Linda Tatreau, MARCH 9, 2010

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

Mission: Fisheries Surveys
Geographical Area of Cruise: Equatorial Pacific
Date: March 9, 2010

TOAD

Sunset
Sunset

It would be easy to start every post with a beautiful sunrise or sunset photo. In this one, you can see Anatahan Island in the background. Just before the sunset, 3 large wahoo were caught. Poke and fried fish are the favorite items on recent menus (breakfast, lunch and dinner).

Steve, Frances and Mills show off their catch.
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.

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.

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.

Linda Tatreau, FEBRUARY 22, 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

 

Rota

Rota
Rota

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 go.
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.

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.