Heavy Metals in Water, Soil and Aquatic Plants from a Rice-Crab Production Base of the Liao River Delta

In order to reveal the transformation of heavy metals in rice-crab ecosystems and to maintain the sustainable development of crab industry, it is important for evaluating the environmental quality of rice-crab production base of the Liao River Delta. Therefore, the contents of heavy metals in water, soil and aquatic plants of the rice-crab production base in the Liao River Delta were monitored from 2008 to 2010. The results showed that the contents of total Pb, Cd, Hg and As in the water and soil of the rice-crab production base were very low and qualified to the requirements for the green food crab. However, the contents of total Pb in some aquatic plants, such as Monochoria trifolia, Ceratophyllum demersum, Elodea Canadensis and Potamogeton distinct us, exceeded the limits of Pollution-free Food Standard for Freshwater Crab (NY 5072-2002). In conclusion, as the feed of crabs, these aquatic plants could affect the quality safety for raising rice-crab in the Liao River Delta, Northeast China.