The Chesapeake Bay received a C-plus for overall health in the 2026 Chesapeake Bay and Watershed Report Card, its highest score in four decades of tracking, the University of Maryland Center for Environmental Science announced Tuesday, Oct. 13. The grade reflects measures including oxygen levels, algae and total nitrogen. Researchers identified oxygen in the water as the strongest indicator of the Bay’s overall condition. They also said below-average rainfall last year reduced the pollution washed from land into waterways, a factor that may have contributed to the improved measurements. The report found improving health trends in tributaries including the Patapsco and Back rivers, waterways with direct importance to communities around Baltimore and central Maryland. Maryland Environmental Secretary Serena McIlwain said the results suggest the state’s restoration spending is directed toward effective work. She cited $1.7 billion spent in Maryland. Chesapeake Bay Foundation President and CEO Hilary Harp Falk urged officials to build on the gains through continued investment in agricultural conservation, stormwater management, wastewater upgrades, habitat and community resilience. Oyster restoration was another focus of the report. Since 2014, 2,400 acres of oyster reef habitat have been restored across 11 tributaries in Maryland and Virginia, and more than 7.5 billion oysters have been planted, according to the university center. Maryland Natural Resources Secretary Josh Kurtz said oyster abundance has tripled over the past five years, noting the species’ ecological and economic value. The Bay and its watershed connect millions of people across six states and the District of Columbia and support regional ecosystems and economies. University center President Fernando Miralles-Wilhelm described the new score as a milestone, not a reason to slow restoration efforts.