In a positive turn of events for the Chesapeake Bay, data collected by the Maryland Department of Natural Resources and Old Dominion University indicates that the dissolved oxygen conditions in the mainstem of Maryland and Virginia were significantly better than the historical average in June 2023. The findings, derived from samples obtained during routine monitoring cruises conducted by research vessels, offer a glimmer of hope for the health of the iconic bay ecosystem.
The measurements revealed that the hypoxic water volume, which denotes waters with less than 2 mg/l of oxygen, notably reduced during early and late June monitoring cruises. Specifically, the volume recorded was 0.22 and 0.33 cubic miles, respectively. These figures represent a substantial improvement compared to the average hypoxic water volume for early and late June since 1985, which stood at 0.87 and 1.30 cubic miles. Notably, this year’s early June data ranks as the second smallest hypoxic water volume on record, while late June marked the smallest volume for their respective periods. The absence of anoxia, characterized by areas with less than 0.2 mg/l of oxygen, further emphasizes the overall condition improvement, as no such areas were observed during either June monitoring cruise. Hypoxia in May was nearly non-existent, registering only 0.007 cubic miles.
The combined results from Maryland and Virginia closely align with the yearly seasonal forecast of prominent institutions such as the U.S. Environmental Protection Agency’s Chesapeake Bay Program, the U.S. Geological Survey, the University of Maryland Center for Environmental Science, and the University of Michigan. This forecast had predicted a 33% reduction in Chesapeake Bay mainstem hypoxic volume compared to the 38-year average for late June. The favorable outcome is attributed to reduced river flows from January through May 2023 and nutrient management efforts, leading to decreased nitrogen inflow to the Bay.
Oxygen availability is crucial for the survival of the myriad of marine life in the Chesapeake Bay, including crabs, fish, oysters, and other creatures. To gauge the potential impacts on bay life, scientists and natural resource managers closely monitor the volume and duration of Bay hypoxia.
Ongoing efforts to combat nitrogen and phosphorus pollution stemming from various sources such as industrial facilities, agricultural land, cities, and towns are key to achieving and maintaining these improved conditions. These pollutants contribute to algal blooms in the water, and when these blooms decay, they deplete the water of oxygen.
The Department of Natural Resources is responsible for computing hypoxia volumes annually from May through October, utilizing water quality data collected by department staff and the Virginia Department of Environmental Quality. The funding for data collection is supported by both states and the Chesapeake Bay Program, illustrating the collaborative effort to preserve the health of the Bay. As summer progresses, the monitoring and reporting of bay hypoxia will continue, enabling timely responses to any changes in conditions.
Detailed resources can be accessed on the Eyes on the Bay website for further Maryland water quality data and information, including the Department of Natural Resources hypoxic volume calculation methods.
Overall, the encouraging data from June 2023 provides an optimistic outlook for the Chesapeake Bay’s ecological recovery and underscores the importance of ongoing conservation efforts in preserving this invaluable natural treasure for future generations. With continued dedication to reducing pollution and promoting sustainable practices, the Chesapeake Bay may continue to thrive and support the diverse array of life that calls it home.