Julia West: CTD and much more, March 27, 2015

NOAA Teacher at Sea
Julia West
Aboard NOAA ship Gordon Gunter
March 17 – April 2, 2015

Mission: Winter Plankton Survey
Geographic area of cruise: Gulf of Mexico
Date: March 27, 2015

Weather Data from the Bridge

Time 1300; clouds 10%, cirrus; wind 330° (NNW), 10 knots; air temp. 18°C; water temp. 22°C; wave height 1 ft.; swell height 2-3 ft.

Science and Technology Log

We had some high winds (25 knots) these past couple of days, and the seas got too rough to work. Last night we headed closer to shore to find calmer water, and all ops were called off. Today we are back on (a new) course! Here’s the map with our rerouted course on it:

Sampling stations 3/27

Plankton sampling stations covered through 3/27/15

I want to start off this post answering two really good questions that have come up. Why do we send the samples all the way to Poland, only to have the data and some specimens come right back here? Is that typical U.S. outsourcing? Well, I had heard a rumor, and now I have a definitive answer about that, and it’s rather interesting! I had no idea I’d be learning history lessons on this journey, but this post has two important events in history.

If you have studied World War II, you may have heard of the Marshall Plan, otherwise known as the European Recovery Program, where the U.S. provided grants and loans for the rebuilding of war-ravaged European countries. Poland needed to pay off their war debt to the U.S., and the U.S. had a need. Here’s what I learned:

“The ‘father of the Polish Sorting Center’, Ken Sherman, visited a number European counties participating in the Marshall Plan looking for one that would be interested in setting up a Plankton Sorting and Identification Center. Poland was the one that took him up on the offer. Actually the leader of the Province of Pomerania in western Poland saw the economic possibilities for his state and thus was born the U.S.-Poland Agreement. By the way, the agreement lasted the entire time Poland was an eastern block country under the domination of the old Soviet Union. That in itself is a remarkable tale!” Information courtesy of Joanne Lyczkowski-Shultz, renowned Plankton scientist.

There you have it. Who knew? I think debt is paid off, but we have a great working relationship with the Polish Sorting Center, and they are good at what they do, so we continue.

Another good question was, why do we sample every year? Do the samples change? The reason is because just like for so many things (think of climate change as an example), it is by monitoring long term that we get the big picture and see change, if it is occurring. I asked if the samples change over time, but the answer isn’t known among the scientists on this ship. There are other departments that analyze the data; these scientists specialize in collecting it.

Today I want to introduce the CTD (Conductivity, Temperature, and Depth) unit. This expensive (think $20,000 and up) piece of equipment provides a hefty amount of data about the water column in our 200 meter sampling range. This is the last unit we deploy when we get to a station, after the neuston net comes back on board. Here’s what it looks like (the actual CTD part is on the bottom):

Here are some close-up pictures:

niskin bottles

There are 3 niskin bottles on the unit now (one not visible). It can hold 12.

The niskin bottles collect samples of water at whatever depth we determine. They are lowered into the water with both ends open (see the top and bottom lids are cocked open), so water flows through them. When they get to a certain depth, we can “fire” a bottle, and an electric signal trips a little lever at the top, and the top and bottom lids spring shut. We collect samples at the surface, at the bottom of the photic zone (200 meters or the ocean floor if we can’t go that deep), and at whatever place in the water column there is the maximum amount of chlorophyll. How do we know that, you should be wondering? Well, that’s where this unit comes in. This is officially the CTD – the expensive part:

CTD unit

The CTD is the “brains;” it does all the technical work.

It’s hard to see because it is on a black mat. The CTD sends constant information back to our computers. Water is pumped through the unit (see the tubing?) It is recording temperature, depth (by water pressure), oxygen level, salinity, turbidity (water clarity) and fluorescence. The conductivity, or the ability to pass an electric current, gives a measure of the dissolved salts in the water, or salinity (there’s chemistry and physics for you!) Fluorescence is one indicator of chlorophyll content. If you have learned about photosynthesis, it is chlorophyll in plant leaves that absorbs the sunlight and makes a plant green. The chlorophyll, therefore, is an indicator of the phytoplankton, such as single-celled algae, that are in the water. Remember, some zooplankton (mostly the invertebrates) eat phytoplankton, and most of our baby fish eat the zooplankton, so it’s good to know what is going on at the base of the food chain.

All of these things create cool little lines on a graph as the CTD is lowered. After capturing water at the bottom, we bring it up to approximately what the chlorophyll maximum was on the way down, by watching the data feed as it comes in, and fire another bottle to grab a sample of that water. Then we do it again at the surface.

So far I’ve shared what we do on the deck – how we collect the samples. In another post I will share with you what all this stuff looks like in the lab on the computer screen. Remember I said there is constant communication between the lab, the bridge, and the deck? Well, in the lab (but not the deck) we know exactly where the bottom is, and we have to give the order to stop the descent of the CTD (or bongos). “All stop!” is the command on the radio. “All stop,” the winch operator repeats as he stops the winch. If conditions are not right, the bridge or the scientists can put off or call off a deployment. We had some strong winds and high seas these past couple of days, so working with flying nets can get dangerous. The neuston is the first to get cancelled – that’s a big net!

In the next few blog posts I’m going to share with you some micrographs (pictures taken through a microscope) of what we’ve been catching. It is awe-inspiring to see all these little specks that fill our sieves close up!

Again, here’s what they look like in a jar:

Bongo sample

This is a nice sample from one of the bongo nets. Lots of little guys in there!

And here’s what happens when they are sorted under a microscope:

Larval fish

These are all larval fish. Top left: lizard fish. The bigger one in center is cutlass fish. These are both 8-9mm long. Photo courtesy of Pamela Bond, NOAA.

Personal Log

The other day we saw pilot whales from the bridge. It was pretty cool – they were right in front of the ship. If it was a kind of slow moving whale, we would have slowed down to avoid hitting them, but pilot whales move fast, and got out of our way easily. I didn’t get pictures – sorry! But here is somebody who was taking refuge on the deck:

yellow-crowned night heron

Yellow-crowned night heron taking a rest.

Sometimes birds get blown off course, or get tired while crossing a big expanse of water. We had two big cattle egrets sitting up high on the deck a few days ago. And often songbirds land on deck, completely exhausted.

We had another fire drill and abandon ship drill; these happen once a week. This time we practiced crawling (because smoke rises) to the nearest exit with our eyes shut.

fire escape practice

Here I am feeling my way to the exit. Photo credit: A.L. VanCampen

abandon ship drill

Everyone gathers on deck with their survival suits (and hats required) in the abandon ship drill

Here’s a random picture that I took. Occasionally we get plastic in our nets, and all this is recorded, of course. But if a man o’war is plankton, and this mylar balloon acts like plankton, is it plankton?


No, it’s pollution!

I’d like to introduce Tony VanCampen, our Electronics Technician (ET). Without him, operations would come to a stop around here. Tony is in charge of all the electronics on the ship. That includes things like the SeaCAT, the CTD, the computers, the radar, radios, GPS, meteorology gear, the internet connection….to name a few. Tony says “ET” stands for “Everything Tech.”


Our internet! VSAT (Very Small Aperture Terminal) – this is how I am posting to this blog.

Tony spent 20 years in the US Navy before joining NOAA. He spent 6 years on the USS Berkeley in the Pacific, followed by a couple of years of shore duty, during which time he went back to school to learn all the new equipment that was being used on the new ships. In 1994, Tony started a new tour on the brand new Navy ship USS Cole. He was on two deployments of the USS Cole. Where were you on October 12, 2000 – were you even born yet? Tony was on the Cole, in Yemen, when two men in a normal looking small boat came up to the ship, waved, and then blew themselves up, destroying a section of the Cole and killing 17 sailors and injuring another 40+. Tony was not visibly injured, but we now know that PTSD (Post Traumatic Stress Disorder) is a very real and serious affliction. Tony thought he was doing well until Sept. 11, 2001, when he and his wife realized he was not well at all. He credits his family and friends for seeking help and saving his life.

Why do I mention this? Because you never know, when you go to a new place, what the people you meet have been through. How important it is to remain sensitive and raise awareness of PTSD! Thanks to Tony for his willingness to share his story and thanks to those men and women who serve our country.

Lastly, here are a few pictures from our day with 5-7 foot seas. I have not been seasick – yay!

big waves

Big waves from the lower deck as we were trying to sample.

Gulf of Mexico


sunset on the Gulf

The day ends.

6 responses to “Julia West: CTD and much more, March 27, 2015

  1. very cool. How many miles have you traveled (just Approximately). also how many times do you put the CDT in the water, once twice, three times.

  2. Good question, Scott! I’ll find out how many miles. The CTD goes in the water at every station. The stations are about 30 miles apart, so we usually get 6 per day (24 hours). We travel at a max of 10 knots.

  3. The CTD does a lot of work.
    Does the ship have lifeboats on board? How was it crawling with your eyes closed?

  4. Of course there are life rafts, Emalie! Today, our last day at sea, I’m going to take a bunch of video. I wasn’t able to put up video because of our internet, but when I get back to land, I will post the video for you to see. It might take a few days!

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