Jessica Cobley: Not Just Fishing, August 1, 2019

NOAA Teacher at Sea

Jessica Cobley

Aboard NOAA Ship Oscar Dyson

July 19 – August 8, 2019


Mission: Midwater Trawl Acoustic Survey

Geographic Area of Cruise: Gulf of Alaska (Kodiak to Yakutat Bay)

Date: 8/1/2019

Weather Data from the Gulf of Alaska: Lat: 59º 18.59’ N Long: 146º 06.18W 

Air Temp:  14.8º C

Personal Log

We made it to Prince William Sound the other day, but I was asleep by the time we got all the way up. The part I did see, near the entrance, was pretty, but fog and clouds blocked the majority of the view. One of the beaches we attempted to fish by had what looked like an old red train car washed up on it. We wondered where it came from and how it got there!

Sunrise over Gulf of Alaska
Sunrise the day before we headed into Prince William Sound.

We are sailing the last few transects of the trip now and headed towards a small bay, called Broken Oar Bay, near Yakutat. Once we arrive, we need to calibrate the instruments used for collecting data and compare the results to the start of the trip. This will let the scientists know that their instruments are stable and making consistent measurements.

While calibrating we may have an opportunity to get a glimpse of the Hubbard Glacier at the head Yakutat Bay. The Hubbard Glacier is approximately 6 miles wide and when it calves, makes icebergs 3-4 stories tall. Fingers crossed we get to see it! 

On a side note, I have been drawing while on the boat. Here are some photos!

Jessica's sketch of a squid
One of the squids we caught… it was just a tiny little guy, about 2 cm.
Diagram of commercial fishing methods
Gus Beck, lead night fisherman, sat down with me yesterday and explained the main types of commercial fishing methods. Now I won’t get them mixed up.
Abigail's prowfish sketch
This is my favorite one! Abigail’s drawing of a prowl fish. They have the best facial expressions.


Science and Technology Log

The majority of my time has been spent above deck with the science and deck crews. Yesterday, I took the opportunity to head down below and learn some of the ways Oscar Dyson is kept running smoothly. 

Danielle and deck crew
Some of the deck crew that are responsible for putting the nets out. Danielle, one of our senior survey techs, is up top and controls the movement of the net.

There are several areas/rooms that hold different types of equipment below deck. One of the largest rooms is the engine room, where not 2 or 3, but 4 engines are located. At night, 2 of the engines are needed since the ship sails slowly for camera drops. During the day, when traveling along the transects and fishing, 3 engines are used. Engines 1 and 2 are larger with 12 cylinders and 3 and 4 are smaller with 8 cylinders. These engines are attached to generators. The engines give moving force to the generators, which they then convert into kilowatts/power and as a result, power everything on board. Also, I learned that the boat has at least 2 of every major piece of equipment, just in case!

Engineers Kyle and Evan
Two of the engineers, Kyle Mulkerin and Evan Brooks, who gave me a tour below deck. They are standing in front of engine #1.

The engine room also stores the water purification system, which Darin had mentioned to me the other day. He knew the ship converted seawater into potable water, but wasn’t exactly sure how the process worked. Here is a brief summary. 

  1. Seawater is pumped onto the boat and is boiled using heat from the engine.
  2. Seawater is evaporated and leaves behind brine, which gets pumped off of the ship.
  3. Water vapor moves through cooling lines and condenses into another tank producing fresh water. 
  4. The water is then run through a chemical bromide solution to filter out any left over unwanted particles.
  5. The finely filtered water is stored in potable water holding tanks.
  6. The last step before consumption is for the water to pass through a UV system that kills any remaining bacteria or harmful chemicals in the water.
Evan's notes
Notes from Evan Brooks on how to convert seawater into potable water. I wish all my student’s notes were this neat and organized!

After the engine room, Kyle and Evan took me one level deeper into the lower engine room. There are a few other lower areas but, being a bit claustrophobic, I was happy we didn’t explore those. The lower engine room (or shaft alley) holds the large rotating shaft which connects directly to the propeller and moves the ship. It was neat to see! 

Jessica descends to lower engine room
Heading down into the lower engine area.

We rounded out the tour in a workshop that holds most of the tools on board. The engineers help fix things from engines to air conditioners to plumbing. This week I may even be able to see them do some welding work. 

Did you know? 

If a large piece of equipment needs to be replaced, they do not take it apart and lug it to the upper deck and off the boat. Instead, they cut a giant hole in the side of the ship and get the parts in and out that way. I had no idea!

Cheers, Jess