Photos: Shad Restoration on the Potomac River

Two fishing nets were laid in the choppy Potomac River near Mason Neck on Monday afternoon, and the crew of biologists, fishermen and students waited on Brad Harley's weathered 21-foot pontoon boat for American shad - the world's largest herring. 

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Once caught, the fish were brought aboard and analyzed for fertility. The males were kept, and so were the females full of eggs. The others were thrown back.  

"We've got a long ways to go," said Mike Isel, a biologist with the Virginia Department of Game and Inland Fisheries. "Our goal is four million eggs by May 15. Right now we're at around three million."

The Department has stocked over 20 million baby shad from the Potomac into the depleted Rappahanock River since 2003. 

Harley's crew included Jim Cummins, Director of Living Resources with the Interstate Commission on the Potomac River Basin (ICPRB), students Alexa Calomiris and Peter Haffenreffen of the D.C.-based Maret School and their chemistry teacher Jeanne Deslich. 

What are the shad good for? 

The Potomac's shad population has come a long way from dangerously low levels in the 1980s, but only after undergoing environmental improvements and a restocking project of its own in the 1990s. 

"Now's the best time of the year for shad," said the 43-year-old Harley, "and I've seen the Potomac go from green slime to clean… When we were kids we weren't allowed in the water. It would stick to your legs."

According to Cummins, shad are a major food source for "everything from bears, bald eagles (who time the hatching of their young to the run) ospreys, to striped bass, catfish, minnows, crabs and… plankton."

The results

The female shad can carry as many as 20,000 eggs apiece, but the group ended up securing about 7,000 eggs on Monday.

The process of acquiring them involves killing the females by pushing the eggs from their bodies. The process is similar for taking sperm from the males. The results are mixed in a bowl until fertilization occurs - and are then stored away for future deployment into the Rappahannock.