December 20, 2012
by Shelley DawickiClick on photo to launch slide showResearchers in two small boats look for harbor seals near Moriches Inlet. The pink top of the gillnet, used to capture seals, is visible to the left. Photo credit: Lanni Hall, NERO/NOAA
Superstorm Sandy Sandbags Harbor Seal Study on Long Island
A pilot study of harbor seals (Phoca vitulina) on eastern Long Island conducted earlier this month didn’t go quite as planned.
NOAA researchers and their colleagues had hoped to capture, tag and release up to 20 seals on sandbars close to the inlets of Shinnecock and Moriches Bays but found fewer animals than expected. After trying different locations over several days, the researchers captured two harbor seals just east of Moriches Inlet. The team was able to collect a full set of biological samples and affix satellite and flipper tags to one seal. The other seal got away.
One likely factor for the low number of seals: superstorm Sandy. Winds and water moved masses of sand into inlets and onto nearby seal haul-out sites along the south shore of Long Island. Dredging was ongoing to clear navigation channels of debris, more or less in areas where seals would usually be and where researchers would need to maneuver to capture them for sampling and tagging. Several hundred seals would typically be in the area at this time of year.
"Our primary sampling location was going to be near Shinnecock Inlet, but we saw so few seals there that we decided to focus on the secondary site at Moriches Inlet," said Gordon Waring, who heads the seal research program at NOAA’s Northeast Fisheries Science Center (NEFSC). "Initially we saw 30-35 seals at one haulout site at Moriches Inlet, but they quickly dispersed and stayed away. The beach itself and the shoals offshore have changed significantly since the storm. We don’t know what additional effects the dredging work is having on the seals. They are probably uneasy with the disruption in the water and on the beach and don’t aggregate or stay around for long."
The December 6-10 pilot field program, part of the ongoing seal research program at the Northeast Fisheries Science Center, was the first conducted by the Center on Long Island. The project is intended to learn more about how the seals use local habitats, where they go in the winter, and what routes they use to travel to their usual breeding grounds in Maine and Canada.
Tagged animal movements can be tracked by satellite. Biological samples collected can be used for health assessment studies and for comparison to samples from stranded animals encountered in 2011-2012, when an unusually high number of young seals stranded dead in northern New England. Studies similar to those planned on Long Island were conducted in Chatham, Mass. and Rockland, Maine in March and April 2012. (http://www.nefsc.noaa.gov/news/features/seal_capture/)
"Weather conditions, limited hours of daylight, and the availability of researchers and equipment are among the realities of conducting this type of field research in December," Waring said, noting that seals in the area looked healthy but appeared more skittish than usual when the researchers approached.
"Although we didn’t get the data we had hoped for, we learned a lot about the locations and how the habitats have changed, and we plan to return next year with more options," Waring said. "It will be interesting to follow the one seal that we did tag, a female, to see where she goes and what she does in the coming months."
A dozen experienced marine mammal researchers, most of whom have worked together on seal field programs in Massachusetts and Maine, based their local operations at the Riverhead Foundation for Marine Research and Preservation in Riverhead, New York, on the south shore of Long Island. The team included five researchers from the NEFSC’s Protected Species Branch in Woods Hole, Mass., two colleagues from NOAA Fisheries Northeast Regional Office in Gloucester, Mass., one researcher from the Woods Hole Oceanographic Institution, and four researchers from the Riverhead Foundation. Co-leaders of this field program were Gordon Waring from the NEFSC and Robert DiGiovanni from the Riverhead Foundation for Marine Research and Preservation.
"We know the animals migrate and do not stay in one place. Satellite tags give us a great deal of detailed information about seal behavior, from physical location, water temperatures and dive depths, to how long they haul-out and where," Waring said. "The tag should stay on the seal we tagged on December 9 until she molts or sheds her fur next summer, which we expect to occur in July or August."The Protected Species Branch at the NEFSC’s Woods Hole Laboratory is responsible for assessing the status of marine mammal populations and other federally protected species off the northeast U.S. coast, from Canadian waters to Cape Hatteras, N.C. Among the animals studied are whales and dolphins, seals, and sea turtles.
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# # #
NOAA Fisheries Service is dedicated to protecting and preserving our nation's living marine resources and their habitat through scientific research, management and enforcement. NOAA Fisheries Service provides effective stewardship of these resources for the benefit of the nation, supporting coastal communities that depend upon them, and helping to provide safe and healthy seafood to consumers and recreational opportunities for the American public. Join NOAA Fisheries on Facebook, Twitter and our other social media channels.
NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Twitter, Facebook, Instagram, and our other social media channels.