Animals
Eastern Oysters
Eastern Oysters Status Rating:
Good
and staying the same
Here’s Why:
Oysters are essential to the Delaware Estuary because they create a diverse habitat and support the economy by providing food and jobs. The oyster population is stable but faces threats from disease, which has led to historical fluctuations in their population.
Oysters are more than just a delicious seafood delicacy.
These salty gems are ecosystem engineers, creating underwater paradise in the form of reefs that provide habitat for themselves and many other species as they grow in mounds on top of one another. They also enhance the quality of their environment by filtering large amounts of water. This section dives into the oyster life cycle, their contributions to biodiversity, the threats they face, the importance of careful mana.
Chances are you’ve come across oysters’ distinct shells, whether you’ve enjoyed them as a delicacy at a restaurant or stumbled upon them while wandering your local beach. However, there’s a lot more to these little marvels than meets the eye. Dubbed “ecosystem engineers,” oysters significantly contribute to the health and vibrancy of underwater habitats, especially in places like the Delaware Bay.
Oysters thrive in the brackish waters of the Bay, where the freshwater of the Delaware River meets the saltwater of the ocean. They create structures known as reefs, formed by cementing themselves onto dead or adult oyster shells as larvae and growing to larger sizes. In doing so, oysters provide a home for diverse saltwater creatures like barnacles and anemones. These reefs form bustling underwater cities that attract birds, fish, and many invertebrates.
Healthy oysters are vital to our ecosystems, but two diseases, dermo and Multinucleated Sphere Unknown (MSX) have affected oysters in the Delaware Bay since the 1950s and the late 1980s, respectively. While the oysters have adapted to fend off MSX, dermo continues to pose a significant threat, leading to a drop in their numbers in certain parts of the Bay.
Oysters were a vital resource in the Delaware Bay for indigenous people long before the arrival of European settlers. Today, their numbers are diligently tracked and managed to sustain the seafood industry. Over the past 75 years, disease-related challenges have shaped the oyster population trend into a cycle of booms and busts. Between the 1970s and mid-1980s, the average oyster population reached 17 billion animals when disease pressure was low. Today’s 1 billion to 2 billion oyster population in the Delaware Bay serves a multi-million dollar seafood industry and is a vital indicator of the ecosystem’s overall health. Regular surveys have been conducted since 1953 to monitor disease, mortality, and harvests. Rutgers University’s Haskin Shellfish Research Laboratory in New Jersey holds an annual workshop to discuss oyster population status and trends and make recommendations for sustainable harvest levels and management improvements.
Oysters are sensitive to changes in their environment, particularly the salinity (saltiness) and the temperature of the water in which they live. Researchers pay close attention and carefully monitor these conditions to understand how oysters will perform in the future. While oyster populations are currently considered stable, continued changes to our environment, like rising sea levels and climate change, can influence where oysters may thrive and where they may suffer.
These factors make the consistent surveying of the oyster population and diseases even more critical. By tailoring management plans based on these surveys, we can better understand our region’s unique environmental conditions and population dynamics. Enhancing oyster habitats and their ability to stick to one another brings many benefits to the ecosystem and the Delaware Bay, ensuring a sustainable future for all.
What is Being Done?
PDE, as part of its oyster shell recycling program, partners with Wilmington and Philadelphia restaurants to collect used oyster shells. Volunteers bag the shells, which PDE uses for living shorelines and shellfish restoration throughout the Delaware Estuary.
For more than 30 years, Rutgers University’s Haskin Shellfish Research Laboratory has completed oyster stock assessments in the Delaware Bay. These assessments involve dredge surveys of the New Jersey-owned, naturally seeded oyster beds in the Bay.
The Delaware Bay (NJ) Shellfish Council, comprised of experienced environmental professionals familiar with the Delaware Bay shellfish industry, annually gives oyster stock recommendations.
PDE and Haskin Shellfish Research Laboratory regularly collect data about oyster bed growth along living shorelines.
Building Connections
How does the Eastern oyster population connect to the Delaware Estuary Program’s Comprehensive Conservation and Management Plan (CCMP)?
CCMP STRATEGY H3.2: Restore oyster beds and productivity in and around the Delaware Bay.
This Eastern oyster indicator status report is based on research compiled in the 2022 Technical Report for the Delaware Estuary and Basin (2022 TREB). Please refer to this document for more information.
