NOAA Teacher at Sea
Amelia Black
Aboard NOAA Ship Oregon II
July 6-17, 2026
Mission: SEAMAP Summer Groundfish Survey
Geographic Area of Cruise: Gulf of America/Gulf of Mexico
Date: July 8, 2026
Weather Data from the Bridge:
Latitude: 28.41N
Longitude: 90.12W
Sea wave height: 1 ft
Wind Speed: 7 kt
Wind Direction: 180
Visibility: 10 miles
Sea Temperature: 88.34℉
Air Temperature: 85℉
Barometric Pressure: 30.03 inHg
Humidity: 70
Sky: Overcast
Science and Technology Log
“Toto, I’ve a feeling we’re not in Kansas anymore.” Judy Garland as Dorothy Gale in The Wizard of Oz
Transcript: [Amelia]: And meet Dorothy! Dorothy is the CTD. And she’s named Dorothy II because we are on the Oregon II.
The entire instrument is called a rosette, but aboard Oregon II it is nicknamed Dorothy II. The rosette is the large circular frame that holds multiple bottles and scientific instruments. At the very bottom of the rosette is the CTD, affectionately known as Toto. CTD stands for Conductivity, Temperature, and Depth and it is one of the instruments scientists use to measure the health of the Gulf.

Diagram created by Amelia Black, NOAA Teacher at Sea,
with input from NOAA Senior Survey Tech Stephanie Stable
The first measurement the CTD collects is conductivity. Conductivity measures the salinity or how much salt is in the ocean. The higher the conductivity, the saltier the water (https://www.epa.gov/national-aquatic-resource-surveys/indicators-conductivity)
You may be wondering, how salty is the ocean? This depends on the temperature of the ocean water. The warmer the water, the more salt the water can hold. The Gulf’s average salinity is 36 parts per thousand or 3.6 percent. That’s roughly equivalent to a little under ½ a cup of salt dissolved in a gallon of water. Now that’s salty!
Next, the CTD measures the temperature of the water. Both temperature and conductivity are measured at different water depths. As the rosette approaches the seafloor, an altimeter uses sound waves to determine the distance to the bottom. An alert is sent to the scientists starting when the rosette is 100 meters from the ocean floor. The altimeter ensures that the rosette doesn’t run into the ground (bottom of the sea).
The next two sensors, the fluorometer and the transmissometer measure different particles within the water. According to NOAA Ocean Exploration page:
A fluorometer measures the amount of chlorophyll in the seawater by shining ultraviolet (UV) light through the water and measuring the amount of red light that is produced by the chlorophyll in response to the UV. (https://oceanexplorer.noaa.gov/expedition-feature/19gulfofalaska-logs-july26-2/)
Yes, chlorophyll, similar to the chlorophyll that plants use to change carbon dioxide into oxygen (photosynthesis). The fluorometer looks at fluorescents (types of chlorophyll and other compounds) that are in the water. This information helps the scientists to determine the overall productivity, or health, of the water. Similar to the fluorometer, the transmissometer uses a beam of light to measure the turbidity of the water. Turbidity is how clear the water is (https://www.epa.gov/system/files/documents/2021-07/parameter-factsheet_turbidity.pdf). The clearer the water, the farther the light travels. Think about the difference between a clear clean creek versus a muddy river. Which would you rather swim in?
Transcript: [Stephanie]: We go over and we check to make sure all the bottles are open, none of the lanyards are stuck. These air vents at the top of the bottles? We want them closed. And then samples valves at the bottom, we want them pulled out all the way so all water stays in the bottle. We take the caps off the sensor: so there’s two red caps and then one white cap at the bottom as well. And then she’s ready to go!
One final piece of the CTD that is very crucial is the cable. This cable transmits (sends) data in real time back to the ship’s dry lab. Scientists receive the data and decide whether to close the rosette’s sampling bottles to collect water for further analysis. Common water samples are tested for chlorophyll, oxygen, and nutrient levels.
Back in the dry lab, scientists analyze the incoming data using multiple displays. There is an incredible amount of information flowing in before a single fish is ever caught!


NOAA Scientist Adam Pollack analyzing real-time data from the CTD
And all of this happens before the crew even deploys the otter trawl nets to collect the groundfish sample for SEAMAP.
Personal Log
I am really enjoying my time at sea. I’m not sure if it’s the beautiful ocean, getting to handle fascinating sea creatures, the delicious meals prepared by Chief Steward Missy, or simply the incredible people abroad Oregon II, but so far this has been an amazing experience!
Speaking of the great crew, I would like to introduce you to one of my coworkers, Senior Survey Technician Stephanie Stabile.
Stephanie works with NOAA as part of the relief pool. Rather than being permanently assigned to Oregon II, she gets the opportunity to work aboard many different NOAA ships and crew as relief help, similar to a substitute teacher.
Survey technicians are responsible for data acquisition. They oversee the collection and quality of the scientific data gathered by the ship. “Data is our ‘cargo’, it is why we are out here,” Stephanie explains.

Stephanie has worked for NOAA since 2015. The part of her job she enjoys most is being part of a team, accomplishing the mission, and spending time at sea.
“There are moments where I can’t believe that I get paid to be out at sea,” Stephanie says. “I look out at the horizon and see how vast the world is. It is very humbling.”

“There are moments where I can’t believe that I get paid to be out at sea. I look out at the horizon and see how vast the world is. It is very humbling.”
– Stephanie Stabile
Her advice for anyone unsure of their future career: “Whatever it is that you want to do, try to be around it as much as you can. Volunteer, work at an aquarium, get the experience.”
I absolutely love this advice! Sometimes the best way to discover whether something is the right path/career is simply to get involved and experience it firsthand.
Did You Know?
The ocean produces over half of the Earth’s oxygen! Check out this article from NOAA to learn more: https://oceanservice.noaa.gov/facts/ocean-oxygen.html
Don’t forget that you can follow along on my journey through the Gulf at https://www.windy.com/station/ship-wtdo?waves,27.501,-92.356,8,m:esbadxt
Be sure to check back for my next blog as I continue exploring life and science aboard Oregon II.
Adventure awaits!
Sources
- https://oceanexplorer.noaa.gov/technology/ctd/
- https://www.fisheries.noaa.gov/west-coast/science-data/oceanographic-and-ecosystem-sampling-during-pacific-hake-survey
- https://oceanexplorer.noaa.gov/ocean-fact/ctd/
- https://www.epa.gov/national-aquatic-resource-surveys/indicators-conductivity
- https://oceanexplorer.noaa.gov/expedition-feature/19gulfofalaska-logs-july26-2/
- https://www.epa.gov/system/files/documents/2021-07/parameter-factsheet_turbidity.pdf







































