The signing of the original one-page Chesapeake Bay Agreement in 1983 was a historic moment that marked one common-sense idea: the Chesapeake Bay estuary is an interconnected watershed and working together to improve its health would benefit everyone that lives, works and recreates there. This cooperative approach helped end the oyster wars, brought about collaboration across the jurisdictions and led to advancements in science.
Reducing pollution was a hallmark of the first agreement, leading the Environmental Protect Agency (EPA) in 2010 to establish the Chesapeake Bay Total Maximum Daily Load, which sets limits on the amount of nitrogen, phosphorus and sediment pollution that can enter the Bay and its tidal rivers. Reductions in these three areas have led to many successes in improving water quality, but a wide range of other contaminants continue to degrade and pose threats to public and ecosystem health.
The Chesapeake Bay Program Science and Technical Advisory Committee (STAC) recently released a report covering what we currently know about contaminants harming the Bay, the challenges they pose, what opportunities exist to help with their reduction and emerging toxics that threaten watershed health.
What is a contaminant and how do they harm our waterways?
Substances that negatively affect the health of humans and the environment are collectively referred to as contaminants. Even substances that are initially positive and intentional—like medications—can become toxic and harmful in the wrong locations and quantities.
Known contaminants include pesticides, pharmaceuticals, flame retardants, salt from deicers and chemicals from industrial uses, such as polychlorinated biphenyls (PCBs)., As researchers reviewed information on these contaminants, they uncovered that microplastics, hormones and personal care products are adding to the complex mix of pollution harming our ecosystem. Each contaminant can cause problems on its own, but also have unexpected impacts when mixing with others. While there is limited research on these interactions, existing evidence suggests high levels of contaminants in air, water and soil strongly impact our fisheries, waters and lands.