Category: 2010

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Linda Tatreau, FEBRUARY 17, 2010

NOAA Teacher at Sea: Linda Tatreau
Onboard NOAA Ship Oscar Elton Sette

Mission: Fisheries Surveys
Geographical Area of Cruise: Equatorial Pacific
Date: February 22, 2010

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.

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Linda Tatreau, FEBRUARY 15, 2010

NOAA Teacher at Sea: Linda Tatreau
Onboard NOAA Ship Oscar Elton Sette

Mission: Fisheries Surveys
Geographical Area of Cruise: Equatorial Pacific
Date: February 15, 2010

Autonomous Underwater Vehicle

Deployment
Autonomous Underwater Vehicle
Autonomous Underwater Vehicle

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.

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Linda Tatreau, FEBRUARY 13, 2010

NOAA Teacher at Sea: Linda Tatreau
Onboard NOAA Ship Oscar Elton Sette

Mission: Fisheries Surveys
Geographical Area of Cruise: Equatorial Pacific
Date: February 22, 2010

A HAPPY Valentine’s Day

Deploying the BotCam from a crane
Deploying the BotCam from a 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.
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.

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Linda Tatreau, FEBRUARY 12, 2010

NOAA Teacher at Sea: Linda Tatreau
Onboard NOAA Ship Oscar Elton Sette

Mission: Fisheries Surveys
Geographical Area of Cruise: Equatorial Pacific
Date: February 22, 2010

Sonar and CTD

Jeff & Jonathan prepare the CTD
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.

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Linda Tatreau, FEBRUARY 11, 2010

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.