It's been more than a century since oysters thrived in the Patapsco River, but on Thursday two groups unveiled an ambitious plan to try to bring them back to the Chesapeake Bay's most degraded tributaries.
The Waterfront Partnership, an Inner Harbor business group, and the Chesapeake Bay Foundation announced plans to plant 5 million hatchery-spawned baby oysters over the next five years near Fort Carroll, an abandoned 19th-century military installation in the lower Patapsco, just beyond the Key Bridge.
"Our goal is, if we can build up the oyster population enough at the Fort Carroll reef, we'd like to see oysters start reproducing on their own there," said Adam Lindquist, director of the partnership's Healthy Harbor Initiative.
Experts are "not sure if it's possible or not,'' he added, "but that's what we're testing out here."
The tiny bivalves are to be placed on the river bottom atop a new reef made of rubble provided by the Maryland Port Administration, Lindquist said. The two groups, as well as the Living Classroom Foundation, have done smaller-scale plantings near Fort Carroll for years.
On Thursday, the Patricia Campbell, a 60-foot vessel used by the bay foundation for oyster restoration efforts, put 200,000 spat, or baby oysters, overboard by the old fort, which occupies a 3.45-acre island in the middle of the river. The area is a sanctuary off limits to commercial harvesting.
"They seem to be surviving very well," Bill Goldsborough, senior fisheries scientist for the foundation, said of earlier plantings.
The reef on which the bivalves were growing also appeared to be drawing fish and other marine life, he said.
Baltimore was a center of oyster processing and canning in the 19th century, with more than 100 packing houses in the city by 1870. But the oysters that landed in the Inner Harbor increasingly came from elsewhere in the bay.
The 1906 annual report of the city's sewerage commission said that "oysters were caught in the Patapsco as far up as Sparrows Point on the north and Rock Point on the south, but that in recent years the dumping of garbage and other refuse into the river in this neighborhood had smothered out all these oyster beds."
The Patapsco and Back rivers, which bracket Baltimore, have ranked in recent years as the most degraded of the bay's tributaries. The University of Maryland Center for Environmental Science found the rivers last year still in very poor ecological health, fouled by nutrient pollution, algae and generally murky water. Even so, the 2014 assessment reported "significantly improving" overall conditions.
To celebrate the restoration effort, an oyster festival is planned from 1 p.m. to 5 p.m. Saturday at the Inner Harbor's West Shore Park. The event will feature live music, vendors and displays, oyster boat tours and a selection of raw and grilled oysters — from elsewhere around the bay.