Lead, aquatic plant contamination

Rooted aquatic plants, such as wild rice (Zizania aquatica), can accumulate up to 67 mg Pb/kg dry weight when cultured in tanks contaminated with high concentrations of powdered lead (equivalent to 7400 kg Pb/ha) however, this level is not considered hazardous to waterfowl feeding on wild rice (Behan et al. 1979). Lead content in plants collected from heavily hunted areas near refuges did not differ from those collected in the protected areas (Behan et al. 1979), which suggests that lead bioavailability to rooted aquatics is substantially lower from shot than from powdered lead. 

Very small fishing weights may no longer be made of lead because they can be ingested by waterfowl and contaminate soil where aquatic plants grow. Once entering the food chain, they further contaminate birds of prey and aquatic life feeding on these animals and plants. ... 

Lead may also interact detrimentally with aquatic life. Once lead deposits in soil, it sticks to soil particles and is only displaced by rain water, ending up in water sources where it affects the aquatic life. Some plants accumulate Pb from both contaminated soils and water sources or more specifically water in the rhizosphere. Besides, contaminated soils are liable to remain polluted with lead this will affect soil fertility.3,4 The fact that large changes in the lead content of soil are required to produce changes in the aerial parts of the plants as compared to changes in aerial lead concentration is closely reflected in the leaf lead concentration. Accumulation of Pb in grasses remains a potential hazard to livestock.3... 

---