Richard Chewning – Page 2 – NOAA Teacher at Sea Blog

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