State sets new record for oyster restoration

750 million spat placed in rivers that feed the bay

By PAMELA WOOD, Staff Writer Published 10/12/09

Maryland has once again set a new record for oyster restoration in the Chesapeake Bay.

Nearly 750 million baby oysters - called spat - were created in a hatchery and placed in the rivers that feed the bay. The count bested last year's record of 600 million.

Most of those oysters were dumped directly onto oyster reefs. Some where coated onto "reef balls," which are holey domes made of concrete. Others were sent to volunteer oyster gardeners, who grow them under their piers before planting them on reefs.

"This record planting - along with record involvement by citizen stewards in oyster restoration - gives us tremendous confidence for increasing the bay's oyster population," Gov. Martin O'Malley said in a statement.

Many of the baby oysters ended up in local waters, including:

  • Magothy River: 4.33 million.
  • Severn River: 46.51 million.
  • South River: 3.33 million.
  • Patuxent River: 34.86 million.
  • Eastern Bay: 42.72 million.
  • Lower Chester River: 170 million.

The oysters are created at the University of Maryland Center for Environmental Science's Horn Point Lab in Cambridge.

At the lab, workers carefully control conditions to induce the oysters to spawn. Once the oyster larvae attach to something solid - generally old oyster shells - they are called spat.

The spat are then distributed to a variety of oyster restoration programs. Several government agencies and nonprofit groups are involved in deciding where the oysters go, including: the Oyster Recovery Partnership, the U.S. Army Corps of Engineers, the National Oceanic and Atmospheric Administration, the University of Maryland, the Maryland Watermen's Association and the Chesapeake Bay Foundation.

Oysters are a key part of the effort to restore the health of the Chesapeake Bay and its rivers. They are nature's great filter feeder, taking in water and gobbling up impurities.

Healthy oyster reefs also serve as a home for all kinds of marine life, including fish and crabs.

But the bay's oyster population has declined dramatically. Oysters were once so abundant that watermen literally had wars over them and they were the bay's main food export.

Today, the oyster population is at just 1 percent to 2 percent of historic levels due to past overharvesting, disease and pollution.

And efforts to restore oysters have been controversial, with differing ideas of how to best go about bringing oysters back for the sake of the environment as well as watermen who harvest them and diners who eat them.

A state-appointed Oyster Advisory Commission is working on new plans for the oyster's future.

Scientists soon expect to be able to create even more oysters in the lab for restoration.

With state funds, the Cambridge lab is building a new "setting facility," where the larvae are put into giant tanks in which they grow and attach to oyster shells. Officials have said they hope the new facility will help the lab top the 1 billion mark for annual oyster production.

(Revised October 2009)