2026/07/01 by Stephen J. Jacquemin, Stephen Jacquemin, Morgan C. Grunden +3
Environmental Science · Social Sciences · #Aquatic Invertebrate Ecology and Behavior #Flooding and Environmental Impact #Water Quality and Resources Studies
paper · pdf · doi:10.1016/j.jglr.2026.102883
openalex publication_date 2026/07/01 · openalex created_date 2026/07/10 · openalex updated_date 2026/07/11
Constructed watershed connections can alter natural flow regimes, contribute to nutrient loading, lead to loss of biodiversity, and serve as conduits for aquatic invasive species transfer. Herein, we create a hydrologic budget for the Grand Lake St. Marys Watershed (Ohio, USA), an understudied system whose manmade outflows join both the Great Lakes and Mississippi River drainages, carrying potential negative ecological implications as a consequence of flow changes, nutrient loading, and aquatic invasive species. Constructed in the 1830s as part of the canal system, Grand Lake St. Marys (GLSM) has two outflows: the Miami & Erie Canal which still drains to Lake Erie, as well as a spillway which drains to the Wabash River. A combination of precipitation monitoring, USGS tributary gaging station data, evapotranspiration estimates, and area-velocity sensors were used to estimate two water years of hydrology. GLSM average annual outflows to Beaver Creek (Wabash River) and the Miami & Erie Canal (St. Marys and Auglaize rivers) were 32.6 million and 15.5 million m 3 , respectively. GLSM outflows contributed an annual average of 6894 kg P to the Wabash River and 4132 kg P to Lake Erie. Average annual residence time of GLSM was calculated to be 292.7 days. While GLSM outflows represented relatively small portions of the watershed budgets for the Great Lakes and Mississippi River, this study is the first to document, describe, and quantify their direct connection, improving our understanding of hydrology, nutrient loading, and potential aquatic invasive species exchange points.