Observations made from a submarine showed that the bed-rock surfaces at water depths of about 5 to 14 m on Stannard Rock and Superior Shoal in Lake Superior were covered with a dense, fleece-like blanket of periphyton. Examination of the periphyton revealed that it consisted primarily of structurally complex, diverse, diatom communities, but occasional small thalli of the green algae Cladophora and Stigeoclonium were also noted. Extensive windrows of detritus-like material, apparently from the local periphyton community, were seen on soft bottoms at depths of about 20 to 60 m near the reefs. Our observations suggested that these periphyton communities may be locally important to the food web at these remote and oligotrophic sites, which are 22 to 77 km from the nearest mainland shore and are surrounded by water at least 140 m deep.
Additional publication details
Periphyton accumulation at remote reefs and shoals in Lake Superior