amberjack – NOAA Teacher at Sea Blog

NOAA Teacher at Sea
Anne Marie Wotkyns
Onboard NOAA Ship Pisces
July 7 – 13, 2010

NOAA Teacher at Sea: Anne Marie Wotkyns
NOAA Ship Pisces
Mission: Reef Fish Survey
Geographic Area: Gulf of Mexico
Date: Friday, July 9, 2010
Latitude: 27⁰51.20
Longitude: 91⁰48.60

Weather Data from the Bridge

Air Temperature: 29.6 ⁰ C
Water Temperature: 30.5⁰C
Wind: 2 knots
Other Weather Features:
70% humidity, approx. 30% cloud cover
Swell Height: .3 meter
Wave Height: .2 meter

Science and Technology Log

Friday started bright and early as we met in the dry lab on the Pisces to plan our day. Today would be the first day of work on the SEAMAP reef fish survey, the main purpose of our cruise.

The Southeast Area Monitoring and Assessment Program (SEAMAP) is a long term survey of offshore reef fish designed to provide an index of the relative abundance of fish species associated with topographic features such as banks and ledges located on the continental shelf of the Gulf of Mexico in the area from Brownsville, Texas to the Dry Tortugas, Florida. For this cruise, the sampling occurred off the coast of Louisiana.

The SEAMAP offshore reef fish survey began in 1992. Bathymetric mapping (as was conducted yesterday on the Pisces) provided scientists with contour maps of the ocean floor, then sampling sites measuring 10 nautical miles by 10 nautical miles (“blocks”) were selected in areas with known topographic features. Within each “block”, specific sampling sites are chosen randomly.

The main equipment used in the survey are 4 camera units housed in a special metal “cage”. Each camera unit holds two black and white still cameras and a digital video camera, for a total of 8 still cameras and 4 video cameras which download images to a 1ZTB GB hard drive. The camera pod is lowered to the bottom and left for 45 minutes. The cameras record for 25 minutes of bottom time. Each night the images and videos are downloaded onto another external hard drive, then later recorded onto blue ray discs. Scientists view the video to identify and count all fish observed.

During a sampling day, some sites are randomly chosen to collect fish for measurement and sampling. One method used is a chevron fish trap, a large wire cage which is baited with squid, lowered to the bottom, and left for 60 minutes. Another collection method is the bandit reel, which deploys a vertical line strung with 10 hooks baited with mackerel pieces. This line is lowered over the side until the bottom weight touches the substrate and left for 10 minutes, then reeled back in.

When fish are caught in the chevron trap or on the bandit reel, they are identified, measured, weighed, and gender is determined. Then if the fish is a species commercially or recreationally fished, it is frozen and returned to the NOAA National Seafood Inspection Lab to be available for further analysis.

So now that I’ve explained the science behind the reef fish survey, here’s a description of our first day assisting Chief Scientist Kevin Rademacher and Joey Salisbury, Field Party Watch Leader. Liz and I arrived in the dry lab (headquarters for the surveying and sampling activities) at 7:00 am, excited to begin working. The Pisces arrived at the first site and the camera array was lowered at 7:17 am (one hour after sunrise.) The camera “cage” was lowered using a hydraulic A-frame which extended over the starboard side of the ship. For the first “drop” we watched through windows from inside the lab, as well as on a video monitor. Then as the camera “soaked” for 45 minutes, the crew deployed a CTD (conductivity, temperature, and depth recorder.)More about the CTD in the next journal entry!

By the second site, or “station” we were outfitted with a hard hat and PFD (personal flotation device), required attire when working on deck. As the day went on, we learned to reset the cameras after each station, assist with fish collection and measurement, and enter data collected from the TDR (temperature-depth recorder) into the computer. Throughout the day, we followed a routine of

1) deploy cameras

2) deploy and retrieve CTD

3) on selected stations, move to second site and drop chevron fish trap

4) return to first site, retrieve cameras

5) on selected stations, use the bandit reel to deploy a vertical fishing line

We repeated this process for 7 stations.

No fish were caught in the chevron traps, however, fish were caught both times the bandit reel was used. Each reel station brought in a red snapper Lutjanus campechanus and a red porgy Pagrus pagrus. Liz measured and weighed the fish and Joey determined the sex of the fish. The snapper were frozen to be taken back to NOAA’s National Seafood Inspection Lab.

When there was no work to do on deck, we spent time reading fish identification books, learning about other aspects of the reef fish survey, visiting the bridge, checking in with the bird observers, and watching for dolphin or whales. On one break we took turns using a handline to fish off the side – I caught 2 blue runners, Caranx crysos and Liz caught one. We worked until approximately 7:15 pm. The cameras do not use any artificial light, so the work stopped as dusk fell. We’ll see what tomorrow’s stations bring!

Personal Log

After the first night’s rough seas, I was thrilled to wake up to calm seas on Friday, with the crew promising even smoother seas to come. I really enjoyed the variety of work we assisted with. We were initially disappointed after the first fish trap came up empty. After waiting for an hour while the trap soaked, then donning our hard hats and PFD’s, when the empty trap emerged from the dark depths, we compared it to being “all dressed up with no place to go!” But Kevin reminded us that “The hardest thing to learn about science is that ‘0’s are numbers too!”

I am somewhat “technologically challenged” so I was happily surprised how quickly I learned to log the TDR (temperature depth recorder) data. I was also happy that I remembered much of the physical oceanography I learned years ago.

Liz and I are becoming familiar with the ship-the lab and galley are on the main deck, our cabin is on the 01 deck, other cabins are on deck 02, the bridge is the 03 deck, and above the bridge is the 04 deck. And there are decks 2, 3, and 4 below the main deck, Each deck can be accessed by indoor or outdoor ladders (not stairs!) that are much steeper than your stairs at home. The interior doors are heavy and it’s hard to remember whether to push or pull, this has been a source of much amusement for us! The hatches (doors to outside decks) are very heavy and secured with a wheel that often takes two hands and a lot of muscle to open or close. And don’t forget to step up over the approximate 13” step. There are many reasons we only wear closed-toe shoes!

After we finished with our fish survey work, Liz and I went out to the back deck with our laptops to work on our journals. Some of the crew started fishing with fishing rods off the side of the ship. Within a few minutes they had caught a small mahi-mahi and a few other fish when one of the deck hands slowly started reeling in something big. Of course, our computers were put aside so we could watch as he slowly hauled in a 55+pound greater amberjack – it was huge!!!Lots of excitement and picture taking followed! Then he caught another one – just a bit smaller! Another rod brought in a large yellowedge grouper. I have never seen such large fish! It was very exciting to watch! We thought maybe since we didn’t catch much during the day, we saved our fishing “luck” for the evening! The fishing ended around 9:00 for the night as the ship needed to start moving to tomorrow’s location. We headed up to the bridge to take the CO up on his offer to steer the ship. More on this in the next journal entry!