Man-Made Reef May Help Stem Oysters' Decline

On top of a 50 foot barge, a crane hoists a 1500 pound bag of surf clam and quahog shells.
(nats)
Crews guide the bag to the edge of the barge, untie the bottom, and dump the shells into the Oyster River.
(sound)
Doctor Ray Grizzle is a marine biologist with the University of New Hampshire’s Jackson Estuarine Lab.
(Basically what we try to do, we put down a starter reef it’s hard shell dead shell but it provides a substrate for the natural oysters to settle on)
Grizzle is hoping that oyster larvae from a one acre natural oyster bed will float downstream and cling to the new shells, which cover about 1/5th of an acre.
Timing is everything; oysters begin to spawn in mid-July.
Grizzle and the Nature Conservancy are partners in this 25-thousand dollar project.
They’re trying to turn a man made reef into a living ledge of wild Eastern oysters.
If successful, Grizzle says it could benefit the rest of the Great Bay Estuary.
(this is one step in the long term restoration of the oyster populations in the state, we’re in the neighborhood of five percent or less of what they were even 15 years ago)
A Nature Conservancy report shows that the Great Bay was once home to 1200 acres of oyster beds.
Now there are less than 50 acres.
Researchers believe a disease called MSX wiped out much of the population.
Although overharvesting and pollution have also played a role.
But Ray Konisky, Director of Marine Science at the Nature Conservancy, says it’s important to bring the oysters back because they filter and clean the water.
(the latest measures show about a 60-percent increase in nutrients in our system and oysters can remove a lot of those nutrients you get algae blooms and oysters feed on that and can take them out at the same time we’ve got increase in the amount of sediment in the system that makes water quality poor and oysters can trap sediments as well)
Konisky says today it takes about 500 days to filter the same amount of water the historic oyster population would have filtered in three to four days.
Doctor Grizzle with UNH has worked to restore about six acres of oyster reefs since 1999.
He’s also planted disease tolerant baby oysters on reefs to help jump start the population.
But the success rate of the reefs is a mixed bag.
(the amount of success would be dependent on when we sample, all this is up and down, one of the ten year old reefs is completely gone, others have come back, the shell material was left, we lost a lot of the oysters we put out, but we caught a good natural set.)
Grizzle says part of the problem for researchers boils down to money.
Grants may pay for only one or two samples over a two year period.
To really determine a reef’s sustainability more time is needed.
(The funding needs to be longer term so that we can have a longer term protocol developed to better ensure their success, the fact that I can’t even tell you the conditions of my reefs is because I don’t have the funding to go back and sample the reefs.)
Ultimately, researchers hope to build oyster reefs in all five of the rivers that feed into the Great Bay.
Again, Ray Konisky with the Nature Conservancy.
(This is a very small footprint for a very big problem, a fifth of an acre of a reef is a start but it’s a long way to go)
For NHPR news, I’m Amy Quinton.