Like living motors, each individual oyster is able to filter 50 gallons of water every single day. Multiply that by thousands and you can see why environmentalists are keen on repopulating the waters around Long Island with these busy little bivalves.
On both the North and South Shore, people are planting oyster beds to help bring the water quality on Long Island back to pre-1970s levels.(Shellfish are filtering only 1 percent of the water right now, compared to 1976 when they filtered up to 40 percent.)
Recently, the Town of Brookhaven was awarded a Long Island Sound Futures Fund (LISFF) grant to investigate the potential of using oysters to improve water quality in the Long Island Sound. The $79,640 LISFF grant aligns with a Brookhaven Town match of $87,500.
Oysters will be used to remove aqueous pollutants like nitrogen and suspended sediment, and to examine if planted oysters can reseed depleted populations.
Setauket Harbor Task Force Trustee, George Hoffman said he was happy to learn that the Town of Brookhaven included Setauket Harbor and Conscience Bay as part of its Long Island Sound Study grant for spawning and seeding oysters in Port Jefferson harbor.
“Oysters have an extraordinary ability to filter water and remove excess nitrogen and C02 from harbor waters,” said Hoffman.
The 2021 LISFF grant is an extension of Brookhaven Town's 2019 LISFF oyster grant, which the Town days was a great success. The grant fosters collaboration between Brookhaven Town and Stony Brook University as the project will help support a graduate student to do the field, diving and analytical work.
Pictured at left are Supervisor Romaine and Councilwoman Jane Bonner with oysters raised at the Town’s Mariculture Facility at Mount Sinai Harbor. Pictured at right are planted oysters in cages.
“Oysters play a major role in keeping our waterways clean and reversing the damage done by years of over-harvesting, neglect and pollution,” said Brookhaven Town Councilwoman Jane Bonner. “They are part of a natural plan to filter the water and keep it clean for years to come. Thanks to the LISFF grant, the Town’s Mariculture Center will continue to provide the oysters needed to continue our efforts.”
Although analytical results are still preliminary, some highlights from the 2019 project include:
- 200,000 oysters raised at the Mt Sinai Mariculture Facility at Mount Sinai Harbor were placed in oyster cages in two locations within Port Jefferson Harbor (100,000 oysters per location) in early June 2021.
- Water quality examined every two weeks using “in situ” instruments, known as Sondes, found that oysters are filtering about 40% of the microalgae and increasing water clarity by about 50%, greatly improving water clarity.
- Preliminary analysis of water samples, collected every two weeks, suggest that oysters are removing about 50% of nitrate/nitrite and about 30% of the organic carbon.
- Planted oysters are promoting oyster recruitment up to 10 meters (33 feet) away, with highest recruitment close (<5 meters) to the planted oysters.
- In late October, all oyster cages were removed with 200,000 oysters scattered on the seafloor Like the LISFF 2019 project, the 2021 grant fosters collaboration between the Town and Stony Brook University as the project will help a Brookhaven graduate student gain valuable experience in ecological science.