GWYNN ISLAND, Virginia -- On a bright, sweltering summer morning, a crane stacked clusters of granite into the brackish waters of the Piankatank River on Virginia's middle peninsula . The crane's hum broke the tranquil silence, steadily plunging the rock into a white swath of waves.
Here, hidden beneath rows of cypress and pine trees near the shores of Virginia's sparsely populated coastal plains, the Army Corps of Engineers built a $2 million project -- a 25-acre artificial reef in the lower section of the river near the Chesapeake Bay.
On the river's eastern edge where the Piankatank empties into the bay, the reef marks a small step in the hopes of creating a sustainable oyster population as part of the Chesapeake Bay Program. Corps leaders hope the restoration of the American Oyster will help resuscitate the bay and create a myriad of positive effects on the ecosystems and the Chesapeake watershed.
"We invest in oysters because it creates habitat," said Susan Conner, chief of planning for the Corps' Norfolk District. She said the goal is not just to grow oysters, but to achieve an "authentic diversity of organisms" on the bottom of the bay that oysters help bring about.
The Chesapeake originally boasted a great diversity of plant and animal life.
A BAY CHANGED
When English explorer John Smith travelled to the New World to settle what would later become Jamestown, Virginia, he marveled at the abundance of wildlife in the surrounding Chesapeake. The bay and its watershed still host more than 3,600 species of animals and plants, but about 360 are on the endangered list. The Chesapeake is the largest estuary in North America and third largest in the world, measuring in at 4,500 square miles -- more than double the size of the Grand Canyon.
Smith mapped 3,000 miles of the bay and its watershed, which historians say looked much different than the Chesapeake of today. The eastern American oyster, once numbered in the millions, grew so abundant that oyster reefs were an obstacle for navigating ships.
In the three centuries since Smith's expedition, the bay has changed dramatically. The Chesapeake's once crystal clear waters has been replaced by murky brown liquid in some parts. Full of sediment, harmful minerals and a growing algae population, the bay's health and water quality has become an alarming concern. Centuries of human occupation has decimated or caused the extinction of several of the region's native species. The bay's watershed has grown in population and urbanization has crept into much of the natural habitat.
Overharvesting and pollution had already wreaked devastation on the oyster population when the MXS and Dermo bacterial diseases surfaced in the 1940s and 1950s. Then sediment and pollution flooded the bay's freshwater, threatening species dependent on the bay's unique ecosystem for survival.
"The ability to sustain the habitat and the species that rely on that habitat is why the Chesapeake Bay restoration is important," Conner said. "So we do consider it a unique watershed -- a unique ecosystem within the United States. There are other ecosystems that are also unique and special but certainly Chesapeake Bay is one of those that is worth protecting."
More than 400 islands in the bay have disappeared due to erosion and rising sea levels. Several islands remain in danger including Tangier Island, located near the southeast tip of Virginia's Eastern Shore.
The project managers hope Piankatank, along with four other sites within the region, can help restore some of the depleted oyster population within the Bay. The project is part of the larger Chesapeake Bay Oyster Restoration effort, which began nearly 20 years ago to help return the once-plentiful oyster population back to the bay.
The Corps, whose numbers include more than 37,000 military and civilian members, has partnered with six states, the District of Columbia and the Defense Department to restore 20 Chesapeake Bay tributaries by 2025.
Recent successes still pale before the restoration work that remains . More restoration work will need to continue to improve oyster population in the bay.
"I do think it's still very critical," said Angie Sowers of the Corps' Baltimore District. "We started the ball rolling. We did not tip the scale for the system to progress on its own. Not yet."
Despite the efforts of the Corps and other government and civilian agencies, the oyster population still hovers at just 1 percent of the Bay's historic levels. The restoration is a monumental task that has drawn the interest of politicians, scientists and conservation groups.
THE PIANKATANK
Circling the barge in a small boat, three members of the Army Corps of Engineers and Andrew Button of the Virginia Marine Resources Commission gathered to discuss the project's progress and what it means for the local marine life. For nearly two months, barges have hauled 3,400-ton loads of granite from a quarry in Havre De Grace, Maryland, at the northernmost tip of the Chesapeake. Once a week, a barge made the 160-mile voyage to southern Virginia, passing through the Bay Bridge near Annapolis and winding past the southeast mouth of the Potomac before reaching Gwynn Island.
The Piankatank team began research for the project in 2014. The team used data from the National Oceanic and Atmospheric Administration's analysis to map ideal locations. The Corps completed a 20-acre reef at Fishing Point and a smaller reef at Iron point. Building reefs requires meticulous planning and Conner said the Corps learned from past mistakes.
Previous reefs built by the Corps were built too deep and did not pick up the desired amount of oysters. Some reefs such as those built at Harris Creek, have been built too high and disrupted boat traffic. Harvesters have also poached oysters from Corps-built reefs illegally. Conner said that the Corps chose 12-18 inches as the ideal height for building the reefs. Four days a week for 10 hours, crews worked stacking the granite in 30-foot wide rows with 45-foot spacing between each row.
The tributary restoration projects pose a different challenge for the Corps; instead of restoring habitat from the ground up, they will be using life to restore life.
"The animal itself is the habitat," said Andrew Button, an oyster replenishment officer at the Virginia Marine Resources Commission.
The Corps calls the oyster an "ecosystem engineer." The oysters act as a natural filter, improving water quality. A single oyster can filter 20-50 gallons of water a day, removing and trapping sediment from the bay's waters. Reducing sediment clears room for sunlight to penetrate the Chesapeake waters, which benefits plant and animal life.
Oysters are born male, but change into females as they age. The oyster's unusual anatomy allows the young oysters to latch onto the adult females.
Tributary planning teams scouted 63 tributaries of the bay in both Maryland and Virginia, but decided on the 24.4-mile Piankatank because of its ample supply of oyster spat, or young oysters. The river also carried a higher concentration of oxygen than much of the Chesapeake and had fewer "dead zones" or areas with low oxygen.
Oysters, because of their unique biological composition, can survive in areas of low oxygen levels for one to two days, but their immobility can prove fatal when they fall into a dead zone of the bay.
"They can't move away from that area," Button said. "So if there's a persistent dead zone over an oyster area, you will have significant death."
The Corps and the tributary research teams also had to consider several factors: including depth, water salinity levels and hydrology (how water moves in an area). Researches also had to check the softness of the river bottom, because the rock may sink if the surface is too soft.
THE WAY AHEAD
Button said it will take three years to determine whether the Piankatank restoration proves to be a success. To monitor the success of the large-scale restoration reef, the Corps will dispatch a team of divers after one year to descend into the river to take water samples, measuring the oyster population size and density.
In the meantime, the Corps hopes to continue its restoration efforts in other rivers.
"We want to put enough substrate out there that we have enough oysters that we don't have to continue to build (more reefs)," Button said. "That's the goal we're working toward: How many (reefs) do we need so that population takes care of itself?"
Farther north, 23 miles up the bay at the Great Wicomico River, the Norfolk District built the world's largest restored oyster population in 2010. That is, until 2015 when the Baltimore District finished building reefs in 377 acres of Harris Creek in Talbot County, Maryland, on the western side of the Delmarva Peninsula.
The massive project proved to be a rousing success, as the Corps planted 2 billion baby spat on artificial reefs in Harris Creek. The creek now boasts 200 oysters per square meter, a level not seen for decades.
While construction has completed at Harris Creek, the Corps will continue to monitor the growth of the oyster population with more spat scheduled to be planted later this year.
(This is the first in a three-part series on Chesapeake Bay restoration projects undertaken by the Army Corps of Engineers.)
Social Sharing