On a hot summer day in July, drivers crossing the Naval Academy Bridge might spot a strange looking boat flinging oysters into the Severn River off a conveyor belt.

The specially designed ship is called the Patricia Campbell, and the Chesapeake Bay Foundation (CBF) owns it.

Captain Karl Willey describes the vessel as "a lean, mean oyster-spreading machine."

In just a few hours on July 7, the boat dumped more than 3 million baby oysters, known as spat-on-shell, into a reef off Jonas Green State Park. 

Volunteers push the oysters from a holding container onto a long conveyor belt, and the boat mechanically shoots them into the water making a loud, popping sound.

“If it just dropped off at the end of the conveyor belt, the oysters would just clump up and be in a pile down at the bottom,” Willey said.

He compares it to the way a salt truck spreads ice on a snowy winter day.

The ship's other unique feature is its twin set of spuds, which are long, column like anchors running through the center of the boat.

"The spuds are designed to stop the boat, and we can spin on them to do exact placement (of the oysters) using GPS," Willey said.

This is the second year that he and the Patricia Campbell have spread spat-on-shell at this reef.

"We came out here last fall in October and put down the first spat-on-shell," Willey said. "Every time you pick a new location you take a risk on whether or not the oysters will survive."

So far it seems to be working: Sampling done by the CBF show that oysters in this new half-acre reef are thriving.

CBF spokesman Tom Zolper said the goal is to create self-sustaining reefs throughout the Severn River.

Harvesting and disease have decimated the bay's oyster population to less than 1 percent of historic levels, and that's a problem because oysters need a critical mass in order to reproduce.

Male and female oysters spray reproductive clouds into the water that mix and create new oysters. Zolper said these new oysters need to attach to something, and they prefer the old shell of a dead oyster.

If there aren't enough available shells in the water, the babies don't make it, Zopler said.

The reef off Jonas Green Park is also unique because of its proximity to the shoreline.

"Most oyster reefs are well away from shore. People hear about them, and they sort of understand in their head the value," Zolper said. "The point of this one was to put one right next to a park where people are fishing. Hopefully people will understand that this is a really valuable benefit to the river."

Editor's Note: Tom Zolper is a blogger for Annapolis and Edgewater-Davidsonville Patches. You can read his posts here.

CORRECTION: This article has been updated to correct the spelling of Tom Zolper's name. Patch regrets the error.