The quality of mud at the bottom of Presque Isle Bay has taken a turn for the better. Experts from the Environmental Protection Agency reported they have lifted one of two water quality impairments. The sediment improvement survey conducted by the EPA found that contaminants in the sediment were no longer degrading the ecosystem. Presque Isle Bay was listed as an "area of concern" in the great lakes by the EPA because the bay sediment was found to be contaminated by human and industrial activity. In addition to problems with the bay sediment, deformities and tumors observed in brown bullhead catfish were also of concern.Now that the sediment has improved restrictions is now lifted on dredging in the bay.