by Allie Wagner
February 26, 2019
Looking up at the 13 towering 10,000-gallon water tanks, it’s difficult to imagine the thousands of microscopic oyster larvae growing inside. These baby oysters, now in the early stages of their life cycle, will eventually grow up to filter water from the Chesapeake Bay, provide habitat to other aquatic species and stimulate the economy.
Over time, native oyster populations have declined due to over-harvesting, habitat loss and disease. In 1972, rain from Hurricane Agnes overwhelmed tributaries flowing into the Chesapeake with sediment, causing a record low salinity level that in part, led to major losses for the Bay’s oyster population.
In response to the devastation, University of Maryland researchers proposed creating a facility to assist in their rehabilitation. Two years later, the Horn Point Oyster Hatchery was opened on the Choptank River in Cambridge, Md. The invaluable laboratory for education, research and restoration was updated in 2004 with the state-of-the art hatchery that stands today. This facility is one of the largest oyster hatcheries on the East Coast and is making strides in restoring the Bay’s oyster population.
It is the mission of scientists at the Horn Point Laboratory to conduct cutting edge research and restoration activities, which so far have led to the deployment of over one billion oyster spat to Bay waters and tributaries. This is accomplished by leading oysters through an entire life cycle at the hatchery.
The process begins when scientists trigger a group of adult oysters to begin spawning. During the spawning process, the adult oysters are separated by sex, so that the eggs can be fertilized in a controlled environment. When the eggs begin growing, they are transferred to larval tanks where they will continue to grow for 14 to 20 days. Once the larvae reach a certain size, scientists move them to outdoor setting tanks filled with shells. After about 48 hours, they check the shells to see if larvae have successfully attached and become spat. The spat hardens and grows, until they are ready to be moved to the nursery in the Choptank River or planted at a prepared site by the Oyster Recovery Partnership.
In an effort to help this species and its accompanying fisheries flourish once again, the Chesapeake Bay Program partnership committed to continually increase shellfish habitat and water quality benefits from restored oyster populations in the 2014 Chesapeake Bay Watershed Agreement. Furthermore, the partnership pledged to restore native oyster habitat and populations in 10 tributaries by 2025 and ensure their protection. This includes planting oyster spat grown from hatcheries, including Horn Point Laboratory.
Nine Chesapeake Bay tributaries have been selected for oyster reef restoration, each at varying stages of progress. This process involves development of a tributary restoration plan, building and seeding reefs, and monitoring and evaluating restored reefs at three and six-year intervals.
A challenge facing Horn Point Hatchery is the limited availability of oyster shells necessary for successful oyster restoration. Locals are doing their part to recycle shells from restaurants, seafood businesses and the public with the Shell Recycling Alliance. With programs like this, we can return shells to local waterways, create new oyster reefs and keep this valuable resource out of our landfills.