Journals 2003/2004

Margaret Brumsted
Dartmouth High School, Dartmouth, Massachusetts

Today, among other tasks, we completed the quahog sorting, sizing and counting. The work is hard, but rewarding and the views across the Great Salt Pond are beautiful. There is a constant parade of vessels and we can almost chart the passage of the day by means of the train-like whistle of the heavily loaded tourist ferryboat.

The Floating Upweller System or "FLUPSY" is a marvelously simple piece of engineering. Built to withstand the wakes thrown by the hundred of boats that pass by daily, the upweller looks just like any floating dock. The FLUPSY is a proven method for culturing small shellfish seed through their delicate nursery stage.

Seed sized shellfish are vulnerable to many predators including but not limited to, crabs, toadfish, flounders, and various waterfowl. It is vital to grow the juveniles out to a "predator proof size" before beginning the process of reseeding areas in the salt ponds that were impacted by the North Cape Oil Spill. The FLUPSY, not only protects the vulnerable young bivalves from predators, but tremendously increases their growth rates by providing a constant flow of water laden with nutritious phytoplankton.

So how does this thing work? There are four "silos" which look like large plastic boxes, about three cubic feet in volume, on each side of a long (eight feet) trough. The silos have screen material on the bottoms and the quahogs rest on the screen. Each silo is attached to the trough at the top by a PVC tube. At the end of the trough there is a small, one half horsepower, electric motor with a propeller. The propeller basically sucks water out of the trough, which in turn sucks water through the PVC pipe and up from the bottom of the silo. This forces a steady stream of water up through) the silos and provides a constant flow of food past the hungry juvenile quahogs. Approximately 100 gallons of water per minute flow through this system bringing food and oxygen to the quahog seed.

The quahogs are now separated into slow growers and fast growers. Stocking densities have been thinned out and we are now able to make some estimates of numbers of quahogs currently residing in the upweller. I am absolutely astounded by the lack of mortality. All of these millions of individuals being reared with very little lose from predation. It is also amazing to me that this entire operation is so low impact. No food costs, very little waste and a modest expenditure for electricity!