NOAA Teacher at Sea
Aboard NOAA Ship Gordon Gunter
August 22-31, 2018
Mission: Summer Ecosystem Monitoring Survey
Geographic Area of Cruise: Northeast Atlantic Ocean
Date: August 26, 2018
Weather Data from the Bridge
- Latitude: 39.487 N
- Longitude: 73.885 W
- Water Temperature: 25.2◦C
- Wind Speed: 13.1 knots
- Wind Direction: WSW
- Air Temperature: 26.1◦C
- Atmospheric Pressure: 1017.28 millibars
- Water depth: 30 meters
Science and Technology Log
As if catching plankton and sneaking a peak with the microscope wasn’t exciting enough (see the picture of the larval eel!), there’s a lot more data being collected on this ship. All of it helps scientists understand what’s going on in this part of the Ocean. And some of it I am able to help with, which is my favorite thing about this cruise (well, maybe that and the incredible views).
At some of our stations, we lower a big and important science tool (called a rosette) into the ocean that contains niskin bottles (bottles used for water sampling) and a Conductivity, Temperature, and Depth meter (CTD). As the rosette is lowered into the depths and raised back up, the scientists can remotely operate the open niskin bottles to snap shut at specific depths. This allows each bottle to come up to the surface with a sample of water from many different depths! Meanwhile, the CTD can take measurements of conductivity (which indicates the salinity of the water), temperature, and pressure, among other things. Scientists have thought of many ways to collect A LOT of data at one time.
When the CTD comes back onto the ship, it’s time for us to use the samples for different purposes. We collect water from 3 different bottles (so 3 different depths) to test the amount of chlorophyll in the water. Do you know what the chlorophyll comes from? If you said plants, you’re right! What are some plant-like things that are drifting all over the ocean? You guessed it! Phytoplankton! So the amount of chlorophyll gives scientists evidence as to how much phytoplankton is in the water. But first, we need to extract (take out) the chlorophyll from the water. We run the water through special filters and soak the filters in a chemical that extracts the chlorophyll. Then we can put the sample through a special machine that uses light to sense the amount of chlorophyll. Wow. One thing I am learning on this trip is how important light is in understanding a water ecosystem.
Do you remember what a hypothesis is? It’s an educated guess that answers a scientific question. When scientists come up with a hypothesis, it gives them something to test in an investigation. If you were presented with the question, “At what depth is phytoplankton most abundant?”, what would be your hypothesis?
Harvey – EcoMon started in 1992 but it was modeled after a program that started in 1977. The bongo plankton sampling has not changed much since it started, but with new technology we have added the water chemistry
testing, optics, and other instruments.