The OEPA collected 85 sediment samples from harbor, bay, and estuary (the portion of a river where lake water overdeepens the river water) sites along the Lake Erie shore in Ohio in 2011 and 2012 .

Benthic and sedimented diatoms were sampled from natural substrates from 0.5 to 3 m depth. Surface sediments were sampled using a 6.5 cm diameter push corer and core tube. Sediments were extruded in the boat and the top one cm of sediment was carefully removed using a spoon and/or spatula. The top one cm is estimated to be one year’s sedimentation. In areas where using a push corer was not feasible approximately one cm of material was scrapped from the available solid substrate. Approximately 95% of the samples were cored. All samples were iced at 4°C until processing in the lab at 80°C for 24 hours. The processed sediment samples were delivered to John Carroll University for further processing and analysis.

The chemistry samples were analyzed at the Ohio Environmental Protection Agency lab. The suite of water chemistry parameters included: Aluminum, Ammonia, Arsenic, Barium, Cadmium, Calcium, Chlorophyll_a, Chromium, Conductivity, Copper, Hardness, Iron, Lead, Magnesium, Manganese, Nickel, Nitrate+nitrite, Nitrite, dissolved Orthophosphate, pH, Pheophytin_a, Potassium, Selenium, Sodium, Strontium, Sulfate, TKN, TOC, Total Dissolved Solids, Total Phosphorus, Total Solids, Total Suspended Solids, Total Volatile Solids, and Zinc.