Pearl of an idea: Ban the Chesapeake Bay oyster dredge

Back in 1891, Maryland’s first oyster commissioner, William K. Brooks, raised alarms about overharvesting of the Chesapeake Bay’s keystone species, which watermen were dredging from the bay at ruinous rates.

“Everywhere, in France, in Germany, in England, in Canada, and in all northern coast U.S. states, history tells the same story,” Mr. Brooks, a biology professor at Johns Hopkins, wrote. “In all waters where oysters are found at all they are usually found in abundance, and in all of these places the residents supposed that their natural beds were inexhaustible until they suddenly found that they were exhausted.”

His plea for a pause in oyster harvesting was ignored. As a result, the bay’s oyster population collapsed to one-third of 1 percent of historic levels by 2009, with parasites and pollution also playing contributing roles in the decline in recent decades. The mollusks rebounded slightly between 2010 and 2014 to about 1 percent of their former abundance because Maryland imposed sanctuaries to protect a quarter of its remaining oyster reefs.

But that’s not enough. More than a century later, it’s time we listen to Mr. Brooks. Maryland and Virginia should impose a ban on the harvest of wild oysters to allow the shellfish to reproduce. As an investment in the future of the Chesapeake, the states should provide grants to watermen to accelerate their transition from hunter-gatherer operations to modern oyster farming, which is more sustainable and more lucrative.

Recently, a coalition of nonprofit organizations called the “10 Billion Oyster Partnership” announced a goal of planting billions more shellfish in the bay by 2025. About three quarters of these shellfish are to be planted in sanctuaries that were created in 2009. But the partnership is also seeding shellfish into zones where watermen can scoop them right out. More significantly, the partnership is not calling for even a temporary moratorium on the continued power dredging of oysters from the bay, a step that would be necessary for any meaningful rebuilding of the bay’s reefs.

Power dredging is the dragging of heavy rake-like devices with net bags across the bay bottom by power boats. It’s an ecologically destructive practice that unleashes an unholy trinity of troubles for the Chesapeake:

1) Dredging crushes and flattens oyster reefs that are the three-dimensional homes of many other bay-dwelling species.

2) The dredges scrape away the hard foundation needed for the reproduction and survival of future generations of oysters.

3) The rakes remove oysters that should serve as natural water pollution filters to clean up the estuary.

Opponents of a moratorium on oystering sometimes argue that it wouldn’t do any good because the bottom is already so silty in many areas that the survival of oysters is impossible. This challenge can be overcome, however, in part through the increased use of rock, concrete and other recycled materials to serve as the bases of artificial reefs.

Seafood industry lobbyists protest that a ban would harm the income of watermen. But oystermen will soon put themselves out of business if they don’t adapt to more modern techniques and start planting their own oysters as part of aquaculture businesses.

Most importantly, failing to ban dredges leaves oyster sanctuaries vulnerable to the chronic poaching that has plagued the bay’s no-harvesting zones. Given the region’s shrinking number of natural resource police officers, effective enforcement of sanctuaries will be impossible unless we physically remove the dredges.

Simply dumping more oysters into the bay won’t solve the problem. We’ve seen this strategy fail in the past.

Eighteen years ago, a multi-state agreement called Chesapeake 2000 established a goal of increasing the bay’s oyster population tenfold by 2010. Taxpayers paid for the planting of tens of millions of oysters in the bay between 2000 and 2010. But the bay’s oyster population actually plummeted by 70 percent over this decade — instead of growing — because watermen quickly dredged them out and sold them. It was a wasteful, taxpayer-funded “put and take” fishery that did nothing to restore the bay’s health.

Let’s give our nearly extinct wild oysters a break and instead eat only the farmed oysters that are already the most popular shellfish on the menu. Our bay desperately needs a rest from the dredging that robs us all of our most powerful ally in the bay cleanup.