Researchers studying historic pollution levels in the Chesapeake Bay found their answers in a somewhat out-of-the-ordinary subject: oyster shells. A recent study from the University of Alabama looked at nutrient levels in Bay oyster shells dating back over three thousand years, finding that humans have been polluting the Chesapeake Bay since the early 19th century.
Because they live stationary lives, oysters can make useful study subjects, serving as snapshots of environmental conditions in one location. As filter feeders—they eat by pumping water through their gills—the bivalves remove nutrients from the water, absorbing much of it into their shells. This study was one of the first to use oyster shells, commonly found at archaeological sites in the region, to backdate nitrogen levels. Using that data, researchers could determine when nitrogen levels increased and what role humans may have played.
Studying oyster shells dating back to 1250 BC, researchers found a dramatic increase in nitrogen content that began in the early 1800s and increased almost exponentially until present day. That timeline corresponds what is known about human activities in the Chesapeake Bay region at that time: dramatic increases in population, agriculture and forest clearing. While American Indians altered their environment and contributed to higher nitrogen levels in the water, the effects were local. Beginning in the 17th century, an influx of European colonizers led to an increase in agriculture and forest clearing— but it wasn’t until the 19th century that human effects began to dramatically alter nitrogen levels in oysters.
Industrialization and population increases in the 1800s left their mark on the Chesapeake Bay. Between 1830 and 1880, the area’s population tripled. As a result, over 80 percent of forests surrounding the Bay were cleared for farming and development. Plowing and erosion increased the amount of sewage and sediment entering the water, increasing nitrogen levels in the water as well. Oyster populations also declined, thus limiting the ability of the Bay to filter out this influx of pollution.
While this research focused on historical nitrogen levels, nutrient pollution is still a problem in the Chesapeake Bay today. Nitrogen is necessary for plants and animals to survive, but too much of it can lead to algal blooms, which create harmful conditions for underwater life. Manure and fertilizers can wash off of agricultural fields into nearby waterways, and stormwater runoff can pick up nutrients from excess lawn and garden fertilizers, pet waste and other sources in urban areas. Chesapeake Bay Program partners work with states, local governments, farmers, businesses and many more stakeholders to implement practices that can reduce and even eliminate pollution entering waterways.
The study, “δ15N Values in Crassostrea virginica Shells Provides Early Direct Evidence for Nitrogen Loading to Chesapeake Bay,” is available online in Scientific Reports.
A staff member from the National Aquarium holds a recently hatched diamondback terrapin during a visit to Poplar Island in August 2016. The turtle is one of several dozen that were raised at area schools in the Aquarium’s “Terrapins in the Classroom” program.
Through the program, hatchling diamondback terrapins (Malaclemys terrapin) are collected from Poplar Island and provided to students at Maryland schools to study and observe: monitoring their growth, examining their behavior and learning more about the species. The students grow and connect with the terrapins, while the young reptiles get an increased chance of survival.
The official state reptile of Maryland, diamondback terrapins live in the coastal marshes and mudflats of the Chesapeake Bay and its tidal tributaries. But the popularity of terrapin meat—particularly for dishes like terrapin soup—led to populations of the reptiles being decimated in the 18th and 19th centuries. Today, many regulations are in place to protect terrapins, but nest predation, loss of habitat, boat propeller strikes and entrapment in crab pots continue to threaten the turtles. Terrapins in the Classroom works to bolster terrapin populations while giving young learners a unique role in conserving the species.
In late spring each year, students travel by boat to Poplar Island—located in the middle of the Chesapeake Bay—to release the reptiles back into the marshes where they were hatched. From 2008 to 2016, more than 189 terrapins have been released into the wild.
Image by Will Parson
Caring for the environment is a year-round activity. But as temperatures rise, flowers bloom and the natural world springs to life, it can be easier to get outside and get involved. In the Chesapeake Bay region, there are countless opportunities to volunteer, no matter your interests or age level. April is National Volunteer Month, and to celebrate, we’re highlighting a few ways you can help protect the environment that surrounds us.
1. Pick up trash
Litter is often one of the most visible forms of pollution we encounter in our day-to-day lives. Trash cleanups collect this litter—from plastic soda bottles to old tires—from sites across the Chesapeake Bay region, often along the shores of the watershed’s rivers and streams.
One of the area’s largest cleanup initiatives is the Alliance for the Chesapeake Bay’s Project Clean Stream. In 2016, close to 3.3 million pounds of trash were collected at more than 3,700 Project Clean Stream sites. While the bulk of events take place on the first Saturday in April, cleanups continue to be held through the beginning of June.
Another event, held on the first Saturday in June each year, is Clean the Bay Day. Sponsored by the Chesapeake Bay Foundation, the cleanup takes place in Virginia along the shores of the Bay and its rivers and streams. Since its start in 1989, close to 6.4 million pounds of trash have been removed from almost 6,900 miles of the state’s shorelines.
2. Plant a tree
By improving air quality, trapping water pollution and providing habitat for wildlife, trees play a critical role in a healthy ecosystem. Landowners can individually plant trees along their property, but many organizations also host tree planting events, during which volunteers can assist in planting large numbers of trees on both private and public lands.
Celebrations like Earth Day (April 22) and Arbor Day (April 28) are particularly popular for tree plantings, but events can be found throughout the spring and fall. In the Chesapeake region, April, May and October tend to be the best times for plantings, both for tree survivability and for the comfort level of volunteers working outside. To find a tree planting opportunity near you, you can contact your local watershed organization or check the events calendar of organizations like the Chesapeake Bay Foundation.
3. Be a citizen scientist
Gathering data about the natural world helps scientists and decision-makers detect changes over time and better understand the complex workings of the Bay ecosystem. But time and resources limit the number of sites and frequency of monitoring, especially in the smaller creeks and streams that thread through the region. Networks of trained volunteers can assist in activities like measuring water quality, tracking wildlife and identifying invasive species.
Organizations throughout the Chesapeake Bay region engage citizen scientists in their efforts. The Alliance for the Chesapeake Bay’s RiverTrends program, for example, provides training to water quality monitoring volunteers in the Virginia portion of the Bay watershed. Other initiatives like Project Noah use mobile apps to track sightings of wildlife. Contact your local watershed organization to learn about citizen science opportunities in your area.
4. Support wildlife
Hundreds of species depend on the Chesapeake Bay and its surrounding region, whether as seasonal visitors or as permanent residents. A variety of factors affect the ability of these critters to thrive, from the availability of sufficient food and habitat to surviving in a world of unfamiliar, man-made obstacles. Wildlife organizations and refuges provide support and sanctuary to thousands of animals each year, and they rely on volunteers to help carry out their mission.
Organizations like the Wildlife Center of Virginia assist in wildlife rehabilitation, using volunteers to transport, treat and care for injured wildlife. Volunteers help City Wildlife in D.C. care for urban wildlife, track injured migratory birds and monitor duck nests in the city.
The Chesapeake Bay watershed is also home to fifteen national wildlife refuges, protecting the forests, fields, wetlands and shorelines that wildlife depend on. Many of these refuges have “Friends” groups—such as Friends of Blackwater National Wildlife Refuge—that provide volunteer opportunities like leading nature walks, helping with trail maintenance and staffing information desks.
5. Educate others
More than three million students in kindergarten through 12th grade live in the Chesapeake Bay watershed—and soon, they’ll be the caretakers of its well-being. Teaching these students the knowledge and skills they need to care for the natural world builds the foundation for future environmental stewardship.
That’s why groups across the region are focused on providing meaningful outdoor experiences to students, connecting them with the environment that surrounds them. Audubon Naturalist Society near D.C., for example, uses volunteer teaching assistants to help lead lessons about planting trees or stream science. And volunteers can help the Sultana Education Foundation on the Bay’s Eastern Shore by both leading environmental education programs and working aboard the organization’s replica 1768 Royal Navy schooner.
Have another favorite way you like to volunteer? Let us know in the comments! Or if you’re looking for an opportunity near you, use our Join a Group page to find watershed organizations in your area.
Images by Will Parson
Blackwater National Wildlife Refuge in Dorchester County, Maryland, is seen from above on March 20, 2017. Established as a sanctuary for migrating birds, the refuge spans more than 28,000 acres along the Chesapeake Bay's Eastern Shore. Nearly one-third of Maryland's tidal wetlands—critical habitat for birds traveling along the Atlantic Flyway migration route—are encompassed in Blackwater's boundaries.
Since the mid-20th century, however, close to 8,000 acres of Blackwater's wetlands have been lost. Each year, erosion, land subsidence and rising sea levels have claimed more than 150 acres of marsh. As areas are flooded with saltwater, sensitive marsh plants are unable to survive. Tidal marshes have begun migrating to higher ground, creating new wetland areas, but the gain of less than 3,000 acres since the 1930s has not been enough to offset the losses.
According to recent projections, the changing landscape shows no signs of slowing. The Maryland Commission on Climate Change has documented sea levels rising more than one foot in the last century, and they predict a rise of 3.7 feet by the end of this century. A 2013 assessment by The Conservation Fund and Audubon Maryland-DC found that, with a three-foot rise in sea levels, virtually all of Blackwater's tidal marshes would be underwater.
Refuge managers are working to curtail the effects of a sinking refuge though a variety of projects, including a "thin layer spraying project"—pumping mud from the bottom of the Blackwater River and spraying it in a thin layer to raise the wetland's elevation. Managers hope the work will not only protect existing habitat, but also support the marsh's natural ability to rebuild itself.
Learn about the Chesapeake Bay Program's work to bolster climate resiliency in the Chesapeake Bay region.
Image by Will Parson, with aerial support provided by SouthWings