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: Saturday July 10, Sunday, July 11, 2010
Latitude: Saturday 27⁰54.8057 N Sunday 27⁰51.098 N
Longitude: Saturday 093⁰18.2990 W Sunday 093⁰04.100 W
Weather Data from the Bridge
Air Temperature: Saturday 30.3⁰C Sunday 30.4⁰C
Water Temperature: Saturday 30.5⁰C Sunday 30.35⁰C
Wind: Saturday 2.55 knots Sunday 1 knot
Other Weather Features:
Saturday 62% humidity, cloud cover 20% Sunday 67% humidity, cloud cover 35%
Saturday Swell Height .2 meter Sunday .4 meter
Saturday Wave Height .05 meter Sunday .25meter
Science and Technology Log
There are several types of sensing equipment we have been using on this cruise. Each time we drop the camera array at a site attached to the array is a little device called a Temperature Depth Recorder or a TDR. As the camera array sinks to the bottom, the TDR records the temperature and depth. When the camera array is brought back on board the ship one of the scientists, or one of us teachers, unclips it and brings it into the lab. To get the information off you hit it once with a magnet that communicates with the chip inside telling it you want to download the information. Then you place a stylus on the device and it downloads the information to the computer. The data is saved under the name of the site and then the information is entered into a spreadsheet that converts the information from the psi(pounds per square inch) to meters of depth. To clear the TDR you hit it four times with the magnet and when it flashes red it is clear! Liz and I learned to do this the first day we did stations and we usually took turns entering the information. This was done 8 times on Saturday and 7 times on Sunday.
At every station, a CTD is also dropped into the water. A CTD (Conductivity Temperature Recorder) gives a hydrographic profile of the water column. The CTD is attached to the bottom of a rosette or carousel that also contains water sampling bottles. Attached to the rosette is a conductive wire that sends information to the lab. Mike, the survey technician, comes into the lab after every camera array is dropped and runs the CTD process. The CTD is placed in the water and allowed to acclimate for 3 minutes before they begin taking readings. The CTD is dropped to the bottom of the seafloor and then raised again. Mike monitors this from the dry lab. Once a week he uses the water bottles to take water samples. To take a sample he uses a remote from inside the dry lab to trigger the bottles at a given depth to close them. The CTD can also be programmed to close different bottles at different depths. It was very interesting to watch the EK60 echo sounder screen as the CTD lowered and raised.
Each morning, Chief Scientist Kevin goes through the video footage from the previous day. For each site he identifies what the bottom substrate was (“sandy flat bottom”, “coralline algal bottom”, “malacanthus mounds,” etc) and then he identifies briefly any fish that he sees. When he is doing this, he will call us over and explain how he can tell what the species is or what behavior a fish is exhibiting.
Saturday, we dropped the camera array at 8 different stations on Bright Bank sites. The two chevron fish traps brought up NO FISH! On the bandit reel we caught one fish. It was a sand tile fish, Malacanthus pulmieri, a “banana shaped” bottom dweller that lives in large rock-covered mounds. Wearing rubber gloves, I weighed and measured him quickly and then we threw him back alive. He was 494 mm (49.4 cm) long and weighed .550 kg. I’m not very comfortable touching the fish or the bait we’ve been using, so I was quite proud of myself!
That was the only fish we caught all day! Today was a little frustrating. It even got Kevin a little down!
Sunday brought our last day of work on the reef survey. The Pisces was on the north half of Geyer Bank, still off the coast of Louisiana. I was determined to fully participate in all aspects of the science, so I bravely donned my gloves and baited the bandit reel’s 10 hooks with chunks of mackerel. We were positive we would catch more fish today!
The camera cage came up with some interesting “hitchhikers” aboard. One was a round sponge, about the size of a softball. At first we thought it was a rock, but when I grabbed it, it was soft and squishy. Sponges are filter feeders which draw in water through many small , incurrent pores. Food and oxygen are filtered out and then exit through one or more larger excurrent openings.
In the fish lab, Kevin found a large cymothoid isopod, a crustacean that attaches to fish using its hook-like legs and scavenges food as the fish feeds. It reminded me of a cockroach more than a “rolly-polly”, the land isopod found in our gardens.
The day continued with seven camera drops, the bandit reel deployment, and two chevron fish traps. Despite positive thinking and Liz doing her “fish dance,” both fish traps came up empty. So the 2nd bandit reel was our last chance for fish. We were excited to see the “fishing pole” part of the reel bouncing up and down. It was reeled in and here’s what we caught!
It was a great barracuda, Sphyraena barracuda, 939 mm (93.9 cm) long and weighing 3.49 kg. Joey measured and weighed it, carefully avoiding its sharp teeth. He released the large predator and our last catch quickly swam away.
An interesting souvenir I will be taking home are some fish otoliths. Otoliths are fish earbones. Bony fish lay down layers of bone on their otoliths as they age, similar to the rings on a tree. Scientists use the otoliths to determine the age of a fish. Kevin collected the otoliths from a yellowedge grouper one of the crew caught and gave one each to Liz and I. Then he helped me remove the otoliths from a red porgy – quite a messy procedure, but very rewarding to cut open the skull and see the earbones!
In tomorrow’s log, I’ll share what we learned on our tour of the engine room, and about the different job opportunities on the ship.
Two nights ago, the ship’s captain (Commanding Officer Jerry Adams) had invited Liz and I up to the bridge to help “steer” the ship. He explained that we were driving a 52 million dollar vessel with 30 lives on board, so we were feeling pretty nervous! The Pisces was moving to the next day’s work area so the bridge crew would be driving all night. I got to steer first, my hands tightly gripping the wheel Captain Jerry and Ensign Kelly Schill explained how to drive and the proper language to use. When steering, you are following a set course using a gyroscopic compass as well as a digital heading read out. You are steering the rudder by degrees. The heading is stated in single digits so 173 would be one seven three.
We were sailing at night, so all the bridge lights were kept turned off to better see the lights of other boats and oil rigs. The bridge crew even had red flashlights so they wouldn’t ruin their night vision. Liz and I both got a chance to steer the ship in circles. I even did a Williamson turn, which is done when there is a man overboard. You turn 60⁰ in one direction and then turn the other direction so you are back on your reciprocal course to pick up the person who is overboard. While I was doing this, the ETA (estimated time of arrival to our next destination) display changed from “ 6:10 am” to “NEVER.” We both laughed pretty hard about that!
The Dynamic Positioning system (similar to an automatic pilot system) is called Betty. She can talk to the crew on the bridge and is reportedly extremely polite. I find is amazing how the ship can maintain such a steady course, with the computers adjusting for the constant changes in current, wind, and other factors which affect the ship’s steering. The DP also keeps the Pisces in one place when we are at a science station. The Captain promised to show us more about the DP on our next bridge visit. Everything on the bridge is electronic. You can click a button and see how much fresh water is on board, how much fuel, which engines are working and even wake someone up! The technology is truly amazing. I keep thinking about my grandfather who sailed in the Swedish Merchant Marines in the 1930’s. What would he have thought all this?
Where has Pascy the penguin been in the last 2 days? Check out his pictures!
Safety is very important! Pascy wears his hardhat whenever he works out on the deck with equipment.