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MISSION DISPATCH 9 August 30, 2005 | Brian Cousin - @SEA Correspondent Parts for the sequence valves that control the braking function of the submersible's tow winch arrived from Ohio and, unbelievably, Alabama, which is struggling with the aftermath of hurricane Katrina. Ship's engineer Kevin Bradley took the parts to Diamond Hydraulics to be calibrated before installation into the winch. If it seemed things couldn't get any worse, one of the specially made bolts in one of the new valve assemblies broke in half as it was being prepared for calibration. 
The good people at Diamond stayed open while a replacement bolt was drop-shipped from Houston, Texas, to finish calibration that day. If the sequence valves can be installed and the system checks out operational, we'll depart Galveston and head back out into the gulf towards our last site at Vioska Knoll, about 40 hours transit. At 9:00 pm captain Aric Anderson's voice came over the ship's intercom to inform all hands that the Seward Johnson will be leaving port in 45 minutes. The crew readies for departure, securing the gangplank, lines and other items on deck. The early part of the transit is expected to uneventful as far as conditions at sea are concerned. We shouldn't have to worry about encountering any potential debris until we are within about 18 hours of our destination. In fact, we'll deviate south from a straight-line track to Vioska to avoid the concentration of oil platforms located closer to shore, that may have been affected by the storm. 
Dr. Tammy Frank called a brief meeting of the science crew to suggest that we continue to dive on Saturday, rather than returning to Panama City Saturday evening as planned, since we lost so many dives due to the hurricane. This means that everyone will have to stay up all Saturday night to pack their gear in order to offload as soon as we get to port on Sunday, as the next science party will be arriving to load up on the same day. Reservations for flights and rental vehicles must also be changed but all agree to the plan. When we arrive at Vioska, JOHNSON-SEA-LINK I (JSL) will be test launched to verify operation of the winch. The sub will be boomed out over the stern and lowered into the water with only sub crew aboard. The drop lock that connects the sub to the A-frame will be released so the load of the sub in the water is borne by the tow winch. We all hope that the hard work undertaken by members of the ship and submersible crew is successful, and that the science team can continue their deep-sea research. Dr. Edie Widder especially is anxious to recover her Eye-in-the-Sea (EITS) camera system. It is unknown if the passing of the hurricane will have affected anything 2,000 feet down, though first mate Mike Schoeller relates the story of a scientist who had a current meter on the bottom 500 meters down during hurricane Ivan last year. The meter clocked currents of over one meter per second - very strong for that depth. That raises the possibility that Tammy's lightweight traps and the sonar pinger left to mark the location of science packages could have moved, or even been buried by silt stirred up by unusual currents. It's uncertain how the Eye-in-the-Sea, being much larger and heavier would fare, but Edie is optimistic. 
Lab work continues for Tammy and her post-doc Jon Cohen, though Tammy is now experimenting with the one of the very small galatheid crabs she caught on the last JSL dive several days ago. Jon had the foresight to do several plankton tows on the way into port, and stockpiled a handsome collection of sargassum shrimp, which he has been steadily working on ever since. Tammy was lucky enough to have the last dive, and was able to stockpile several deep-sea crabs for her experiments. Tammy has been using her electrophysiological prep since she came to Harbor Branch as a post-doc herself, in November 1992. Tammy has configured her prep in a way practical for shipment anywhere in the world and for set-up on any research ship. Its essential components include a computer, micro-electrode amplifier, a monochrometer that splits white light into its various parts, a computer controlled shutter, a light guide that channels light via fiber optic to the darkroom, and a water bath to keep the sample in while it is being examined. A chiller keeps the water at the same temperature where the animal came from. In the depths of the gulf where we are working, the water temperature is about 7 degrees Celsius, a little more than 45 degrees Fahrenheit. Data recorded during light flashes includes, response amplitude, wavelength, frequency and intensity. From these values, Tammy can begin to determine the spectral sensitivity and temporal resolution in the eyes of her subjects, and speculate on what they see in the darkness of the ocean's depths. 
Until recently, the small crustaceans she captured for her studies came from the pelagic region of the ocean, obtained by deploying trawl nets to the depths beyond the reach of all sunlight. A special container, or codend, at the end of the net keeps the animals in darkness until they can be transferred to the shipboard lab. For the Deep Scope missions, Tammy traded her trawl net for the JOHNSON-SEA-LINK submersible, and the mid-water regions of the ocean for the seabed. Along with Harbor Branch engineers she has developed ingenious traps in which to capture and preserve specimens from this new environment. Tammy continues to refine the traps year-by-year, and even day-by-day at sea. Working on the bottom has posed challenges she did not encounter in the midwater using a trawl net. Large crabs 'guard' the traps and prevent her target animals from approaching. Non-target animals, most notably disgusting hagfish, enter the traps and try to steal the bait. Even if they manage to get out again, she can count on a coating of putrescent slime to mark their visit. Whatever the challenge, Tammy remains undaunted. She can deal with problems like those with a tweak here, a modification there, a strategy shift there. With the passing of hurricane Katrina and repairs made to the winch, she only wants to get back to Vioska Knoll and get on with the work. 
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