We are into the last day of work before returning to Guam. The first set of BRUVs is being recovered as I write. We will have time for one more set (8) and then we’ll secure the equipment and head for home (home for me anyway―everyone else will still be far from home). Steve is getting great data on the fish populations on the west side of Saipan. As much as we like watching the fish, we got more excited to see a turtle checking the bait, a moray eel chewing on the bait bag, and yesterday, a large tiger shark cruising back and forth nudging the bait bag. Unfortunately, the video ended while the shark was still at the BRUV. When we brought it up, the bait bag was gone.
reef to assess coral coverage and other bottom features. They were particularly happy to have found several areas of reef with the coral Euphyllia paraancora. This coral is found in the tropical Western Pacific and the Indian Ocean, but it is not common. It is heavily harvested for the aquarium trade and more susceptible to bleaching than more robust coral species. It is listed as vulnerable and is further threatened by the predicted threats of climate change and ocean acidification. It was put on the IUCN Red List and is protected via CITES, both as of October, 2009. 
Above: HARP Diagram
One night we deployed a HARP, a High-Frequency Acoustic Recording Package used to study cetaceans (whales and dolphins). The scientist in charge of this equipment was not onboard but had arranged with the Chief Scientist to put out this equipment near Saipan. This HARP will sit on the seafloor for 2 years collecting sounds. HARPs record ambient ocean noise including low-frequency baleen whale calls, high-frequency dolphin clicks, sounds in between and man-made sounds from ships, sonar, and seismic exploration. When the HARP is retrieved, the sounds can be analyzed and we will learn more about the cetacean populations of the Mariana Islands.
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A few days ago, Glen gave me a great tour of the engine room. It is beyond the scope of this blog to describe it here, but I can’t resist including a few pictures. I am always amazed by what it takes to keep a ship like this running. They call it an “unmanned engine room” because an alarm will ring if something needs attention like overheating or low oil pressure. It may be called “unmanned” but it takes a lot of man-hours to keep it that way. The engine room and machine shop are really clean and well organized―I didn’t see a drip of oil or a smudge of grease..jpg)
Right: One of 4 diesel engines that provided the electricity for the ship and run the electric motors that drive the propellers..jpg)
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This photo/diagram shows how sonar waves ping the seafloor and also shows the bathymetric map that is made from the data.
We used the multibeam sonar to map shallow banks north of Farallon de Mendinilla and east of Anatahan and Sarigan. The multibeam work continued day and night and produced huge amounts of data that needed to be processed. I can only sit at the computer for short periods, but the map team members work 10 hour shifts and most of that time is spent processing the data and making new maps. There are always 2 or 3 people processing the data.
Left: The TOAD seen with cameras facing forward.
Monday night, we put out the TOAD (Towed Optical Assessment Device). This camera is towed behind the ship and sends video directly to the control room. We were able to see some of the seafloor we had been mapping. The first run of the camera went for 2.25 hours, covered a distance of 3 miles and went to a maximum depth of 400 feet. The second run went for 3.5 hours, over 4.5 miles to a maximum depth of 300 feet. Towing the camera sounds easy, but someone must be on the controls to keep the camera from crashing into the bottom. The camera needs to be close to the bottom for the best video, but without someone on the controls, it can crash. Driving requires constant attention. Most of the seafloor had a sand coverage with some algae. Occasionally, there would be oohs and aahs over something other than sand and sea weed: sea stars, large sea cucumbers, sponges, sea urchins or the infrequent fish. I really enjoy watching real time video of previously unseen seafloor, but I found myself falling asleep on my feet. I finally had to give up and head to the bunk.
Right: Steve & Viv prepare the TOAD for launch.
Today, we are near Saipan planning to do BRUV work during the day and the TOAD tonight. A nap might be a good plan so I can watch the TOAD through the night, but I don’t want to miss the BRUV action either.
