Callie Harris: Life Above and Below Deck, August 24, 2019


NOAA Teacher at Sea

Callie Harris

Aboard NOAA Ship Oscar Dyson

August 13-26, 2019


Mission: Fisheries-Oceanography Coordinated Investigations

Geographic Area of Cruise: Gulf of Alaska

Date: 8/24/19

Weather Data from the Bridge

Latitude: 57° 01.84 N
Longitude: 151 ° 35.12 W
Wind Speed: 8.45 knots
Wind Direction: 257.79°
Air Temperature: 15.3°C
Sea Temperature: 14.6°C
Barometric Pressure: 1010 mbar

Science and Technology Log

Chief Scientist Matt Wilson showed me how to collect otolith samples from pollock. Otoliths are the inner ear bones of fish that keep a record of a fish’s entire life. Similar to tree rings, scientists count the annual growth rings on the otolith to estimate the age of the fish. The size of the ring can also help scientists determine how well the fish grew within that year. To remove the otolith, a cut is made slightly behind the pollock’s eyes. Using forceps, you then remove the otoliths carefully.

Pollock Otoliths
Pollock Otoliths
extracting otoliths
To extract the otoliths, Callie first makes a cut into the top of the pollock’s head. Photo by Lauren Rogers.
extracting otoliths
Next, Callie uses tweezers to extract the otoliths. Photo by Lauren Rogers.

NOAA Junior Unlicensed Engineer Blair Cahoon gave me a tour of the engine room yesterday. Before venturing below deck, we had to put on ear protection to protect our ears from the loud roars of engine equipment.

JUE Blair Cahoon
JUE Blair Cahoon
Oscar Dyson control panels
Oscar Dyson control panels
Oscar Dyson control panels
Oscar Dyson control panels

The Oscar Dyson has a total of four engines. The two larger engines are 12 cylinders and the two smaller engines are 8 cylinders. These engines are attached to generators. The motion of the engines gives force motion to the generators, which in turn power the entire ship. On a safety note, NOAA Junior Unlicensed Engineer Blair Cahoon also pointed out that the ship has two of every major part just in case a backup is needed.

Oscar Dyson engine
Oscar Dyson engine
Oscar Dyson generator
Oscar Dyson generator

 The engine room also holds the water purification system, which converts seawater into potable water. Each of the two evaporators can distill between 600-900 gallons of water a day. The Oscar Dyson typically uses between 800-1000 gallons of water a day. The engineers shared with me how this system actually works:

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.       This water is then run through a chemical bromide solution to filter out any leftover 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.

evaporator
One of two evaporators on board.
down the hatch
Down the ladder we go to the lower engine room

We then got to explore the lower parts of the engine room where I got to see the large rotating shaft which connects directly to the propeller and moves the ship. I have learned from my years of working on boats to be extremely careful in this area near the rotating shaft. You must make sure you do not have any loose clothing, etc. that could get caught or hung up in it.

Rotating shaft
Rotating shaft that connects to propeller.
Rotating shaft
Another view of the rotating shaft


Personal Log

I was unsure of what life would be like for two weeks on a scientific research vessel. We are now steaming towards station number 72 on day twelve at sea. We have done 65 bongo tows and 65 trawls. So yes, there is a lot of repetition day in and day out. However, each day brings its own set of challenges and/or excitement. Weather (wind direction, wave direction, current, etc.) makes each station uniquely challenging for the NOAA Corps Officers on the bridge and the deck crew below. I stand back in awe watching it all come together on our 209 foot ship. I get excited to see what new creature might appear in our latest trawl haul besides the hundreds of kilograms of jellyfish, haha. 


Did You Know?

One of the coolest things I learned on my engine tour is that when large equipment parts need to be replaced (like an engine or generator), engineers actually cut a giant hole in the side of the ship to get the old equipment out and the new parts in rather than take it apart and lug it up through the decks piece by piece. 

 
Animals Seen Today

The overnight science shift found a juvenile Wolf Eel in one of their trawl samples. It is not actually a wolf or an eel. It is in fact, a fish with the face of a ‘wolf’ and the body of an eel. Its appearance has been described as having the eyes of a snake, jaws of a wolf, and the grace of a goldfish. They can grow up to eight feet in length and weigh upwards of ninety pounds. Juveniles have a burnt orange hue and the adults are brown, grey, or green. Check out this website for more info about the super creepy wolf eel: https://www.alaskasealife.org/aslc_resident_species/44

adult wolf eel
Adult wolf eel. Image credit: Monterey Bay Aquarium.


Something to Think About

In one of our trawls, we processed 850 kilograms of jellyfish…. That’s 1,874 pounds of jellyfish!!!

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