Turning a River Into an Oyster Factory

They say it takes a village to raise a child. When it comes to oysters, it takes several CBF scientists, four partner groups, a bunch of hearty volunteers, and on Tuesday of this week the U.S. Coast Guard, to raise a million baby oysters and send them on their way to the Chesapeake Bay.

It was all part of an effort to restore native Chesapeake oysters to Virginia’s Piankatank River, a Bay  
tributary wedged between the Rappahannock and York rivers on Virginia’s Middle Peninsula. Historically, the Piankatank (Pee-YANK-a-TANK) has been one of the Bay’s most fecund rivers, producing millions and millions of baby “seed” oysters for the commercial oyster industry.

Not so in recent years, however. Decades of overharvesting, pollution, and disease had reduced the river’s oyster population to record low levels by 2006.

That’s when the Chesapeake Bay Foundation (CBF) partnered with The Nature Conservancy (TNC), the Virginia Institute of Marine Science (VIMS), the Virginia Marine Resources Commission (VMRC), and the National Oceanic and Atmospheric Administration (NOAA) and began a serious effort to restore oysters to the river.

In a nutshell (or oyster shell), here’s the process: VMRC piles oyster shells on the river bottom to create new, manmade reefs where natural oyster reefs once flourished; CBF then repeatedly “carpet bombs” these shell piles with millions of baby oysters over the course of several years in an effort to create a thriving colony on the reef. 

The hope is enough of the oysters will survive, mature, and reproduce until the reefs are self-sustaining and the river is repopulated with shellfish. The Piankatank is what’s called a trap estuary, a river whose circular water flow tends to trap and keep floating objects, such as microscopic baby oysters, in the river. So if the river’s rebuilt oyster reefs can be coaxed into regularly spawning, their offspring should quickly settle on and repopulate nearby public oyster grounds, making the river a commercial oystering mecca once again. All those oysters will also help filter and clean the water in the river.

But the challenges are many – voracious cow nose rays that love to eat young oysters; omnipresent oyster diseases that tend to kill less hearty oysters before they’re old enough to spawn; mild winters that seem to make the diseases more virulent; boring sponges that degrade the shell piles; and shortages of money, shells, and manpower to consistently stock the reefs on a sufficiently large scale for success.

This week, CBF Virginia Oyster Restoration and Fisheries Scientist Tommy Leggett and Oyster Restoration Specialists Jackie Shannon and Laura Engelund readied a million baby oysters for their part in the saga. First, they led groups of hard-working volunteers in washing and bagging thousands of oyster shells donated by local restaurants and raw bars as part of CBF’s Save Oyster Shell (SOS) program.

Next they stacked the mesh bags of shells into large tanks beside the York River on VIMS’s Gloucester Point campus. The tanks were then flooded with water teeming with millions of hatchery-produced, microscopic oyster larvae. In just a few days, the tiny oysters settle and attach themselves onto the shells in the bags, becoming “spat on shell.” On average, about 11 spat attach to each shell.

More volunteers then help drain the tanks, break the mesh bags apart, load the spat-covered shells into bushel baskets, and haul them to the Piankatank River for transplanting onto the reefs.

On Tuesday, crewmen from the Milford Haven Coast Guard Station at the mouth of the Piankatank lent a hand – actually many hands and two boats, one of which was a 55-foot buoy tender. Chief Ben Brown and his mates enthusiastically helped transfer 65 bushels of shell from a CBF truck to the deck of the vessel, then ferried the shells out to the river’s Burton Point reef. There Leggett and CBF volunteers quickly dumped them over the side between two signed markers declaring the reefs protected and off-limits to poaching.

In all during this week’s three-day effort, about a million oysters were placed in the Piankatank. Leggett will repeat this routine four more times this summer, keeping pace with the project’s goal of adding 5 million oysters a year to the river. He’ll also introduce 150 concrete reef balls to the river later this summer and next year to see how they work at building up the reefs.

Restoration progress in the Piankatank has been up and down, Leggett said, but he’s convinced the river has many more oysters today than just a few years ago. His goal is to jumpstart the river’s oyster population enough to allow commercial watermen to harvest juvenile oysters and transfer them to other rivers for grow-out to market size and eventual sale.

That not only would be a boon to the Piankatank and watermen, Leggett points out, but would also expand oyster restoration in ways CBF and its restoration partners could never attempt. How? As more and more of the Piankatank’s young seed oysters are moved around the Bay to fatten for market, they will regularly spawn and help repopulate other Bay rivers with oysters.

And the Piankatank may once again become an oyster factory for the rest of the Bay.

By Chuck Epes

Comments

[Tommy Leggett]

What a Job I have!

[Johnny Oyster Seed]

Good on 'ya Tommy - yours is important work, and helps set an example for approaching oyster restoration in strategic, "bite size" pieces. Besides a lot of physical and demanding labor, do you think this type of project necessarily requires specialized knowledge or advanced equipment/technology? Here in Maryland, a few innovators have successfully created millions of spat-on-shell using simple, low-budget technologies; i.e. backyard, above-ground swimming pools and pumps. Do you think it might be possible to approach large-scale oyster restoration efforts through a "divide and conquer" fashion - in which numerous "backyard" operations simultaneously focus on creating/planting oysters in their local tributaries?

[Tommy Leggett]

I don't see why that wouldn't work. VA has been approaching it that way since we started using spat on shell since we do not have a facility or organization such as Horn Pointy Lab and ORP. Our CBF facility in VA is realtively small; we only produce about 9-10 million sos ("spat on shell," or young oysters) per year. VMRC has been working with oyster processors and they too have been producing sos and placing them on sanctuary reefs. Guys on VAs E. Shore have been producing sos in swimming pools, and no there really isn't too much specialized expertise required, just some basic knowledge

[Johnny Oyster Seed]

Thanks Tommy. Along the lines of VA's approach, I'd like to see Maryland experiment with using public/private partnerships to support oyster restoration efforts.

[Steve Wann]

"Leggett will repeat this routine four more times this summer..."
Tommy:
When and where? I would be willing to help.
-Steve Wann

[Chuck Epes]

Steve...forward your email address to me -- cepes@cbf.org -- and I'll be sure Tommy and Jackie put you on the volunteer list so you'll receive help-needed alerts. Thanks for your offer.
Chuck Epes

[Gerald Higgins]

I am studying Environmental science at Towson University. I also was an oysterman for 25 years.My goal is to help the bay and oysters are my passion. I'm grateful that we have some good people like Tommy Leggett working on the restoration of oysters.