News Column

Eelgrass Recolonizing Coastal Bays After Long Absence

June 3, 2013

Eelgrass once thrived in Virginia's coastal bays -- lush meadows of slender blades undulating just below the surface.

The species of seagrass provided critical habitat to scallops, blue crabs, shrimp and other marine creatures. It trapped sediment and improved water quality.

But by the 1930s, eelgrass was in trouble, devastated by a wasting disease that was slowly wiping it out. Then a powerful hurricane estimated at Category 1 strength slammed into Hampton Roads in 1933 and finished the job.

Bay ecosystems were irrevocably altered. The commercial bay scallop fishery collapsed.

"In 1987, there wasn't one blade of grass on this entire bay," said Robert "J.J." Orth as he helmed a motorboat skimming along South Bay behind Wreck Island last week off the Eastern Shore. Orth is a marine scientist with the Virginia Institute of Marine Science, or VIMS, in Gloucester Point.

That was then.

Now South Bay is a rare success story in seagrass restoration, with more than 4,200 acres returned to eelgrass meadow. Every year, the meadow expands, aided by Mother Nature and a navy of volunteers.

Today, VIMS' seagrass restoration project is the largest and most successful in the world, by acreage. It draws scientists and technicians from other countries to study the process and determine how it might be adapted to their own bays, rendered barren by pollutants and sediment.

Every spring, it's backbreaking labor conducted under a ticking clock to harvest millions of seed, store them in large flowing seawater tanks in nearby Oyster to ripen over the summer, then, come fall, sow them by hand.

Eduordo Infantes, a Majorca-born marine scientist with the University of Gothenburg in Sweden, was onsite Wednesday to observe the harvesting process and determine if it could be adapted to the rolling seabeds of Sweden's coastal bays. He said 80 percent of the country's seagrass beds have been lost.

"So it's a very big loss," Infantes said. "Now there's interest to try to recover the habitat. They're realizing how important they are."

He donned a wetsuit, grabbed an underwater camera and sank into the chest-deep water to see the eelgrass firsthand.

"It's like a forest underwater," Infantes marveled.

How it's done

No one was sure it was feasible to restore native eelgrass until the South Bay itself showed it could be done.

In 1996, small patches of eelgrass were discovered naturally recolonizing its former habitat. According to VIMS marine scientist Scott Marion, it may have started with shoots washing into the bay, perhaps from around Chincoteague Island, and implanting on the bare seabed.

The next year, Orth led a team of volunteers to manually plant seeds and shoots in a 4-square-meter test plot to boost the recovery.

Since then, more teams have broadcast tens of millions of seed across hundreds of acres in four coastal bays. Natural reseeding has expanded the acreage many times over.

Six years ago, VIMS began partnering with The Nature Conservancy to collect seed using recreational divers and snorkelers.

Other partners include the University of Virginia, which stores seed at its research facility in Oyster, the Virginia Marine Resources Commission and the Virginia Coastal Zone Management Program.

Over the last six years, Marion has been developing a specialized "harvester" to do the job faster and a little easier.

Now in its third iteration, the harvester consists of a large net at the end of a rope and pulley system that's fixed to a large wooden frame and attached to the bow of a boat.

Under the bow, a set of blades mows the eelgrass as the net scoops them up.

Marion, along with VIMS graduate student Erika Schmitt and marine scientist Sarah Sumoski, haul the catch aboard in a kind of tug of war with the net, heavy and dripping with wet eelgrass. Infantes lent a hand, too.

They dump the haul onto a platform, load up a trash can by the fistful, then upend each trash can load into a netted bag.

The eelgrass is so slick, green and shiny it looks like it belongs in an Easter basket.

Each haul typically nets some unsuspecting creature or other that gets tossed back into the bay -- a striped burrfish, a sponge crab, a slim, slippery pipefish that could easily be mistaken for a blade of eelgrass.

It's a 15-minute process that repeats countless times throughout the day. By the end of it, Marion estimates they've filled more than 100 bags.

They have about a week to harvest the seeds -- the size of rice grains and stored in the reproductive blades of eelgrass -- before they begin to flower.

If the harvest is a good as last year, Marion said, they'll collect 12 million seeds.

Only one word

The South Bay and three other coastal bays used in the project are perfect sites for eelgrass restoration and research, VIMS says: They're part of the Virginia Coast Reserve, their waters are relatively pristine and cool in summer, and their coastline is largely undeveloped.

The reserve is managed by The Nature Conservancy as a Long Term Ecological Research site administered by the University of Virginia.

According to Orth, this gives marine scientists a unique, low-impact, natural lab to study the ecological benefits of restoring eelgrass as a dominant species.

The Chesapeake Bay is less hospitable for restoration work because its waters are warmer and less clear.

According to VIMS, studies are showing eelgrass meadows have boosted key "ecosystem services" that result in the removal of harmful nutrients and the trapping of suspended sediments. This leads to enhanced water quality, which in turn stimulates more eelgrass growth.

This intrigues Leo Mosgaard Nielsen of Denmark and Per Nystrom of Sweden, who arrived last week to study the harvesting and seeding process.

Nielsen is manager of MultiDyk and Nystrom is director of NyFam, businesses which specialize in environmental restoration.

According to Nielsen, 90 percent of the eelgrass disappeared from his country's coast in the '70s, 80s and '90s as water quality deteriorated from fertilizer and sewage runoff.

After much effort, the water has been cleaned up, he said, "but the eelgrass still doesn't come -- it spreads so slowly."

A five-year project was launched to study eelgrass restoration, he said, with the first three devoted to researching and developing the best techniques.

The two explored the shallow waters of the bay from a Nature Conservancy barge as snorkelers methodically harvested and bagged eelgrass shoots by hand -- a laborious method used for the past 16 years.

At low tide, on the boat trip back to the landing in Oyster, Nielsen and Nystrom lay flat and face-down across the bow -- the better to watch acres and acres of eelgrass undulating a few feet below, just beneath the surface.

"There's only one word for it," Nystrom said. "Success."

___

(c)2013 the Daily Press (Newport News, Va.)

Visit the Daily Press (Newport News, Va.) at www.dailypress.com

Distributed by MCT Information Services





Source: Copyright Daily Press (Newport News, VA) 2013


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters