Detroit River International Wildlife Refuge  The Detroit River International Wildlife Refuge is the only international wildlife refuge in North America. Established in 2001 and managed jointly by the United States Fish and Wildlife Service and the Canadian Wildlife Service, it is in the heart of a major metropolitan area. Detroit River International Wildlife Refuge is one of over 540 National Wildlife Refuges managed by the U.S. Fish and Wildlife Service within the Department of the Interior. It occupies 7.88 square miles (20.42 km2) of scattered property but has drawn boundaries for further expansion. The Detroit River International Wildlife Refuge consists primarily of coastal wetlands, several islands in the Detroit River, and waterfront parks. The Refuge includes islands, marshes, shoals, and waterfront lands along of the Detroit River and Western Lake Erie shoreline. It encompasses Humbug Marsh, a wetland in Gibraltar and Trenton in southeastern Wayne County, which is classified as a wetland of international importance. Much of the land surrounding the Detroit River is urbanized and, in some places, heavily industrialized. This has resulted in excessive water pollution from the unregulated dumping of chemicals and industrial waste for many decades. Much of the garbage and sewage from Detroit's rapid industrialization found its way into the river. Much of the Detroit River and its shoreline were heavily polluted and unsafe for recreational use. Large quantities of this pollution collected around the mouth of the Detroit River at Lake Erie. The pollutants were so high after the spring thaw that thousands of migrating birds were killed by oil slicks and contaminated water every year. Oxygen levels in the river were depleted to the point where fish were unable to inhabit its waters. Because much of this pollution drained into and affected Lake Erie, portions of the lake itself were considered "dead" and unable to support aquatic life. Swimming in the water or consuming any of its remaining fish were considered health risks. In 1961, the Wyandotte National Wildlife Refuge was founded by congressional order thanks in part to Michigan politician John Lesinski, Jr., who was Michigan's 16th congressional district representative from 1951–1965. The refuge paved the way for tighter restrictions on industries and allocated much needed government funding to clean up the river. However, there was little support from Detroit businesses toward cleaning up the river, because it would negatively affect Detroit's industrialism and economy. In 1970, the entire fishing industry in the St. Clair River, Lake St. Clair, the Detroit River, and Lake Erie had to be temporarily closed due to toxic levels of mercury found in the water.