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THE MAINE EVENT: FALL 2004 Predation by Gelatinous Zooplankton in the Gulf of Maine MISSION DISPATCH 6 • Sunday, September 19, 2004 Dispatch by Francesc Pages - Institute of Marine Science, Barcelona, Spain Today the ship steams nowhere. The captain has positioned us south of Nantucket to escape from the worst effects of gale force winds. Submersible dives are cancelled 
for the next 24 h. However, all
of us are busy, either examining fauna already collected (Franz, Per, Francesc and Brian), photographing
animals in the plankton kreisel (David and Per), updating the databases (Chuck
and Jessica) and conducting respiration experiments (Marsh, Chuck, Celeste, Jessica, Ulf, Calle,
Ebba and Sophie). The uncertainty about when the next dive will be scheduled and the lack
of new material from the deep fill the atmosphere onboard.
Last night, the submersible descended to 2,985 feet (910 meter) in Oceanographer Canyon. The sea floor at this location was quite vertical and large bolders were common. The strong current rubbing the canyon walls probably enhanced the abundance of particles suspended in the water. Large mats of a pinkish octocoral extended perpendicular to the wall, and pairs of bright eyes, probably shrimps,were seen among the large 
polyps. Solitary scleractinians, sponges, brittlestars and
seastars were obvious. We searched for benthopelagic medusae living attached to the bottom, as we
know that they occur in submarine canyons of other oceans, but none were seen.
On the slow ascent towards the sea surface, we encountered a very high diversity of pelagic life forms, higher than observed on the dives conducted in this canyon during 2002 and 2003. At 2,628 ft (801 m), we observed a large bright red shrimp with whitish branches attached to its rostrum. We think that the branches were hydropolyps. Sub pilot Phil Santos carefully maneuvered the submersible and attempted to suck the shrimp into the starboard funnel. But when one of its long antennae touched the funnel surface, this crustcean responded like a rocket leaving us as astonished as when we first saw the animal. Another red shrimp with hydropolyps attached was noted at 2,881 ft (878 m) depth. But there was no chance to collect this individual. Ctenophores, myctophid fishes and cephalopods were the most abundant animals in the water column. The most noticeable increase in density was recorded for hydromedusae, in particular the narcomedusan Cunina sp. and the trachymedusan Crossota rufobrunnea Kramp (1913). Their identity 
was verified onboard after examining several specimens. These two species were not
observed during
previous cruises and their tiny size (0.7-2.5 cm diameter) made the verification
of the identifications impossible from the sphere. Cunina and Crossota were abundant in the 2,308-2,999 ft
(711-914 m) and 2,395-2,940 ft (730-896 m) ranges, respectively. We tried to catch eelpouts that
occured from 2,356-2,972 ft (718-906), but we were unsuccessful. The
physonect siphonophore Nanomia
cara was numerous from 1,670-2,979 ft (509-908 m) and this species was the only physonect observed
throughout the dive. We collected several colonies to continue our investigations of the fauna they
consume.
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