm how they would prevent or solve the problems these maladies posed the refuge. Lead poisoning 212 lead pellets are contained in every shotgun shell. These do not bio-degrade, but remain in the environment and have been accumulating in marshes since at least the 1930 s when many were forced to rely on hunting to provide for their families. Birds pick the pellets up as they do small stones, to grind food in the gizzard. The lead pellets are transformed into lead salts which go into the blood stream and poison the birds.
Affected birds lose muscle tone and die.
Wildlife managers have tried to minimize the effect of lead in the habitat by draining wetland areas and turning over the soil to cover the pellets, then re-flooding. Because the bugs eat the soil, the bacteria accumulates in their body in greater number than is generally distributed through the soil. Then, because there are many bugs at the water s edge, they are gobbled up by the ducks. When sufficient numbers of toxic-containing bugs are eaten, the bird dies. This is termed simple mortality.