CTD sensor – NOAA Teacher at Sea Blog

August 7, 2014August 21, 2021

Gregory Cook, The Dance, August 7, 2014

NOAA Teacher at Sea

Gregory Cook

Aboard NOAA Ship Oscar Dyson

July 26 – August 13, 2014

Mission: Annual Walleye Pollock Survey

Geographical Area: Bering Sea

Date: August 7, 2014

Science and Technology Log: Abiotic Factors in the Bering Sea

Ecosystems are made up of biotic and abiotic factors. Biotic is just another word for “stuff that is, or was, alive.” In a forest, that would include everything from Owl to Oak Tree, from bear to bacteria, and from fish to fungi. It includes anything alive, or, for that matter, dead. Keep in mind that “dead” is not the same as “non-living.”

Salmon and Black-Legged Kittiwake — The salmon and the black-legged kittiwake are both biotic members of the sub-arctic ecosystem.

“Non-living” describes things that are not, cannot, and never will be “alive.” These things are referred to as “abiotic.” (The prefix a- basically means the same as non-). Rocks, water, wind, sunlight and temperature are all considered abiotic factors. And while the most obvious threat to a salmon swimming up river might be the slash of a bear’s mighty claw, warm water could be even more deadly. Warm water carries less dissolved oxygen for the fish to absorb through their gills. This means that a power plant or factory that releases warm water into a river could actually cause fish to suffocate and, well, drown.

Bering Panorama — A 90 degree panorama of the Bering Sea from atop the Oscar Dyson. I’d show you the other 270°, but it’s pretty much the same. The sea and sky are abiotic parts of the sub-arctic ecosystem.

Fish in the Bering Sea have the same kind of challenges. Like Goldilocks, Pollock are always looking for sea water that is just right. The Oscar Dyson has the tools for testing all sorts of Abiotic factors. This is the Conductivity Temperature Depth sensor (Also known as the CTD).

CTD Deployment — Survey Technicians Allen and Bill teach me how to launch The Conductivity Temperature Depth Probe (or CTD).

The CTD sends signals up to computers in the cave to explain all sorts of abiotic conditions in the water column. It can measure how salty the water is by testing how well the water conducts electricity. It can tell you how cloudy, or turbid, the water is with a turbidity sensor. It can even tell you things like the amount of oxygen dissolved in the ocean.

To see how abiotic factors drive biotic factors, take a look at this.

I know, you may want to turn the graph above on its side… but don’t. You’ll notice that depth is on the y-axis (left). That means that the further down you are on the graph, the deeper in the sea you are. The blue line represents the water temperature at that depth. Where do you see the temperature drop?

Right… The temperature drops rapidly between about 20 and 35 meters. This part of the water column is called the Thermocline, and you’ll find it in much of the world’s oceans. It’s essentially where the temperature between surface waters (which are heated by the sun) and the deeper waters (typically dark and cold) mix together.

OK, so you’re like “great. So what? Water gets colder. Big deal… let’s throw a parade for science.”

Well, look at the graph to the right. It was made from another kind of data recorded by the CTD.

Fluoresence: Another depth-oriented graph from the CTD… the green line effectively shows us the amount of phytoplankton in the water column, based on depth.

The green line represents the amount of fluorescence. Fluorescence is a marker of phytoplankton. Phytoplankton are plant-like protists… the great producers of the sea! The more fluorescence, the more phytoplankton you have. Phytoplankton love to live right at the bottom of the thermocline. It gives them the best of both worlds: sunlight from above and nutrients from the bottom of the sea, which so many animals call home.

Now, if you’re a fish… especially a vegetarian fish, you just said: “Dinner? I’m listening…” But there’s an added bonus.

Look at this:

CTD Oxygen — Oxygen data from the CTD! This shows where the most dissolved oxygen is in the water column, based on depth. Notice any connections to the other graphs?

That orange line represents the amount of oxygen dissolved in the water. How does that compare to the other graphs?

Yup! The phytoplankton is hanging down there at the bottom of the thermocline cranking out oxygen! What a fine place to be a fish! Dinner and plenty of fresh air to breathe! So here, the abiotic (the temperature) drives the biotic (phytoplankton) which then drives the abiotic again (oxygen). This dance between biotic and abiotic plays out throughout earth’s ecosystems.

Another major abiotic factor is the depth of the ocean floor. Deep areas, also known as abyss, or abyssal plains, have food sources that are so far below the surface that phytoplankton can’t take advantage of the ground nutrients. Bad for phytoplankton is, of course, bad for fish. Look at this:

The Cliff and the Cod — The blue cloud represents a last grouping of fish as the continental shelf drops into the deep. Dr. Mikhail examines a cod.

That sloping red line is the profile (side view of the shape of the land) of the ocean floor. Those blue dots on the slope are fish. As Dr. Mikhail Stepanenko, a visiting Pollock specialist from Vladivostok, Russia, puts it, “after this… no more Pollock. It’s too deep.”

He goes on to show me how Pollock in the Bering Sea are only found on the continental shelf between the Aleutian Islands and Northeastern Russia. Young Pollock start their lives down near the Aleutians to the southeast, then migrate Northwest towards Russia, where lots of food is waiting for them.

Pollock Distribution — Alaskan Pollock avoid the deep! Purple line represents the ocean floor right before it drops off into the Aleutian Basin… a very deep place!

The purple line drawn in represents the drop-off you saw above… right before the deep zone. Pollock tend to stay in the shallow areas above it… where the eating is good!

Once again, the dance between the abiotic and the biotic create an ecosystem. Over the abyss, Phytoplankton can’t take advantage of nutrients from the deep, and fish can’t take advantage of the phytoplankton. Nonliving aspects have a MASSIVE impact on all the organisms in an ecosystem.

Next time we explore the Biotic side of things… the Sub-arctic food web!

Personal Log: The Order of the Monkey’s Fist.

Sweet William, a retired police officer turned ship’s engineer, tells the story of the order of the monkey’s fist.

William and the Monkey's Fist — Sweet William the Engineer shows off a monkey’s fist

The story goes that some island came up with a clever way to catch monkeys. They’d place a piece of fruit in a jar just barely big enough for the fruit to fit through and then leave the jar out for the monkeys. When a monkey saw it, they’d reach their hand in to grab the fruit, but couldn’t pull it out because their hands were too big now that they had the fruit in it. The monkey, so attached to the idea of an “easy” meal wouldn’t let go, making them easy pickings for the islanders. The Monkey’s Fist became a symbol for how clinging to our desires for some things can, in the end, do more harm than good. That sometimes letting go of something we want so badly is, in the end, what can grant us relief.

Another story of the origin of the monkey’s fist goes like this: A sea captain saw a sailor on the beach sharing his meal with a monkey. Without skipping a beat, the monkey went into the jungle and brought the sailor some of HIS meal… a piece of fruit.

No man is an Island. Mt. Ballyhoo, Unalaska, AK

Whatever the true origin of the Order is, the message is the same. Generosity beats selfishness at sea. It’s often better to let go of your own interests, sometimes, and think of someone else’s. Onboard the Oscar Dyson, when we see someone committing an act of kindness, we put their name in a box. Every now and then they pull a name from the box, and that person wins something at the ship store… a hat or a t-shirt or what have you. Of course, that’s not the point. The point is that NOAA sailors… scientists, corps, and crew… have each other’s backs. They look out for each other in a place where all they really have IS each other.

And that’s a beautiful thing.

July 9, 2013August 11, 2021

Sherie Gee: Male or Female? June 29, 2013

NOAA Teacher At Sea
Sherie Gee
Aboard the R/V Hugh R. Sharp
June 27 — July 7, 2013

Mission: Sea Scallop Survey
Geographical Area of Cruise: Northwest Atlantic Ocean
Date: June 29, 2013

Science and Technology Log:

Most of the shifts consisted of sorting out the animals from the dredges and carrying out the process of weighing, measuring and counting. One other component to the process is that on every dredge, five of the scallops are scrubbed, weighed and dissected. Once this is done, gender can be determined since this species of sea scallops have separate sexes. Then each scallop is numbered, labeled, tagged, and bagged. These five sea scallops will be brought back to the lab on land to be analyzed and aged. This is done by counting growth rings on the shell. The part of the scallop that is used as food is not the actual animal but the adductor muscle that is located in the middle of the shell. This is the muscle that can open and close the scallop’s shell. This is the only bivalve to be motile. Often times other organisms find a nice little resting spot inside of the shells of the scallops. This is a form of commensalism where the organism benefits while not harming the host. We saw a small red hake living inside the shell of a dissected sea scallop.

After every other dredge, the crew brings out the CTD which is an apparatus that collects conductivity, temperature, and depth. This data enters the database and is used in the labs on shore. We could always tell when they were lowering the CTD because the ship had to come to a complete stop while collecting data. Then they would bring the CTD back in and the ship would resume forward.

The CTD - Conductivity, Temperature and Depth — The CTD – Conductivity, Temperature and Depth

Did you Know:

The male sea scallop’s gonad is white and the female’s gonad is red. Gonads are reproductive organs.

Personal Log:

I learned the secret to gearing up efficiently with the boots and foul weather overalls from Larry. When you are ready to take them off, pull the overall part down toward the boots and leave about an inch of the boots exposed. Then just step out of the boots into regular shoes. I’m glad I brought some slip-on shoes which made things a lot easier. Then when it is time to gear up again, all I had to do was slip back into the boots and pull up the pants and suspenders. We also had to wear rubber work gloves that kept us from cutting ourselves during the dredges.

I interviewed our steward, Lee, for one of my requirements by NOAA. I found her to be a very interesting and social person. She is also the cook so she takes on two responsibilities at one time. She has to plan the meals, cook the meals and clean up after the meals. In addition to taking care of all kitchen duties, she also has to clean the heads (bathrooms), vacuum the carpets, clean the staterooms and do the laundry. She had to take some extensive courses on basic safety training for commercial vessels. Her satisfaction to the job is making food that people like and keeping up morale on the ship. She has a designated drawer which serves as a treasure chest of gold only the gold is actually tons of candy. All kinds of candy. She also keeps one big freezer full of ice cream and a refrigerator full of most types of can sodas.

Lee's Shrimp Jambalaya — Lee’s Shrimp Jambalaya

The Ship's Treasure — The Ship’s Treasure

Lee- The Ship's Cook and Steward — Lee- The Ship’s Cook and Steward

June 28, 2011April 28, 2021

Steven Wilkie: June 26, 2011

NOAA TEACHER AT SEA
STEVEN WILKIE
ONBOARD NOAA SHIP OREGON II
JUNE 23 — JULY 4, 2011

Mission: Summer Groundfish Survey
Geographic Location: Northern Gulf of Mexico
Date: June 26, 2011

Ship Data:

Latitude	26.56
Longitude	-96.41
Speed	10.00 kts
Course	6.00
Wind Speed	4.55 kts
Wind Dir.	150.72 º
Surf. Water Temp.	28.30 ºC
Surf. Water Sal.	24.88 PSU
Air Temperature	29.20 ºC
Relative Humidity	78.00 %
Barometric Pres.	1012.27 mb
Water Depth	115.20 m

Safety First! — Before getting down to work, it is important to learn all precautionary measures. Here I am suited up in a survival suit during an abandon ship drill.

Science and Technology Log

After two days of travel we are on site and beginning to work and I believe the entire crew is eager to get their hands busy, myself included. As I mentioned in my previous post, it is difficult if not impossible to separate the abiotic factors from the biotic factors, and as a result it is important to monitor the abiotic factors prior to every trawl event. The main piece of equipment involved in monitoring the water quality (an abiotic factor) is the C-T-D (Conductivity, Temperature and Depth) device. This device uses sophisticated sensors to determine the conductivity of the water, which in turn, can be used to measure salinity (differing salinities will conduct electricity at different rates). Salinity influences the density of the water: the saltier the water the more dense the water is. Density measures the amount of mass in a specific volume, so if you dissolve salt in a glass of water you are adding more mass without much volume. And since Density=Mass/Volume, the more salt you add, the denser the water will get. Less dense objects tend to float higher in the water column than more dense objects, so as a result the ocean often has layers of differing salinities (less salty water on top of more salty water). Often you encounter a boundary between the two layers known as a halocline (see the graph below for evidence of a halocline).

Temperature varies with depth in the ocean, however, because warm water is less dense than cold water. When liquids are cold, more molecules can fit into a space than when they are war; therefore there is more mass in that volume. The warm water tends to remain towards the surface, while the cooler water remains at depth. You may have experienced this if you swim in a local lake or river. You dive down and all of a sudden the water goes from nice and warm to cool. This is known as a thermocline and is the result of the warm, less dense water sitting on top of the cool more dense water.

The C (Conductivity) T (Temperature) D (Depth) Sensor — Here is the fancy piece of technology that makes measuring water quality so easy: the CTD.

Temperature also influences the amount of oxygen that water can hold. The cooler the temperature of the water the more oxygen can dissolve in it. This is yet another reason why the hypoxic zones discussed in my last blog are more common in summer months than winter months: the warm water simply does not hold as much oxygen as it does in the winter.

The CTD is also capable of measuring chlorophyll. Chlorophyll is a molecule that photosynthetic organisms use to capture light energy and then use to build complex organic molecules that they can in turn be used as energy to grow, reproduce etc. The more chlorophyll in the water, the more photosynthetic phytoplankton there is in the water column. This can be a good thing, since photosynthetic organisms are the foundation of the food chain, but as I mentioned in my earlier blog, too much phytoplankton can also lead to hypoxic zones.

Finally the CTD sensor is capable of measuring the water’s turbidity. This measures how clear the water is. Think of water around a coral reef — that water has a very low turbidity, so you can see quite a ways into the water (which is good for coral since they need access to sunlight to survive). Water in estuaries or near shore is often quite turbid because of all of the run off coming from land.

CTD Data — This is a CTD data sample taken on June 26th at a depth of 94 meters. The pink line represents chlorophyll concentration, the green represents oxygen concentration, the blue is temperature and the red is salinity.

So, that is how we measure the abiotic factors, now let’s concentrate on how we measure the biotic! After using the CTD (and it takes less time to use it than it does to describe it here) we are ready to pull our trawls. There are three different trawls that the scientists rely on and they each focus on different “groups” of organisms.

Neuston Tow — The neuston net captures organisms living just at the water's surface.

The neuston net (named for the neuston zone, which is where the surface of the water interacts with the atmosphere) is pulled along the side of the ship and skims the surface of the water. At the end of the net is a small “catch bottle” that will capture anything bigger than .947 microns. The bongo nets are nets that are targeting organisms of a similar size, but instead of remaining at the surface these nets are lowered from the surface to the seafloor and back again, capturing a representative sample of organisms throughout the water column. The neuston net is towed for approximately ten minutes, while the bongo nets tow times are dependent on depth. Once the nets are brought in, the scientists, myself included, take the catch and preserve it for the scientists back in the lab to study.

Bongo Nets — The bongo nets will capture organisms from the surface all the way down to bottom.

The biggest and baddest nets on the boat are the actual trawl nets launched from the stern (back) of the boat. These are the nets the scientists are relying on to target the bottom fish. This trawl net is often referred to as an otter trawl because of the giant heavy doors used to pull the mouth of the net open once it reaches the bottom. As the boat moves forward, a “tickler” chain spooks any of the organisms that might be lounging around on the bottom and the net follows behind to scoop them up. This net is towed for thirty minutes, and then retrieved and we spend the next hour or so sorting, counting and measuring the catch.

Otter Trawl Net Waiting to be Deployed — Here you can see the otter trawl net extending off the starboard side of the Oregon II. When lowered into the water the doors will spread the mouth of the net.

Personal Log

I thought that adjusting to a 12 hour work schedule would be tough, but with a 5-month old son at home I feel I am more prepared than most might be for an extended day. I might go as far as to say that I have more down time now than I did at home! Although the ship’s crew actually manages the deployment of the majority of the nets and C-T-D, the science team is always involved and keeping busy allows the hours to tick away without much thought. Before you know it you are on the stern deck of the ship staring at a gorgeous Gulf of Mexico sunset.

Sunset Over the Plankton Station — As we steam back East, the sun sets in our stern every day, and we have been treated to peaceful ones thus far on this trip.

The sun has long since set. As I write this it is well after midnight and my bunk is calling.

September 15, 2009April 15, 2021

Christine Hedge, September 15, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Chukchi Sea, north of the arctic circle
Date: September 15, 2009

MST2 Tom Kruger and MST3 Marshall Chaidez retrieve a meteorological buoy on September 14.

Weather Data from the Bridge
Latitude: 73⁰22’N
Longitude: 156⁰ 27’W
Temperature: 31⁰F

Science and Technology Log

The past few days have brought much change. The depth of the ocean changed dramatically as we got closer to Alaska. The ocean went from depths of over 3500 meters to depths of less than 100 meters. More birds are showing up and we are getting about 9 hours of darkness each day. This morning at about 4 AM, the watch observed the Aurora Borealis and stars!!! I am so jealous.

FOR MY STUDENTS: Why do you think we have more hours of darkness now?

As we head home to Barrow, the science party is busily completing their “Cruise Reports” and making sure that their data is stored safely for the trip home. Much has been accomplished on this trip:

132 XBT deployments (measures temperature, depth)
8 CTD deployments (measures conductivity, temperature, depth)
5 Dredge operations and hundreds of pounds of rock samples collected and catalogued
1 Seaglider deployed and retrieved
2 HARP instruments retrieved and 3 deployed
3 Ice buoys deployed
8 Sonobuoys deployed
9585.0 lineal kilometers of sea floor mapped
1 METBUOY retrieved (meteorological buoy)

Coast Guard Marine Science Technicians

MST3 Marshal Chaidez operates the winch during a dredging operation.

Science parties come and go on the Healy, each doing a different type of research. A constant for all the scientific cruises is the good work done by the Coast Guard MSTs (Marine Science Technicians). Running the winch, taking daily XBT and weather measurements, working the dredge, and helping to deploy buoys are just some of the many tasks these technicians do. The scientists could not get their experiments done without the assistance of our team of MSTs.

MST3 Daniel Purse, MST2 Daniel Jarrett, MST3 Marshal Chaidez, MST2 Thomas Kruger and Chief Mark Rieg have done a masterful job of helping the science party accomplish their goals. I asked them to tell me a little about their training for this job. Each MST attends a 10-week training school in Yorktown, VA. Most of their training involves how to clean up oil spills and inspect cargo ships which means they are usually stationed at a port. Being assigned to a ship is not the norm for an MST. But, because the mission of the Healy is specifically science, a team of MSTs is essential.

Personal Log

My commute to work is different lately. We have about 9 hours of darkness each day. It gets dark around midnight and stays dark until about 8:30 in the morning. So, walking the deck to the science lab is a bit of a challenge at 7:45. It will be strange to drive to work in a few days! On September 16^th, we will depart the Healy via helicopter if all goes according to plan. It will be strange to be on land again.

We will be back in Barrow, AK on September 16th. I cannot believe that our expedition is almost over. I have learned so much from the members of the science party and the crew of the Healy. They have been very gracious and patient while I took their pictures and asked questions. Now comes the task of sharing what I have learned with folks back home. I know one thing for sure; the Arctic is no longer an abstract idea for me. It is a place of beauty and mystery and a place some people call home. I hope to convey how important it is that we continue to study this place to learn how it came to be and how it is currently changing.

Jon Pazol and I next to the bowhead whale skull in Barrow. When we return to shore the bowhead hunting season will have started.

Thanks to the folks at NOAA Teacher at Sea, Captain Sommer, and chief scientists Larry Mayer and Andy Armstrong for allowing me to take part in this cruise. You can be sure that I will be following Arctic research and the adventures of the Healy for many years to come.

August 25, 2009April 6, 2021

Christine Hedge, August 25, 2009

NOAA Teacher at Sea
Christine Hedge
Onboard USCGC Healy
August 7 – September 16, 2009

Mission: U.S.-Canada 2009 Arctic Seafloor Continental Shelf Survey
Location: Beaufort Sea, north of the arctic circle
Date: August 25, 2009

Weather Data from the Bridge
Temperature: 30.15⁰F
Latitude: 81.31⁰N
Longitude: 134.28⁰W

Science and Technology Log

This multibeam image of the new seamount is what I saw in the Science Lab.

A Day of Discovery…

Today, our planned route took us near an unmapped feature on the sea floor. A 2002 Russian contour map showed a single contour (a bump in the middle of a flat plain) at 3600 meters. This single contour line also appeared on the IBCAO (International Bathymetric Chart of the Arctic Ocean) map. We were so close that we decided to take a slight detour and see if there really was a bump on this flat, featureless stretch of sea floor.

The contour was labeled 3600 meters and the sea floor in the area averaged about 3800 meters so a 200 meter bump was what the map suggested. As the Healy traveled over the area we found much more than a bump! The feature slowly unfolded before our eyes on the computer screen. It got taller and taller and excitement grew as people realized this might be over 1000 meters tall. If a feature is 1000 meters or more, it is considered a seamount (underwater mountain) and can be named. Finally, the picture was complete, the data was processed, and a new seamount was discovered. The height is approximately 1,100 meters and the location is 81.31.57N and 134.28.80W.

The colors on this 3-D image of the newly discovered seamount indicate depth.

Why Isn’t the Arctic Mapped?

Some areas of the sea floor have been mapped and charted over and over again with each improvement in our bathymetric technology. Areas with lots of ship traffic such as San Francisco Bay or Chesapeake Bay need to have excellent bathymetric charts, which show depth of the water, and any features on the sea floor that might cause damage to a ship. But in the Arctic Ocean, there isn’t much ship traffic and it is a difficult place to collect bathymetric data because of all the ice. Therefore, in some areas the maps are based on very sparse soundings from lots of different sources. Remember, older maps are often based on data that was collected before multibeam echosounders and GPS navigation – new technology means more precise data!

Personal Log

This is the IBCAO. (International Bathymetric chart of the Arctic Ocean) It is a great resource for ships exploring the Arctic Basin.

It is still very foggy. We are about 625 miles north of Alaska and plowing through ice that is 1-2 meters thick. This time of year it is the melt season. Increased evaporation means more water in the atmosphere and more fog. Even though we are usually in water that is 90% covered by ice (REMEMBER 9/10 ice cover?) we rarely have to back and ram to get through. It is noisier lately and the chunks of ice that pop up beside the ship are more interesting to look at. There are blue stripes, brown patches of algae and usually a thin layer of snow on top.

I cannot send a current sound file because of our limited bandwidth on the Healy. When we are this far north it is difficult to get Internet access. But, if you would like to hear what it sounds like when the Healy is breaking ice, click on this link from a past trip through Arctic sea ice.

Sea Ice at 810N after the Healy has broken through — Sea Ice after the Healy has broken through