NOAA Teacher at Sea
Onboard NOAA Ship Pisces
June 14 – July 2, 2010
Mission: SEAMAP Reef Fish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: June 17, 2010
Weather Data from the Bridge
Time: 1000 hours (10:00am)
Position: latitude = 26.52.6 N, longitude = 096.46.7 W
Present Weather: 3/8 cloudy
Visibility: 10 nautical miles
Wind Speed: 17 knots
Wave Height: 1-2 feet
Sea Water Temp: 29.5 degrees Celsius
Air Temperature: dry bulb = 29.2 degrees Celsius, wet bulb = 27.5 degrees Celsius
Science and Technology Log
We reached our first research station 40 miles off the coast of Southern Texas sometime in the early morning. To maximize the use of daylight, the scientists begin collecting data one hour after sunrise (around 0730 hours) and work until one hour before sunset (around 1930 hours). At each station, a camera array is lifted and lowered by a crane into the water column, down to the ocean floor.
The depth of the ocean varies at each station but today the depth was somewhere around 68 meters (223.04 feet). The camera array has 4 sets of cameras pointing in each direction. Each set of cameras contains one video recorder and two still-shot cameras that take turns snapping pictures, sort of like closing your right eye, then your left eye, then your right eye, and so on. The purpose of the still-shots is to help the scientists, along with the use of lasers, to estimate the length of the fish in the images. The cameras stay submerged for 45 minutes and then they are hauled back up to the surface.
The next thing that happens at each station is the lowering of a CTD (conductivity, temperature, and depth) into the water column. The CTD measures the changes in salinity (salt level), temperature, and dissolved oxygen as it passes through the water column.
This data is transmitted directly to a computer graph where a technician watches and monitors to make sure the CTD is working properly and stays within 2 meters of the ocean floor.
The camera array and CTD are lowered at every station, but two stations are chosen randomly to drop a Chevron trap and two stations are chosen randomly to lower a Bandit Reel. The Chevron trap is baited with squid and physically picked up and thrown over the deck. The trap is fitted with weights on the bottom to make sure it lands in the right position on the ocean floor and soaks for one hour before being hauled back to the surface. During the first drop of the trap, we hauled in a giant Warsaw Grouper weighing over 16 kilograms (35.2 pounds)!
The Bandit Reel is like a long line sent straight down to the bottom of the ocean. It has 10 hooks that are baited with fresh mackerel and lowered to soak for 10 minutes.
Luck was on our side again as the first drop of the bandit reel hooked 9 Red Snapper! This was our first look at the fish that is the main subject of our Reef Fish Survey.
WHOOO HOOOOO! I’ve just done REAL NOAA science!!!!! Today we are dropping the CTD and the camera ray and then dropping the Bandit Reel line that has 10 hooks. The first Bandit Reel drop we caught 9 big red snapper. The largest one was 1.89 kilos (4.15 lbs).
This is the camera array – four cameras take footage of the fish down there.
The next time we dropped the line, they let ME take the snapper off the hook, weigh them, and then measure them. I measured the total length, the fork length, and the standard length. Then I bagged them all up and put them in the freezer to take back to the Pascagoula lab.
I also got to hold a sucker fish that accidently got caught on the line. Its sucker was on the top of the head. It looked like someone had stepped on his head and left tennis shoe marks! The sucker fish attaches itself to the bottom of a shark and rides along with him. We saw 2 sharks hovering around as we brought up the line which is baited with mackerel. The next time we deployed the Bandit Line they let me bait the hooks with mackerel and then put the hooks on the line. It was great! I love getting messy!
This is a sucker fish that attaches to shark.
This afternoon the crew got out their personal fishing poles and fished off the stern. The XO caught a shark but he didn’t bring it on board. It was impressive to me. Then we threw out the fish trap that was sunk to the bottom of the ocean. We caught a HUGE Warsaw grouper in the trap. One of the scientist said it was the largest grouper he’d ever seen – 16 kilos (35.2lbs). Its eyes were bulging and its mouth was huge! Teeth and all! Nicolle and I were left alone with it in the bay when it started flopping and flipping all over the place. We squealed like little girls!
So far we’ve had two “never seen before” experiences! This is GREAT!
CTD – conductivity, temperature, and depth
“Something to Think About”
Why do you think it’s important to take measurements and weights of the fish for NOAA research? What are they doing with all that research?
“Did You Know?”
Boyle’s Law at Sea
Did you know that when the fish are brought up from the deep (60-70 meters) the decrease in pressure causes the swim bladder to expand? That’s because the swim bladder is full of air and if you’ll remember Boyle’s Law, a decrease in pressure creates an increase in volume. Here you see a swim bladder that came out of the mouth.