Last Day of Research
October 14, 2007
Program Coordinator, COSEE-West
University of California, Los Angeles
It has been very eventful around here for the last few days as we tried to finish taking samples and doing surveys here in the Celebes Sea.
On Thursday morning, October 11, the second RopeCam came back onboard with video of deep sea fishes starting to aggregate around the bait. At some point on the video you can see the RopeCam being dragged by the water currents to a whole new location, a few miles away from its deployment location. Good thing it has a strobe light and a radio tracker (a readily available dog tracker) so that we could find it! Late that afternoon, the RopeCam was deployed again to be picked up first thing in the morning on Friday.
Early on Friday before I woke up, the ship spent some time searching for the RopeCam because it had drifted during the night. Then, when they tried to pull it up, they found that it was caught on something. The Philippine Navy Seals and Erich Horgan took the rubber boat out to try pulling the rope in different directions to see if they could tug the camera rig loose. Though they gave it a valiant try, 11,800 feet of rope was out there, and we lost our second RopeCam! Emory Kristof has used RopeCams about 300 times before and never lost one — until a few days ago. Now a second one is gone! Everyone's spirit was dampened by that loss, because we were hoping to see what deep-sea predators might show up on the video.
Mid-morning on Thursday, Erich, Talina Konotchick, Nick Loomis, Val Borja, Joseph Rayos, Noe Gapas, and Toshi Mikagawa rigged the Tucker trawl (or “Trucker haul” as it is called at 3am in our sleepless delirium!), a midwater trawling net with a 10 x 10 foot opening, instead of the heavier and more complex MOC 10. This is yet another example of the teamwork on this trip by people with different interests and different backgrounds coming together to get the science done. The trawl was supposed to be towed at 1,000 meter (m) depth, but the winch's level wind, which guides the wire to spool evenly as it is reeled in, had problems, so the net was towed a bit shallower at around 600 m. When the net finally came back onboard, everyone crowded into the lab to see the kinds of larval fish, jellies, crustacean larvae, and other assorted planktonic and slow swimming organisms that it caught.
Because many organisms in the ocean migrate up and down on daily basis, a second Tucker trawl began around midnight on October 11 to see how our catch might differ from the daytime sample. The winch level wind failed again when the trawl was only about 15 m down, so the trawl was aborted and the net was brought back in. Even though the trawl didn't go very far, we still caught several fish, jellies, and crustaceans, some of which were different species from the ones caught in daytime. It was interesting to see how different the samples were from each other.
Yesterday (Saturday, October 13) we attempted another Tucker trawl during the day, and this time the the wire successfully reeled out to 1,200 m. When the net was being reeled back in, they gave the winch a break so it could cool off. But suddenly, a very scary thing happened; the winch went into free fall. The cable was uncontrollably pulling off the spool under the weight of the net and the cable, and the hand brake was not working. After about 400 m of cable spun off the reel, the hand brake finally engaged and the cable stopped. Luckily, no one was hurt and the level wind was fixed again by "cannibalizing" parts from another winch onboard. The Tucker trawl net made it back onboard in the mid-afternoon and our scheduled daytime bluewater dive turned into a late sunset dive.
I've had a lot of late nights, helping with the ROV deployments which keep lasting longer and later into the night and early morning hours. Thursday was the ROV team's first day off for this whole trip. On Friday, October 12, the ROV made a dive to find the sea floor at 2,000 m. We, of course, thought we had all the little problems worked out and we did, but the unexpected happened. Everything went well while the ROV was on the bottom, but as we started to pull it up about 8 pm, we noticed something weird on our viewing screen. It turned out that a one inch thick piece of blue polypropylene rope had looped around the clump weight, and we had towed this thing 700 m up into the water column. By the angle of the rope, we could see that it was heavily weighted by something somewhere below. The rope was putting a lot of strain on the ROV’s winch, and Mike had to keep stopping the winch every few minutes to let it cool down. Toshi and Joe, who both did some of the flying (ROV piloting), had to maneuver carefully because the rope was sliding against the clump weight’s cable and it could cut all power from the ship to the vehicle by crimping the cable.
Larry, Emory, Toshi, and many others offered their input on what should be done. It was finally decided to pull up the clump weight and ROV slowly, 100 m at a time, letting the winch cool for 10 minutes in between. As the rope slid across the clump weight, something suddenly appeared in the middle of the line. Tied neatly between two pieces of blue rope was a tire with a large rock stuffed inside that clearly was meant to be an anchor. The tire slid around the clump weight and unhooked most of the line so that it was only caught on the wire handle at the bottom of the weight, which meant that the fiber optic cable and power line inside the winch cable were no longer in danger. The ROV came up slowly and each time it stopped to let the winch cool, we explored for organisms in midwater. We found a Praya (siphonophore), radiolarians, larvaceans, worms, and many other interesting organisms.
When the ROV finally reached the surface, the current was quite strong. It was quite a feat to bring the vehicle alongside the ship so that it could be hooked with the crane and lifted onboard. The clump weight was lifted up onto the stern rail and Toshi cut away the blue rope, which dropped back into the darkness. I guess we'll never know what was at the other end of that mysterious rope from 2,000 m! Today, the ROV team has started to dismantle the ROV. The lights and samplers have been removed for packing. It makes me a little sad to see it being deconstructed because it’s a reminder that our cruise will soon be over.
Things that are going well and have been done safely on this trip include the scuba dives and deployment of the bongo nets and VPR — although, we did have a scare this evening at the end of the very last sampling tow just a few minutes ago. We had attached the bongo net to the VPR (video plankton recorder) and towed them both at once. When they were being brought back to the surface, the upper winch on the ship stopped working. We thought there would have to be yet another rescue attempt, but a short time later, the winch was repaired and the equipment was quickly lifted back on deck.
Another success on this cruise is the way that 61 of us, crammed together on a ship designed for 40, have gotten along so well. There are a lot of personalities crammed together in close quarters, many of us lacking sleep, and we have experienced far more challenges than any of us could anticipate, yet a healthy sense of humor and a positive attitude still remain.
Well, it's October the 13th, our 13th day at sea, and it's our last day of research. Tomorrow morning we will anchor near the Navy station at Zamboanga to drop off Mely, Mon, and Adonis to return to their hometowns, then we'll be making our way back to Pier 13 in Manila. I'm not superstitious, but that's a lot of 13's! The ocean has been taking (and threatening to take) our gear left and right, and we'll be glad to go home with what we have left. We should arrive back in port mid-morning on the 16th, giving us time to clean up the labs and our cabins and pack up all that we have brought, before leaving Manila for our many different destinations.