Coupled Dynamics of Wetlandscape Properties and Phytoplankton Bloom Magnitude and Extent in Lake Winnipeg

Abstract Wetlandscapes—networks of hydrologically connected wetlands—can influence the transport and transformation of nutrients across watersheds. As climate change and human activity reshape wetland extent and connectivity, these landscape‐scale processes are being altered in ways that may intensify eutrophication in downstream lakes. We used Landsat‐derived inundation data (1984–2020) to evaluate how long‐term changes in wetlandscape properties have affected nutrient loading and phytoplankton bloom dynamics in Lake Winnipeg, Canada. Over this period, wetlands generally increased in number and size and exhibited greater connectivity to rivers and the lake but with declines observed after ∼2015. These changes coincided with periods of substantial increases in the magnitude and spatial extents of phytoplankton blooms followed by declines in 2015 in the North Basin. Sub‐watersheds with shorter runoff travel distances to the lake showed stronger relationships between wetland connectivity and bloom metrics ( p ≤ 0.10), suggesting reduced opportunity for nutrient retention and transformation. Incorporating runoff travel distance into wetlandscape assessments improved correlations with nutrient inputs and bloom extent. Rising surface temperatures further contributed to bloom intensification. These findings highlight how climate‐driven changes in wetland connectivity influence lake nutrient dynamics and demonstrate the potential for globally available satellite data to support spatially targeted water quality management.