In 2017 the Wisconsin DNR reported observation of a high incidence of fish with fin erosion in Newton Creek, which originates near the site of the Calumet (later Husky) oil refinery and flows approximately 2 miles through the city of Superior, WI, before discharging at the Hog Island Inlet of the Superior Bay. In fall 2017, the United States Environmental Protection Agency’s (US EPA) Office of Research and Development (ORD), Mid-Continent Ecology Division (now Great Lakes Toxicology and Ecology Division; GLTED) conducted several studies (two caged fish exposures and one resident fish collection) aimed at elucidating potential causes of the fin erosion phenotype reported. These studies were conducted in coordination and cooperation with both the Wisconsin DNR and Calumet/Husky refinery.

Results include: 1) Morphological data for fathead minnows caged in Newton Creek or Faxon Creek (reference) from September 27-October 11, 2017 (pilot study). 2) Morphological data for resident fish collected from Newton Creek and Faxon Creek on October 12, 2017 (resident fish collection) 3) Morphological data for fathead minnows caged in Newton Creek or Faxon Creek from October 16-30, 2017 (2nd study), along with analytical data on metals, PAHs, selected ions, suspended solids, nutrients, and in vitro bioactivity for composite water samples collected at the same locations and over the same time period.