NOAA, NY town and Oyster Farmer collaborate to understand impact of floating shellfish nursery

With demand for seafood growing, shellfish farmers often use a floating nursery called a FLUPSY, or Floating Upwelling System, to improve growth of very young shellfish known as seed and increase their chances of surviving until they are harvested. Little has been known about the possible impact of these floating systems on the local environment.

A collaborative project between a commercial oyster farmer, the Town of Riverhead, N.Y., and scientists at the Northeast Fisheries Science Center's (NEFSC) Milford Laboratory in Milford, Conn., is measuring the effect of a FLUPSY on water quality and sediment characteristics in Riverhead's East Creek.

"The Town of Riverhead was interested in knowing the potential effect, if any, of the FLUPSY on the water quality in East Creek before issuing any further permits to local oyster growers," said Gary Wikfors, who heads the Milford Lab's Biotechnology Program. "A commercial grower, Karen Rivara, also wanted to know if there was any effect since her livelihood depends on a healthy environment for growing shellfish. We were interested in conducting water quality studies that might help commercial shellfish farmers and the town."

A FLUPSY is a floating dock with small silos or barrels underneath that contain shellfish seed on screens. Surrounding water is pumped up through the silos, enabling the one to ten millimeter long (less than a third of an inch) seed to grow much more quickly and more uniformly than in natural conditions because the young oysters receive a constant supply of food and oxygen from the water.

FLUPSY's have grown popular in coastal areas in the last few decades to culture and protect small shellfish seed through the delicate nursery stage, from the time they leave a hatchery until they are large enough to be placed in shellfish beds in coastal waters to grow to harvest size.

Wikfors' team of biologists, microbiologists, ecologists, chemical oceanographers and lab technicians visited the East Creek site for a pilot study in 2008. They returned four times during the summer and fall of 2009, the last time in early October.

Each time the team brought a mobile laboratory, complete with sophisticated analytical instruments like a variable fluorescence fluorometer and a flow cytometer. The fluorometer measures how much light for photosynthesis or growth a phytoplankton sample is exhibiting, while the flow cytometer measures physical and chemical characteristics of individual cells in the water samples.

When the team arrived on site for a 24-hour experiment in September, Mark Dixon, a biological science technician, set up eight large clear plastic bags suspended from floats on the side of the FLUPSY. Four of the bags were filled with water from the creek before it had been pumped through the FLUPSY, while the other four were filled with water that had come through the FLUPSY. Water samples were then taken from the bags every three hours and split into many smaller samples for various studies.