Lindsay Knippenberg: Oceanography Day! September 11, 2011

NOAA Teacher at Sea
Lindsay Knippenberg
Aboard NOAA Ship Oscar Dyson
September 4 – 16, 2011

Mission: Bering-Aleutian Salmon International Survey (BASIS)
Geographical Area: Bering Sea
Date: September 11, 2011

Weather Data from the Bridge
Latitude: 58.00 N
Longitude: -166.91 W
Wind Speed: 23.91 kts with gusts over 30 kts
Wave Height: 10 – 13ft with some bigger swells rolling through
Surface Water Temperature: 6.3 C
Air Temperature: 8.0 C

Science and Technology Log

On a calm day letting out the CTD is easy.
On a calm day letting out the CTD is easy.

Today Jeanette and Florence took me under their wing to teach me about the oceanographic research they are conducting onboard the Dyson. At every station there is a specific order to how we sample. First the transducer, then the CTD, then numerous types of plankton nets, and then we end with the fishing trawl. The majority of the oceanographic data that they collect comes from the CTD (Conductivity, Temperature, Depth). The CTD is lowered over the side of the ship and as it slowly descends to about 100 meters it takes conductivity, temperature, and depth readings. Those readings go to a computer inside the dry lab where Jeanette is watching to record where the pycnocline is located.

The results from the CTD. Can you spot where the pycnocline is?
The results from the CTD. Can you spot where the pycnocline is?

The pycnocline is a sharp boundary layer where the density of the water rapidly changes. The density changes because cold water is more dense than warm water and water with a higher salinity is more dense than water that is lower in salinity. So as the CTD travels down towards the bottom it  measures warmer, less salty water near the surface, a dramatic change of temperature and salinity at the pycnocline, and then colder, saltier water below the pycnocline. Once Jeanette knows where the pycnocline is, she tells the CTD to collect water at depths below, above, and at the pycnocline boundary. The water is collected in niskin bottles and when the CTD is back on deck Florence and Jeanette take samples of the water to examine in the wet lab.

Filtering out the chlorophyll from the CTD water samples.
Filtering out the chlorophyll from the CTD water samples.

Back in the lab, Jeanette and Florence run several tests on the water that they collected. The first test that I watched them do was for chlorophyll. They used a vacuum to draw the water through two filters that filtered out the chlorophyll from the water. As the water from the CTD passed through the filters, the different sizes of chlorophyll would get stuck on the filter paper. Jeanette and Florence then collected the filter paper, placed them in labeled tubes, and stored them in a cold, dark freezer where the chlorophyll would not degrade. In the next couple of days the chlorophyll samples that they collected will be ran through a fluorometer which will quantify how much chlorophyll is actually in their samples.

Jeanette collecting water from the CTD.
Jeanette collecting water from the CTD.

Besides chlorophyll, Jeanette and Florence also tested the water for dissolved oxygen and nutrients like nitrates and phosphates. All of these tests will give the scientists a snapshot of the physical and biological characteristics of the Eastern Bering Sea at this time of year. This is very important to the fisheries research because it can help to determine the health of the ecosystem and return of the fish in the following year.

Personal Log

One of the high points for me so far on the cruise has been seeing and learning about all the new fish that we catch in the net. We have caught lots of salmon, pollock, and capelin. The capelin are funny because they smell exactly like cucumbers. When we get a big catch of capelin the entire fish lab smells like cucumbers…it’s so weird. We have also caught wolffish, yellow fin sole, herring, and a lot of different types of jellyfish. The jellies are fun because they come in all different shapes and sizes. We had a catch today that had some hug ones and everyone was taking their pictures with them.

Now that is a big jelly fish.
Now that is a big jelly fish.

Today we also caught three large Chinook or king salmon. Ellen taught me how to fillet a fish and I practiced on a smaller fish and then filleted the salmon for the cook. What is even cooler was that at dinner we had salmon and it was the fish that we had caught and I had filleted. Fresh salmon is so good and I think the crew was happy to get to enjoy our catch.

The catch of the day was a 8.5 kg Chinook salmon.
The catch of the day was a 8.5 kg Chinook salmon.
Salmon for dinner, filleted by Lindsay.
Salmon for dinner, filleted by Lindsay.

What else did we catch?
Walleye Pollock
Walleye Pollock
A juvenile Wolffish
A juvenile Wolffish
Yellow Fin Sole
Yellowfin Sole
 A squid
A squid
Lots of little Capelin
Lots of little Capelin

Steven Wilkie: June 26, 2011

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
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.

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.

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.

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.

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.

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.

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.

Tanya Scott, June 17, 2010

NOAA Teacher at Sea
Tanya Scott
Onboard NOAA Ship Miller Freeman
June 16 – 21, 2010

Mission:  Ecosystem Surveys
Date: Thursday, June 17, 2010
Current Location: Oregon/Washington Coast  44 55 N  124 37 W off Siletz Bay

Traveling from Newport, North Carolina to Newport, Oregon has been quite an adventure.  The most obvious difference has been the weather. When I left NC, the weather was typical for early June:  hot and muggy!!  Here in Oregon, it is a different story.  When I arrived, the skies were clear and the temperature was a comfortable 81 F.  It soon turned to overcast skies and cooler temperatures.  While I have enjoyed the cooler temperatures, I must admit that I do miss the NC sunshine!

One of the most striking differences between Newport, NC and Newport, OR is the coastline.  The coastline of Oregon is marked by cobblestone beaches made of breccia (a common igneous rock of the western coast), steep cliffs, and very unlike our sandy, quartz beaches of NC.  The Oregon beaches are breathtaking.  I have watched sea lions swim and rest on rocks jutting from the Pacific Ocean, seen thousands of nesting birds such as the Murre and Puffin, and collected many interesting pieces of driftwood to share with you when I return.

We made the drive north from Newport, OR to Astoria, OR yesterday morning after the captain determined that it was not safe to enter the harbor in Newport.  The Miller Freeman was underway at 1200 yesterday and we have steamed ahead since.  Currently, we are 26 miles off the coast of Oregon and are heading out to 50 miles offshore.  Along the way, scientists from Oregon State University have been preparing their gear and running tests to ensure that all equipment is running properly. Just as we do in science class, they conduct trials so that the data collected is reliable.  Remember, few things work correctly the first time around.  That rule is true even at sea!

Today marks the beginning of my first duty rotation. This means that I am responsible for helping the scientists with any jobs they have such as deploying equipment overboard and collecting data from 12:00 pm until 12:00 am.  I will be helping with one instrument called a “CTD”.  This device is lowered to 100 meters below the surface of the water and measures salinity, temperature, density, turbidity, dissolved oxygen, and fluorescence.  Those of you who went with me to Hoop Pole Creek in Atlantic Beach measured some of these same parameters. Using the Secchi disk determines the turbidity or the cloudiness of the water.  The CTD does the same thing except for the fact that everything is measured using a computer and sent directly to a monitor on the ship for all to see!  The CTD is much more advanced than any equipment we have used in class, but offers the same data that you have already collected.

Tonight, I look forward to helping deploy a number of different nets or trawls that will be used to collect juvenille fish species.  I am keeping my fingers crossed and hope to see some interesting organisms to share with everyone tomorrow.  In the meantime, I am anxiously scanning the horizon in search of a whale.  I did see a pod of Pacific Whiteside Dolphin this morning. They were bowriding, which is when they ride along the bow of the ship and jump from the wake. It seems that many species of dolphin do this purely for the fun of it. These dolphin are notably smaller than the Common Bottlenose Dolphin seen in NC. They are dark grey on the top half of their body and white on the bottom.  I was close enough to them to see scars on their dorsal fins.
I look forward to sharing my adventures with you tomorrow.  Wish me luck as I will be up until midnight tonight helping with large trawl nets and hopefully collecting many exciting marine organisms.