From 2011-2017 a series of research projects in the Bronx River in New York City and near Bridgeport Harbor were conducted, involving federal and university scientists, a commercial shellfish grower, a local youth organization, and an aquaculture high school to evaluate the potential of shellfish aquaculture and seaweed cultivation to remove excess nutrients in Long Island Sound. Photo by NOAA Milford/Mark Dixon

The Bronx raft was built, installed, and maintained by Pemaquid Mussel Farms, a commercial mussel-aquaculture firm. Pictured is the raft being assembled at Rocking the Boat in the Bronx.

The raft is lowered into the Bronx River for transport to the mouth of the river.

Mark Dixon and Gary Wikfors, of the NOAA NMFS Northeast Fisheries Science Center Milford Laboratory are deploying a few meters of socked mussels on the Bronx River to test attachment and retention of ribbed mussels on the raft dropper lines that were designed for a different mussel species, the blue mussel.

Students from Rocking the Boat, a local youth development organization, help hang lines during the raft installation.
Mussel Raft Installation, Photo by NOAA Milford/Mark Dixon

A student from Rocking the Boat installs a coconut fiber log in a salt marsh along the Bronx River. These logs were used to try to catch baby mussels to hang from the raft.

Ribbed mussels in their natural salt marsh habitat. Photo by NOAA Milford/Mark Dixon

Ribbed mussels suspended from a “pegged rope.” These ropes are hung underwater from the mussel raft. The cage is used to protect the mussels from predators.

An underwater example of a mussel sock hanging from a raft.

NOAA scientist Mark Dixon filters water in the Bronx to see how much food is naturally available for the ribbed mussels. NOAA’s Milford Laboratory monitored local Bronx water quality, mussels from the Bronx raft, as well as mussels found naturally in the Bronx River, to measure impacts of the mussels on local water quality.

Individual mussels in experimental chambers. Bronx River water is pumped over the mussels in order to measure how much plankton they eat.

Gracilaria tikvahiae, a seaweed, is cultivated at a tank Tank cultivation of  Bridgeport Regional Aquaculture Science and Technology Education Center(BRASTEC), a high school aquaculture school. UConn scientists transported the juvenile  kelp to to install and monitor seaweed grown on longlines alongside the mussel in the Bronx, and in Bridgeport.

Longlines “seeded” with juvenile kelp

Charles Yarish, a marine biologist from University of Connecticut, second from left,  leading a team pulling the Gracilaria, a seaweed, attached on lines, off Bridgeport Harbor on Sept. 15, 2011.

Eight-month old kelp plants grown from microscopic spores.

Graphic explains how nutrient bioextraction, growing shellfish and seaweed to remove excess nutrients such as nitrogen, can improve water quality. EPA’s Office of Research and Development provided funding to model the potential benefits of Connecticut’s oyster aquaculture industry on reducing excess nutrients in Long Island Sound, and to provide an economic assessment of shellfish nutrient bioextraction. Project summaries of the nutrient bioextraction pilot studies and the economic assessment are available on the Long Island Sound Study website.