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
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.
NOAA Teacher at Sea Donna Knutson NOAA Ship Oscar Elton Sette September 1 – September 29, 2010
Mission: Hawaiian Islands Cetacean and Ecosystem Assessment Survey Geograpical Area: Hawaii Date: September 16, 2010
Midway
It is hard to smile wearing a mask!
September 16, 2010
Teacher at Sea: Donna Knutson
Ship Name: Oscar Elton Sette
Mission and Geographical Area:
The Oscar Elton Sette is on a mission called HICEAS, which stands for Hawaiian Islands Cetacean and Ecosystem Assessment Survey. This cruise will try to locate all marine mammals in the Exclusive Economic Zone called the “EEZ” of Hawaiian waters. The expedition will cover the waters out to 200 nautical miles of the Hawaiian Islands.
Data such as conductivity, temperature, depth, and chlorophyll abundance will be collected and sea bird sittings will also be documented.
Science and Technology:
Latitude: 28○ 22.6’ N
Longitude: 177○ 28.5’ W
Clouds: 6/8 Cu, Ci
Visibility: 10 N.M.
Wind: 8 Knots
Wave height: 3-4 ft.
Water Temperature: 28.0○ C
Air Temperature: 26.8○ C
Sea Level Pressure: 1020.2 mb
History:
Memorial surrounded by Bonin petrel underground nests.
Midway is the second to the last island in the line of islands/atolls extending northwest of Hawaii. Midway has a lot of history dating back to 1859 when it was first discovered by Captain N. C. Brooks. The island, called Sand Island, at that time was nothing but sand and an occasional tuft of grass with birds everywhere.
In 1870 after the Civil War it was felt necessary to have access to Midway for political reasons and a company was hired to cut a path through the coral for steam engine ships to come and refuel. It became too costly and never was finished.
On 1903 the Pacific Commercial Cable Company set to work to provide communication between Guam, Waikiki, Midway and San Francisco. At this time President Theodore Roosevelt put Midway under the protection of the Navy because of Japanese poachers. The workers for the cable company became the first planned settlement on Midway.
In 1935 Pan American Airlines built a runway and refueling station for their Flying Clipper seaplane operation. They also helped the little community prosper as they transferred goods between Manila and Wake and Guam.
An inside corridor to the Naval facility. The pictures were still on the wall.
Midway was made famous in 1942 during World War II. The island had been named Midway as it is “midway” between the continental United States and Japan. The United States had naval control over the island for approximately thirty years, but it wasn’t until 1938 that the Navy made it into a full naval base.
They hauled in over a hundred tons of soil in order to plant gardens and trees, to make it appear more like home, and also to build roads and piers. The navy base at one time housed ten thousand people, and was a very important strategic base. Hawaii was at risk from an invasion from Japan and Midway was added defensive support.
The Japanese recognized Midway as a threat and attacked it on June 4-6, 1942. It was a fierce battle with many fatalities. It was reported that the Japanese lost 2,500 soldiers while the United States lost 320. The victory of the Battle at Midway was a major turning point in WWII.
The airstrip has not been used since the ’60’s.
After the war ended there was less need for the Midway Naval Base. Most of the people left Midway 1950, leaving behind buildings with the holdings intact. In 1988 the military released the island to the United States Fish and Wildlife Service and Midway became a national park and refuge to protect the shorebirds, seabirds, and threatened and endangered species.
The upkeep of the naval base has fallen on the shoulders of the U.S. Fish and Wildlife Service. They have torn down some of the buildings constructed before 1950 that are not repairable. The fish and wildlife service is making room for more birds by clearing out some of the ironwood trees which have overgrown the island. There are sixty-three places on Midway that are considered eligible for National Historic Landmarks.
Dr. Tran and Stephanie riding ahead of me on the old runway. The trees were filled with common myna birds.
In addition to the historical significance of Midway, many animals find a sanctuary within the atoll. Nineteen species of birds, approximately two million birds, nest on Midway. In the water there are about two-hundred fifty spinner dolphins, the threatened green sea turtles, about sixty endangered Hawaiian monk seals, more than two-hundred sixty-five species of fishes, and forty plus species of stony corals that make Midway atoll home.
Resources:
Isles of Refuge, Wildlife and History of the Northwestern Hawaiian Islands, by Mark J. Rauzon, copyright 2001.
A white tern chick. White terns lay an egg without a nest. The chick must have strong feet to hold on to it’s precarious perch.
Personal Log:
Today I am lucky enough to go to Midway! I have read up on it and expect not only to see a beautiful destination with an abundance of wildlife, I will be seeing first hand a historical site few people have had the pleasure to explore.
My swimming suit is under my clothes so I’m also ready to try out the beaches! Mills and Chris are escorting me, Dr. Tran and the XO, Stephanie, on the small boat to the island. Mills has to weave in and out because of all the coral. Mills is one of the few who have had the opportunity to see Midway and he is giving us last minute advice.
We are met at a small dock by John, a warden for the U.S. Wildlife Service, he is going to be our tour guide. As I watch the small boat head back to the Sette, I can’t help thinking that it feels like the beginning of one of those “stranded” movies. This is not what I pictured. There is trash everywhere. To the right I see the rocky shore littered with garbage. Plastics everywhere, all shapes and sizes right next to the sparkling clean water. Ugh! Piles of twisted metal are heaped in piles twenty feet high. Then there are the piles of uprooted trees and old lumber. I guess it is organized waiting to be hauled out, but I didn’t see any of that in the literature I read.
I am standing on the deck at”Captain Brooks”. It was named after the man who claimed the island for the United States. This was my first view of North Beach!
Unfortunately the garbage people throw out to sea is being collected on the atolls and banks of the Northwestern Hawaiian Islands. Crates, buckets, balls, anything and everything imaginable that is made from plastic is showing up on these unpopulated, remote islands. It is the currents that carry the debris to the islands and the corals and beaches trap and collect the material. Very sad. People are so uncaring and oblivious to what they do daily to the environment.
John is very friendly and laid back, ok, I don’t feel like the star in one of those silly sci-fi movies I love to watch, any longer. We three hop on a Kawasaki “mule” and head away from the dock. Most of the buildings we pass are left-overs from the war, rusty, broken windows and even bullet holes. John drives up to the Visitor Center/Office. He gives us a general briefing on how things work there and mentions some of the sites we should see, and off we go again. Now our mode of transportation is a golf cart. He shows us where we can go on our own and tells us where not to go – the air strip. Now I’m thinking “bad movie plot” again.
John described how the cannons were bolted to the center. At that time there were no trees and the guns were aimed at the Japanese ships in the ocean.
He gives us bikes and we start our own tour. We need to stay on paths or roads because the land is covered with holes for Bonin petrels. They are nocturnal birds and burrow underground to nest and lay their eggs. At one time Midway had a rat problem and they ate the chicks and eggs, so now that they have been eliminated, this is a true bird paradise. It is fun to ride around and look leisurely at the island.
Doc had been there before so he was in the lead. As we look around at the wonderful wildlife the ground is also littered with small plastic objects. I see a toothbrush, a lighter, and bottle tops all over! Other plastic objects with strange shapes seem to catch my eye. What is going on?
Doc explains to me that the albatross that go to feed in the ocean will see something resembling a fish, swoop down to get it and bring it back to shore for its offspring. Once regurgitated, the fledgling may also eat it and then die with a stomach full of plastic. Great! Where is this plastic coming from? Why hasn’t it stopped? I am told later that tons of trash washes up every year. Ugh! Back to our tour.
A monk seal basking in the sun at “Rusty Bucket”.
Little white terns are above us following us on our paths. There are so many trees! From once an island with only a few tufts of grass, and now seventy years later, Midway has a forest. It smells musty, old and slightly sweet, if you didn’t look too close, you would think you had fallen back in time.
We head for the beach! Nothing eerie about the beach! Absolutely spectacular! Soft white sand bordered by lush, thick leaved tropical plants. The water was so clear, not a rock, not a piece of garbage, if it hadn’t been for the four beach chairs you could have imagined discovering an untouched pristine utopia. I could not help but stand and stare at the soft pale turquoise water. It felt as good as it looked. We all loved our limited time playing in the water as though we were kids in the biggest swimming pool imaginable.
One of the machine shops. All the tools were left behind.
Unfortunately we had to get back to the Visitor Center so we trodded up the incline back to the bikes. With John on the golf cart, we resumed out guided tour. One of the first places we go is the “rusty bucket”. It is a site along the shore where ships and other vehicles have been left. We see a basking Monk seal. Monk seals are nearly extinct, they only live on the shores of the Hawaiian Archipelago.
John shows us where the large cannons were bolted to shoot into the bay, a graveyard of the early inhabitants, and in town many old buildings. Some of the shops have all the tools still in them. It is as if it is being left just so, waiting for the people to return and continue their projects.
One of the buildings that is still in pretty good shape is the theater. It has all the old felt covered seats, the wood floors and the dull yellow colored walls you see in old movies. The stage is still intact and you can almost picture the place full of people watching Bob Hope perform. He stayed at Midway entertaining the troops off and on throughout the war. John gives us a great tour, but has other jobs to do, so we are alone once again to fend for ourselves. Where do we go…the beach!
It is called North Beach. A Coast Guard ship has docked on the other side of the beach around a corner. I just lay and float trying to appreciate every second I have been given! A green sea turtle swims up to check out the strange humans and off he goes. They are threatened and this is a refuge for him. Mills has lent me his snorkel and fins so off to explore I go. We are within the atoll and can see waves crash on the corals miles away. No risk of anything catching you off guard with such great visibility.
The movie theatre still decorated with the original pictures.
It was truly spectacular! The Sette is coming back to the area and the small boat will be coming to get us soon. We head back to the dock. On the radio Stephanie hears we have one more hour to be tourists. John suggests snorkeling by the cargo pier and that sounds wonderful to me!
Stephanie and I jump off the pier to the water fifteen feet below. The water is thirty feet deep and looks and feels wonderful! There are fish of all shapes and sizes! I feel as though I am swimming in a giant aquarium.
I even saw a sleeping green sea turtle on a broken pier support. Incredible! We were weaving in and out of the pier supports looking all the way down thirty feet and seeing everything crystal clear.
All good things come to an end and our little vacation at Midway was over. Doc, Stephanie and I had a “fabulous” time! The small boat was back. It was time to go back home to the Sette.
Midway is definitely a place of contrasting sites and interests. I leave with mixed emotions, which are the seeds for memories, of a place I will never forget.
Senior Survey Technician Colleen Peters and crewmember Dennis Boggs recover the CTD equipment.
Science and Technology Log: What Does the Survey Technician Do?
Among the crew of each NOAA research vessel are typically one or more survey technicians. On each cruise a team of scientists come on board to do research; the survey technicians are the onboard scientists who provide continuity in data collection during all operations, as well as maintaining a number of onboard laboratories. The survey technicians are responsible to ensure all the scientific equipment is running and is accurate, as well as assisting the science team with their research. One task that falls to the survey technician is to collect data as needed using the Conductivity, Temperature and Depth (CTD) sensor. The CTD equipment is mounted on a frame called the “rosette,” and is deployed over the side of the ship at the request of the science team. The survey technician coordinates between the science team, the bridge and the deck crew to successfully complete these casts.
The science team can indicate the position at which the data are to be collected, and the officer on the bridge holds the ship in position and on station. The deck crew then assists the survey tech in lowering the delicate rosette into the water. Once the pumps are running, the rosette is lowered to the required depth. Information from the sensors is relayed back to the ship through the cable, and if needed a water sample can be collected from any point in the water column. After the CTD is brought back on board, the survey tech processes the data and relays it to the science team.
Senior Survey Technician Colleen processing CTD data
On the OSCAR DYSON, Sr. Survey Technician Colleen Peters must also maintain several labs: the dry lab, chemistry lab, hydrographic lab (nicknamed “the garage” by the crew), and the fish processing, or wet, lab. The Survey Techs also participate in shooting and hauling the trawl nets by setting up and retrieving sensors on the nets. When the catch is brought on board, they work alongside the scientists to process the sample. There are several other systems to be maintained such as the Scientific Computer System (SCS), which continuously collects data from hundreds of sensors mounted all around the ship, the scientific seawater system, which measures sea surface temperature and salinity, and the Continuous Underwater Fish Egg Sampler (CUFES), whish filters the surface water for plankton and fish eggs for analysis. Colleen is a graduate of Maine Maritime Academy, where she obtained a Bachelor of Science degree in Marine Science. “I chose marine science because I knew I wanted to be at sea and I like doing science in the field,” she commented.
Personal Log
The late shift has become easier, though I still struggle between 1-4:00 a.m. if we’re not processing fish. We passed very near St. Matthew Island yesterday, but the infernal fog prevented us seeing it or many of the seabirds that are surely nesting there. Each time we reach the northern end of a transect the water temperatures are too cold for pollock, and our sampling slows down considerably. We have done some jellyfish and euphausid samples, and we’re back in an area with plenty of fish, so plenty of sampling, too!
Question of the Day
The answer to yesterday’s question (What is an “otolith” and why is it important?): In fish, the otolith is a calcareous “bone” that plays a role in hearing and balance; it is often referred to as a fish’s “ear bone.” Otoliths are used by scientists studying many types of fish to learn the age of the fish. As the fish grows, two rings are visible in the otolith: one for winter, and one for summer. The two rings together can be counted as a year in the life of the fish, and thus scientists are able to find the age of most fish by harvesting the otolith, cutting it in half, and counting the rings.
Visibility: 1.5miles fog Sea Water Temperature: 9.9C
Wind Direction: 221. Barometric Pressure: 1012 high pressure
Wind Speed: 9.1 kts Cloud Cover: complete 100%
Haul Data: CTD (conductivity / Temperature / Depth) Depth of haul: 90 meters
Temperature at depth: 10° C surface – 2° C at bottom
Species breakdown: Informational gathering / no species collection
Science and Technology Log:
The CTD is a device that is hard to explain. Scientific in nature similar to an inverted cone that has a six inch diameter at the top. Today we will look at the condition of the water, the liquid habitat for this ecosystem. Conductivity will give the scientists, with some calculations, the percent of salt in solution. This is important information as the salinity affects the density of the water which in turn affects the speed of sound. Knowing the speed of sound is vital in acoustic fisheries surveys as the scientists use back scatter data in determining fish location and density. The density of water is also affected by the salinity and temperature of the water.
Today’s temperature at 90 meters was 2°C, at the surface it was a balmy 10°C. Ocean water like our atmosphere is in layers, each a distinct unit. The thermo cline was at 35 meters, with a graphic representation showing a distinct differentiation between the two water masses.
The CTD data is used in looking at correlations between where fish populations are found and if their placement is not only affected by the condition of the water, but if there are conditions that they prefer.
Personal Log:
Understanding the CTD has been difficult for me. This ecosystem is literally poles apart from a ponderosa pine type forest. I am learning an amazing amount of information and at the same time realizing how much I do not know. Oceanography is an amazing science, and phenomenally diverse.
Once again I spent an hour on the bridge, 2400-0100, standing watch. I did not realize that this nautical term is in fact correct as there are no seats on the bridge except the CO’s chair which is off limits. I was told that there is a common yarn that the captain’s chair is directly above his stateroom, and attached to a bell. If someone sits in the chair the bell will ring indicating that sacred territory has been breached. When a person stands watch for four hours, they stand watch. There are some counters with cushions to brace against, but that is it. While standing watch last night I got my first glimpse of a dall’s porpoise. The pictures that are commonly seen of porpoises show the entire animal usually gliding gracefully with a wave. Our view last night was a glimpse, a peak into the life of a marine mammal. It was Mark, the field operations officer who first spotted the sign, a brief splash within the bow wave of the boat. The porpoises travel the wave of a boat, literally catching rides. At one time there was the splash of three heads effortlessly coming up for air, a brief splash and again they were lost in the wave only to be seen moments later literally in the same place even though we were all moving forward.
There is a calmness here when the fog moves in, a sense of peace. We are out of touch with time, yes there are news briefs, but one does not need to read what is going on in other places. I am ok with the solitude, the sound of the engine the gentle rocking of the boat. This is a serene place to be, in summer!
