Old Dog, New Trick

What is the most exciting, most awesome, most unusual event of the expedition? These are the most common questions I have received from students following the blog. The whole trip has been exciting and awesome. It’s also been unusual as I don’t normally spend a lot of time at sea.

Unexpectedly for me, on February 23rd came the most exciting, most awesome and most unusual event of this trip. By then, I was familiar with the Autonomous Underwater Vehicle. I had read about it, talked about it, written about it and taken dozens of pictures. What I didn’t know was that Chris (see Meet the Science Team) was working to teach the AUV a new trick. AUVs run a preprogrammed route for about 4 hours and then return to the surface. It’s not until the AUV is back in its cradle on deck that the cameras can be retrieved. Only then can the photos be seen. Chris spent the trip devising a method whereby the AUV can send pictures to the ship while still underwater.

Left: Seven miles of cabel used by the Remotely Operated Vehicle Jason II.

Keep in mind that the AUV is not attached to the ship. Remotely Operated Vehicles (ROVs) are attached to the ship via cables and can send pictures and receive instructions from the control room on the ship. On the AUV’s last dive, Chris’s program worked―underwater pictures on his computer. He got 13 photos at about 20 minutes each. The information is sent to the computer in small bits that must be assembled. HE DID IT! I wanted to break out the champagne in celebration, but there is none onboard so we had to settle for enthusiastic applause. I still get chicken skin (goose bumps) just thinking about the magnitude of his success.

Right: AUV, no cables.

In the following paragraph, Chris talks about AUVs and communication.

"Wirelessly communicating with Autonomous Underwater Vehicles (AUVs) is very difficult―the type of wireless communications that we rely on in our day-to-day lives does not work underwater. Most wireless systems, like WiFi or mobile phones, rely upon high frequency electromagnetic waves―millions or billions of cycles per second. Underwater, high frequency signals are attenuated, or blocked, over short distances. That is part of why when you are snorkeling or SCUBA diving everything looks blue―the higher frequency red light has been blocked out. To communicate with SeaBED AUVs, we rely upon sound waves, which use only around 12 thousand cycles per second. Echoes, other noise, and a number of other challenges presented by the ocean result in us having a very slow connection to the robot. Also, like using a walkie talkie, only one person can be talking at a time. If we are sending commands to the robot, it can't be sending us information. Finally, sound travels slowly through the water, so it takes time for the message to even get to the boat (this is called latency). That all means we have to heavily compress images so that they are very small on disk before we transmit them, and we don't get all the pieces in the right order. Putting together the image ends up being like putting together a puzzle―you have to make sure you have all the pieces, and then put them together in the right order. The compression means that the images look pretty rough, but they still give us an idea of what the robot is doing, and an early glimpse at the seafloor. For the rest, you have to wait until it comes back up! SeaBED AUVs can take over a thousand images every hour! "

OK, me again. Chris will continue working on this project. He wants to make it easier and faster. With this new trick, the scientists will know, while the AUV is still below, that all systems are working and the AUV is taking quality photos.

New BRUV Video Clip

We have been at the dock in Saipan for 3 days so I have taken a bit of a vacation: hiking, swimming, snorkeling. We leave for Farallon de Mendinilla in an hour so, more science soon. In the meantime here is a great new video clip from the BRUV team.

Rota

Jeff (AUV Team) has written an article about the SeaBED AUV we are using on this expedition. You can see it here as a newly published page titled, coincidentaly, AUV SeaBED.

This is day #3 working off-shore of the beautiful island of Rota. While working at Galvez Bank we could see Guam at a distance of about 14 miles, but it was just a big bump on the horizon. While working in this location, we are close to shore and can enjoy the view of tropical vegetation, white sandy beaches and carbonate cliffs. The work in Rota has included BRUVs, multibeam and the AUV.

Linda, Viv and Tony with Rota in the background.

The AUV work has gone smoothly. Launching occurs each evening about 8:00 with recovery at midnight. The AUV has 2 cameras, one facing downward to photograph the geography and one facing forward for better fish identification (it’s difficult to identify a fish from the top, looking down). At night the AUV takes only still photographs. A strobe illuminates the scene every 5 seconds and the cameras shoot in synchronicity. A 4-hour trip produces more than 2,500 photographs with each camera. Processing that many pictures is a time consuming job. The AUV also has a CTD and records data for future analysis. Chirs (see Meet the Science Team) is working on a program that will allow the AUV to send pictures to the ship in real time. To date, this has only been accomplished when a ship is directly over the AUV. Chris is very close to success―maybe tonight.

Linda cutting bait for the BRUV bait bags.

BRUV boys loaded up and ready g0.

The BRUV team says this trip has been the easiest BRUV work ever. In the next breath, they say this trip has been the most difficult BRUV work ever. The easiest―Galvez Bank where launch and recovery were from the ship. Launching was accomplished by simply tossing them off the stern. They were brought back aboard using an electric winch. The most difficult―Rota where the work is close to shore and the ship can’t go. Now they are using a small boat. With all the equipment piled on the boat, there is barely space for 3 people―the driver and 2 to handle the BRUVs. They have 4 BRUVs nestled on the little boat along with all the associated lines and buoys . Add bait, bait bags, lunch and drink and there is not much working area. Once rigged, the BRUVs are tossed over the side in 100 to 150 feet of water. Recovery is accomplished using a hand winch―at 150 feet deep, that is a lot of manual turns of the handle. Difficult as it may be, yesterday they managed 13 BRUV drops in 8 hours.

OK, every entry in this blog has been mostly science. For me, that’s the greatest fun. For the next entry, I’ll try for some of the non-science fun onboard a ship.

BRUV Galvez Bank Highlights

Guppies

Yesterday was a picture perfect day at sea. The sunrise was accompanied by 6 dolphins frolicking in front of the bow. The day was sunny, the sea was calm and we could see the bottom in 100 feet of water. It doesn’t get better. Steve and Sparky are preparing video clips from the BRUVs. New footage shows a feeding frenzy of snappers and at one point, a stingray parks itself on top of the bait bag. I am anxious to post these clips, but I must be patient. The BRUV boys and the BotCam girl have 85 hours of video to watch. Analyzing it will take much longer.

The preliminary bathymetric map of Galvez Bank is completed and shown below.


There is a new page on the blog. Click on the page titled, “Mutibeam Sonar.” Joyce Miller gives the basic information on how the multibeam works and how they generate these great bathymetric maps.

We have said good-bye to Galvez Banks and, after a bit of multibeam work west of Guam in the middle of the night, we are cruising towards Rota.

Steve swinging in the long-line pit. This is the area that is used for recovery of the BotCams, BRUVs and the AUV. On other expedtions the area is actually used for long-line fishing as a survey method.





Pet guppies getting some sun and enjoying the view on the ship's deck.

Daily Routine

Sparky cutting bait

The days are settling into a routine. As the sun rises, the multibean sonar is lifted and secured or Eric turns off the echo sounder he uses for locating schools of fish. By 7:30 A.M., the camera teams are ready with the 2 BotCams and 8 BRUVs. The deployment depths have been determined so each rig is set with the appropriate length of line. The camera batteries have been charged over night (10 rigs make for a total of 20 cameras). The bait has been cut and stuffed into the bait bags. Deployment of all 10 sets takes about 1.5 hours. Each set of cameras runs for just over an hour so as soon as the last cameras are deployed, the first are ready to be retrieved. Retrieval is more time consuming. Each camera set is marked by 2 orange buoys. The ship must approach with the buoys on the lee side (sheltered from the wind ). A crew member then throws a line with a big 4-pronged hook to snag the line between the buoys. If the ship is too close, it runs over the buoys―too far away and they have to come around for another try which can take up to 30 minutes. Generally, the morning cameras are back on board in time for lunch. Afternoons are a repeat of the morning and the cameras are back on board just in time for dinner.

Mills with a mahi mahi

We have a couple of fishing enthusiasts on board. They put out troll lines whenever they get the chance, usually at sunrise or sunset when the captain kicks up the speed to about 10 knots to reach the next study location. There has not been much time for fishing but we have eaten a few mahi mahi. This makes everyone happy―the fishermen of course, and the rest of us for the fillets.

Night time operations with the AUV

After dinner, the AUV team prepares the vehicle for deployment. The AUV is the most time consuming project. They spend hours with the electronics and hours more getting it ready to go underwater. When the communications work, the AUV follows a pre-programmed path about 4 hours in duration. When communications cannot be established, they have to bring it back on board and try again the next night. They have been so busy that we have not yet been able to see their pictures. Soon, I hope. It will be interesting to see the differences between daylight and night time activities on the sea floor.

Autonomous Underwater Vehicle

Deployment
The past two days have been spent working with the Autonomous Underwater Vehicle. On Sunday, the AUV was put in the water but never set free because it was having communications problems. On Wednesday, it was communicating perfectly, but just as it was to be released, the last line holding it to the ship became entangled and The AUV had to be brought back aboard. The afternoon deployment went perfectly. The AUV stayed on track for about two hours. It brought back pictures and video but I haven’t seen them yet.

The AUV without its protective housing.

There are many different kinds of AUVs. The AUV being used on this trip is called the SeaBed from Woods Hole Oceanographic Institute (WHOI). It can be programmed to fly slowly or hover over the seafloor to depths of 6,000 feet. It is used to gather detailed sonar images and pictures of the seafloor.
http://www.whoi.edu/page.do?pid=10078








Retrieval




WHOI's newest vehicle is the Nereus. Nereus is actually a Hybrid Remotely Operated Vehicle (HROV). It can operate autonomously or by remote control. In May of 2009 it explored the depths of the Marina Trench at a depth of almost 7 miles. This was only the third time man has been able to see the deepest spot on Earth.
http://www.whoi.edu/page.do?pid=10076

AUVs are an excellent tool to explore depths not easily accessible to divers. Although they are expensive and sensitive high tech machines, they are not as expensive as Remotely Operated Vehicles (ROVs) and manned submersibles.

A HAPPY Valentine's Day

Deploying the BotCam. It's in the top of the photo, dangling from the crane.

The camera team got spectacular results with the BotCam and the BRUVs. I got to watch just a bit of the footage this morning. Everyone is talking about the great shot from the BotCam showing the stern of the ship and the propeller as the camera descends, then fading and picking up the sea floor. (You can see this video clip here.) The BotCam filmed lots of fish and a spotted eagle ray too.




Steve and Sparky preparing the BRUV for deployment.

The BRUV footage is beautifully clear. I watched only a short section and saw a white tip reef shark, grey reef shark, barracuda, red snapper (Lutjanus bojar), grouper and dogtooth tuna. Also seen were unicornfishes, groupers, Tanguisson wrasses and lots of tangs and butterflyfishes. The depth of the cameras was about 200feet.

Earlier today, the AUV (Autonomous Underwater Vehicle) was deployed. It travels the sea floor following a pre-programmed path for about 4 hours . It keeps itself about 8feet off the bottom. Unfortunately, it was not communicating with the ship, so it had to be retrieved for repairs. In 5 minutes they will deploy the TOAD. I’ll be back. Well, that was great fun and it worked perfectly. The TOAD (Towed Optical Assessment Device) lets us watch the video as the camera is towed above the sea floor. The ship was just drifting at a good speed for the camera. One of the scientists works the controls to keep the TOAD just a few feet off the bottom. This gives great video of the bottom cover, but the fish seem to shy from it. We did see some triggerfishes, jobfishes and a beautiful ray. We spent two hours watching the sea floor starting in an area about 90 feet deep with a lot of coral. We passed through a large sand flat and then dropped off the edge. It got deep so fast that the camera could not be lowered fast enough to keep sight of the bottom. The crew is bringing the TOAD back aboard and soon we will be working with the multibeam sonar to complete the map of Galvez Bank.

Sonar and CTD

Left: Jeff & Jonathan prepare the CTD

Right: Retrieving the CTD (check the feet)

All day Friday, all night, and into Saturday has been spent with the multibeam sonar collecting data and mapping the area of study. The “fish people” need an idea of the bottom contours to decide where to put the cameras. Yesterday afternoon, the scientists used a CTD tool to measure conductivity, temperature and density. The results of this test were used by the map makers to most effectively use the sonar data for accurate maps. Currently the camera crew is preparing to launch 5 sets of cameras. The BotCam (bottom camera bait station) has an anchor and floatation that will keep it a few feet above the bottom. The BRUVs (Baited Remote Underwater Video) will sit directly on the bottom. We should have fish data later tonight but, 10 cameras will make a lot of video to watch.

We're off!

With great anticipation (at least on my part) we departed Guam at 11:30 A.M. Thursday. The scientists have great expectations and most of them matched my excitement. The ship's crew is mellow - they sail all the time. We went about a mile off shore and spent a few hours while scientists calibrated their equipment. We then went back into Apra Harbor so the multibeam sonar could be calibrated. During the night we actually set sail and are now at Galvez Banks, our first study site. The scientists are continuing their work with the sonar. This will probably take all day today and maybe part of tomorrow. We need the sonar to get good maps of the seafloor so the fish experts can place their gear in the best spots to find fish. We have at least four ways to survey the fish: acoustically, with an AUV (autonomous underwater vehicle), with a towed camera and several rigs that have 2 cameras each and use bait to attract fish. I will share more when the equipment is being used.

Sailing on Thursday

Oscar Elton Sette departs on Thursday at 09:30. Watch for updates.