NOAA Teacher at Sea: Story Miller
NOAA Ship: Oscar Dyson
Time: 0754 AKST
Wind: 13-20 knots (approx. 14.96 – 23.02 mph)
Direction: 239° (SW)
Sea Temperature: 8.28°C (approx. 46.9°F)
Air Temperature: 8.03°C (approx. 46.5°F)
Barometric Pressure (mb): 1017
Wave Height: 4 feet
Sea Swells: 6 feet
Combined Wave Height: 10 – 12 feet
This afternoon, we conducted a test with a drogue which is like a large sea anchor. Sea anchors allow a boat that is simply sitting in the water to not drift so far with the waves. This drogue will stabilize the camera of an experimental trawl net device, called a Cam-Trawl, and prevent it from fluttering when it is photographing the fish. The Cam-Trawl was designed by Kresimir Williams. Currently the objective of this new device is to observe the fish we see in the backscatter which are the animals we can see in the echosounder
(See Figure 1).
In short, the ship’s hull has transducers that send pings of sound energy down through the ocean and when they hit some object, such as the bottom of the ocean or a fish, some of the energy in the sound ping is returned to the ship and received by our echo sounding system in the acoustics lab of the ship.
When we locate a group of fish we want to study with the echo sounder, we have two primary methods of collecting data from the fish. The device we use the most is the AWT(Aleutian Wing Trawl) net and the other is an 83-112 bottom trawl net. The AWT is used for catching fish located at midwater depths and the other, as stated in the name, trawls the sea floor. To imagine the shape of these devices in the water, imagine a large funnel with a catch sack on the end. The beginning portion of these nets, nearest to the boat, has large meshes and its primary function is to funnel the fish toward the catch sack. As fish move farther down the net, the meshes get smaller until they reach the catch sack, which we call the codend, and once in there, the fish cannot escape. We then pull them to the surface and begin collecting data, such as size and species. The largest drawback to these methods is that the fish caught in the net will most likely die. To understand why, think of a diver in the deep ocean. If the diver comes up too fast, the body cannot adjust to the pressure fast enough as air expands, potentially causing lungs to rupture. For the fish, bringing them up too quickly causes their swim bladders to rupture. Rockfish tend to have their stomachs inverted out of their mouth. While killing the fish for research is unfortunate, it is one of the few ways we can learn about their patterns of behavior, health, and diversity.
The Cam-Trawl is an innovative experimental design that may help reduce the killing of fish and allow us to collect data from endangered or nearly extinct fish species. For example, many Rockfish species off the west coasts of California, Washington and Oregon are endangered and as a result, we do not want to catch them in our nets because we would most likely kill them. The Cam-Trawl would remedy that and would allow us to receive continuous data at each depth along its path. The other trawls catch all the fish in their path which means the collection of fish is mixed and we cannot tell the depth at which they were originally swimming or which species was at what depth. To picture how the Cam-Trawl works underwater, imagine a funnel again, except this time, there is no codend attached. At the end of the funnel, the stereocamera is positioned to photograph the fish that pass through the funnel. The resolution of the fish photos is much more advanced than what we have ever had before. This sampling technique is supposed to give us a better resolution of what we are able to “see” using acoustics (echo sounder) than the traditional midwater (AWT) and bottom trawls (83-112).
Sleeping at sea was a new experience for me. The seas were only four to eight feet high which are marginal compared to the conditions this ship experiences in the winter months. Overall, I enjoyed being rocked to sleep but my 0330h alarm was not as pleasant. My room is located four flights of stairs below the bridge deck and I’ve been told it is one of the better places to be because the rocking of the boat is not as intense. The rooms are pretty cozy as space is limited but there is room for a desk, two closets and a bathroom (called a head on a ship) that reminds me of the sizes found in European hotels. I have the top bunk and each has a curtain that wraps around the entire bed so that if your roommate has a different shift than you, the light to the main room won’t be a disturbance. Of course, since I have lived in Alaska for two years, I have become accustomed to sleeping in bright conditions.
Something the non-boating community may not realize is that on a ship, it is very important that there is a night crew and a day crew operating. On the bridge where the main controls of the ship are located, there must always be a NOAA Corps Officer, with qualifications to drive the ship, on watch 24/7. However, all crews, with the exception of the kitchen, on the ship are operating around the clock. For example, there are always engineers operating in case there is some type of mechanical issue and scientists operate because there are still fish in the ocean and their behavior needs to be observed at all times.
The entire crew participated in a fire drill and abandon ship drill yesterday so that all hands on the ship knew where to muster for a head count and to learn how to operate the life rafts in case the ship was sinking. Additionally we needed to learn how to get into our survival suits (Gumby Suits). My first experience putting on the suit was during a field trip onto this vessel with my seventh and eighth grade students in May so I was aware of the cozy fit! Fire and abandon ship drills are practiced once a week when the ship is underway, which is very important as the crew onboard are not just NOAA employees but also in charge of fighting fires and responding to any onboard emergencies. So, if you want to be a fireman and a scientist and cannot choose, perhaps serving aboard a NOAA ship would be right up your alley!
To end my day (remember bedtime for me is early as my alarm is set for 0330) I had a “late” supper of sushi, spring rolls, meatloaf, and for dessert a fabulous set of s’mores! Who says you can’t have them on the ship?
Something to Ponder:
When we are asked, “What do you want to be when you grow up?” usually we say one occupation – firefighter, actor, scientist, teacher, soldier, waitress. However, most jobs require many skills. For example, the scientists on board put a variety of skills into practice and as mentioned in the Scientific Log, scientist Kresimir Williams engineered the Cam-Trawl which employed his knowledge of the biological sciences (fish/oceanography), physical science (how to deploy the device without it breaking), and photography! So for my students, what do you want to be when you grow up?