Where Have All The Oysters Gone?

by Dave on March 22, 2010

by Michael Short

There was a time when one to two million bushels of oysters were harvested every year from the Delaware Bay.

Succulent and juicy, many of the salty morsels made their way to Philadelphia where there was an oyster bar on nearly every block. Fried, stewed or simply swallowed on the half shell, the Delaware Bay oyster was a huge seafood industry.

Thomas Campanius Holm, an early Swedish settler, wrote in 1642 that Delaware Bay oysters are “so very large that the meat alone is the size of our oysters, shell and all.”

But that all changed in the 1950’s with the outbreak of an oyster disease called MSX.

MSX decimated oyster beds beginning in 1957 and in 1990, a second oyster disease called Dermo, caused further distress for the remaining oysters. While deadly to oysters, the diseases are not harmful to humans.

The Delaware Bay oyster harvest fell from 711,000 bushels in 1956 to 49,000 bushels in 1960.

A combination of heavy harvesting, loss of habitat and the two diseases brought the oyster to what some consider the brink. But a program that plants clam shells in Delaware Bay, part of an oyster restoration effort, has helped pull the oysters back from the brink.

The tiny juvenile oyster spat need a hard surface on which to attach and grow. Clam shells, left over from surf clam processing, work perfectly. Jennifer Adkins, executive director of the Partnership for the Delaware Estuary, said that many feel the shell planting “really brought oysters back from the brink.”

While oyster numbers remain a fraction of what they were in the 1950’s, the successs of the Oyster Restoration Task Force is a bright spot in the environmental future of the Delaware Bay. It’s one of several efforts to restore shellfish in both Delaware Bay and Delaware’s Inland Bays for a variety of reasons.

The Partnership for the Delaware Estuary, a national estuary program, is one of many organizations that make up the Restoration Task Force. A few of the many other members include: the Delaware Department of Natural Resources and Environmental Control, the U.S. Army Corps of Engineers and the New Jersey Department of Environmental Protection.

The effort has won a 2008 Coastal America Partnership Award, a 2009 gold medal from the Federal Executive Board and a 2008 Government Award from the Water Resources Association of the Delaware River Basin. In October, the partnership was recognized by the President of the United States with the Coastal America Partnership Award.

The Partnership for the Delaware Estuary has been working with the Haskin Shellfish Research Laboratory of Rutgers University to help re-establish ribbed saltwater mussels along eroding shorelines in New Jersey. That’s because the thick mats of mussels do more than taste good with garlic, butter and a glass of chardonnay. They also help hold the shoreline in place and prevent coastal erosion by providing a “living shoreline”.

The Partnership has also been working with Cheyney University to re-establish freshwater mussels in upstream areas that feed into the Delaware Bay and River. Many freshwater mussel species are among the most endangered of all wildlife species. Of the 12 to 14 species found in the watershed, only one is considered relatively common.

In addition, the Center for the Inland Bays (CIB), the Delaware Sea Grant College Program and citizen volunteers have developed a program in which volunteers grow oysters in small enclosures in Delaware’s Inland Bays. The oyster gardeners grow the oysters, which are carefully screened to make sure no disease is present, in the enclosures, which protect them from predators like crabs in Rehoboth, Indian River and Little Assawoman Bays.

When they are large enough, the oysters are planted in the inland bays. Many have been placed at a man-made oyster reef at Pasture Point in Indian River Bay.

All those efforts have various benefits. The ribbed mussels protect shorelines from erosion and the oysters help to create habitat for barnacles, sponges, worms, and other small animals. In effect, an oyster reef serves as a kind of artificial reef that creates habitat for other species.

A brochure on the oyster gardening effort says “oysters feed by filtering bay water to remove phytoplankton and other particles floating in the water.
Increased filtration by healthy oyster populations can also help to prevent harmful algal blooms, outbreaks of algae that can affect the health of the water and wildlife living in and around it. Oyster gardens and field plantings create habitats that attract small bottom-dwelling organisms like grass shrimp and worms that in turn support populations of crabs, larger fish and other important species.”

For more information on the oyster gardening program, visit darc.cms.usel.edu/ibog.

All of the shellfish, whether oysters or mussels, have one thing in common. All are filter feeders that filter and clean large quantities of water as they feed. There are estimates that an adult oyster can filter up to 50 gallons of water every day.

All of which means there are environmental benefits aplenty provided by the various programs. But that doesn’t mean the process is easy. Even if oyster stocks rebound, as they have to some extent, there is still the threat of disease outbreaks.

And the funding for the shell planting program expired last year. Adkins is hopeful that a new source of funding can be found to continue the program, but right now, none exists. The Partnership newsletter had this to say in 2008. “Without additional funding, the four years of progress made by the bi-state Delaware Bay Oyster Restoration Project could slow considerably, creating an uncertain future for Delaware Bay’s Eastern oyster population, as well as the many businesses and communities that have staked their livelihoods on the shellfish industry for more than a century.

Since 2005, the Delaware Bay Oyster Restoration Task Force has strategically placed, or “planted” almost two million bushels of clam and oyster shells on to historic reefs in Delaware Bay thanks to $5 million provided by Congress and administered by the U.S. Army Corps of Engineers.”

In 2007 alone, 681,500 bushels of shell were planted.

There are estimates that the program has returned $30 to $40 for every dollar of federal money spent on the shell planting. Adkins said that makes the program “a great economic development tool.”

“It is absolutely vital that Congress and the states of Delaware and New Jersey continue to support the Delaware Bay Estuary Program,” said Dr. Eric Powell, director of Rutgers University’s Haskin Shellfish Research Lab, in that 2008 article. “It has proven to be a wise investment economically and, at the same time, a great benefit to the Delaware Estuary’s ecosystem.”

Still, officials remain optimistic, especially if a new funding source for the shell planting program can be found.

A fact sheet published in approximately 2000 called “History of the Eastern Oyster”, notes that there are indications that oysters are developing some resistance to MSX.

The sheet put out by the Partnership for the Delaware Estuary, the Delaware Estuary Program and the New Jersey Division of Fish and Wildlife goes on to say “Today, oystermen, managers and scientists are hopeful that the oysters are again on their way to recovery. There is consensus that the biological potential for oyster production in the Delaware Bay remains quite high. It will, however, take a consistent and expanded effort in enhancement activities such as shell planting, transplanting and oyster bed restoration projects.”

This article first appeared in Coastal Sussex Weekly, March 18, 2010.

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