NOAA Teacher at Sea
Aboard NOAA Ship Oscar Dyson
May 24 – June 2, 2012
- Mission: Fisheries Surveys
Geographical Area: Eastern Bering Sea
Date: May 28, 2010
Our sampling of Pollock larvae continues around the clock. It is interesting to see what stations have a lot of Pollock and which ones don’t. From my own observations of the condition of the bongo nets when they are retrieved, I have started to predict if there will be a lot of Pollock or only a little. If the nets are covered in reddish– brown algae, they usually do not have many Pollock, or anything else in them. The nets that are clearer, but still have some red from the copepods, seem to have more Pollock larvae. (I wonder why?)The scientists say that we have found more Pollock larvae than in the past couple of years. (Again, I wonder why?) That’s a good sign for the fishery, though. I told you in an earlier blog about how Kevin Bailey is using the data that we collect to create a model that will predict the future population of harvestable Pollock. The other two research projects that are going on have to do with determining how fast the Pollock are growing and how healthy the Pollock larvae are. Annette Dougherty, the chief scientist, is studying the otoliths, (small inner ear bones) in the Pollock. The ear bones add a layer of bone each year and create a pattern similar to the growth rings of a tree. The Pollock that are preserved are shipped to her lab where she will look at the otoliths and determine the age of the Pollock to the day. She can then compare that to the size of the Pollock and determine how fast they’re growing. Steve Porter, another scientist on board, is looking at the amount of DNA in the muscle tissue. If the muscle cells are growing and dividing into new cells, there will be a higher amount of DNA in the cells. This data shows how healthy the Pollock larvae are by showing how much their muscle cells are growing.
Today’s feature is on engineering. The engineering department on the ship is responsible not just for maintaining the engines of the ship that move us through the water, but also for all the major systems on the ship. They maintain the heating, cooling, electrical, plumbing and sewage systems. The ship is powered by 4 diesel generators that make the electricity for the ship. The ship is then propelled by the use of electric motors. Using electric motors to turn the propellers decreases the vibrations being transmitted to the propellers and allows for the ship to run much more quietly. This is a good thing for a ship that wants to study fish, or anything else in the water that might be scared off by the noise. The ship has 2 desalinization units that use heat from the engines to distill the water. The heat makes the water boil leaving the salt behind. It is then condensed back into fresh water. Ships that have engines that produce a lot of heat can use this method which is very energy efficient. Other ships have to use reverse osmosis (remember that word from the cell unit?) Finally, engineering is responsible for collecting and treating sewage. Maybe in the old days ships would just dump their sewage into the ocean, but not anymore. The toilets are flushed by vacuum action rather than pushed through pipes by water. This decreases problems in the pipes that run throughout the ship. The waste water including what goes into the toilets is collected in a storage tank called an active tank. The active tank contains bacteria and yeast that break down the waste. From there, the water is filtered into a “Clean tank.” Here chlorine is added to make the water crystal clear before it is released into the ocean. The system contains one more tank for storage. It is used when the ship is within 3 miles of the shore and at dock so water is not released right by the land.
Answers to your questions
Hannah M. – The reason that the procedure was developed for how we sample is to minimize the shrinkage of the fish once they are caught. The scientists are trying to get an accurate measure of the fish so we try to collect and photograph them as quickly as possible. Keeping them cold helps to decrease the amount they shrink. They are preserved so that their DNA and otoliths can be examined back at the NOAA labs in Seattle. The larvae that we are collecting are about 4 weeks old.
Elaina – I haven’t spoken with each person about if they get bored on ship or not, but being on a ship is different from being on land. You have your work to do during your shift. Sometimes that can be very repetitive. On your off hours, there is not a lot to do. There are however, 2 exercise rooms, you can read or watch a movie or play video games. You can’t, however, just go out somewhere to do something.
Adeline and Deborah – Adeline asked me what my favorite job is and Deborah asked which crew member I would like to be. These are difficult questions to answer as I don’t see every aspect of each job. For what I’m doing, I enjoy seeing what we’ve caught in the net each time, and finding the Pollock larvae. As far as the different jobs on the ship, I think it would be very cool to be in charge of navigating the ship safely through the water. (See, I always want to be in charge)
Lucy – The steward started collecting lunchboxes over 20 years ago. He did it for fun. Eventually he had so many he started to sell them. He sold an underdog lunchbox that he bought for 50 cents for $2500.00. He has sold the entire collection, now. The Oscar Dyson stays close to Alaska. She and her 4 other sister ships were built to be used all over the US. Because of that, she is outfitted with air conditioning although it is seldom used. Her sister ships, that stay in warmer waters, also have de-icers on the windows that they never use.
Jasmine – In addition to studying the Pollock fisheries, the Oscar Dyson is also used for ecosystem studies, marine mammal and bird studies.
Your Question to answer
Find out more about one of the following jobs on board the ship: Include a description of their duties and requirements needed to get this job
1. Deck officers include CO – Commanding officer, XO – Executive officer, FOO – Field operations officer, Navigation officer, Safety officer, Medical officer
2. Ship engineer
4. Survey technician
5. Electronics technician
6. Deck crew- includes Boatswain, able-bodied seaman