Chesapeake Bay health score held steady in 2020

June 22, 2021

New health scores added for Chesapeake watershed include stewardship, protected lands, and heat vulnerability

ANNAPOLIS, MD (June 22, 2021) — The 2020 Chesapeake Bay Watershed Report Card issued today by the University of Maryland Center for Environmental Science (UMCES) gives the Chesapeake watershed a grade of B- for 2020. The Chesapeake Bay health score improved to a C in 2020. This year’s report card has new indicators of watershed health, including stewardship, protected lands, walkability, and heat vulnerability.

“UMCES scientists continue to lead the way on assessing not just the environment, but also the social and economic factors that influence ecosystem health. This year’s report card provides new insights in our journey of restoring the Chesapeake Bay,” said Dr. Peter Goodwin, President of the University of Maryland Center for Environmental Science. “Improvements in our environment go hand-in-hand with improvements in our communities particularly those that are traditionally disadvantaged.”

Individual indicators of Bay health had mixed results in 2020, but the overall Bay-wide trend continues to improve over time. In addition, 7 out of 15 regions showed significantly improving health trends.

Dissolved oxygen and total nitrogen scores improved, while chlorophyll a and total phosphorus scores declined. Water clarity, benthic community, and aquatic grass scores decreased slightly. Due to the pandemic, there was a monitoring gap from March to May. Impacts of the COVID-19 pandemic on the ecosystem health of Chesapeake Bay are not yet known, besides a reduction in atmospheric nitrogen, which has a declining trend, continued by reduced travel during 2020.

“Our close collaboration with partners at the federal, state, and local levels will continue to improve the long-term vitality of the Chesapeake Bay,” said Congressman John Sarbanes, Co-Chair of the Chesapeake Bay Watershed Task Force. “I applaud the University of Maryland Center for Environmental Science – and all of our advocates in Maryland and across the region – for their tireless efforts to monitor Bay health. Although we have lots of work ahead of us, I am confident that our shared commitments will help ensure that the Chesapeake Bay remains one of America’s great environmental treasures for generations to come.”

The analysis of Chesapeake Watershed health uses 23 reporting regions and incorporates both ecological and social indicators in its scores. Four new watershed health indicators were assessed this year: Stewardship Index, Protected Lands, Heat Vulnerability Index, and Walkability. The Stewardship Index looks at actions that residents are taking to support the Bay, volunteerism, and civic engagement. The Protected Lands indicator measures the valuable lands protected in the watershed that maintain water quality and habitat; sustain forests, farms, and communities; and support cultural, indigenous, and community values. The Heat Vulnerability Index focuses on climate safe neighborhoods throughout the watershed and includes data on tree canopy, impervious surface, temperature, and poverty. Walkability describes how many people can walk to a park in 10 minutes, which was particularly important in a pandemic year.

“This report card would not have been possible without courage and resilience of Chesapeake Bay scientists and resource managers who risked so much and worked so hard to maintain our ability to keep our fingers on the pulse of Chesapeake Bay during the pandemic,” said Dr. William Dennison, Vice President for Science Application, University of Maryland Center for Environmental Science. “The progress in developing meaningful social and environmental justice indicators was a major accomplishment.”

The Chesapeake Bay Report Card continues to embrace environmental justice with new indicators to support people of color and underrepresented communities. The new indicators for heat vulnerability and walkability, and the social index incorporated last year, provide insights into environmental justice. To further expand these indicators, graduate students within the University System of Maryland are developing an environmental justice index. Additional indicators will be added next year, especially those that address economic disparities.

“During the nation’s worst public health crisis in 100 years, people sought out and found comfort and joy in green spaces, like parks, beaches, historic landmarks, and local ball fields,” said Wendy O’Sullivan, Superintendent of the National Park Service’s Chesapeake Bay Office. “There is no doubt that our parks and recreational spaces are more important than ever. Conserving and protecting lands and ensuring equitable public access are key priorities for the overall health of the Chesapeake watershed and its communities.”

The University of Maryland Center for Environmental Science’s Integration and Application Network produces the annual report card, which is the most comprehensive assessment of the Chesapeake Bay and its watershed. Support from the National Fish and Wildlife Foundation allows for the expansion to include social and economic indicators across the entire watershed. For more information, visit

Quotes from partners in Chesapeake Bay and Watershed health


The University of Maryland Center for Environmental Science leads the way toward better management of Maryland’s natural resources and the protection and restoration of the Chesapeake Bay. From a network of laboratories located across the state, UMCES scientists provide sound evidence and advice to help state and national leaders manage the environment, and prepare future scientists to meet the global challenges of the 21st century.


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