Resurgence of the fisheries began after passage of clean water legislation like the Clean Water Act and the Great Lakes Clean Water Pact. The walleye fishery began a resurgence in the early 1980s when the Michigan Department of Natural Resources initiated a fingerling stocking program. The sport fishery soon remerged, but the commercial fishery for walleye which was formally closed in 1970, remained closed. The recreational fishery harvest averaged 80,000 walleyes annually from 1986 to 2002 but was hatchery dependent with as much as 80% of the harvest being hatchery fish. A profound food web shift in Lake Huron took place in 2003 with the near disappearance of the invasive alewife. Alewives used Saginaw Bay's near-shore waters as spawning and nursery grounds and were a formidable predator and competitor on newly hatched percid (walleye and yellow perch) fry. In the absence of alewives, walleye and yellow perch reproductive success greatly increased. The Michigan Department of Natural Resources discontinued stocking in 2006, and walleye recovery targets were formally met in 2009. Recreational harvest since then has ranged from about 150,000 per year to as much as 350,000 per year. The Michigan Department of Natural Resources liberalized walleye recreational harvest (higher daily possession limit and lower minimum length limit) in 2015. Although yellow perch also benefitted from the absence of alewives with greater reproductive success, the numbers of adults has declined and remained depressed. This is because of a high mortality rate in their first year of life, believed to be predation from walleye and other predators.