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THE MAINE EVENT: FALL 2003 Predation by Gelatinous Zooplankton in the Gulf of Maine MISSION DISPATCH 1 • Tuesday, September 9, 2003 Location: Wilkinson Basin (42° 28'N, 69° 42'W) Dispatch by Harry Breidahl - Marine Education Society of Australasia [MESA] After sailing from its home base in Fort Pierce, Florida the R/V Seward Johnson berthed at the NOAA Pier in Woods Hole, Massachusetts on Sunday September 7th. The ships' crew, some of the science party, technical support group and the submersible crew were on board for the long and rather lumpy transit north. The remainder of the ships' compliment flew into Boston on Monday 8th then drove south to join their shipmates. 
The new arrivals made for a complement of around 30 on board for the Fall 2003 Maine Event. As is the case with most
HBOI research cruises, the scientific party had flown in from far and wide. Nations represented include Finland, Norway,
Spain and Australia. Some of the marine scientists have participated on previous Maine Event cruises and bring many years
of oceanographic experience to the program. Other important components of the science group are the graduate and
undergraduate university students who will conduct thesis projects and broaden at-sea skills. The main research tools
are the manned submersible JOHNSON SEA-LINK II (JSL) and
a multi-net system called MOCNESS.
Early plans had the R/V Seward Johnson steaming out to the deep water canyons south of Georges Bank on the evening of Monday 8th. However, the influence of storms to the east and south revised this schedule. We slipped away from the dock at 7.30 am on Tuesday and sailed for the relatively calm, 300-m deep site in Wilkinson Basin. A few days of JSL sub dives and MOCNESS tows are planned at this location, during the first segment of this 19-day cruise. 
As we traveled through the Cape Cod Canal, it was fascinating to see the science party and sub crew engaging in the usual
process of outfitting the JSL with detritus samplers, 'critter gitter' buckets, scaling lasers and environmental sensors.
This passage also provided a brief period of calm water before those of us who needed a little time to find our sea-legs
headed below as we entered a choppy sea.
Once reaching Wilkinson Basin, the Fall 2003 Maine Event research program began with a JSL sub dive at 8.30 pm. This plunge was number 3436 for Johnson-Sea-Link II. It is amazing to think that this versatile submersible is approaching its 3500th dive. Although a few things didn't happen as to plan, the initial dive was regarded as a successful shake-down. Siphonophore Nanomia cara colonies were scarce and appeared only at 20 m near the base of the thermocline. However, other gelatinous zooplankton called ctenophores (Bolinopsis infundibulum and Beroe cucumis) were common throughout the water column. A few of these ctenophores were collected to begin tests of micro opodes, special optical devices that will be used to measure respiration 
rates. Copepods were also obtained for University of Rhode Island graduate student
Whitley Saumweber to begin his study of
the respiration rates of the resting stage of the
copepod Calanus finmarchicus.
More detail about these studies of metabolism
will appear in subsequent dispatches.
Fun facts for the day • The R/V in the name R/V Seward Johnson I stands for Research Vessel. • There are two critter gitters on JSL. They are composed of tubes with a funnel at one end (you could say the business end), a series of 12 rotating storage buckets, and finally a pump at the other end that creates suction. These tubes can capture a vaitey of planktonic organisms and are especially useful for obtaining the fragile colonies of our main target species, the siphonophore Nanomia cara. • Detritus samplers are another kind of collection device. They are mounted on a rack situated in front of JSL. The hydraulically operated lids (both top and bottom) dswivel from open to closed to capture the very delicate gelatinous fauna. • Here's one for you to work on yourself, what does the acronym MOCNESS stand for? (hint the words multiple, opening and closing are in there somewhere). The answer will be in the next dispatch.   |  |
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