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MISSION DISPATCH 8 • 4/23/01 Today's Weather - images courtesy of NOAA & RSMAS 0600 - Back to Shore for a Quick Drop-off The R/V SEWARD JOHNSON steamed in to the fueling dock in Fort Pierce early Monday morning to drop off Science Team member Alexander Bochdansky and to change out a member of the ship's crew. Then the ship headed back out to the Gulf Stream to resume a series of planned science dives aboard the JOHNSON SEA-LINK I 
research submersible. Adverse wind and wave conditions had forced the suspension
of submersible operations for the past two days.
1100 - Sea Conditions Begin to Improve By the time we made the western Gulf Stream, the winds had dropped to 18 knots, and seas had calmed to approximately 3-5 feet. Plans to conduct another day of MOCNESS sets began to look less appealing as the chances of resuming sub operations improved. By 1445, the Sub Crew had consulted with ship's captain, Ralph Van Hoek. Shortly thereafter, Chief Sub Pilot Don Liberatore green-lighted an afternoon dive. 
The next hour was spent preparing the submersible to make the dive, and readying the
shipboard labs to receive animals for study.
Unlike the three prior successful science dives of the mission, this afternoon's dive was a long (3.5 hour) dive targeting deepwater (>1,400 feet) appendicularian species. Shallow dives to collect the large Bathochordaeus stygius are not possible by day because they inhabit the photic zone and are difficult to see within the sunlit water column. 4/23/01 • JOHNSON SEA-LINK I - DIVE #4283 28°32.37' N • 79°45.81' W • Western Gulf Stream, off the northern Canaveral Peninsula, Florida Personnel - Sphere • Sub Pilot: Don Liberatore • Scientist Observer: Russell Hopcroft Personnel - Aft Chamber • Tender: Alan Fuller • Diver: Christina Bendix Launch Time: 1553 • Time to Surface: 1920 • Dive Duration: 3 hours, 27 minutes 
By 1640, the JSL I had begun exploring the water approximately 30-50 feet above the sea floor,
in 1,500-1,600 feet of water. Extensive video footage was shot of several deepwater appendicularian
species during the dive, and samples of living animals and/or feeding houses were collected in
detritus samplers.
While the sub dive is underway, minute-by-minute progress is monitored from the Bridge of the R/V SEWARD JOHNSON. First Mate Robbie Shakespeare, and Sub Crewmen Phil Santos, Jim Sullivan, and Dan Boggess track closely the position and movements of the JSL, despite its location more than 1,500 feet below the sea surface. It's serious work, but that doesn't stop Dan from subjecting the rest of the group to several painful jokes that went something like: "My Uncle Otto was an amateur photographer until he met a tragic end; he accidentally locked himself in his darkroom and died from exposure." Fortunately for the team on the Bridge, the sub can only stay down for a few hours. 1930 - Meanwhile, Back in the Lab... Upon return to the surface and safe recovery aboard the R/V SEWARD JOHNSON, the Science Team sets to work on a variety of research tasks. Dr. Vicki Fabry adds a seawater suspension of Latex microspheres of various dimensions to appendicularian-containing detritus samplers, to determine if certain particle sizes are preferentially retained by particular species. Thus far, the rigors of being collected and subsequently 
jostled about within the JSL's samplers has lead to all animals abandoning their feeding
houses before the shipboard science team could make observations. For the animals in the
microsphere feeding experiment to successfully consume and process particles, they must first
construct and take up residence in new feeding houses. Some species do this more readily
than others under laboratory conditions, and we are currently inspecting the animals every
fifteen minutes to ascertain whether they have inflated new houses.
Meanwhile, Drs. Marsh Youngbluth, Per Flood, and Russ Hopcroft pour over video footage from the sub dive, scrutinize the animals in today's collection, and attempt to verify the taxonomic identities of the species collected. At first look, it appears two or three distinct species are represented by the collection, but conclusive identifications are still forthcoming. Among the less exciting tasks of the evening, fecal pellets must be retrieved from the bottoms of the detrital samplers. Examination of the fecal casts of the appendicularians will provide information on the types and origins of the food particles that the animals have consumed. Specifically, notes Chief Mission Scientist Dr. Marsh Youngbluth, analyzing fecal pellets will tell us about the sorts of food ingested but not assimilated by the animals. 4/24/01: 0137 - Three More Dives Set For Tuesday As I finish up this dispatch in the early hours of Tuesday, there is still considerable activity aboard the ship. The Science Team investigators are still at work in the lab, making observations, taking notes, happy to be back in business. Some of the Sub Crew are talking in the dining room, while others play cards in the lounge with some of the junior members of the Science Team. 
The first of three Tuesday dives is scheduled for 1630. It will be a short (1 to 2-hour) dive, but it will focus on collecting deepwater species, similar to the dive this afternoon. The final two dives of the current mission will take place over the evening and early morning hours on Tuesday and Wednesday, and will return to shallow waters (less than 100 meters). Hopefully the weather will hold out for our final 36 hours at sea, and the Science Team will be able to accomplish its primary research objectives. Join us here to see how the cruise wraps up. This expedition is made possible through a grant from the Biological Oceanography Program of the National Science Foundation with additional support from Harbor Branch Oceanographic Institution.  | |
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