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Shellfish Gardening Program

The Center's Shellfish Gardening Project is now a demonstration, but with an eye toward becoming a restoration project. The Center provides juvenile oysters and clams, and apparatus to raise them, to citizens with waterfront properties. If successful, the program may help restore shellfish to areas where they have been depleted.

Oyster Gardening in the Inland Bays 2008
Oyster Gardening Location Map

Oyster Restoration
E.J. Chalabala deploys oyster spat at an oyster gardener's dock hoping for another year of exceptional growth.
photo
"Oysters are Habitat Forming"

The Center for the Inland Bays' Shellfish Gardening Program is a cooperative effort between the CIB, the University of Delaware, Sussex County Council and Volunteers! Original support for the program was provided through a generous grant from the National Fish & Wildlife Foundation's Five-star Restoration Challenge Grant Program. The program brings together scientists and volunteers in a effort to restore the American Oyster (Crassostrea virginica) to the waters of Delaware's Inland Bays.

Based on a successful program implemented in the Chesapeake Bay region, our program hoped to accomplish the following objectives:
  • Research on oysters;
  • Improve water quality through oyster filtration;
  • Protect young spat, giving them a chance to grow through better conditions;
  • Create habitat for other marine species which are the base of the food chain for fish, crabs and other species;
  • Educate volunteers and the general public about the ecology and value of a healthy population of Inland Bays oysters.


The first year of operation for the Shellfish Gardening Program was 2003. For more information about the program, please contact the Restoration Coordinator at restoration@inlandbays.org or call 302.226-8105.


FREQUENTLY ASKED QUESTIONS

Don’t we already have oysters in the Inland Bays?

Delaware's Inland Bays have been virtually devoid of a natural population of oysters for more than thirty years. The CIB believes that oysters were at one time and hopefully, will again be a thriving and important component of Inland Bays' ecology. The goal of our Shellfish Restoration Program (which includes the oyster gardening efforts) is to restore a viable population of oysters to our local waterways, thereby creating critical benthic (bottom) habitat and increasing the filtering capacity of the bays' shellfish population.

Tell me about oysters, why are they so special?

Oysters are like the building blocks of the benthic community and create very important reef habitats for other organisms. Some of the many important species you will find around an oyster reef include: barnacles, mussels, bryozoans, worms, algae, plankton, as well as several kinds of fishes and crabs. Our oysters were not meant for harvest but for creating more reef habitat. Oysters are also filter feeders which means they can remove tiny one-celled plants called phytoplankton and other small particles from the water and improve water quality.

You cage oysters?

Yes. Special cages and floats were built to hold the oysters. We don't have to worry about oysters swimming away, but the cages helped contain the growing spat for a scientific study and survival. The cages allowed a good supply of food and oxygen to reach the oysters near the surface. They also reduced the threat from predators and sedimentation. The cages and floats made it easy for the volunteers to maintain the oyster garden populations. The goal was to provide the juvenile oysters a protected environment which, hopefully, would result in more successful survival rates.

How big are the cages or floats?

Taylor floats and mesh culture bags are ideal for volunteers with access to waterfront property. Each "gardener" was supplied with one float and two plastic mesh bags. The mesh bags are used because they are simply easier to lift and handle. The dimensions of a Taylor float are 2' x 3'. Oyster "spat" are placed inside the mesh bag, which rests inside the Taylor float. Each mesh bag has a carrying capacity of approximately 75-100 shells with spat. The floats are suspended from gardeners' piers, docks or bulkheads. When necessary, they can be lifted from the water in a similar manner as crab traps. However, the Taylor floats must be suspended at least a foot off bottom to avoid oyster drill predation.

Volunteers were the actual "shellfish gardeners?"

Yes, 15 volunteers signed on as participants in our pilot oyster gardening project. They maintained the oysters and kept the cages clear of bio-fouling every week. Volunteers also assisted with measuring and recording oyster growth and mortality as well as water quality parameters, such as temperature and salinity. The volunteers were involved for several reasons: to play a hands-on role in oyster restoration, to educate their neighbors and friends about the benefits of a healthy oyster population, and to provide a diverse array of study sites throughout the Inland Bays system.

Where did the volunteers get the baby oysters to start their project?

The oyster "seed" was obtained from a University of Maryland culturing facility in Cambridge, Maryland. The type of seed we used is called ‘spat on shell’. "Spat" are tiny free-swimming larval oysters that attach themselves (in the tens to hundreds!) on dead oyster shells, also called "cultch." The "spat" were then transferred to the mesh bags, which were placed inside the Taylor floats.

In 2003, only spat on shell were used for the gardening program. This type of settlement of larvae on whole oyster shell produces an oyster cluster that best resembles what happens in nature on the reefs.

Weren't you worried about bringing "diseased oysters" into the State?

One of the conditions for introducing oysters into Delaware's waters is the testing of the oysters for disease. Two diseases of utmost concern are MSX and Dermo. Dermo disease is an infectious oyster disease caused by a very tiny protozoan parasite (Perkinsus marinus). The parasite was observed in Delaware Bay in the mid 1950s following the importation of seed from the Chesapeake Bay. MSX is another oyster disease caused by a protozoan parasite. The disease was first documented in the Delaware Bay in 1957. As part of the monitoring plan for the Center's shellfish restoration projects, we routinely have disease testing conducted on oysters transplanted in the Inland Bays.

You also had research being conducted on these oysters?

John Ewart, Aquaculture Specialist with the University of Delaware's Marine Advisory Service, was studying several aspects of the oysters in 2003. With the assistance of a CIB intern, he counted them, measured them, took water quality readings, and sampled tissues to determine how well the oysters were thriving.

So what was learned from the research?

John was trying to learn about the growth rates of the oysters in different areas around the bays. He learned that oysters grew best in areas of Little Assawoman Bay that had moderate tidal flow. Overall though, oysters demonstrated good growth in all areas of the bays where they were "gardened." As a matter of fact, their growth rates during the nine-week growout period approximated what has has been observed on the created oyster reef over the course of two growing seasons!

How many oysters were grown in total?

Over 100,000 oysters were raised by the volunteer gardeners during the 2003 season. An additional 400,000 juvenile oysters were transported directly to the reef following delivery from the culturing facility in Maryland.

Can the gardeners eat the oysters?

Although the oysters are a tempting, tasty morsel, we discourage our gardeners from consuming the oysters. If we are successful in our efforts to restore oysters to the bays, there may be future opportunities for recreational harvesting of oysters for personal consumption.

Where are you putting the oysters?

In 2003, 15 oyster gardeners contributed approximately 100,000 oysters that were deployed on the reef at Pasture Point Cove in Indian River Bay. This artificial reef was created in 2001 through a $40K grant project supported by the U.S. Environmental Protection Agency. Since the project's inception, the CIB has deployed more than 1.5 million oysters on the reef.

How are you getting the oysters to the reefs?

Prior to distributing the oysters, John Ewart and E.J. Chalabala, a member of the CIB's staff, went to each site to finish collecting the final data. The mesh bags were tagged for identification purposes and the oysters were transported by vehicle or boat to the reef in Indian River Bay. The bags were emptied onto portions of the existing reef that needed enhancement.

What happened to the oysters once they were put on the reef?

We hope they are growing! As a point of information though, oysters start out as mobile larvae floating through the water. They attach themselves to hard substrate on the bottom and begin developing their shells. This substrate can often be another oyster. Once these oysters are established, other organisms begin to grow on them, creating a nice ecosystem for a variety of brackish and marine water organisms. Oysters usually flourish in less than 10 to 15 feet of water, where the substrate is firm, and there is little chance they will be covered up by sedimentation. We hope our oysters will mature, reproduce, and serve as the substrate for future settlements of oysters!

So, what happened in our first year?

Our first year has been a great success and we thank all our many volunteers and partners. We hope this year that our volunteers continue and we can expand the program to other areas. We are currently seeking new funding sources to keep the program afloat.

Since it is estimated that a single mature oyster can filter 50 gals. of water each day, think of the positive impact we could produce by placing 100,000 oysters in our bays year after year! Give us a call if you’d like to be considered for our Shellfish Gardening Program – The Center's office number is 302-226-8105 or contact restoration@inlandbays.org

Posted by: Sally Boswell on Oct 18, 05 | 10:47 am

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