As waters worldwide become more acidic from an increase of carbon in the atmosphere, Maryland is devising a plan to better understand acidification in the Chesapeake and other waters of the state to determine whether it will become a problem for oysters.
A new law, House Bill 118, which passed easily in the 2014 legislative session, established a task force that the Department of Natural Resources will staff. Other task force members will include representatives from the Maryland Department of the Environment, the Maryland Watermen’s Association, the National Aquarium and the state’s aquaculture industry.
Ocean acidification, a byproduct of climate change, has been devastating oysters on the West Coast, where the shellfish oyster industry is valued at $84 million and supports more than 3,000 jobs, according to National Oceanic and Atmospheric Administration officials. Losses were particularly severe from 2005–08. In 2008 alone, the oyster production at Whiskey Creek, one of Oregon’s largest hatcheries, dropped 80 percent. Since then, monitoring has improved the conditions at the hatcheries, allowing managers to better plan oyster spawns and make changes as conditions vary.
In acidic water, oyster larvae take longer to grow, and they die before they can settle on a substrate. Oyster shells also have a harder time calcifying. When the water is more alkaline, the larvae swim in the water column for a shorter time before setting on a hard shell.
Rep. Eric Luedtke, D-Montgomery County, introduced the bill because he feared that Maryland didn’t know enough about acidification in the Bay at a time when the state was investing millions of dollars in oyster restoration.
The wild oyster season is as good as it has been in three decades; aquaculture businesses are growing on both sides of the Chesapeake, and the state is investing in large-scale restoration projects, such as the Harris Creek oyster sanctuary. Things are going well for the Chesapeake’s once-beleaguered bivalve. But that doesn’t mean it will always be that way.
“If you look at the Chesapeake Bay, it’s arguably the most studied estuary in the world. We know a tremendous amount about it. However, we know almost nothing about the carbonate chemistry, and the reason is because we haven’t been taking proper measurements,” said Whitman Miller of the Smithsonian Environmental Research Center, which has been looking at the acidification issue through experiments on its Edgewater campus as well as at other centers nationwide. “If you’re going to understand the basic ecology, yet you’re not going to study a whole dimension of the chemistry, I think that’s potentially short-sighted.”
Maryland natural resources officials have been monitoring pH, a measure of acidity, for several years as part of the Eyes on the Bay monitoring program. It has found that pH swings wildly not only in the Chesapeake as a whole but in small rivers like the Manokin, where the pH chart looks like a roller coaster some months. Bruce Michael, who manages that monitoring program, said he’s looking forward to participating in the task force to get more information about acidification and look at area trends.
Estuaries are different marine environments than oceans. The fact that West Coast area hatcheries saw problems does not mean Maryland will. But, Michael said, the state hasn’t zeroed in on acidification and increased carbon yet. He’s glad the department will have staff on the task force to do that.
“Obviously, it’s something we’re concerned about and we want to get on top of it,” he said. “We’ll look at what other states have done.”
Maine recently passed a similar law to Maryland’s. Oregon and Washington state have been grappling with the problem for several years.