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THE MAINE EVENT: FALL 2003 Predation by Gelatinous Zooplankton in the Gulf of Maine MISSION DISPATCH 13 • Wednesday, September 24, 2003 Location: Oceanographer Canyon (40° 17' N, 68° 07' W) Dispatch by Harry Breidahl - Marine Education Society of Australasia [MESA] As predicted, a cold front passed through the dive site area last night. Strong winds and choppy seas ruled out the sub dive and MOCNESS net tow planned for last night (Tuesday night). This cancellation was quite a letdown because everyone on board is so focused on work that we really didn't know what to do with an evening off. . 
Sadly this morning was a washout as well. Large and lumpy waves seemed to be coming at us from all directions. One
of the deck hands was heard to say "someone really turned on the blender". Some of the science crew took the chance
to snooze, others went on with documentation of recent finds.
Per Flood
continued to update photographic records of
gelatinous fauna collected on this and previous Maine Event cruises.
Francesc Pages reviewed taxonomic descriptions
of similar material.
Aino Hosia, Chuck Jacoby and Marsh Youngbluth
used statistical procedures to analyze micro optode
derived rates of oxygen consumption by siphonophores and ctenophores (comb jellies).
I talked to Second Mate LaVern Taylor about her role at the helm of the R/V Seward Johnson. I learned the ships crew consists of 11 people - 3 on the bridge, 3 engineers, 3 deck hands and 2 galley staff. Watches are set out so that crew members work 4 hour shifts separated by 8 hour off periods. Galley staff adjust their shifts to accommodate the meal periods aboard ship. In addition to the regular crew, Keith Martin and Laurie Roy represent the University of 
Miami technical support team. They are responsible for the MOCNESS and CTD deployments, chemical measurements of
salinity and oxygen, and also keep everyone connected with the world beyond the ship via satellite e-mail links.
Yesterday was Laurie's birthday, our second birthday celebration for this cruise.
Weather conditions gradually improved that afternoon. At 2.00 pm (1400 hours) the announcement of a pre-dive briefing put the spring back into our steps. The Maine Event-2003 was on track again. During this dive Chuck Jacoby occupied the scientist seat next to sub pilot Tim Askew Jr. while, as part of a birthday celebration, Laurie Roy rode in the aft observation compartment accompanied by sub tech Jim Pierce. JOHNSON SEA-LINK II (JSL) dive number 3453 landed on the aft deck by 5.30 pm (1730 hours) carrying a cargo of siphonophores and a dark red deep-sea squid. Most of the Nanomia cara colonies were preserved in situ. These specimens were taken straight to the dry lab for the well-rehearsed routine of gastrozooid (stomach) content analysis. )
One unusual physonect siphonophore was collected. Unfortunately only part of this colony could be captured because the
bright lights of the submersible caused the ultra-sensitive siphonophore to self-destruct, shedding nectophores and
autotomizing half of its stem. Fortunately, the portions that were obtained were sufficient to indicate that the colony
is most likely a new species, according to Francesc Pages. His initial assessment is that this bright red siphonophore
belongs to the genus Marrus. A detailed description required for the establishment of a new species is underway.
The deep-sea squid, also unknown (at this stage), captured on this dive provide an opportunity to test the micro optode system in another way. Oxygen consumption rates by this very active midwater organism were compared to those measured for the less active gelatinous creatures, such as siphonophores and ctenophores. As expected, the squid consumed oxygen at a much faster rate, i.e., about 5 times more in a third of the incubation time. Calm weather prevails now, and the sea will be relatively flat for the next 48 hours. Three more sub dives remain on the schedule. After that we must leave Oceanographer Canyon and return to port at Woods Hole. Fun facts for the day • We know from yesterday that the longest bony fish in the world measured 15 meters (50 feet). It was a rare deep-sea fish called an oarfish. • The largest fish in the world (or should that be the ocean) is a whale shark. Whale sharks can grow to be as long as 18 meters (60 feet). • Now all you need to do is find out how sharks differ from bony fish (hint, sharks are cartilaginous fishes). Also see if you can find out the difference between vertebrate and invertebrate animals because we will be looking at the largest invertebrate tomorrow.   |  |
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