Stepping Stones to Georges Bank

The Provincetown shoreline, with Pilgrim Monument, fades into the distance as Delaware II departs February 9. (Photo by Jerry Prezioso, NEFSC/NOAA)

The rattling anchor chain breaks the Wednesday morning stillness off of Provincetown as the Delaware II leaves its anchorage at 11 AM.   After spending Tuesday night sheltered from the seas in this secure spot at the very tip of Cape Cod, the Delaware is ready to take advantage of the morning’s rapidly diminishing sea conditions and get back to work.  First stop is just outside of Boston Harbor, followed by stations to the southeast.    We work our way along a line of stations arranged like stepping stones to Georges Bank, which we reach by early Thursday morning.

Crewman arranges anchor chain below deck

Crewman Richard Logan arranging the anchor chain below deck as the anchor is raised. (Photo by Jerry Prezioso, NEFSC/NOAA)

Now, in the wee hours of Saturday morning, we are poised to cross over the Hague Line into Canadian waters. The weather has remained workable since leaving Provincetown, not calm by any means, but with alternate periods of increasing, then decreasing winds and seas, allowing us to make good progress sampling our way across Georges Bank.

sunrise at sea from DE II
Sunrise Friday morning, Feb. 11. (Photo by Chris Melrose, NEFSC/NOAA)
DBongo net deployemnt

Double duty: A LISST unit on the tow wire next to the CTD unit and above the bongo net. (Photo by Jerry Prezioso, NEFSC/NOAA)

We’ve modified one of our procedures to accommodate rough sea conditions. The Laser In-Situ Scattering and Transmissometry (LISST) unit  has been transferred from the rosette Niskin bottle array directly onto the tow wire adjacent to the Seabird CTD unit.  Now every time we do a bongo plankton tow we are also collecting data on the size spectrum of water column particles from 2.5 to 500 microns.  This will give us a LISST data set to match with temperature and salinity data from the Seabird CTD unit for all of Georges Bank and the Gulf of Maine.

Plankton catches in the Gulf of Maine have had modest numbers of Calanus copepods at several stations, and moderate numbers of euphausiids in tows done at night. There have been Pleurobranchia comb jellies in some of the samples, but very few fish larvae at either the Georges Bank or the few Gulf of Maine stations we have sampled so far. Many of the Georges Bank samples have some quantities of Phaeocystis, algae whose cells are embedded in a polysaccharide gel matrix that forms a sticky mess when washing down plankton nets and trying to examine what’s in the sample.

Taylor at microscope

Scientist Chris Taylor examines plankton samples under a microscope for Calanus copepods. (Photo by Jerry Prezioso, NEFSC/NOAA)

Chris Taylor, one of the scientists on board, has been looking through a microscope , not an easy feat under these conditions, and picking Calanus from some of the tows. He freezes some in liquid nitrogen and preserves others in ethanol. These will be tested for signs of environmental stress at the Narragansett NEFSC Laboratory.

Even after almost two weeks at sea, everyone aboard remains in good spirits.  Surrounded by weather conditions that often have a scenic beauty and treated

Jon Rockwell, Chief Steward, serving just-baked pizza. (Photo by Jerry Prezioso, NEFSC/NOAA)

to an endless stream of delicious meals from the galley, how could we not be?  We are ready to forge ahead into the Gulf of Maine!

Jerry Prezioso
Chief Scientist
DE 11-02 Winter Ecosystem Monitoring Cruise

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