Bottom habitat on Jeffreys Ledge
(Photo credit: Kathryn Ford, MA Division of Marine Fisheries)
Bottom habitat on Jeffreys Ledge (Photo credit: Kathryn Ford, MA Division of Marine Fisheries)
Cold water coral (Photo credit: Tane Casserley, NOAA)
Ever wonder what unique features a codfish looks for in a home? A team of scientists from federal and state agencies and academic institutions hope to learn more about this when they explore various seafloor habitats where cod and a variety of other marine species live. On Monday, August 29, scientists began a five-day research survey cruise to collect information on the seafloor, sediment and underwater footage of bottom habitat in a historically significant fishing area known as Jeffreys Ledge.
Jeffreys Ledge is a 33-mile glacial deposit that extends from the coast of Rockport, Massachusetts to just southeast of Cape Elizabeth, Maine. The shallow ledge is surrounded by deeper ocean waters. An oceanographic process known as upwelling occurs here that makes it a highly productive habitat. Upwelling involves a wind-driven motion, which brings dense, cooler, and usually nutrient-rich water towards the ocean surface. As a result, the Ledge supports a diversity of life including herring and mackerel, cod, haddock, dogfish, flounder, bluefin tuna and a variety of crustaceans and mollusks, such as shrimp, lobsters, crabs, scallops, and clams, which all come to feed or reproduce here.
Project partners include the National Oceanic and Atmospheric Administration (NOAA), the New England Fishery Management Council, the Environmental Protection Agency (EPA), the Massachusetts Division of Marine Fisheries, New Hampshire Fish and Game and the Army Corps of Engineers, New England District and the Piscataqua Region Estuaries Partnership.
Scientists will work in shifts, around the clock, to deploy video and sonar equipment so they can learn more about the different bottom types that make up this area. Specifically, they will use a sediment profile image system, sidescan sonar and an underwater video camera during the research survey. Collected data will be used by the New England Fishery Management Council to aid in its understanding of the vulnerability of certain habitats to the effects of fishing gear and as a basis for developing management measures to avoid or reduce adverse impacts to habitat. The video camera system will be provided by the School for Marine Science and Technology (SMAST) at the University of Massachusetts in Dartmouth.
NOAA Fisheries, Northeast Region, Habitat Conservation Division scientist, Dr. David Stevenson and Massachusetts Division of Marine Fisheries scientist Dr. Kathryn Ford, who serve on the Fishery Council’s Habitat Team, hope that collected data can be incorporated into the Council’s Swept Area Seabed Impact model, an evaluation tool that will inform future management decisions.
“This study will help us learn more about the bottom types and structures such as sponges and rock formations that create habitat for managed species of fish in this area,” said Stevenson. “It will help us determine which areas on Jeffreys Ledge need to be managed in order to minimize the adverse impacts of fishing on sensitive marine habitats and what areas can be fished without jeopardizing habitat.”
Habitat Team Chair Michelle Bachman added, “The team has spent a lot of time identifying data gaps in the Jeffreys Ledge area. It’s exciting that the sampling plans for the survey will build directly on our efforts by providing much needed additional information. I’m confident this research will benefit the fishery management process.”
According to Ford, who helped organize the cruise with the Environmental Protection and the Army Corps of Engineers, the science crew will be assigned a range of duties. “We will collect and analyze video and photographs to characterize the seafloor and the marine life in specific locations around the ledge. The work will entail deploying the cameras at specific stations and then analyzing the video data for sediment types and marine life.” This work will augment previous research cruises in the area conducted by the University of New Hampshire and SMAST.
The Environmental Protection Agency and the Corps also plan to conduct followup investigations to a 2010 study, which used sidescan sonar to characterize the seafloor and sediment to determine grain size (e.g. whether an area was rocky, sandy or gravel) and using the Sediment Profile Image System to assess benthic diversity/biomass -- that is the number of species, and type of each species present.
“This time we will be working with the Corps to conduct investigations of dredge material disposal sites near Cape Arundel, Maine using our state-of-the-art research vessel,” said Jeannie Brochi, chief scientist for the survey, Environmental Protection Agency.
The Ocean Survey Vessel (OSV) Bold, the Environmental Protection Agency’s ocean and coastal monitoring vessel, will serve as the platform for this research. The OSV Bold is equipped with state-of-the-art sampling, mapping, and analysis equipment including sidescan sonar, underwater video, water sampling instruments, and sediment sampling devices, which scientists can use in various monitoring activities. The vessel is a converted Navy T-AGOS class vessel and is 224 feet long and 43 feet wide. EPA acquired the OSV Bold on March 31, 2004.
The research survey will conclude with an open house on Sunday, September 4 from 10 am to 4 pm at the New Hampshire Port Authority State Pier, 555 Market Street, Portsmouth New Hampshire. The public will have an opportunity to participate in free tours of the vessel and speak to researchers about what they learned on the survey.
Be sure and check back on this site to stay up on what scientists are learning as they complete the survey or check the Environmental Protection Agency site at
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