Richard Chewning – NOAA Teacher at Sea Blog

June 7, 2012March 12, 2021

Richard Chewning, June 15th, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 15th, 2010

Weather Data from the Bridge

Position: eastern Bering Sea
Time: 1530
Latitude: N 55 47.020
Longitude: W 165 24.970
Cloud Cover: overcast
Wind: 14 knots
Temperature: 6.4 C
Barometric Pressure: 1003.7 mbar

Science and Technology Log

In addition to researchers on the lookout for seabirds, the Oscar Dyson is also hosting researchers hoping to catch a glimpse of some the world’s largest animals: marine mammals. Either ocean dwelling or relying on the ocean for food, marine mammals include cetaceans (whales, porpoises, and dolphins), manatees, sea lions, sea otters, walrus, and polar bears. Although marine mammals can be enormous in size (the largest blue whale ever recorded by National Marine Mammal Laboratory scientists was 98 feet long or almost the length of a ten story building laid on its side!), studying marine mammals at sea can be challenging as they spend only a short time at the surface. Joining the Dyson from the NMML on this cruise are Suzanne Yin, Paula Olson, and Ernesto Vazquez. As a full time observer, Yin spends most of the year on assignment on various vessels sailing on one body of water or another and only occasionally is to be found transitioning through her home of San Francisco, California. Paula calls San Diego, California home and spends most of her time when not observing at sea working on a photo identification database of blue and killer whales. Ernesto is a contract biologist from La Paz, Mexico and has been working on and off with NOAA for several years. Ernesto has worked with several projects for the Mexican government including ecological management of the Gulf of California Islands.

chewning_log6_img_1 — Yin keeping warm from the cold

chewning_log6_img_2 — Ernesto keeping sharp lookout for marine mammals

Paula keeping an eye on the horizon

chewning_log6_img_3 — Ernesto keeping sharp lookout for marine mammals

Paula keeping an eye on the horizon

Yin, Paula, and Ernesto undoubtedly have the best view on the Oscar Dyson. Working as a three member team, they search for their illusive quarry from the flying bridge. The flying bridge is the open air platform above the bridge where the ship’s radar, communication equipment, and weather sensors are located. One observer is positioned both on the front left and front right corners of the flying bridge. Each observer is responsible for scanning the water directly in front to a line perpendicular to the ship forming a right angle. Two powerful BIG EYE binoculars are used to scan this to scan this 90 degree arc. These binoculars are so powerful they can spot a ship on the horizon at over ten miles (even before the Dyson’s radar can detect the vessel!). The third person is stationed in the middle of the flying bridge and is responsible for surveying directly ahead of the ship and for scanning the blind spot just in front of the ship that is too close for the BIG EYES to see. This person is also responsible for entering sightings into a computer database via a lap top computer. The three observers rotate positions every thirty minutes and take a thirty minute break after one full rotation. One complete shift lasts two hours. Yin, Paula, and Ernesto start soon after breakfast and will continue observing until 9:30 at night if conditions allow.

Weather can produce many challenges for marine mammal observers as they are exposed to the elements for hours at a time. Fortunately, Yin, Paula, and Ernesto are well prepared. Covered from head to toe wearing insulated Mustang suits (the name come from the manufacturer), they are pretty well protected from light spray, wind, and cold. Although a certain amount of the face is always exposed, a shoulder high wind shield helps deflect most of the spray and wind. In addition to wind chill and wind burn, a strong wind can also produce large rolling waves called swells that make viewing through the BIG EYES next to impossible. Sometimes reducing visibility so much that the bow can barely be seen the bridge, fog is undoubtedly a marine mammal observer’s greatest adversary.

chewning_log6_img_5 — Humpback whales through the Big Eyes

chewning_log6_img_9 — Salmon fishing operation through the Big Eyes

So far during the cruise, Yin, Paula, and Ernesto have spotted many blows on the horizon and have identified several species of marine mammals. A common sighting is the Dall’s porpoise. Your eyes are easily drawn towards these fun marine mammals as they produce characteristic white splashes by repeatedly breaking the water’s surface exposing a white stripe on their side. Blows from fin whales have also been regularly observed. Other sightings include killer whales, humpback whales, Pacific white sided dolphins, and a rare sighting of a Baird’s beaked whale.

Personal Log

Life aboard a constantly moving platform can take a little getting used to! I imagine if a person doesn’t live in an area frequented by earthquakes, one will easily take for granted the fact that the ground usually remains stable and firm underfoot (I know I did!). Over the last view days, steady winds from the south have conspired to create conditions ideal for rolling seas. Large swells (waves created by winds far away) make the Dyson very animated as we push forward on our survey transects. In addition to making deployments of gear more difficult, routine personal tasks soon assume a challenging nature as well. Whether you are simply getting dressed in the morning, trying to make your way to your seat with lunch in hand, or taking a shower in the evening, a constantly pitching and rolling deck will make even a seasoned deckhand wobble and stumble from time to time.

A piece of advice I have often heard during these conditions calls for “one hand for you and one for the ship”. Maintaining three points of contact with ship, especially when moving between decks, can save you from being tossed off balance. The crew is very considerate of these conditions and allows even more understanding than customary when you bump into shipmates. I have also learned the importance of securing any loose equipment and personal items after usage during rough seas as they might not be in the same place when you return. In addition to waking several times during the night and having a restless sleep, these conditions will also leave you feeling stiff and fatigued in the morning after a bumpy night of being tossed around in your rack. Once you muster the strength to get moving, your legs become surprisingly tired as you constantly try to keep your balance. Along with the rest of the crew, the Dyson also feels the effects of jogging through rough seas as you constantly hear the rhythmic sounds of the bow plowing though the next wave and of the ship’s superstructure groaning under the strain.

chewning_log6_img_6 — Measuring the Dyson’s roll

chewning_log6_img_7 — Passing through the fog

Did you know? Fog is essentially a cloud on the ground’s surface.

June 23, 2010March 12, 2021

Richard Chewning, June 23rd, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 23rd, 2010

Weather Data from the Bridge

Position: Bering Sea, east of St. George Island
Time: 0450
Latitude: N 56 38.000
Longitude: W 168 28.030
Cloud Cover: overcast with patchy fog
Wind: 14.0 knots from the east
Temperature: 5.8 C
Barometric Pressure: 1006.6 mbar

Science and Technology Log

Combining science, technology, and leadership, NOAA Commissioned Officer Corps provides skilled leaders for NOAA’s diverse programs. Numbering around 300 individuals, this group of dedicated professionals has a wide range of duties and responsibilities including operating NOAA’s ship and aircraft, managing research projects around the world, conducting diving operations, and manning staff positions on the shore. Officers are rotated every 2-3 years between ship-based and land-based positions. Before joining the Dyson as the Executive Officer for instance, Lieutenant Jeffrey Shoup worked with a satellite-based international search and rescue system as his NOAA shore assignment.

chewning_log10_img_0 — NOAA Corps emblem

All of these officers have completed rigorous training and have degrees in various fields of study relating to NOAA science such as physical oceanography, marine biology, chemistry, fisheries science, engineering, and meteorology. For example, the Dyson’s Commanding Officer, CDR Mike Hoshlyk, studied biology and geology at the University of Rochester.

Part of the U.S. Department of Commerce, NOAA Corps is one of the nation’s seven uniformed services of the United States. You are undoubtedly familiar with the other six: U.S. Public Health Service, Army, Navy, Coast Guard, Air Force, and Marines. During times of war or national emergency, NOAA Corps officers can assume duties with the Armed Forces. NOAA Corps officers have leadership and command positions on NOAA’s various vessels, aircraft, and instillations and manage programs and research efforts.

Personal Log

I wish to extend a heartfelt thank you to all the NOAA Corps officers, crew, and scientists of the NOAA ship Oscar Dyson for their support of my Teacher at Sea experience. I greatly appreciate their time and efforts making my stay comfortable and informative. I recognize that they not only allowed me to observe and learn about their workplace, but they also welcomed me into their home.

chewning_log10_img_1 — Ensign Russell Pate performing a safety demonstration

I have been continuously impressed by the professionalism and dedication of the Dyson’s NOAA Corps officers. Ensuring a safe and successful cruise for all onboard, I am grateful for the many efforts of CO Mike Hoshlyk, XO Jeff Shoup, Field Operations/Acting XO Officer Sarah Duncan, Navigation Officer Nathan Witherly, Safety Officer Russell Pate, and Medical Officer Amber Payne. I credit the entire engineering and electronics departments for their hard work ensuring that the Dyson remained in fine working order throughout the cruise. Jerry, Fred, Jim, Bob, Walter, Dave, Terry, and Steve comprised the Dyson’s engineering and electronics departments. The deck crew deserves recognition for always being ready to fish anytime day or night and for keeping the Dyson in ship shape over the last three weeks. The deck crew included Willie, Dennis, Joel, Glen, Mike, and Buddy. Special thanks to the scientists for sharing their passion for maritime research and for welcoming me as a part of their team. Paul, Patrick, Darin, Rick, Misha, Bill, Liz, Patti, Yin, Paula, and Ernesto each demonstrated personal dedication to better understanding our world’s seas and oceans. Gathering data and assisting the deck crew during the Dyson’s many deployments, Kathy and Jonathan deserve recognition for their many efforts as members of the survey department. Finally, I wish to express a word of thanks to the Dyson’s two stewards, Rick and Floyd, for keeping the crew well fed.

chewning_log10_img_2 — LTjg Nathan Witherly working on a chart

I wish to say a final word of thanks to the NOAA Teacher At Sea staff whose many efforts on my behalf made this experience possible. NOAA’s TAS program director is Jennifer Hammond. Elizabeth McMahon is the deputy director, and Elizabeth Bullock is the program support specialist. Thank you for bringing this amazing experience to life for so many teachers and students around the country.

chewning_log10_img_3 — Richard holding a Chinook salmon

Kodiak and Dutch Harbor As my TAS experience draws to a close, I reflect on where our cruise began and will conclude. Kodiak and Dutch Harbor are regular stops for the Oscar Dyson as she conducts research in the Bering Sea and Gulf of Alaska. Each community has a unique history and serves as a vital link to the outside world for the crew of Dyson.

chewning_log10_img_4 — St Paul Harbor, Kodiak, Alaska

chewning_log10_img_5 — Gray whale skeleton on display at Kodiak National Wildlife Refudge Visitor Center

Kodiak is the main city on Kodiak Island and is the home port of the Oscar Dyson. Carved by retreating glaciers during the last ice age, Kodiak’s most famous resident is the massive Kodiak brown bear. The Alutiiq called this area home for thousands of years before the Russian fur traders arrived in the early 1700s. Kodiak was the capital of Russian Alaska before becoming a US territory in 1867. In 1964, Kodiak suffered a devastating tsunami from the powerful 9.2 magnitude Good Friday Earthquake. Today Kodiak is a quaint commercial fishing community surrounded by beautiful untamed wilderness.

chewning_log10_img_6 — Priest Rock marking the entrance to Dutch Harbor

chewning_log10_img_7 — Church of The Holy Ascension, Dutch Harbor

Located on the on the island of Amaknak in the Aleutian Islands, Dutch Harbor is an industrial fishing outpost on the outskirts of the city of Unalaska. Dutch Harbor is a major industrial seaport serving fishing vessels of every description. Dutch Harbor is steeped in history. Hunting, fishing, and gathering for many generations, the Aleuts lived here long before Russian fur traders arrived in the mid 1700s. The Church of the Holy Ascension was built Dutch Harbor in 1825 and is the oldest Russian Orthodox church in the United States. Japanese and American military forces fought over the Aleutian Islands during the early months of the United States entry into World War II. Many concrete pill boxes and gun emplacements can still be seen along the surrounding hillsides. Dutch Harbor is defined by fishing and at one time was the largest fishing port in the US. Most people today recognize Dutch Harbor as the home of the crab fishermen portrayed in the Discovery Channel’s popular show, The Deadliest Catch.

chewning_log10_img_8 — Sunset in the Bering Sea

June 21, 2010March 12, 2021

Richard Chewning, June 21st, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 21st, 2010

Weather Data from the Bridge

Position: northeast of Dutch Harbor, Bering Sea
Time: 1100 hours
Latitude: N 54 45.610
Longitude: W 167 06.540
Cloud Cover: cloudy
Wind: 35 knots
Temperature: 6.2 C
Barometric Pressure: 1000.8 mbar

Science and Technology Log

Throughout this cruise I have been continually impressed with the engineering of the NOAA ship Oscar Dyson both in terms of modernization and capacity. State of the art technology can be found throughout the ship from the bridge to the engine room. Computer touch screens are used to control such operations as navigation on the bridge, power management in the engine room, and data entry in the wet lab. Junior engineer Walter Daniel summed up the advanced look and feel of the ship well; in comparison to the many vessels he has encountered in his career, he likened the Dyson to the Starship Enterprise of the science fiction franchise Star Trek. Even though the Dyson is one of the most technologically advanced fisheries vessels in the world, the engineers still get their fingers dirty from time to time. Although most of the equipment in the engine room can be adjusted with the simple touch of a button, flip of a switch, or turn of a knob, the Dyson’s veteran engineers still carry a screwdriver and wrench in their back pocket. Fred Ogden, first assistant engineer, told me he always likes to be prepared to bypass the computers and be able to make an adjustment by hand if needed, and you need to have the right tools for the job at hand. Recognizing that sometimes a person needs to get back to basics and that one should always be prepared, Fred says he never goes fishing without packing his sextant. Tracing its origins to the days of Sir Isaac Newton, the sextant is a tool used for navigation that only needs a clear view of the sky and horizon to work!

chewning_log9_img_5 — Diesel fuel centrifuges

At full power, the Dyson can reach 15.0 knots or a little more than 17 miles per hour. A knot is a unit measurement of speed roughly equal to 1.151 miles per hour. Four diesel generators capable of 3,017 horse power turn the Dyson’s shaft and prop. Horse power is a unit of measurement of power. To give you some perspective, modern cars typically only have 125 to 200 horsepower. To ensure these generators operate as efficiently and cleanly as possible, diesel is first cleaned using powerful centrifuges (machines that rotate very quickly to separate oil from the fuel). Fuel is also filtered twice more in each engine using filters. By burning clean fuel, the Dyson reduces pollution output and increases the life of the generators. Most of the oil and dirty water can be filtered on board to remove the impurities and reused.

chewning_log9_img_2 — Two of the Dyson’s powerful diesel generators

The Dyson also has two desalinization machines. What is desalinization and why is it important? ‘Desalinization’ is easy to subdivide and define to reveal its meaning. ‘De-’ is a prefix that means removal or reversal. ‘Salin’ is a French root word that means salt. ‘-zation’ is a noun suffix meaning an action, process, or result of making. If you put the parts together, desalinization means the process of removing salt. Desalinization machines produce fresh water by removing the salt from seawater. The importance of fresh water on a ship at sea cannot be overstated. Fresh water is essential to the crew of the Dyson for drinking, food preparation, waste management, and washing. Fresh water is also used to remove the heat from the generators in the engine room and to cool living spaces throughout the ship. The generators give off so heat much in fact there is never a shortage of hot water for the crew!

chewning_log9_img_1 — The desalinization machine

After touring the engineering spaces of the Dyson, I was surprised to see several work stations comprising of work benches and many hand tools dedicated to servicing equipment and fabricating new parts while at sea. Any one of these machine shops would satisfy any suburban Mr. Fix-it! In addition to these work stations, the Dyson also has numerous storage cabinets and cubby holes located throughout the ship storing everything from screws and zip ties to transistors and electronic circuit boards. The extent to which technology has permeated the Dyson is revealed by the maze of wires found overhead in every room and passageway. The many wires and pipes snaking from one room to another remind me of a giant circulatory system. The Dyson has two rotating Electronic Technicians, Vincent Welton and Stephen Macri, and an Engineering Electronics Technician, Terry Miles, whose job is to keep all these technologically advanced electronics in good working order.

Personal Log

chewning_log9_img_3 — Amber and Sarah keeping a sharp lookout on the bridge

chewning_log9_img_4 — CO Hoshlyk at the helm during 2pt anchoring in Three Saints Bay

One of my favorite places on the Dyson is the bridge. The bridge of the Dyson is the command and control center for the entire ship. The bridge not only allows the NOAA Corps officers to safely navigate the Dyson but allows communication with the entire ship, nearby boat traffic, and the shore. Utilizing radar, electronic charts, magnetic compasses, GPS, sonar, advanced radio and communication equipment, and various weather instruments, the bridge provides a wealth of information at one’s fingertips. The OOD (Officer of the Deck) carefully monitors the numerous screens and readouts on the bridge control panels and keeps a sharp eye on the surrounding seas. While I have become familiar with several of the main systems on the bridge and can deduce a great deal about the Dyson’s current location and movement, I recognize there is much to learn to safely navigate and operate the ship. I am comforted when resting in my rack knowing there are skilled and experienced hands on the bridge 24 hours a day!

chewning_log9_img_6 — Ensign Payne maneuvering from starboard control station

Located five stories above the water, the bridge has a fantastic view. The bridge is wide and open and has windows in every direction. The bridge provides a great view of the operation of the ship and the surrounding seas. I am most impressed with the layout of the bridge. The ship can be controlled from any one of four stations located around the bridge. The bridge is laid out like a capital T: a central control station located in the middle of the bridge, a station positioned on both the port (left) and starboard (right) sides of the bridge, and a station located aft (back) facing the rear of the ship. This allows the OOD to pilot the vessel while keeping a close eye on deployments/operations being conducted anywhere on the Dyson. For example, when conducting an Aleutian wing trawl off the stern (back) of the vessel, the OOD can transfer control to the aft station and pilot the Dyson while facing backwards!

In addition to the view, the bridge is also fun to visit as there is always someone to talk to and usually fun music playing quietly in the background. Recently, I have enjoyed watching the bow crash through 15-20 foot waves as we continue running each transect of our acoustic trawl survey.

chewning_log9_img_7 — Richard holding a sea star, better known as a starfish

While the weather continues to make deployments challenging, we have still managed to fish a few times. Interesting bycatch from these trawls includes seastars and brittle stars from the Tucker trawl and Pacific cod and sturgeon poacher from the Aleutian wing trawl.

Did you know?

The summer solstice marks the longest day and the shortest night of the year. The word solstice comes from the Latin word ‘sol’ meaning ‘sun’ and the word ‘stice’ meaning ‘to stand still’. As summer days lengthen (meaning the sun rises earlier and sets later each day), the sun’s path through the sky takes the sun higher and higher above the horizon forming a greater and greater arc. At a certain point, the sun reaches its highest point. At this point the sun seems to stand still before slowly falling back to the horizon with each passing day. This point when the sun reaches its highest arc in the sky is called the summer solstice. The earth’s tilt on its axis causes the sun to travel slightly different paths through the sky each day and causes the sun’s rays to fall with varying intensity on different regions of the earth. Over the period of one year (one orbit of the sun by the earth), this variation in sunlight explains why the earth has four seasons: summer receives the most direct rays, winter receives the least direct rays, and spring and fall are times of transition between these two extremes. The summer solstice always falls around June 21st in the northern hemisphere (above the equator). With the Dyson surveying southeast of Pribilof Islands in the Bering Sea, the sun will rise at 6:30 AM and will set at 11:50 PM on June 21st. If you were standing at the North Pole during the summer solstice, you would experience 24 hours of sunlight (the sun would never dip below the horizon!) while 24 hours of darkness would be observed at the South Pole.

chewning_log9_img_9 — A sturgeon poacher

June 18, 2010March 12, 2021

Richard Chewning, June 18th, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 18, 2010

Weather Data from the Bridge

Position: Bering Sea, north of Dutch Harbor
Time: 1600 hours
Latitude: N 55 06.120
Longitude: W 166 33.450
Cloud Cover: Mostly cloudy
Wind: 10 knots from the west
Temperature: 7.1 C
Barometric Pressure: 1010.8

Science and Technology Log

In order to manage a public resource such as pollock, fisheries managers must develop a stock assessment. A stock assessment is a big picture overview of a certain population of fish. Fisheries managers use stock assessments to determine opening and closing dates for fishing seasons, catch limits (the number of fish that can be caught by a particular fisherman or boat), and the total allowable catch for the season. Stock assessments are developed from a combination of fishery dependant and independent data. Fishery dependant data includes catch records from commercial fishing boats and reports from processors dockside that prepare and package the fish for market. Combined with this information is fishery independent data. This information is gathered from sources not involved with commercial fishing.

chewning_log8_img_1 — Cod end filled with pollock

chewning_log8_img_3 — Unsorted catch entering wet lab

The Dyson’s acoustic trawl survey is one of the primary sources of fishery independent data for the pollock stock assessment. The Dyson’s transducers provide a wealth of acoustic data from each transect. These acoustic returns must first be identified or deciphered before being used in the stock assessment. Just like you need a key to decode the symbols on a road map or need a scale to interpret the colors on a weather map, the acoustic returns also need to be referenced with actual pollock specimens collected by trawling. By matching up the characteristics of the fish caught in the trawl with their acoustic returns, researchers can interpret all the acoustic data from the entire survey area.

chewning_log8_img_4 — My what sharp teeth you have! Arrowtooth flounder

Pollock specimens are collected with Aleutian wing trawls, or AWTs for short. An Aleutian wing trawl is a single large net deployed off the stern of the Dyson. Large metal fishbuster doors are used to open the mouth of the net in the water. The catch is collected in a bag located at the end of the net called the cod end. The cod end’s mesh size prevents anything larger than 0.5 inches from escaping. Once the net is hauled back on deck, the cod end is emptied in the wet lab, and the entire catch is sorted. Fish are identified, counted, weighed, and measured. The gender and maturity of a subsample of pollock are also recorded. Stomachs are collected to determine what the pollock are eating. Finally, otoliths, the ear bones of fish, are collected. Just like counting the rings of a tree, researchers will count the number of rings in the otolith to determine the age of the pollock. Notable bycatch (fish that were not targeted) include eulachon, arrowtooth flounder, Pacific cod, sturgeon poacher, and yellowfin sole. Misha told me Russians used to dry out eulachon whole and use them as candles because of their high oil content. In fact I learned that one of common names in the US for eulachon is candlefish!

Why gather so much information on a single species of fish like pollock? Fisheries managers are responsible for the sustainable use of public resources. Without careful monitoring, fishing pressure, natural predation, and disease might remove pollock from the population faster than they can replace themselves. There is great demand for pollock both commercially and in the Bering Sea ecosystem. Walleye pollock is the largest US fishery by volume and third largest by value. Annual US catches can average 2.5 billion pounds. Pollock is also an important food source for Stellar sea lion, other marine mammals, birds, and other fish.

chewning_log8_img_8 — The Dyson in Dutch Harbor

Personal Log

On Thursday, I had the pleasure of joining two members of the deck crew, Joel Kellogg and Glen Whitney, to pick up a new addition of the science party in Dutch Harbor. Mike Sigler, a fish biologist with NOAA, is a project leader and principal investigator with the North Pacific Research Board’s Bering Sea Integrated Ecosystem Research Program (BSIERP). He is joining the Dyson for the last week of our survey. BSIERP is a six year long collaborative study with the National Science Foundation’s Bering Ecosystem Study (BEST). More than a hundred scientists from these two groups are investigating the organisms and physical forces that make up and influence life in the Bering Sea ecosystem.

chewning_log8_img_9 — Recovering the Peggy D.

To pick up Mike, the Dyson launched the Peggy D. Named for wife of Oscar Dyson, the Peggy D. is a small power boat used to ferry people to and from shore. Peggy Dyson is a famous Alaskan in her own right, serving as a National Weather Service ship to shore weather broadcaster. Her voice brought vital information and reassurance to Alaskan fisherman. She diligently performed these duties twice a day, seven days a week for 25 years. I really enjoyed having the opportunity to see the Dyson from the water as my only vantage point for the last two weeks has been from the Dyson looking out. I was surprised how quickly the Dyson shrunk on the horizon as we sped away and traveled into Dutch Harbor. Dutch Harbor felt like a true frontier town. The vehicles seemed to reflect the character of the town. While looking rough and weathered on the outside, the beat-up cars and trucks of Dutch Harbor revealed a resilience and gritty determination to keep moving forward and press on against an unforgiving environment. I loved hearing the cry of the bald eagles that were spotted everywhere you looked. While I enjoyed having solid ground under my feet for a few short minutes, I appreciated the sense of familiarity and belonging I felt upon returning to the Dyson.

chewning_log8_img_7 — Scute visits the Bering Sea

Scute, the Georgia Sea Turtle Center Mascot, was spotted visiting the Bering Sea today! Scute, a loggerhead sea turtle, travels the world promoting awareness of sea turtles. We know Scute was only visiting the Bering Sea as these waters are too cold for loggerhead sea turtles. Loggerhead sea turtles are the most abundant sea turtles in US coastal waters. Scute’s home is the Georgia Sea Turtle Center (GSTC) located on Jekyll Island, Georgia. The GSTC is a research, rehabilitation, and education center dedicated to helping sea turtles along the GA coast and around the world. Sea turtles released from the GSTC will often have a satellite transmitter attached to their shell just like Scute. The transmitters allow researchers to track their movements at sea. Only one of the seven species of sea turtles found worldwide can survive this far north – the leatherback sea turtle. The leatherback sea turtle is the largest species of sea turtle reaching six and a half feet in length and weighing as much as 2000 pounds! Leatherbacks have several adaptations such as high oil content in their large bodies that help them tolerate the cold waters of the southern Bering Sea. Leatherback sea turtles feed on jellyfish and can dive to great depths because the protection provided by their leathery shell (a hard shell would crack under the high pressure of the water). For more information about Scute and sea turtles, check out the GSTC website at http://www.georgiaseaturtlecenter.org !

June 17, 2010March 12, 2021

Richard Chewning, June 17th, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 17, 2010

Weather Data from the Bridge

Position: north of Dutch Harbor
Time: 0830
Latitude: N 54 58.080
Longitude: W 165 58.080
Cloud Cover: cloudy with fog
Wind: 20 knots from SW
Temperature: 6.9 C
Barometric Pressure: 1007.9 mbar

Science and Technology Log

In addition to the Tucker trawl, fish biologists onboard the Dyson also utilize the Methot trawl to catch zooplankton in their study of pollock. The Methot is a single net with a large square mouth (the opening of the net) that is deployed from the stern and towed behind the Dyson. The Methot uses fine mesh with openings slightly larger than the Tucker trawl. This larger mesh size allows the net to be towed at higher speeds. A torpedo looking instrument called a flowmeter is suspended in the mouth of net to measure the flow of water moving through the net. The flowmeter allows the researchers to calculate how much zooplankton is found in a certain volume of water. With its larger mouth and faster speed through the water, the Methot is able to catch the larger zooplankton such as euphausiids the Tucker trawl might miss. Pollock seem to love euphausiids as I have seen firsthand stomachs of pollock caught during Aleutian wing trawls that have had stomachs stuffed with euphausiids.

chewning_log7_img_1 — Deploying the Methot trawl

chewning_log7_img_2 — Recovering the Methot trawl

After the Methot is return onboard, the sample is rinsed and poured through a strainer to separate the zooplankton from smaller algae and phytoplankton. After being weighed, a small subsample is removed and preserved for later identification. The number of euphausiids in a second subsample is counted to calculate the total number in the catch. Several individual euphausiids are also frozen so they can later be analyzed for age and development by examining their eye stalks. In addition to catching the small zooplankton pollock eat, the Methot will also catch some of the largest zooplankton in the ocean: jellyfish. Almost all the Dyson’s trawls have yielded large number of Chrysaora melanaster jellyfish. After being removed from the sample, these jellyfish are also weighed and measured. These jellyfish produce only a mild sting but can be quite frustrating to process in large numbers.

The Dyson has also been routinely deploying a piece of equipment known as a CTD (conductivity-temperature-depth recorder). This instrument package allows scientists to measure temperature, depth, dissolved oxygen, chlorophyll, light intensity and conductivity. By measuring conductivity (the amount of electricity carried by seawater), salinity can also be calculated, and from temperature and salinity, density can be calculated. The CTD is deployed once every night before dawn and during selected locations during the day. The CTD is attached to a metal frame called a carousel along with other pieces of scientific equipment. Niskin bottles can be attached to the carousel allowing the recovery of water samples from different depths. The Niskin bottle is a vertical plastic tube that is initially deployed with both ends open allowing seawater to flow through. Once the CTD is lowered to the desired depth, the bottle is ‘fired’. Firing signals the bottle to close the openings, sealing the water sample inside. This water can be brought to the surface and filtered to measure the amount of chlorophyll it contains. By better understanding how the properties of seawater such as temperature and chlorophyll concentration relate to the various biological organisms that form the foundation of the Bering Sea ecosystem, researchers can better understand pollock distribution and abundance.

chewning_log7_img_4 — Recovering the CTD

Personal Log

After getting to know the crew over the last week and a half, I have noticed most have a passion for the great outdoors and enjoy a wide range of physical activities such as hiking and skiing when not at sea. Most enjoy hunting and fishing and several enjoy competitive events such as running and cycling. You would think staying active while sharing a platform only 208.6 feet long and 49.2 feet wide with up to 40 people might seem like a daunting task, but this is surprisingly not the case. I have noticed most of crew members from the CO (the commanding officer) to the guest scientists have dedicated time in their schedule to keeping physically fit.

The deck crew has an upper hand in this endeavor as their work often involves moving heavy lines, chains, and gear. Their labor is aided however by powerful hydraulic winches that can lift even the heaviest objects with ease. The Dyson’s acting XO (executive officer) Lieutenant Sarah Duncan was also willing to suit up in her foul weather gear and life vest to give the deck crew an extra set of hands with two late night pollock trawls. Besides the physical workout of retrieving the gear, she told me that working down on deck gives her better appreciation for how the deck crew is affected by the ship’s movements and weather conditions when deploying and retrieving gear. This is very valuable information for Sarah for when she is high in the bridge working hard to direct the ship’s movement so the deck crew can work efficiently and safely in different weather conditions and sea states.

Maintaining one’s physically fitness benefits every member of the crew regardless of station as rough seas can wear the body down physically and mentally in a very short period of time. The rowing machine seems to be the first choice among the crew although the stationary bike and elliptical machine are also popular. The treadmill is the most challenging workout as you are constantly being thrown off balance. I can’t help but wonder what prisoners chained to the oars of wooden ships of old would think knowing that mariners today use large mechanical engines to power the ship and use stationary rowing machines for exercise!

chewning_log7_img_5 — Measuring Chrysaora melanaster jellyfish

chewning_log7_img_6 — Holding Chrysaora melanaster jellylfish

Did you know? The word ‘plankton’ and ‘planet’ come from the same root word? Both names come from the Greek word planktos that means ‘wander’. Plankton is any plant or animal not strong enough to swim against water currents. Examples include diatoms, dinoflagellates, copepods, and euphausiids. Planets were named because they were observed by early astronomers to drift or wander among the stars. Stars appear to maintain the same spatial relationships with each other as they rotate across the sky because they are located so far away. Although they are actually moving, their position in relation to each other appears to be unchanging. This is the reason why the same constellations (pattern of stars in the sky) have been identified throughout human history. Planets on the other hand move through the star field as they are very close in comparison and are orbiting the sun. Thus planets appear to wander among the stars just like plankton drift among the currents of the ocean.

chewning_log7_img_7 — Saving a euphausiid sample

June 13, 2010March 12, 2021

Richard Chewning, June 13, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 13, 2010

Weather Data from the Bridge

Position: Eastern Bering Sea
Time: 1530
Latitude: N 56 15.380
Longitude: W 164 14.010
Cloud Cover: Overcast with light spray
Wind: 30 knots
Temperature: 5.4 C
Barometric Pressure: 1002.7 mbar

Science and Technology Log

Around 0940 Thursday morning we began our first summer 2010 pollock survey transect. Researchers have been conducting acoustic pollock trawl surveys since 1979 and bottom trawl surveys since the1950’s. The 31 transects in this year’s survey run roughly north south and progress from the eastern Bering Sea across to Russian waters in the western Bering Sea. The transect lines range in length from 60 to 270 nautical miles and are spaced 20 nautical miles apart. A nautical mile is slightly longer than a standard mile and is useful for navigating charts (maps used at sea). Only surveying during daylight hours, the Dyson will continue to run these transects till the beginning of August. A transect is a path (usually a straight line) during which the number of occurrences of an observable fact are counted (such as the abundance of pollock).

The beginning transect was marked by the launching of an expendable bathythermograph (XBT) probe. While the name might seem long and somewhat complicated sounding at first, the instrument and data being recorded are actually quite straightforward. Expendable refers to the fact that the probe is not recovered after being deployed. How is the data sent back to the Dyson you ask? Two long thin copper wires uncoil from the launcher and probe allowing data transfer back to the Dyson. The wires are broken by hand once the probe has reached the bottom. The rest of the story is revealed by subdividing the word ‘bathythermograph’ and defining its parts. ‘Bathy’ is a prefix that means deep or at depth. ‘Thermo’ is another prefix that refers to heat or temperature. Finally the word ‘graph’ means to draw a relationship between multiple variables (such as depth of the water and temperature). So an expendable bathythermograph is a disposable probe that profiles the temperature from the surface to the sea floor.

chewning_log5_img_0 — XBT probe and launcher

The XBT is a very helpful tool that enables the scientists onboard the Dyson to gather temperature data while on the move. Being able to capture this data without slowing down and stopping is a big time saver. Bringing a ship to a stop on the water takes much more time than stopping a car on the highway, and deploying a reusable instrument to the bottom and back takes even more time, manpower, and resources. Temperature data allows fish biologists to better understand how water temperature and the abundance of pollock and their food supply are related.

chewning_log5_img_1 — Darin deploying XBT

Later that afternoon, we also performed our first Tucker trawl. The Tucker trawl is a cleverly designed system of three nets that allows for three discrete (separate) samples during a single deployment. The Tucker trawl is designed to catch the zooplankton (animal-like plankton) that pollock eat such as euphausiids. This net allows researchers to study the differences of zooplankton distribution at various layers in the water.

chewning_log5_img_3 — Deploying the Tucker trawl

chewning_log5_img_2 — Tucker trawl messenger

To catch these small organisms, the net needs to a have very small openings. In fact, the openings in the net are only half a millimeter in width or roughly 1/3 the thickness of a dime! The three nets are attached to a metal frame mounted on metal skis that resembles a backwards dog sled. These skis allow the sled to slide along the seafloor and avoid snagging any obstructions. The Tucker trawl is initially deployed with one net open. The first net is closed and the next net is opened using a heavy brass messenger sent down the wire connecting the Tucker trawl to the Dyson. The messenger is attached to the wire cable at the surface and allowed to slide down the cable to the net being towed in the water. The impact of the messenger triggers a spring in a latch that closes one net and opens another net. The second net is closed and the third net is opened in the same fashion. Samples are taken at the surface, at the bottom, and evenly from the seafloor all the way to the surface. Attached to the sled are sensors to record temperature and depth, the flow of water passing through the net, and the time the net spends on the bottom. The catch is collected at the end of the net in a removable cod end jar. Any jellyfish are removed from the catch, identified, and measured. The remaining zooplankton is weighed, and a small subsample is saved and preserved for later identification.

chewning_log5_img_4 — Richard sending messenger down to the Tucker trawl

Personal Log

At sea, a person can easily lose track of time and even forget the day of the week as work aboard the Oscar Dyson continues uninterrupted seven days a week. I was reminded that today was Saturday by a special meal served by the galley. Rick and Floyd prepared a delicious dinner of real Alaskan king crab, prime rib, baked potatoes, vegetables, and fresh baked bread. This was a real treat (along with the cookies and cream ice cream, always a fan favorite) for the crew. There was plenty to go around, and all were well satisfied.

This was actually not my first encounter with king crab on this cruise. The day before, we had the unprecedented surprise of catching a red king crab with the Tucker trawl during the bottom net deployment. To the best of the knowledge of all the scientists onboard, this had never happened before. You might remember that the Tucker trawl is designed to catch zooplankton, which are typically small in size. This unlucky crab was so large she didn’t even fit in the cod end collection jar at the end of the net. In the end the crab was lucky as we opted to release her after recording her weight and species as we already had enough crab in the freezer for dinner the following night!

chewning_log5_img_7 — Richard holding red king crab

chewning_log5_img_8 — Dinner! Lucky for her, the crab Richard’s holding was released back to the sea!

Leisure Activities

Time spent not working onboard the Dyson can be considered among a person’s most precious possessions. Working long hours, the NOAA Corps officers, visiting scientists, and crew aboard the Dyson usually only have a few hours of time before starting their next scheduled watch or shift. Sleeping is often the first order of business on a person’s to do list. Whether you take only a short nap or can sleep for several blissful hours, time in one’s rack (bed) is essential for a productive, happy, and safe crew. Often one’s sleep schedule will necessitate missing a meal but the rest gained seems well worth the trade off. A very nice service offered by the galley is making and setting aside a plate for those crew members missing a meal if requested.

Other down time activities include reading, listening to music, and working out. The Dyson also has an impressive movie collection (including many recent titles not yet released on DVD) that is administered by the Department of the Navy. New titles are added monthly. The Dyson has a very comfortable lounge for watching movies that also includes a wide selection of magazines and books. Keeping connected with the outside world is also very important while at sea. With relative reliability, people can access the internet to answer emails, pay bills online, and surf the web for news and can call friends and family back home using the satellite phone.

June 10, 2010March 12, 2021

Richard Chewning, June 10, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 10, 2010

Weather Data from the Bridge

Position: Bering Sea
Time: 2147 hours
Latitude: N 56 48.280
Longitude: W 161 48.549
Cloud Cover: Overcast with fog
Wind: 9.2 knots from NE
Temperature: 4.6 C
Barometric Pressure: 1010.8 mbar

Science and Technology Log

In addition to hosting fish biologists studying walleye pollock, the NOAA ship Oscar Dyson also has groups of researchers studying birds and marine mammals aboard. Both the birders and marine mammal observers are conducting supplementary projects taking advantage of the Dyson’s cruise track. As the Dyson sails back and forth across the Bearing Sea along equally spaced parallel transects, these researchers are able to survey a wide area of habitat, investigating not only what animals are present and absent in these waters, but also how many are present (called abundance). These surveys are considered passive since these researchers are not actively directing the ship’s movements but are surveying along the cruise track laid out by the fish biologists.

Our migratory bird observers are Liz Labunsky and Paula Olson from the United States Fish and Wildlife Service (USFWS). They are members of the North Pacific Pelagic Seabird Observer Program and are providing data for the Bering Sea Integrated Ecosystem Research Project. Pelagic seabirds are birds found away from the shore on the open ocean. Liz is from Anchorage, Alaska and has been involved with this project since 2006. Calling Gloucester, Massachusetts home, Paula is new to these waters but has spent years studying the birds of Prince William Sound as part of the ecosystem monitoring efforts resulting from Exxon Valdez oil spill.

Liz and Paula work for two-hour alternating shifts from the bridge. They continuously survey an area of water 300 meters by 300 meters in size. They are looking for birds both on the water’s surface and flying through the air. Liz and Paula must have quick eyes and be very familiar with a wide variety of birds. Identifying birds on the move can be very challenging. Often you only have only a few seconds to train your binoculars on your target before your query becomes a spot on the horizon. In addition, the same species of bird can vary greatly in appearance. Liz and Patti may only see a handful of birds over an entire morning but can also witness hundreds at any given moment!

One constant challenge for observers aboard moving vessels is counting the same bird multiple times. For example, you will often spot northern fulmars flying laps around the Dyson when underway. To avoid introducing this bias (or error) in their survey, flying birds are only counted at certain time intervals called scan intervals. The frequency of these scan intervals are determined by the speed at which the Dyson is traveling. For example, when the Dyson is traveling 12 knots, birds flying are counted every 49 seconds. If the Dyson is traveling slower, the time is reduced.

While very familiar with the coastal birds of Georgia, I have been introduced to several new species of birds found in the Bering Sea. I have become a big fan of the tufted puffin. Easily identified by their reddish orange bills, tufted puffins resemble little black footballs when flying. These birds dive in the frigid waters to catch fish, their favorite prey. The black-footed albatross is another bird new to me identified by the white markings around the base of the beak and below the eye along with its large black feet. One of my favorite observations with Liz and Patti was identifying a group of northern fulmars so tightly packed on a piece of driftwood that it showed up on the ship’s radar!

Personal Log

Just before my shift ended around 1545 hours, a call came over the radio from Yin, one of the Dyson’s three marine mammal observers. She reported that a large number of humpback whale blows had been spotted on the horizon. A blow refers to the spray of water observed when a whale surfaces for a breath of air. Like all mammals, whales have lungs and must surface to breath. The humpback whale is a baleen whale that feeds on krill (small marine invertebrates that are similar to shrimp) and small fish in the summer. Krill is a major link in the marine food web, providing food for birds, marine mammals, and fish such as pollock. Baleen whales have plates made of baleen instead of teeth that are used to separate food from the water. Baleen resembles a comb with thick stringy teeth. Think of the movie Finding Neo when Marlin and Dory are caught in the whale’s mouth.

Not sure how many whales constitute a large group, I eagerly headed to the bridge to see if I could catch a glimpse of this well-known marine mammal. I quickly climbed four companionways (a stair or ladder on a ship) up to the flying bridge from the main deck where the acoustics lab is located. Upon reaching the highest point on the vessel, I was told that I was in for a treat as we were approaching a massive aggregation (a group consisting of many distinct individuals or groups) of humpback whales. Whales often travel in small social groups called pods, but this gathering was much larger than usual. This gathering was more than a single pod of whales as there were so many blows you didn’t know which way to look!

The Dyson’s CO (Commanding Officer), Commander Michael Hoshlyk, carefully maneuvered through the whales affording the growing gathering of onlookers a great view. Observations from the Dyson’s fish biologists and birders supported the hypothesis from marine mammal observers that these whales were almost certainly gathered together to feed. Evidence to support this conclusion included acoustic data and the presence of large numbers of seabirds. The Dyson’s transducers showed large acoustic returns that were most likely from plankton (organisms that drift in the water) such as krill. There were also countless numbers of shearwaters (medium-sized long winged sea birds) gathered where the whales were swimming. Estimating the number of whales and shearwaters proved difficult because of their large numbers. The first group of whales numbered at least 50, and we later encountered a second group of humpbacks that numbered around 30. The shearwaters numbered in the thousands! I was able to capture some great pictures of the flukes (the horizontal tail of the whale used for propulsion) and blows of the humpbacks by holding my camera up to the powerful BIG EYES binoculars. Looking through the BIG EYES gave me the sensation being so close that I almost expected to feel the spray of water every time the whales surfaced for a breath. I counted myself fortunate to see this inspiring and unforgettable sight. Along with the beautiful weather, the opportunity to see these amazing creatures of the deep made for a very enjoyable cruise to the beginning of the pollock survey.

Viewing humpback whales equals a Kodak moment!

New Word of the Day – Bearing

You will often hear the word ‘bearing’ used on the bridge of the Dyson. A bearing is a term for direction that relates the position of one object to another. For example, the Dyson’s lookout might call out, “Fishing vessel, bearing three one five degrees (315°)”. This means the fishing vessel is in front of and to the left of the ship when facing toward the bow. A bearing does not relate distance, only direction. The area around the Dyson is divided into 360 equal parts called degrees. One degree is equal to 1/360th of a circle. When calling out a bearing, degrees allow for precise communication of an object’s relative position to that of the Dyson. The Dyson always has a member of the deck crew stationed on the bridge serving as lookout when underway. The lookout’s responsibility is to monitor the water around the Dyson for boat traffic, hazards in the water, or any other object important to the safe navigation of the ship.

June 8, 2010March 12, 2021

Richard Chewning, June 8, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 7 – 8, 2010

Weather Data from the Bridge

Position: Just southwest of the Semidi Islands, Alaska
Time: 1400 hrs
Latitude: N 55 54.331
Longitude: W 156 54.606
Cloud Cover: mostly cloudy
Wind: 9.2 knots from E
Temperature: 7.2 C
Barometric Pressure: 1019.6 mbar

Science and Technology Log

Calming seas greeted our arrival at Snake Head Bank around 1800 hours on Sunday. Snake Head Bank is an area of the Gulf of Alaska that has been designated as untrawlable habitat. Trawling is a fishing technique where a net is towed behind one or more boats. The Dyson will be using this technique later in our cruise to catch pollock. Fishermen trawl on the bottom or somewhere in the water column depending on what fish is being targeted. Previous NOAA surveys using both acoustic and ROV (remotely operated vehicle) data have indicated that the ocean bottom in this area contains terrain such as large rocks that could snag a trawl net skimming along the bottom.

Our mission was to further study select areas of Snakehead Bank to better understand the seafloor where acoustic research had been conducted but the bottom composition had not been verified. NOAA scientists call this ground-truthing. To accomplish this task, the Dyson deployed a self-contained camera to the seafloor to collect video footage. This operation requires both a specially designed rig to film on the ocean floor and the coordinated efforts from crew members from various departments throughout the ship.

chewning_log3_img_7 — Success! Video footage from the bottom of the Gulf of Alaska

You might be surprised to learn that an over-the-shelf handheld camcorder and lens were used to record the footage of Snake Head Bank. Both the camera and lens are mounted to and protected by a heavy metal frame. Similar to a roll cage of a car, this cage protects the video camera from the weights used to send the rig to the bottom and from any hazards on the seafloor such as large rocks. Since we are sampling areas beyond the depth sunlight penetrates, a light must also be included to reveal the bottom. This means our camera operations can be conducted both during the day and night! The camera and the battery for the light are protected in a waterproof case that can easily be opened to change tapes and batteries.

In addition to darkness and unknown obstacles, filming at depth is also complicated by water pressure. Water pressure refers to the weight of the water pressing down (think about the pressure in your ears build as you dive to the bottom of a swimming pool). A tight seal must be maintained as water will force its way through the smallest opening. Water pressure can be enlisted to serve a useful purpose. Water pressure activates a switch once the rig reaches a certain depth turning the camera and light on and off. This conserves the batteries and ensures only the video at the bottom is recorded.

chewning_log3_img_3 — Richard waiting on the hero deck for camera recovery

The entire rig is deployed using one of the Dyson’s powerful winches using a long wire cable. The wire cable is threaded through a block attached to a metal support structure called the A-frame that can be extended over the side of the ship. The entire rig was constructed to be neutrally buoyant so the rig would hover just off the bottom. Plastic floats tied on top and metal chains hanging down from the rig ensured the camera was angled correctly towards bottom.

In order for a successful deployment, crew members from throughout the ship must work together. Just like any successful workplace or athletic team, these deployments require coordinated efforts, communication, and clearly defined job responsibilities.

The Officer of the Deck and Navigation officer positions the ship at each station and must keep the ship as stationary as possible when the camera is deployed so the camera is not dragged along the bottom. A member of the deck crew operates the winch and raises and lowers the A-frame. Another member of the deck crew assists a survey technician casting and retrieving the camera rig over the side. Two scientists change out the tapes and batteries, transfer and log the video, and adapt the rig as necessary.

chewning_log3_img_4 — Deployments require teamwork and coordination

chewning_log3_img_5 — Recovering remote camera rig at Snakehead

Finally, the unsung hero of this camera deployments was the science team’s IT (Information and Technology) Specialist. The IT specialist on th is cruise is Rick Towler. If you like to solve problems and develop a wide range of skills, then this is the job for you. Rick saved the day on more than one occasion during the camera operations. Using some creative engineering, Rick overcame some technical difficulties with the pressure switch and wiring on the control circuit board for the camera and light. Rick is an indispensible member of the science team and is responsible for maintaining the equipment brought onboard by the scientists. When you are miles from the nearest hardware store or electronics shop, you have to be able to make do with what you have and be able to think outside the box. I think of Rick as the science team’s MacGyver! By the end of the survey’s 42 stations, the crew of the Dyson was a well-oiled machine and had overcome every challenge.

chewning_log3_img_8 — Rick, the Dyson’s MacGyver, is on the job!

Personal Log

The weather continues to improve by the hour. I am starting to find my rhythm after recovering from my drowsiness resulting from the combined effects of jet lag and the seasickness medication from the beginning of the cruise. I was surprised and pleased to learn that the Dyson has a large roll stabilization tank located just in front of and below the bridge. Tall buildings built near earthquake prone areas also use large containers of water to counter the swaying motion that damages buildings during earthquakes.

Meals aboard the Dyson are a key part of any ship routine. Meals are served for one hour starting at 0700, 1100, and 1200 hours. Meals are an interesting time to visit with people. Some crew members at meals are tired as they are just coming off watch, others are wide awake and in a hurry as they are grabbing a quick bite between deployments or projects, and others are still trying to wake up as they have just left their rack even though the meal might be dinner! Dinner Monwas very satisfying: roast beef and game hen with broccoli, steamed rice, and noodles.

You might also see someone headed for their morning workout. I discovered that the little physical exercise. I haven’t tried the treadmill yet as I hear running can be a littletricky on the rolling seas!

After completing our deployments around 0545, we turned southwest for Unimak Pass. We are leaving the Gulf of Alaska behind and now heading for the Bering Sea. I am looking forward to seeing the Aleutian Islands up close as we will be sailing among the islands rather than the open sea. This will give us the benefit of smoother sailing and the added bonus of beautiful scenery along the way!

chewning_log3_img_9 — Headed to the Bering Sea!

Animals Observed from Snake Head Bank Seafloor
Rock Fish
Brittle stars
Skate (similar to a sting ray minus the barb)
Euphausiids (commonly called krill)

June 7, 2010March 12, 2021

Richard Chewning, June 6-7, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Dates: June 6-7, 2010

Weather Data from the Bridge

Position: Snakehead Bank, Gulf of Alaska
Time: 1700 hrs
Latitude: N 56 00.390
Longitude: W 153 46.380
Cloud Cover: Overcast
Wind: 12 knots from the SE
Temperature: 7.1C
Barometric Pressure: 1016.9 mbar

Science and Technology Log

I have been impressed by the wide array of oceanographic research the Oscar Dyson is able to conduct. A few examples include biological studies of organisms ranging from microscopic plankton to massive marine mammals, collecting a variety of weather data, describing both physical and chemical characteristics of seawater (such as temperature, salinity, chlorophyll, and dissolved oxygen), conducting acoustic surveys of marine life and the sea floor, and much more.

chewning_log2_img_1 — Three Saints Bay nautical chart

One of the Dyson’s ‘bread and butter’ surveys is our survey studying the distribution, biomass, and biological composition (male/female ratios and age) of walleye pollock in the Bering Sea. Walleye pollock is a very important fishery for Alaska. You have almost certainly been a part of this fishery as most fish sandwiches in fast food restaurants and fish sticks in the frozen food section of your local grocery store are Alaskan-caught pollock.

One of the Oscar Dyson’s many tools for this research is her impressive array of acoustic sensors located on the ship’s hull and centerboard. The centerboard is an extension of the hull that can be raised and lowered in the water in order to position most of the Dyson’s sensitive acoustic sensors below the bubbles often found near the water’s surface. These air bubbles interfere with sound traveling through the water and degrade the quality of the data being collected. The Dyson has six downward looking centerboard-mounted transducers, each transmitting a different frequency. Why so many frequencies? Since different types of marine organisms interact with sound waves differently producing varying acoustic signatures, the Dyson must be equipped with a variety of sensors to best characterize the variety of marine life encountered during a survey.

For example, lower frequencies are better suited for fish such as pollock and the higher frequencies are better suited for smaller organisms such as plankton. Think of transducers as a downward shining flashlight illuminating the depths of the ocean with sound rather than light.

The Dyson also has other acoustic sensors such as the ME-70 multibeam echosounder that has the unique ability to look over a much wider angle through the water. Acoustic research works on the same echo location principle that bats and marine mammals employ to find food and navigate. By sending out sound waves and measuring the time the sound takes to travel back after encountering an object, one can learn a great deal about that object’s properties such as distance, size, and movement.

Before traveling to the Bering Sea to start our pollock survey, the Dyson’s scientists must take great care to ensure that their echo-sounding equipment is calibrated correctly. Calibrating the transducers is similar in concept to tuning a piano string or zeroing a sight on a rifle. To this end, the Dyson anchored in Three Saints Bay, a sheltered bay protected from the wind, waves, and currents of the open ocean, at least theoretically. While a troublesome storm passed almost directly overhead, scientists from the Midwater Assessment and Conservation Engineering (MACE) Program (part of the Alaska Fisheries Science Center (AFSC) located in Seattle, WA), the US Fish and Wildlife Service (FWS located in Anchorage, AK), and the Pacific Institute of Fisheries and Oceanography (located in Vladivostok, Russia) worked diligently to fine tune their acoustic sensors.

chewning_log2_img_2 — Copper sphere used to calibrate the acoustic sensors

chewning_log2_img_3 — Bill and Patrick positioning spheres under the Dyson

Paul Walline, Patrick Ressler, Darin Jones, Bill Floering, and Mikhail ‘Misha’ Stepanenko worked day and night calibrating their equipment using metal spheres positioned directly under the ship.

Spheres of different sizes and materials with known acoustic signatures (such as tungsten carbide and copper) are used to calibrate the transducers.

The crew of the Dyson works around the clock as ship time is precious. The scientists work 12 hour shifts, either from 4am to 4pm (the shift to which I am assigned) or from 4pm to 4am. The acoustics lab where the data is collected and analyzed is affectionately called ‘The Cave’ as there are no portholes (windows) to tell the time of day outside.

chewning_log2_img_4 — The acoustic lab, a.k.a. “the cave”

Personal Log

I wasn’t sure when the Dyson arrived at Three Saints Bay as I had retreated to my stateroom early in the evening of the 4th as I was feeling the effects of the rolling seas. I am being berthed with the ship’s 2nd Cook, Floyd Pounds, who is also from Georgia but now calls the Dyson home.
Floyd works with the Chief Steward, Rick Hargis, who has been with NOAA for 20 years and is originally from Washington State. So far the meals have been very filling and satisfying (there is even an ice cream bar!).

My stateroom is located on the crew deck, one level below the main deck near the bow (the pointy end of the ship) on the starboard side (the right side when facing the bow). Utilizing every nook and cranny and with no wasted space, my berth is quite cozy and is surprisingly comfortable. Fortunately with the help of some seasickness medication, I soon found my sea legs and awoke feeling refreshed and hungry (always a good sign!). Seasickness comes from conflicting messages received from the inner ear and the eyes by the brain (the inner ear feels the motion of the boat rolling and pitching in the water but the eyes report a stable environment confusing the brain).

chewning_log2_img_5 — Snug as a bud in a rug

chewning_log2_img_6 — Richard, ready for a swim

A person soon observes that safety is paramount onboard the Dyson as with any NOAA vessel. For example, within 24 hours of leaving Kodiak, the entire crew conducted fire and abandon ship drills. These drills are conducted once a week and are essential for maintaining readiness in the event of an emergency. During the abandon ship drill, I was able to practice donning my survival suit just like our visiting Coast Guard kids did in Kodiak! Although the suit is designed to be quite snug to keep cold water out and to keep the body warm, I was thankful I didn’t have to put the suit to the test by going over the side. To my surprise, Chief Marine Engineer Jerome ‘Jerry’ Sheehan and ENS Russell Pate did just that, going for a dip in the frigid 7.3 degrees Celcius or ~45 degrees Fahrenheit waters! Jerry and Russell used dry suits to scuba dive under the Dyson to check the hull, the prop, and the transducers for anything out of place such as barnacles on the transducers or tangled fishing gear. The only discovery was of a piece of bull kelp snagged on one of the blades of the prop which may explain a noise that was heard on the hydrophones (microphones located under the Dyson’s hull) during our departure from Kodiak.

chewning_log2_img_7 — CO Hoshlyk overseeing recovery divers Jerry Sheehan and ENS Russell Pate

After completing our calibrations and safety operations, the Dyson sailed for a site called Snakehead Bank located 60 nautical miles southeast of Kodiak. The name comes from the bathometric profile of the seafloor of this area which resembles the head of a snake. We soon began conducting camera operations for ground-truthing sea floor composition that I will discuss in my next log!

chewning_log2_img_8 — Remnants of Nunamiut, earliest Russian settlement 1792 in three saints bay, Kodiak

chewning_log2_img_9 — Departing Three Saints Bay

Where did the NOAA ship Oscar Dyson’s name originate?

The Oscar Dyson is named for an Alaskan fisherman who was very influential in fisheries development and management in Alaska. From his days as a commercial fisherman, Oscar Dyson was a pioneer and advocate for Alaska fisherman and was very influential in the growth of this important industry. Alaska’s commercial fishing industry spans the state and includes salmon, herring, pollock, various shellfish, and various ground fish like halibut. While traveling through the Ted Stevens International Airport in Anchorage, I learned that Alaska is a land defined by water with more than three million lakes and more coastline than the rest of the United Sates combined! Alaska is also the only state in the US to have coastlines with three different oceans/seas: the Pacific Ocean, the Arctic Ocean, and the Bering Sea.

June 5, 2010March 12, 2021

Richard Chewning, June 5th, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 5th, 2010