Valdosta Daily Times

Community News Network

May 6, 2013

To clean up the Chesapeake Bay, researchers say, we need to unleash oyster power

Behold the tiny oyster.

No, not on the half-shell, with a squirt of lemon, but in its watery habitat, the Choptank River. Out there on a reef with many other oysters, the bivalve is awesome, a janitor that helps remove pollution with incredible efficiency.

A reef seeded with oysters by the state of Maryland - about 130 oysters per square meter - removed 20 times as much nitrogen pollution from stuff such as home lawn and farm fertilizer in one year as a nearby site that had not been seeded, according to a recently released study.

The upshot, said Lisa Kellogg, a researcher for the Virginia Institute of Marine Science who led the four-year study, is that oyster reefs could potentially remove nearly half of nitrogen pollution from that one river on Maryland's Eastern Shore "if you took all the areas suitable for restoration and restored them." A wider restoration could help clean the Chesapeake Bay, where the Choptank and other major rivers drain.

It is a huge deal, Kellogg said. Man-made nitrogen pollution is part of a one-two punch that creates oxygen-depleted dead zones that have bedeviled the bay. At one time, when oyster reefs were so mountainous and plentiful that European explorers complained about navigating around them, the Chesapeake was crystal clear.

Oyster reefs are more than just the rocks of ages. They are the ultimate mixed-use development, inhabited by more than 24,500 marine animals that are not oysters - mussels, clams and sea squirts, to name a few - that also filter nitrogen.

Excessive harvesting of oysters, combined with massive farm and urban pollution, depleted the bivalves, denuded reefs and clouded the water by the 1980s. About that time, two diseases, Dermo and MSX, came out of nowhere to decimate the stock of oysters in Maryland and Virginia.

Oysters in those two states are experiencing a modest recovery because of the restoration and farming known as aquaculture.

In Virginia, 236,200 bushels of oysters were harvested two years ago, up from 79,600 bushels in 2005. Maryland took in 121,000 bushels in 2011, nearly 95,000 more than 2005.

Kellogg and her fellow researchers wanted to show that oyster reefs could greatly improve water quality and are worth the millions of dollars being invested in their restoration.

They also hoped to build on previous studies that had depended on simulations to estimate nitrogen removal at oyster reefs. Their study, started in 2009, used actual measurements of nitrogen levels.

"There was a huge amount of interest in nitrogen removal," said Jeff Cornwell, a researcher at the University of Maryland Center for Environmental Science who contributed to the study.

The researchers measured the amount of nitrogen gas production in water channels on a reef near the Emerson C. Harrington Bridge on the Choptank at Cambridge, Md. They did the same at a site where restoration had not occurred.

The study was funded by NRG Energy.

"The rates we've seen in the Choptank for removal is the highest we've seen anywhere," Cornwell said. "The . . . results are so promising. As we develop data sets we can calculate what oysters did when they were a larger population."

Bivalves scarf up phytoplankton that consume nitrogen. Phytoplankton produce algae blooms that die, turn into a sticky black goo and suck oxygen - needed by pretty much every inhabitant of bay tributaries - from the water. Dead zones deplete the bay of life and rob predators such as eagles and osprey of food.

When oysters and other creatures eat phytoplankton, they poop it into dark areas of the reef where microorganisms feed. Those organisms convert the nitrogen to nitrogen gas that wafts into the atmosphere, Kellogg said.

"The good news about oysters is if we do it right and give them a chance . . . they produce huge numbers of eggs each year," she said. "It's a prolific species that can provide this habitat again, to the extent that we allow it."

That message hasn't fallen on deaf ears. This month, Virginia plans to embark on its largest state-funded oyster replenishment in history, focusing on sites in the James, York, and Rappahannock rivers and in the Chesapeake in Pocomoke and Tangier sounds, according to the Virginia Marine Resources Commission.

The state has already created huge sanctuaries in public waters where watermen are restricted to harvesting oysters on a rotating basis about every two years. In March, the Virginia Marine Police hit 10 people with 115 charges related to oyster violations.

Maryland has been even more aggressive about restoring oyster habitat, pouring $50 million into oyster recovery over the past 16 years. Oyster harvesting is forbidden by the state on a quarter of the bars where they grow; violations can draw fines of up to $25,000 and as many as 15 years in prison.

For years, Maryland scientists at the Horn Point Oyster Hatchery in Cambridge have put oysters in the mood to mate, bathing them in warm water tanks. When the vibe is right, the males spew sperm, the females spread eggs and, soon, larvae develop.

The larvae live on a steady diet of algae until they develop into spat - like teenagers ready to move on to shells of their own. Millions are taken by boat onto the Choptank and Harris Creek and dropped onto reefs.

Cornwell and Kellogg hope their work will encourage states to fulfill a mission to create 98 acres of reef a year - even though the diseases that kill the bivalves continue to be a threat.

"You have to leave them out, have them develop a resistance and have a self-sustaining population," he said. "There has to be a jump-start to have the oysters come back in a more natural way."

Cornwell paused for a few seconds, thinking about the risk. "If they're all dead soon, you have to evaluate the value," he said.

  

1
Text Only
Community News Network
  • Victimized by the 'marriage penalty'

    In a few short months, I'll pass the milestone that every little girl dreams of: the day she swears - before family and God, in sickness and in health, all in the name of love - that she's willing to pay a much higher tax rate.

    April 15, 2014

  • Allergies are the real midlife crisis

    One of the biggest mysteries is why the disease comes and goes, and then comes and goes again. People tend to experience intense allergies between the ages of 5 and 16, then get a couple of decades off before the symptoms return in the 30s, only to diminish around retirement age.

    April 15, 2014

  • treadmill-very-fast.jpg Tax deduction for a gym membership?

    April marks another tax season when millions of Americans will deduct expenses related to home ownership, children and education from their annual tax bill. These deductions exist because of their perceived value to society; they encourage behaviors that keep the wheels of the economy turning. So why shouldn't the tax code be revised to reward preventive health?

    April 15, 2014 1 Photo

  • bomb1 VIDEO: A year after marathon bombing, Boston remains strong

    The City of Boston came together Tuesday to honor those who were injured and lost their lives at the Boston Marathon on the one-year anniversary of the bombing. While the day was sure to be emotional, those affected by last year's race are showing they won't let the tragedy keep them down.

    April 15, 2014 1 Photo

  • Google acquires drone maker Titan Aerospace to spread Internet

    Google is adding drones to its fleets of robots and driverless cars.
    The Internet search company said it acquired Titan Aerospace, the maker of high-altitude, solar-powered satellites that provides customer access to data services around the world. Terms of the deal weren't disclosed.

    April 14, 2014

  • E-Cigarettes target youth with festivals, lawmakers say

    The findings, in a survey released Monday by members of Congress, should prod U.S. regulators to curb the industry, the lawmakers said. While e-cigarettes currently are unregulated, the Food and Drug Administration is working on a plan that would extend its tobacco oversight to the products.

    April 14, 2014

  • Search teams will send unmanned sub to look for missing Malaysian airliner

    Teams searching for a missing Malaysian airliner are planning for the first time to send an unmanned submarine into the depths of the Indian Ocean to look for wreckage, an Australian official leading the multi-nation search said Monday.

    April 14, 2014

  • Why Facebook is getting into the banking game

    Who would want to use Facebook as a bank? That's the question that immediately arises from news that the social network intends to get into the electronic money business.

    April 14, 2014

  • Screen shot 2014-04-11 at 4.49.09 PM.png Train, entertain your pets with these 3 smartphone apps

    While they may not have thumbs to use the phone, pets can benefit from smartphone apps designed specifically for them.

    April 11, 2014 1 Photo

  • Stepping forward: The real Colbert

    Letterman changed the late-night TV game between his run on NBC's "Late Night" and starting the "Late Show" franchise in 1993. And while it's tough to replace a pop-culture icon, Colbert, in terms of pedigree and sense of humor, makes the most sense.

    April 11, 2014

Top News
Poll

What you think about school and workplace rules about Facebook friends?

There have to be rules.
No need for rules, just use common sense.
If people want to be friends, what is the big deal?
Nobody uses Facebook anymore.
     View Results