Sinh Nguyen: What’s the Water Telling Us? July 15, 2025
NOAA Teacher at Sea
Sinh Nguyen
Aboard NOAA Ship Pisces
July 7, 2025 – July 24, 2025
Mission: Larval Bluefin Tuna Slope Survey
Geographic Area of Cruise: North Atlantic Ocean, Slope Sea
Date: July 15, 2025
Weather Data:
6:29 PM Eastern Time
The current temperature is 27°C (80°F). The wind speed is 6 knots. Source: Windy app.
Science Log
Uplift Education, Mighty Primary students: Ahoy from the sea! We’ve set sail this morning to Newport, Rhode Island. There’s a port there that our ship will dock at. NOAA Ship Pisces has been sailing smoothly, or without any issues.
We spotted a lighthouse! Did you know that lighthouses were made to help ships travel safely? They shine bright light at night to warn sailors about dangerous rocks, reefs, or shorelines. They’re almost like traffic signals for boats.
It’s colder inside the Lab Room to make sure the computers don’t overheat. I’m typing this post on one of the deck tables. It feels amazing with the ocean view and breeze.
Today, I’m introducing you to a special instrument, or tool, that helps us learn about sea water. It’s called a CTD instrument.
CTD stands for Conductivity-Temperature-Depth. Video credit: NOAA
The CTD is very important for science missions at sea. Do you remember the goal, or purpose, of our mission? Here’s a hint….
Yes, that’s right. We’re surveying, which means collecting and studying, baby bluefin tuna (larvae). The CTD will help us learn about the sea water where we find the larvae. Like how warm the water is and what it’s made of.
Conductivity tells us what’s in the water, like salt. Salt helps electricity move through water. If the water has more salt, that means it has higher conductivity.
Temperature tells us how warm or cold the water is. Some sea animals like warm water and some like cold water.
Bluefin tuna larvae like warmer water, so that means grown-up bluefin tuna swim a long way to find warm water to lay eggs. The area where they lay eggs in are called spawning areas. Photo credit: NOAA
The life cycle of bluefin tuna. Photo credit: Planet Tuna
Depth tells us how deep the water is. The deeper you go, the darker and colder it gets, so we have find the depth where temperature and conductivity are just right for bluefin tuna larvae.
This information helps scientists learn the physical properties of water where bluefin tuna larvae are found. This is important because larvae need just the right kind of living conditions to grow and survive. Photo credit: Discover Wildlife
By using the CTD, scientists can figure out where the best places are for them to live. This helps protect their habitat and make sure their population can last a long time. It also helps us find them next time, knowing where to come back to find them.
During this mission, we’ll be using the CTD to sample, or study, the water. This requires a big crane like what you see at a construction site! Photo credit: NOAA
The CTD is connected to computers in our Dry Lab. This means we can see water information live, or real-time.
The CTD (Conductivity, Temperature, and Depth) apparatus.
Learning how to read data, or information, from the CTD!
Personal Log
There’s been plenty of time to review, practice, and set up equipment for our mission. Here are some updates.
Do you remember the drifters from our last post? Well, they’re finished! Look at the photos below. These traps will be attached to the drifters. The drifters will be thrown into the ocean. The light will attract bluefin tuna larvae and then trap them in the net. Each drifter also has a GPS so we know where they are always. Here, scientist Kristen was making sure the nets stay in place.
Kristen adjusts a trap
Larval fish trap
Two larval fish traps
Discussing the trap design
Scientists Chrissy and Sarah were helping me review this blog post. I wanted to make sure I can explain everything to you correctly. All scientists have been helpful. They’ve been explaining a lot of scientific words and information that I don’t know.
Scientist Betsy was working on a part of the CTD (right). Bongo nets (left) are also in this picture. They are shaped like a pair of bongo drums and used to catch very small sea creatures.
Scientists were walking me through books that scientists have created to identify sea animals.
Here’s scientific information about Atlantic bluefin tuna larvae. They’re called Thunnus thynnus.
Scientists Amanda and Allison were observing birds.
In the lounge room with Autumn, one of the scientists who will be on 3PM – 3 AM duty with me once we begin our survey. Here, crew members can watch TV, read books, or work on their laptops during free time.
Tomorrow, there’s a full day of practicing emergency drills. I’m about to sleep early to rest and to feel better from sea sickness. The ship’s been rocking back and forth so it’s time to turn off my laptop for the day!
Did you know?
Chief Scientist Dave was tying each drifter to a float.
To make sure each drifter is tied securely to a float, we tied a special knot called the bowline knot.
People have been using this knot for a very long time. It was confusing for me, so Dave and Kristen gave me plenty of chances to practice!
Can you find some rope and try to tie a bowline knot?
Here’s a helpful video! Video credit: Youtuber NightHawkInLight
Here’s a fun way to memorize it!
“The rabbit comes out of the hole, Goes around the tree, And back down the hole.”
