Fewer oysters died from shellfish diseases in Maryland waters last year than at any time in more than 25 years, state officials report, despite late-summer storms that wiped out bivalves in some upper Chesapeake Bay spots.
A fall survey of oyster bars by the state Department of Natural Resources found 92 percent of the bivalves alive, according to an announcement issued by Gov.Martin O'Malley. That's the highest survival rate since 1985, officials said, before the parasitic diseases Dermo and MSX flared up and devastated oysters throughout the Chesapeake Bay.
State officials no doubt felt compelled to trumpet the survey's findings, as they continue to be berated by watermen and their sympathetic politicians for expanding oyster sanctuaries and reducing areas in the bay where bivalves can be freely harvested by 25 percent.
It's the second bit of good news for Maryland's depleted oysters, which are said to be less than 1 percent of historic levels. 2010 saw the highest "spat set," or number of baby oysters produced, since 1997.
In both cases, credit goes mainly to the weather rather than the O'Malley administration's oyster policies. It was unusually dry through summer that year, leading to extremely high salinity levels in the bay, a condition favorable to oyster reproduction.
Higher salinities typically trigger renewed outbreaks of Dermo and MSX, though, which kill off oysters before they mature and offset reproductive gains. But last year saw record-high fresh-water flows from heavy rains, which depressed salinity levels. Fresher waters tend to keep the diseases in check, and scientists report record-low levels of both diseases. Dermo, though still common, remains well below its long-term average frequency for the eighth straight year, officials said.
Fresher water isn't conducive to oyster spawning and can be fatal to the bivalves if severe enough. State officials reported oyster bars north of the Bay Bridge mostly dead after Hurricane Irene and Tropical Storm Lee pumped massive dose of muddy fresh water into the bay in late summer.
DNR Fisheries Director Tom O'Connell reported oyster survival from the fall survey was more than double what it had been in 2002, when record-high disease levels had killed off 58 percent of the bivalves checked that year. And while reproduction wasn't great in much of the bay because of the fresh-water influx, O'Connell said the survey found high spat set last year in areas where salinity levels remained a bit higher, such as in Tangier Sound.
In a bid to rebuild the bay's native oyster population, the O'Malley administration has expanded sanctuaries off limits to public harvest from 9 percent to 24 percent of the remaining waters where bivalves can be found. Officials have sought to buoy the seafood industry by opening more of the bay for private leasing to oyster farmers, while offering financial and technical help to watermen to make the switch.
Since the administration's new policy went into effect two years ago, the state has issued 28 new leases for oyster farming covering 650 acres - more than half to watermen. Another 52 leases are under review. Applicants had complained that their entrepreneurial efforts were being held back by regulatory red tape, but federal and state officials took steps last year meant to streamline the review process and reduce delays in getting needed permits.