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THE MAINE EVENT: FALL 2003 Predation by Gelatinous Zooplankton in the Gulf of Maine MISSION DISPATCH 3 • Friday, September 12, 2003 Location: Georges Basin (42° 18'N, 67° 30'W) Dispatch by Harry Breidahl - Marine Education Society of Australasia [MESA] Today is our third day at Georges Basin and the weather is holding well - for the present. The crew of the R/V Seward Johnson is monitoring the progress of hurricane Isabel to our southeast. This huge storm could make our lives uncomfortable, especially if the turbulence moves toward the Gulf of Maine. Hurricane Isabel is a timely reminder of how much oceanic research is influenced by events beyond human control. 
By midnight Friday the
scientific party had completed five successful dives in
JOHNSON SEA-LINK II (JSL), two
MOCNESS net tows and one CTD cast at this
location. Colonies of
Nanomia cara
are abundant at Georges Basin, and distributed in a narrow 30-meter (100-foot) thick layer beginning
at 220 meters (720 feet). Unfortunately, the failure of a pump aboard the JSL II has curtailed the collection of Nanomia for stomach
content analysis. The problem is minor and the sub crew will be able to solve it before the next dive tomorrow morning.
While this aspect of The Maine Event 2003 program is currently limited, other segments are firing along nicely. Per Flood has been comparing and documenting morphological differences among midwater appendicularians collected during last year's Maine Event. Many of these fragile animals are undescribed species and we'll be searching for more specimens on this cruise. The work of graduate students Aino Hosia, Whitley Saumweber and Brian Ortman is progressing well. Much of Aino's time is spent monitoring recently developed optical technology that uses fluorescence quenching to log oxygen consumption rates of freshly captured colonies. Nanomia is maintained in one of two cold rooms on the R/V Seward Johnson for these experiments. This project provides an opportunity 
for comparison with Whit's study of copepod respiration rates. Brian is collecting and flash-freezing a range of gelatinous fauna for
genetic studies. The DNA content of these samples will be investigated with special instruments when he returns to laboratory
facilities on land.
Over the past few days, all three graduate students have taken their first dive into the deep-sea aboard JSL II. This versatile submersible has two crew compartments. The front chamber is an acrylic sphere that provides almost 2700 of view for a scientist. The aft chamber, which is made of aluminum, has room (just) for a second member of the sub crew and a second scientist. There are two small viewing ports on either side of this compartment. The opportunity to see planktonic animals behave in their natural habitat is, in a commonly expressed word, "awesome." 
The youngest person on board the R/V Seward Johnson,
Nicole Shach made her initial dive
on September 12, her 22nd birthday.
What better treat (at least for a budding marine biologist) than a up-close visit to the briny realm of Nanomia cara and its
gelatinous cousins. This JSL II dive was number 3440. Scientist
Marsh Youngbluth shared the front compartment
with sub-pilot
Dan Boggess and sub-pilot Tim Askew Jr dove in the aft compartment with Nicole. Following her dive, Nicole donned bright orange
overalls and helped process colonies for analyses of the prey they consumed.
Fun facts for the day • You should already know what MOCNESS stands for but what about CTD? Go back to the first dispatch to find that one out. • Now for more bathy words. Remember bathy is Greek for deep and Bathybiologica means the study of deep life. Here are a couple more - bathysphere and bathyscaph. The term bathysphere was coined by scientist William Beebe and engineer Otis Barton in 1930's to describe the steel pressure sphere they used near Bermuda to explore as deep as a half mile down. Bathyscaph means deep boat (bathy = deep and scaphos = boat). In 1960, bathyscaph Trieste descended to 35,813 feet (10,916 meters) with two men aboard. The bathyscaph Trieste held the record for the deepest diving vessel for over 40 years. • The two men aboard Trieste for this historic dive were Jacques Piccard from Belgium and Don Walsh from the United States. They dove in the Marinas Trench, the deepest ocean trench on earth. It is interesting to note that only these two men have reached the bottom of the ocean while 12 men have walked on the moon.   |  |
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