Research: Fisheries and aquaculture. Innovative research to support the world's growing demand for sustainable seafood.
 

DEVELOPING SUSTAINABLE FISHERIES AND JUMPSTARTING DELAWARE'S AQUACULTURE INDUSTRY

Global seafood demand is growing by more than 2% each year and the fishing industry provides more than $60 million to Delaware's economy annually. Delaware Sea Grant funds research on commercial-scale aquaculture, sustainable seafood, and seafood handling technology to keep our state's fishing industry at the leading edge of economic development and environmental responsibility.

 

 

Recent Projects

 Oysters in shallow water.

Deciphering the Role of Commensal Microbial Communities in the Health and Fitness of the Eastern Oyster, Crassostrea Virginica

Investigators: Drs. Shawn W. Polson, K. Eric Wommack, and Patrick Gaffney

The eastern or American oyster, Crassostrea virginica, is a keystone species in coastal ecosystems along the east coast of North America. The ecosystem services this species provides have been severely reduced over the past centurythrough overharvesting, habitat degradation, and the emergence of lethal diseases. This study will assess the microbiome of natural and restored populations in order to determine the impact commensal microorganisms have on the success of the eastern oyster.

Deciphering the Role of Commensal Microbial Communities in the Health and Fitness of the Eastern Oyster, Crassostrea Virginica

Investigators: Drs. Shawn W. Polson, K. Eric Wommack, and Patrick Gaffeny

The eastern or American oyster, Crassostrea virginica, is a keystone species in coastal ecosystems along the east coast of North America. Healthy oyster populations are ecologically important as their filter-feeding activities consume plankton and help to clarify the water where they live. Oysters are also economically important as oyster harvesting and aquaculture provides jobs and revenue to coastal communities.

Regrettably, these important services have been severely reduced over the past century, first through overharvesting and habitat degradation, and more recently from the emergence of lethal diseases that kill significant proportions of infected adult oysters each year. An emerging field of research has begun to look at entire communities of microorganisms (the microbiome) that are associated with a host animal. An essential question driving this research area has been the role the microbiome plays in the health and disease of its host animal. For example, we now know that specific bacterial communities within the gut are associated with obesity in humans. Thus, the physiology of an oyster “holobiont” is very likely due to a complex interplay of the animal and its associated microbiome.

This study will assess the microbiome of natural and restored populations, and maricultural bred lines of C. virginica. We will also investigate whether the genetic make-up of an individual oyster (the oyster genotype) influences its microbiome by examining both wild oysters and oysters that have been bred for disease-resistance. We will accomplish these goals by leveraging cutting-edge DNA sequencing technology to obtain detailed views of the oyster holobiont, including the individual oyster genotype and its associated bacterial and viral microbiome. With the help of the Delaware Sea Grant Marine Advisory Service and the Center for the Inland Bays, fieldwork will be conducted over an annual cycle in the Delaware Bay and the Delaware Inland Bays.

In particular, our scientific objectives are:

Obj. I) Through a seasonal survey, establish baseline commensal microbial (viral & bacterial) communities within oysters from natural and restored populations in the Delaware Bay and Inland Bays.

Obj. II) Compare commensal microbial communities between natural and maricultured oysters, including disease-resistant oyster lines.

Obj. III) Investigate linkages between the composition of oyster commensal microbial communities and oyster genotype.

It is our hope that this fundamental research will lead to new maricultural approaches for improving oyster health and to controlling or preventing lethal oyster diseases. Ultimately, achieving these goals will help to ensure the ecological and economic benefits of oysters for coastal communities.

 

Mini-Grant: Preliminary Assessment of New Technology for Oyster Purification

Investigator: Dr. Dennis McIntosh

To improve seafood safety, post-harvest processing of shellfish is becoming the industry standard. Delaware Sea Grant is funding a mini-grant to test new depuration (cleansing or purification) or post-harvest treatment of bivalve shellfish. Two related proprietary disinfecting technologies, alone and in combination, are being compared to conventional ultraviolet disinfection. Researchers are exploring suitability for use on live shellfish in an early exploratory phase of this research.

 Shucked oysters on a plate.