A closer look is needed on oyster catch

THE BALTIMORE SUN

HOW'S MARYLAND'S oyster harvest going this winter? Depends upon whom you ask.

"Perhaps we are just in that final, inevitable stage for many once highly abundant, commercially harvested species - cod, passenger pigeons, bison," says Roger Newell, a longtime oyster researcher at the University of Maryland.

The harvest "is appropriate ... it's sustainable. We don't see there's an issue," says Chris Judy, a longtime oyster manager for the state Department of Natural Resources.

Both were talking about the growing portion of the oyster catch coming from boats plowing the bay bottom, using motor power to haul a heavy, toothed dredge to scoop the bivalves.

Power dredging, as it's called, was banned in 1867. It was considered too efficient at gathering up oysters. From then until very recently, Maryland has tried to sustain the bay's oysters by limiting harvesters to dredging under sail or using tongs from stationary vessels.

The lure of power never went away, though. As the state's oyster skipjack fleet began to struggle during the 1960s, the legislature allowed power dredging two days a week.

"Push days" and "sail days" - the difference was initially significant: decks laden with a 150-bushel limit by midmorning versus half that after a dawn-to-dark effort under sail.

As diseases, pollution and overfishing continued diminishing oysters, the skipjacks worked only on power days. Those surviving mostly carry tourists or participate in festivals.

By 1999, the Maryland oyster harvest, measured for most of the 20th century in millions of bushels annually, had fallen to the unthinkable low of 423,000 bushels.

As with the skipjacks in 1966, watermen again lobbied for more power, and from 1999 to 2003 the DNR and the legislature allowed watermen to power dredge with their work boats in about a quarter of the Maryland bay.

The harvest by last winter fell to 26,000 bushels, about 6 percent of 1999's. And now DNR is negotiating with watermen about further expanding power dredging into the Little Choptank and Miles Rivers, and parts of Eastern Bay by Kent Island. (No final decision has been made, Judy says.)

With any species but oysters, a decision to boost harvests in the face of ever steeper declines would be unthinkable.

But the diseases MSX and Dermo, which have been ravaging bay oysters for decades, provide at least a veneer of legitimacy.

The DNR's Judy points out that power dredging has been allowed only in areas with higher salinity, where the oyster diseases are most destructive.

"It's a fiction to think oysters would be coming back [in those areas] even with no harvesting," he says.

But the University of Maryland's Newell says power dredging is "taking out the last of the spawning stock of adult oysters - oysters that may well have developed some resistance to the diseases."

The DNR's evaluation of the past few years of power dredging says the dredged areas show "consistent spatfall" - i.e., baby oysters continue to be produced.

But it's not clear what "consistent" means. The fact is, the bay hasn't seen a really good spatfall anywhere since 1997, including the drought years around 2001, usually an excellent time for reproduction.

And although this winter's harvest might turn out a bit higher than last year's all-time low, that likely reflects recent wet years that checked diseases, hardly proof that power dredging is sustainable.

Newell's research convinces him that the density of adult, spawning oysters is too low to ensure good reproduction under any circumstances. Power dredging just makes it worse, he says.

Some oyster experts say there's nothing inherently bad about power dredging. "Managing oysters by mandating inefficient gear [sail and tongs] hasn't proven that effective," says Ken Paynter, a University of Maryland scientist.

"Power dredging could have a legitimate role and could be the way we harvest oysters in the future," says Bill Goldsborough of the Chesapeake Bay Foundation.

But both say that works only if substantial areas of the bay are also set aside as oyster sanctuaries and managed intensively to provide reproduction for oysters baywide.

What the DNR is doing now doesn't come close to filling that bill, both say.

The issue of power dredging deserves a more public and thorough examination than it has gotten, one that involves legislators, environmentalists, sport fishermen and university scientists, as well as watermen and the DNR.

Restoring oysters is too important to overall bay health - they filter the water and provide rich habitat for other species.

The day when we manage them primarily for commercial harvest is gone, but I'm not sure the DNR understands that.

Copyright © 2020, The Baltimore Sun, a Baltimore Sun Media Group publication | Place an Ad
46°