A boat on a large body of water on a foggy day

A fishing boat on the open waters of the Chesapeake Bay

Welcome to Below the Surface of Monitoring, a four-part series in which we dive deep into the nuances of the Alliance’s Water Quality Monitor program. Follow along as we release fun trivia and information on our social media and blog as we take the numbers off of the data sheet and out into the world!

In Algonquin, the word “chesepiooc” is believed to translate to a shellfish bay, or a village at the mouth of a big river. If this word sounds somewhat familiar, that’s because it is: as the namesake of the Chesapeake Bay. This linguistic connection is indicative of the importance of shellfish and rivers to the region, where humanity’s dependency on these keystone critters dates back thousands of years. However, climate change and ocean acidification pose major threats to the survival of shellfish ecosystems, and those who rely on them.

The parameter of interest this month is pH, which is measured using a pH probe by our monitors. pH is a measure of how acidic or basic water is on a scale of 0 to 14, where 7 is neutral. Lower pH indicates higher acidity, caused by higher levels of dissolved hydrogen ions. Like water temperature and dissolved oxygen concentration, pH is an essential parameter in assessing habitat suitability for aquatic life. This is because pH determines the solubility and availability of nutrients and minerals for the survival of a species. For example, phosphorus and nitrogen, which are essential plant nutrients, can only be converted to usable forms at a low pH. Generally, pH is used as an indicator of water quality because it is associated with chemicals and dissolved ions in water.

Although not classified as an ocean, the Chesapeake Bay is not spared from the effects of ocean acidification, which notoriously threaten coral reefs worldwide. pH is the keystone to the acidification of global waters, which negatively affects the growth of shellfish. When pH is lower, excess hydrogen ions in the water bond to the calcium, leaving shellfish with no available calcium to form strong carbonate shells. The increased acidity of the water is caused by the burning of fossil fuels, because excess carbon dioxide in the water produces carbonic acid.

So how can humans mitigate the effect of ocean acidification in the Chesapeake Bay and around the world? Other than reducing carbon emissions, there is actually already a resident of the Bay that is already working tirelessly to help. Located in the Susquehanna Flats in the northern bay, this fearless conversation leader is a type of seagrass that produces a mineral that neutralizes acidity. As the grasses pull carbon from the water in order to grow, they sequester some of that carbon as calcium carbonate, which they fortify their leaves with in order to resist acidic poisoning. 60 miles down the Bay, these tangible crystals have been estimated to reduce acidity by as much as .6. Considering that pH is measured on a log scale, these grasses work to make the water six times less acidic than it would otherwise be. In addition, these grasses provide other ecosystem services like water purification, providing habitat for crabs and shellfish, and stabilizing muddy banks during storms. Unfortunately, these heroic grasses are threatened by anoxic conditions caused by algal blooms, making seagrass restoration even more essential to fighting acidification in the Bay.

An aerial view of a coastline next to a large body of water

The Susquehanna Flats in the upper Chesapeake Bay

Rising carbon emissions, ocean acidification, and species endangerment wasn’t always the norm in the Chesapeake. In fact, minority coastal communities once harvested oysters primarily for communal stability, fostering healthy reefs in tandem with a healthy economy. These conservation-focused practices have been threatened by the commodification of waterways via licensure and private land ownership, limiting access to the sacred oyster reefs. Global Environmental Justice expert J.T. Roane describes how these “extractive operations” effectively destroyed the regenerative capacity of the natural oyster populations. By codifying “fisheries” as a resource to be exploited, and therefore managed, states gain control over formerly Black or indigenously owned lands and assert riparian power over their livelihoods.

Vertical structures of oysters growing next to water

Oyster castles growing in Norfolk, Virginia

In a similar case in the Pacific Northwest, the Quinault Indian Nation centers their economy around the razor clam, used for subsistence, cultural practices, and trade. Today, their harvesting is now severely limited by treaty restrictions on land use and water access. Although the nation uses sustainable practices, worldwide carbon-emitting industrialization has driven the decline in razor clams, mainly due to ocean acidification and unsustainable harvesting.

But conservation of shellfish habitats and seagrass is not necessarily hopeless in the Bay. With the reintroduction of Traditional Ecological Knowledge of Indigenous Peoples and the return of waterway autonomy to community-managed harvesting businesses, it is possible to address social justice issues as well as environmental crises. North America’s largest estuary, the great shellfish bay, can only be saved with the care and consideration akin to those who provided its namesake.

By Kate Marston, Water Quality Monitoring Intern, Alliance for the Chesapeake Bay