Description of Work In separate studies, bighead carp and silver carp were raised in waters of varying hardness. Survival, correct development, and hatching success were monitored. Additionally, a search of the Asian literature (including Chinese-language literature) on water hardness in areas where Asian carp are native was performed. Relevance & Impact If soft water limits Asian carp hatching success, then this would mean that large areas of the Great Lakes and east and west coast drainages would not be at risk of Asian carp establishment. Key Findings Both bighead carp and silver carp developed normally and the eggs hatched normally in all water hardnesses tested, including very soft water. The Yangtze River, evolutionary cradle [...]