Another externality from Dam control and diversions. Inter basin water transfers and foreign biota and invasive species. Excerpt from ‘Dire’ USGS REPORT:
“If Asian carp spread into the Great Lakes, knowing where to expect them to spawn is a critical step in controlling these invasive species,” said USGS scientist Elizabeth Murphy. “Our study combines the biology of Asian carp early life stages with the physics of rivers to identify potential spawning tributaries, thus giving managers an opportunity to develop targeted control strategies.”
The researchers studied four tributaries for their report: the Milwaukee and St. Joesph Rivers leading to Lake Michigan, and the Maumee and Sandusky Rivers that connect Lake Erie. Scientists have long believed that although adult carp prefer calm waters, carp eggs must be carried along fast currents or else they sink and die. However, it is now found that the river does not necessarily have to be lengthy for the eggs to survive. Given the right temperatures and water-quality characteristics, even short rivers will do. All four tributaries in the study proved sufficient for carp to spawn. This discovery, according to the report, “would expand the number of possible tributaries suitable for Asian carp spawning.”
Scientists also found that dams can be instrumental in creating “settling zones” where the Asian carp eggs collect and sink. Unfortunately, the settling zones caused by dams or natural features in the studied tributaries were not enough to stop the development of Asian carp young, which only required a relatively short distance before they hatched.
The Council of Great Lakes Governors met again for the first time since 2005 earlier this month to discuss the future of invasive species in the region, foremost being the siege laid against the lakes by Asian carp. According to Fox News, Illinois Governor Pat Quinn supported a national project to separate the Great Lakes and Mississippi river systems.
“Ultimately, I think we have to separate the basins,” Quinn said at the meeting. “I really feel that is the ultimate solution.”