SFS Researchers Featured at Annual Meeting of MWAA, Jan. 28

The annual meeting of the Midwest Water Analysts Association (MWAA) on January 28 will feature three research presentations by SFS Scientists Russell Cuhel and Carmen Aguilar and graduate student Ryan Roekle, who will present on the field sampling and analytical work he conducted with Russell and Carmen during the COVID closures that took place in 2020 and 2021.

“Release of nitrogen and phosphorus nutrients from granular vs organic rich surface sediments during resuspension events.”
Increased dredging activity in the vicinity of drinking water intakes has brought up the question of collateral damage. Legacy sediments, particularly organic-rich sediments that have been anoxic for decades, harbor exceptionally high concentrations of “compost nutrients” such as ammonia, phosphate, and iron that are released into the water during dredging. This is especially pronounced when modern dredging operations dilute legacy sediments with oxygenated water to enable pipeline transport. This presentation focuses on nitrogen and phosphorus resuspension and leaching from contrasting sediment types, indicating substantial release of algal (including HAB) bloom-promoting materials.

“Biogeochemical studies of Lower Milwaukee River, Milwaukee Harbor, and Coastal Lake Michigan receiving waters before and during pristine COVID closure flows.”
Widespread closure of 2020 industrial and social activities during COVID-19 resulted in several favorable ecosystem effects for watershed, riverine, coastal, and SW Great Lake Michigan water. These included greatly reduced air and water contamination from human actions, while sewage sources remained the same or higher. Between March and July aquatic resources had extended relief from inhibitory inputs and would have flushed existing dissolved and suspended materials of human origin. It is likely that water quality improved greatly during the pandemic. This induced biological responses that may have led to very rare recruitment success for decimated Yellow Perch and Alewife fish populations.

“Use of Chloride as a conservative normalizing factor in assessment of dilution vs (bio)chemical consumption of nutrients in Milwaukee area coastal waters and tributaries.”
Human activities in urban centers can alter the chemical composition of local waters via processes such as wastewater discharge and rainwater runoff. Rarely is there an opportunity to study urban waterways in the absence of these influences. The 2020 COVID-19 shutdown in Milwaukee, Wisconsin—a temporary, near total cessation of commercial, social, and industrial activities in the city— provided one such opportunity. Researchers assessed changes in local water chemistry among samples collected during early-shutdown, mid-shutdown, and late-shutdown (partial recovery) from locations along the lower Milwaukee, Menomonee, and Kinnickinnic Rivers, in the outer Milwaukee harbor, and up to 25 km offshore into Lake Michigan. Comparison of water chemistry between the different stages of the shutdown and to samples predating the shutdown may elucidate the extent to which urban activities affect local water chemistry.

MWAA is a professional, non-profit, organization interested in all water resource–related issues.