By the mid-1980s, Lake Erie phosphorus the IJC a role in assessing progress, engaging the public loadings were reduced by more than half from 1970s and providing scientific advice to help the two coun- levels, and many of the problems associated with eu- tries restore and maintain the chemical, physical, and trophication were reduced or eliminated, confirming biological integrity of the waters of [...] This can occur during the summer months in deeper lake basins such as the central basin of Lake Data-driven models show the existence of “hot spots” Erie, where the water column stratifies in layers and – locations in sub-basins within the major watersheds the warmer oxygenated waters at the surface are – that contribute a disproportionate share of the total separated from the colder, denser botto [...] The Governments of Ontario, Ohio and disposal; Pennsylvania should prohibit the sale and use • how various factors, such as the interaction of of phosphorus fertilizers for lawn care, with lake water with land-based runoff and tributary the exception of the establishment of new discharges, can be used to predict. [...] The five Great Lakes, created 10,000 years and maintenance of the chemical, physical, and biologi- ago at the end of the last period of continental glaci- cal integrity of the waters of the Great Lakes. [...] Science investigations explored the issues of harmful algal blooms (HABs)6 in the lake’s western basin Lake Erie is the shallowest and the smallest of all the and oxygen depletion or hypoxia in the central basin.