August 29, 2006
Ferries that connect Cape Cod and the islands of Martha’s Vineyard and Nantucket are taking on another role – research vessels.
Woods Hole Oceanographic Institution (WHOI) biologist Scott Gallager
and colleagues have installed a package of sensors on the 235-foot
freight ferry Katama to measure water quality and to photograph
plankton as the ferry crisscrosses the western side of Nantucket Sound
year-round, several times daily.
“Hitchhiking science on a ferry provides a terrific opportunity for us
to better understand how water quality and ocean life change over
time,” Gallager said. The measurements for the Nantucket Sound
Ferry Scientific Environmental Monitoring System began in May.
With the interest and cooperation of the Woods Hole, Martha’s Vineyard
and Nantucket Steamship Authority, which operates the ferry service
between Cape Cod and the islands, Gallager and colleagues developed a
sensor package to measure water temperature, salinity, oxygen,
chlorophyll, and water clarity, and take images of plankton living in
the water column. Real-time data from the sensors travel over a
wireless connection to Gallager’s shore-based lab, where he and WHOI
colleagues Steve Lerner, Emily Miller, Andrew Girard, Andy Maffei, and
collaborator Kevin Fall from Intel Corporation make them available to
scientists and the public on the project Web site,
The WHOI team will be installing another instrument
package on the Steamship Authority ferry Eagle, which runs between
Hyannis and Nantucket on the eastern side of Nantucket Sound. Their
objective is to build up a detailed, continuous portrait of changing
water conditions and plankton communities in Nantucket Sound over long
Nantucket Sound is a triangular area of coastal
ocean between Cape Cod, Martha’s Vineyard, and Nantucket and is known
for its changing water conditions and diverse marine life. The cold
south-flowing Labrador Current nearby collides with warm water in the
relatively shallow Nantucket Sound, creating a perpetual front just
inside the eastern Sound. As water shifts with the wind and the tides,
warm-water and cold-water species are thrust into the same space.
Waters loaded with nutrients, from septic systems and runoff along the
developed Cape Cod coastline, also mingle in the Sound with North
Atlantic waters that have far fewer nutrients.
Gallager studies plankton, the tiny and abundant swimming animals that
serve as food for coastal fish and marine mammals. The numbers and
proportions of different plankton in coastal oceans change with the
seasons and ocean conditions, and Gallager is interested in the
processes and their time scales that control those changes.
The availability of plankton can make the difference
between healthy and undernourished stocks of commercial finfish and
shellfish. Storms, nutrient runoff from coastal development, and the
warming of coastal ocean waters could drastically alter the types of
plankton that flourish in Nantucket Sound, and therefore the quantity
and quality of food for fish, marine mammals, and ultimately people.
“A long-term archive of how conditions change in Nantucket Sound could
provide an early warning about the health and function of coastal
regions important to our economy and our quality of life,” Gallager
The Nantucket Sound Ferry Scientific Environmental Monitoring System project is supported by the Woods Hole Sea Grant program.