Lake Erie had to be temporarily closed due to toxic levels of mercury found in the water. This caused the fishing industry and all those related to lose substantial amounts of money. This, in turn, spurred a massive conservation effort aimed at cleaning up the Detroit River. For years before, conservation efforts were halted by the enormous multimillion-dollar cost of removing pollutants from the river. In addition to that, industries, which had significant political influence, detested the regulations necessary to lessen the amount of pollutants in the river. The Wyandotte National Wildlife Refuge was very small though and only occupied the area surrounding Grassy Island, and the refuge's existence could not prevent Grassy Island from becoming highly contaminated from toxic soil dredged from the nearby River Rouge. In 2001, the Wyandotte National Wildlife Refuge was absorbed into the much larger Detroit River International Wildlife Refuge, which was largely advocated by veteran Michigan representative John Dingell. The refuge was officially signed into law as the Detroit River International Wildlife Refuge Establishment Act (H.R. 1230) by President George W. Bush on December 21, 2001. The Congressional Budget Office originally estimated that the creation of the Detroit River International Wildlife Refuge would cost between $13–21 million over the first five years, in which the majority of the money spent would be through land acquisitions. Millions of dollars so far have been used for land acquisitions and to improve the environment around the river. The recent cleaning up and restoration of the Detroit River is remarkable, although other problems are still at hand. Today, many species of native animals—some endangered species—are returning to the area after being driven out by human development. The Detroit River is home to a growing number of bird species, such as eagles (including reintroduced bald eagles), ospreys, and peregrine falcons. Fish species in abundance in the area include lake whitefish, sturgeon, salmon, perch, and walleye. Numerous mammal species also occupy the coastline throughout the refuge. The area serves as a vital migratory route and resting place for countless species of birds. Over 30 species of waterfowl, 17 species of raptors, 31 species of shorebirds, 160 species of songbirds, and 117 species of fish live along or regularly migrate through the Detroit River. Current area At its inception, the Detroit River International Wildlife Refuge included only areas that were part of the former Wyandotte National Wildlife Refuge. This included only