they dredged the public fishery during oyster season, and harvest oysters from their aquaculture beds the rest of the year. >> for the past 3 years we've been putting around 50 million baby oysters on our leases. and each one of those oysters has the potential of filtering 50 gallons of water a day, and once when you start doing the math, you start enteringg into the trillions of gallons of water that get filtered just by your little operation. >> starting a lease is extremely challllenging becausese you are tasked with taking bare end bottom and improving it to the point where you can harvest oysters. >> eric wisner had to add 4 inches of substrate before he planted spat on shell in his oyster farm. his investment seems to be payingng off. he s saw some mamarket sized oys in about 18 months. another challenge to restoration for both sanctuaries and aquaculture is shell. at one time there were hundreds of shucking houses in maryland, but today, there are only a handful, and only one year round operation, harris seafood on kent island. >> up until the last 3 years, we sold alll our she

the bay and look for areas to attach, typically that would be other shells from--in an oyster reef. in aquaculture, we can give it a substitute oyster shell in the form of these tiny little pieces of shell. each of these are probably only about 5 times larger than the larvae itself. and because the shell chip is so small, when it grows up, it's basically a single individual oyster. >> we're going to was this--this microcorch which is a 300 micron in size down through this 500 micron screen, and the oysters 500 microns will set on this screen while the shell just goes through, so we'll [indistinct] off the oysters from the shell. so what we're doing here is just washing right on through here. through all we'll have left are the oysters themselves. >> dr. allen is revered for developing the triploid oyster. a sterile oyster that doesn't become thin and watery smer months like a reproductive oyster does. >> oysters have been described as reproductive machines inside two shells, and so, if we can shut down that reproductive mechanism, we can get the oyster to devote that otherwise reproductive energy