NOAA takes a deep dive into shellfish population
GREENWICH — The National Oceanic and Atmospheric Administration is expected Friday to wrap up a week’s worth of work examining the shellfish population in the waters off the coast of Greenwich.
The NOAA fisheries research vessel the Victor Loosanoff has been in Greenwich since Monday, conducting a shellfish population survey. That research will provide data on the value of shellfish beyond just the seafood market, according to the town Shellfish Commission. It will also look at the role played by shellfish in cleaning the waters of Long Island Sound.
“I’m not sure this has been done anywhere else,” Roger Bowgen, chair of the town Shellfish Commission, said of the research. “It is very important to get this information because clean water is something that can have a lot of impact on the economy of the town.”
Bowgen said he expects to receive a status report on Friday and more comprehensive material by the end of the year.
NOAA, which has a fisheries lab in Milford, is partnering with the Shellfish Commission as well as Stony Brook University to conduct the research. As part of its work, the research team is developing a method for estimating the population of all the clams and oysters in Greenwich’s waters.
The team is working with the commission to connect with Greenwich’s oyster growers so their commercial shellfish resources can be included in the model. The growers have been providing estimates of population destiny, the types of gear they use and the mortality rates, Bowgen said.
“Greenwich is a good model for investigating the benefits of shellfish: the town has a long tradition of shellfish cultivation, has committed to active shellfishing management, and has improved its water quality substantially in recent years,” the Shellfish Commission said in a statement.
The research team is looking at more than 100 randomly selected “stations,” from natural beds to commercial leases. At each station, a 1-foot-square sample is taken from the seabed to a depth of about 6 inches. Using the data from the samples, scientists can determine the clam density across the entire Greenwich seabed, map the relative density of clams and measure the size distribution of clams.
This data is critical in generating a realistic model of Greenwich’s waters and then accurately appraising the town’s shellfish resources.
The importance of shellfish in Greenwich goes beyond the economic benefits for fishermen. Shellfish such as hard clams and oysters feed by filtering algae and other organic materials, which leaves the water cleaner and clearer. Healthy shellfish can improve water quality and prevent the growth of excess nutrients in the water, which can create an overabundance of algae.
This natural cleaning process by the shellfish can make costly work such as wastewater treatment unnecessary.
NOAA’s work in Greenwich is part of a pilot study documenting the local environmental benefits of shellfish and determining how clams and oysters improve the water quality. The study will produce a methodology that other coastal communities can use to quantify the benefits of shellfish, Bowgen said.
This research comes as the Shellfish Commission and the University of Connecticut are partnering on a study of microplastics in Greenwich’s waters. A study in late August in Greenwich examined the shellfish beds close to the shore and in deeper waters. UConn is expected to provide an update later this month or in early November, Bowgen said.
Microplastics come from plastic garbage that gets into the water. Physical degradation and exposure to light can transform plastic into microplastics, which can be practically invisible to the human eye. That barely visible plastic can combine with other pollutants such as pesticides, heavy metals and PCBs in the water.
Microplastics and other pollutants can impair the growth, development and reproduction of oysters, clams and other aquatic organisms and damage the aquaculture industry along the Connecticut coast.