Avery Marvin – NOAA Teacher at Sea Blog

August 13, 2013August 13, 2021

Avery Marvin: Brown bears, fish guts, WW2 bunkers and fossils, OH MY! Adventures in Kodiak, Alaska, August 6, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier
July 8 — 30, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: August 8, 2013

Current Location: 57° 47’ 35” N, 152° 23’ 39” W

Personal Log:

My Teacher at Sea experience ended on the island of Kodiak where the Rainier docked for a few days to stock up on supplies and give the crew a much-needed rest. They departed Kodiak 3 days later to begin the next 2-3 wk leg of their survey season. I had the good fortune of staying on the island for 4 days to explore its unique natural landscape and rich cultural history.

As I walked around downtown, perused the storefronts and enjoyed a latte at Harborside Coffee and Goods, one thing was very clear to me: this town is centered around fish, not tourists. Shelikolff drive is an entire street lined with fish processing plants. Trident Seafood, housed inside an old ship sprawls out on the other side of town. The harbor itself is home to over 1000 fishing vessels, ranging from huge 125 foot crab boats to 18 foot set net skiffs. Xtra Tuff fishing boots are the preferred footwear by all the locals and smelling of fish is a natural occurrence.

Avery at the NOAA Kodiak Fisheries Research Center — Avery at the Alaska/NOAA Fisheries Research Center in Kodiak where a lot of important shellfish research is conducted.

Reindeer (Caribou) sausage sandwich–The MOST delicious sauauge I have ever tasted!

When I was in the coffee shop, I noticed a young women in her late twenties with a toddler next to her, writing a letter to her husband who presumably was out at sea fishing. The letter had pictures of her son taped onto it and lots of hearts and colorful doodles–a gentle reminder that living in Kodiak is not for the faint-hearted. The life of a fisherman is physically demanding and maintaining relationships can be trying.

Kodiak has always been an industrious port and its people have always had a strong connection to the ocean. The first people of Kodiak, the Aleut from Kamchatka, inhabited the island 10,000 years ago and lived off the nutrient-rich waters for 7,500 years. They were true “nature engineers” using resources around them for fishing, clothing, dwellings and other needs. Nothing was wasted. Fishing with nets made of nettle fiber and sinew (tendon). Catching bottom dwellers with seaweed line and bone hooks. Using whalebone for door frames and sod for walls. Lighting the way with whale and seal oil lamps. Dressing in mammal skin and intestines.

I had the chance to see many original Aleut artifacts at the Baranov Museum in Kodiak. The most interesting piece was the Kayak splashguard made of mammal skin, the predecessor of the modern nylon kayak skirt used today. The translucent thin waterproof jackets made of mammal intestines also fascinated me. They looked very delicate but were actually strong and flexible when wet. Suspended from the museum ceiling, was an actual seal skin kayak or Bairdarka used by the Aleuts. They wrapped seal skin around a wood frame, tied the seams with sinew and then added a layer of seal oil for waterproofing. Aleut craftsmanship at its finest!

Avery in front of the Baranov Museum (I am waving in the back right.)

Bairdarka splashguard — Baidarka splashguard made of mammal skin

Aleut waterproof jacket made of mammal intestine

Aleut kayak or Bairdarka — Aleut kayak or Baidarka

The Aleuts clearly adapted well to their island home, making use of all that surrounded them but never exploiting these resources. Sadly in 1784, this peaceful existence was abruptly terminated by the Russians who, armed with muskets and cannons, took the island by force. Having already decimated both the sea otter and native Aleut population around the Aleutian islands, the Russians under the command of Grigory Ivanovich Shelikhov established a permanent settlement in Three Saints Bay on Kodiak to capitalize on the remaining otter population in North Pacific waters. Following the success of the fur trade industry on Kodiak, the Russians expanded their colonization on the Alaska mainland, establishing several subsequent fur trade centers.

Russian conquest was bittersweet. They brought with them diseases and modern necessities such as flour, tea, tobacco and sugar. They built several structures for their needs including fur warehouses, a school, a hospital, a stone quay, a saw mill and an ice making plant. They forced the Aleuts to be their skilled craftsmen and otter hunters. Between old world diseases, murder and abuse, many Aleuts lost their lives and those left standing witnessed the slow demise of their ancient seafarer culture.

The 126-year Russian occupation of Alaska finally came to an end when tired and poor from the Crimean war with France and England, they sold the territory to the U.S. for 7.2 million (2 cents per acre) in 1867. With high-powered firearms, the Americans continued to slaughter the otters at an unsustainable rate. Teetering on the brink of extinction, an international treaty banning the killing of otters was signed in 1911. Post otter years, Americans tried their hand at other industries including trapping, whaling, clamming, cattle ranching, fox farming and gold mining. Salmon fishing though proved to be the most reliable and profitable natural resource so the U.S. quickly established several salmon processing plants around Kodiak. Wooden dories replaced Baidarkas and by the end of the 19^th century, Kodiak had transitioned from a fur-trading hub to a fishing mecca.

Things progressed unchanged until World War II, when Kodiak seen as a strategic waypoint between Asia and the North American west coast, was transformed into a military town. The population went from 400 to several thousand in a short time. A huge self-sufficient navel base was built along with new roads around the island. In preparation for a Japanese attack, several concrete bunkers and underground bomb shelters were constructed. With all of this new infrastructure came indoor plumbing and electricity to the island. When Pearl Harbor was bombed on December 7, 1941 followed by Dutch Harbor on June 3, a Japanese attack on Kodiak seemed imminent but surprisingly the emerald isle went untouched.

Avery in WW2 bunker — Avery in WWII bunker

Today Kodiak remains an important fishing port with a wide variety of crab and fish species (salmon, cod, halibut, Pollack) caught and processed. Modern fishing equipment and boats have replaced older, more natural gear but many of the fishing methods are still the same. Similarly, the factories along Sheikolf Drive have become more automated, with less human hands along each assembly line. Also, the fish industry as a whole on Kodiak has become much more regulated.

Kodiak is a fascinating place to explore because you can see several remnants of its past interspersed around the island: concrete WWII bunkers at Fort Abercrombie, Russian Orthodox church in downtown, old WWII ship anchors lying around, a 200 year old fur warehouse (now the Baranov Museum). Unfortunately, many historical landmarks were destroyed in the 1964 Alaska earthquake. The tsunami that followed the earthquake wreaked more havoc, killing 106 Alaskans and a family of 4 camping at Beverly Beach State Park near Newport, Oregon.

Besides a rich cultural history, Kodiak Island is full of natural beauty and an assortment of cool creatures. Rosalind and I got the chance to explore fossil beach on the south-eastern side of Kodiak where we collected many unique fossils. My top finds were a snail fossil and a shale rock with encased petrified wood.

Avery finds a cool fossil at Fossil beach

After Rosalind left, I was blessed by another Teacher at Sea, Katie Sard, who spent the day with me on a spontaneous adventure around the island. We did all sorts of fun things like tide pooling, checking out WWII bunkers at Fort Abercrombie and eating Greek food at sunset at Monashka bay.

TAS's Avery and Katie Sard :) — TAS’s Avery and Katie Sard 🙂

One of the highlights of my entire Alaska trip, was the float plane trip I took to the Kenai Peninsula on the mainland to see Brown bears. These are the 2^nd largest bears in the world (next to Polar Bears), living off a rich diet of berries and salmon. I had never been in a float plane before and was impressed by how soft the landing and take off were. The aerial views were also incredible. I spotted 2 Humpback whales on the way over to the peninsula from Kodiak and on the way back another passenger spotted a pod of about 45 Orca whales! The pilot was just as excited as we were, and circled around this giant pod for about 10 minutes giving us all good views of their movement and sheer numbers. Incredible!

We landed about a football field away from the peninsula, and waded in hip deep water to the beach. The scenery was beautiful with snow-covered mountains as a backdrop and wild flowers and meandering streams in the foreground. This was perfect bear country! Within about 3 hours we saw the Brown bear Trifecta: Brown bear trying to catch salmon, Brown bear mother with 2 cubs and to cap it all off, Brown bears mating. All of these sightings were of different bears and within a stones throw away. I was surprised at how okay the bears were with our close presence. As I learned from my guide, human safety is ensured by the ability to read nonverbal bear clues which can be very subtle. For example, if a bear turns its back to you, it is saying “Please leave me alone.” You also never make eye contact with a bear or walk directly towards it. You want the bear to feel like he/she has plenty of surrounding space and an escape route if need be. Jo, our guide said that in the 20 years of leading bear tours, she has only had to get out her bear spray 3 times. And one of these times involved a naïve group of students eating Subway sandwiches in front of the bears!

The last day of my Kodiak stay was spent touring several fish factories where I got to experience the real backbones of this city. At all 3 factories, it was Pink salmon processing time which meant the machines were in full swing, with humans at various checkpoints along each assembly line. The machines did everything from decapitating each salmon to cleaning out its guts to skinning it. Each factory processed about 200,000 pounds of Pink salmon per day. In peak season with several different fish species being processed at once, the factories can see around ¾ million pounds of fish processed per day! At one factory, I learned that the big money comes from making surimi (ground fish) which is used as imitation crab all over the world. The most common fish used in surumi is the Alaska Pollock which is very plentiful in Kodiak waters. I am glad to hear that imitation crab is actually fish and not some other protein filler.

Check out these videos to see the factory process in action. It’s fascinating!!!

As you saw from the above videos, the most hands on section of the whole process is in the production of roe (salmon eggs). This is because the roe must be gently handled and graded (1-3 scale) in preparation to be sold to Japan. At $50 per pound, roe is a delicacy in Japan and often eaten raw over rice or in sushi. Also Pink and Chum salmon produce the most desirable roe called ikura or red caviar. This roe is about the size of a pea and is sold as individual pieces. In contrast, the smaller eggs of Coho and Sockeye salmon produce sujiko, which is roe still connected in the sac. Throughout each of my fish processing plant tours, I was curious to know HOW the roe was graded. To my surprise, none of the factory managers could tell me how and I unfortunately could not communicate with the highly skilled Japanese roe technicians.

So I looked it up and it turns out roe is graded using the following criteria: size (larger is better), salt content (lower is better), drip (zero is best), firmness (firm is better but not so firm the egg breaks), color (bright, red-orange outer color with a center the color and consistency of honey), luster (eggs should be shiny and slightly transparent).

It was fitting to end my Kodiak stay with some down and dirty fish factory tours as this is the lifeblood of the city (and Alaska) and a good representation of the Kodiak spirit. These factories operate 24/7 with workers on their feet for 12 hour shifts. From the Aleuts to now, the Kodiak people have always been a hardy bunch with an incredible work ethic, and the ability to adapt to one of the most challenging environments in the world. This is the ring of fire: weather and natural disasters are unpredictable. So why do people stay? It’s the sea. Beautiful. Vast. Mysterious. Full of life. She calls them back day after day, year after year. Welcome to Kodiak life.

Fun Factoid: The infamous Kodiak brown bear, the sole species of bear on the island of Kodiak, is a sub-species of the Alaskan mainland Brown bear population. Hunters come from all around the world to hunt this sub-species, paying thousands of dollars per expedition.

August 5, 2013August 13, 2021

Avery Marvin: Cool Science on the Ship and final Reflections of My Rainier Adventure, July 30, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 30, 2013

Current Location: 54° 55.6’ N, 160° 10.2’ W

Weather on board: Broken skies with a visibility of 14 nautical miles, variable wind at 22 knots, Air temperature: 14.65°C, Sea temperature: 6.7°C, 2 foot swell, sea level pressure: 1022.72 mb

Science and Technology Log:

Sometimes in school you hear, “You’ll need this someday.” You have been skeptical, and (at times) rightfully so. But here on the Rainier, Rosalind and I encountered many areas in which what we learned in school has helped us to understand some of the ship operations.

How does a 234 ft. ship, like the Rainier, float?

If you take a large chunk of metal and drop it in the water, it will sink. And yet, here we are sailing on a large chunk of metal. How is that possible? This all has to do with the difference between density (the amount of mass or stuff contained within a chunk of a substance) and buoyancy (the tendency of an object to float). When you put an object in water, it pushes water out of the way. If the object pushes aside an amount of water with equal mass before it becomes fully submerged, it will float. Less dense objects typically float because it doesn’t take that much water to equal their mass, and so they can remain above the water line. The shape of a ship is designed to increase its buoyancy by displacing a greater quantity of water than it would as a solid substance. Because of all the empty space in the ship, by the time the ship has displaced a quantity of water with equal mass to the ship itself, the ship is still above water. As we add people, supplies, gasoline and so on to the ship, we ride lower. As evidenced by the sinking of numerous ships, when a ship springs a hole in the hull and water floods in, the buoyancy of the ship is severely compromised. To take precaution against this, the Rainier has several extra watertight doors that can be closed in case of an emergency. That way, the majority of the ship could be kept secure from the water and stay afloat.

How does a heavy ship like the Rainier stay balanced?

Another critical consideration is the balance of the ship. When the ship encounters the motion of the ocean, it tends to pitch and roll. Like a pendulum, the way in which it does this depends largely on the distance between the center of gravity of the ship (effectively the point at which the mass of the ship is centered) and the point about which it will roll. Ships are very carefully designed and loaded so that they maintain maximum stability.

Ballast is often added to the hulls of ships for the following reasons:

to help keep them balanced when there is not enough cargo weight
to increase stability when sailing in rough seas
to increase the draught of the ship allowing it to pass under bridges
to counteract a heavy upper deck like that of the Rainier, which itself contains 64, 000 pounds of launches.

Ballast comes in many forms and historically rocks, sandbags and pieces of heavy metal were used to lower a ship’s center of gravity, thus stabilizing it. Cargo ships, when filling up at port, would unload this ballast in exchange for the cargo to be transported. For example, in the 1800s, the cobblestone streets of Savannah, Georgia were made with the abandoned ballast of ships. Today water is used as ballast, since it can be loaded and unloaded easier and faster. Most cargo ships contain several ballast tanks in the hull of the ship.

It is thought that the capsizing of the Cougar Ace cargo ship bound for the west coast of the US in 2006, was caused by a ballast problem during an open-sea transfer. The ship was required to unload their ballast in international waters before entering US waters to prevent the transfer of invasive species carried by the stored water. The result of the Cougar Ace snafu: 4, 700 Mazdas scrapped and millions of dollars lost. Oops!

Couger Ace capsized in open ocean — Cougar Ace capsized in open ocean

Because the Rainier is not loading and unloading tons of cargo, they use a permanent ballast of steel rebar, which sits in the center of the lower hull. Another source of ballast is the 102, 441 gallons of diesel which is divided between many gas tanks that span the width and length of the ship on the port and starboard sides. These tanks can be filled and emptied individually. For stability purposes the Rainier must maintain 30% of fuel onboard, and according to the CO, the diesel level is usually way above 30% capacity. The manipulation of the individual diesel tank levels is more for “trimming” of the boat which essentially ensures a smoother ride for passengers.

Where does all the freshwater come from for a crew of 50?

If only humans could drink saltwater, voyages at sea would be much easier and many lives would have been saved. Unfortunately, salt water is three times saltier than human blood and would severely dehydrate the body upon consumption leading to health problems such as kidney failure, brain damage, seizures and even death. So how can we utilize all this salt water that surrounds us for good use? Well, to avoid carrying tons of fresh potable water aboard, most large ships use some type of desalination process to remove the salt from the water. Desalination methods range from reverse osmosis to freeze thawing to distillation. The Rainier uses a distillation method which mimics the water cycle in nature: heated water evaporates into water vapor, leaving salts and impurities behind, condensing into liquid water as the temperature drops. This all is happening inside a closed system so the resulting freshwater can be kept. To speed up this process, the pressure is lowered inside the desalinator so the water boils at a lower temperature. Much of the energy needed to heat the water comes from the thermal energy or waste heat given off by nearby machines such as the boiler.

Distillation purifies 99% percent of the salt water and the remaining 1% of impurities are removed by a bromine filter. The final step of the process is a bromine concentration and PH check to ensure the water is potable. The bromine should be about .5 ppm and the PH between 6.8-7.2.

Everyday the Rainer desalinates 2500 gallons of saltwater to be used for drinking, cleaning and showering. The toilets, however, use saltwater and if you are lucky like me, you can see flashes of light from bioluminescent plankton when flushing in darkness. It’s like a plankton discotec in the toilet!

How does the chicken cross the road when the road is moving?

The difference between a road map and a nautical chart is that a road map tells you which way to go and a nautical chart just tells you what’s out there and you design your course. Thus, navigating on the ocean is not as simple as “turn left at the stop sign,” or “continue on for 100 miles”, like directions for cars often state. Imagine that the road beneath you was moving as you drove your car. In order to keep following your desired course, you would need to keep adjusting to the changes in the road. That’s a lot like what happens in a ship. If you want to drive due west, you can’t simply aim the ship in that direction. As you go, the ship gets pushed around by the wind, the currents, and the tides, almost as if you drove your car west and the road slid up to the north. Without compensating for this, you would end up many miles north of your desired location. If you have a north-going current, you have to account for this by making southward adjustments. In a physics class, we might talk about adding vectors, or directional motion; in this case, we are considering velocity vectors. When you add up the speed you are going in each direction, you end up with your actual speed and direction. In the ship we make adjustments so that our actual speed and direction are correct.

Which way to the North Pole?

Did you know that when you look at a compass, it doesn’t always tell you the direction of true north? True north is directly towards the North Pole, the center of the Earth’s axis of rotation which passes directly to the true south pole. However, compasses rely on the location of the magnetic pole which is offset somewhat.

Compass showing true north and magnetic north

The combination of the solid iron core and the liquid iron mantle of the Earth create a magnetic field that surrounds the Earth (and protects us from some really damaging effects of the sun). If you visualize the Earth like a bar magnet, magnetic north is located at an approximate position of 82.7°N 114.4°W, roughly in the middle of northern Canada. If you stood directly south of this point, your compass would point true north because true north and magnetic north would be on the same line of longitude. However, as you get farther away from this west or east, the North indicated by your compass is more and more offset.

Our navigational charts are made using “true” directions. Because of our location in Alaska, if we were steering by compass, we would have to offset all of our measurements by roughly 14° to account for the difference in true and magnetic north. Fortunately, due to the advent of GPS, it is much simpler to tell our true direction.

Why so much daylight and fog?

Every hour, the crew of the Rainier measures the air temperature, sea water temperature, atmospheric pressure, and relative humidity. Aside from keeping a record of weather conditions, this also allows the National Weather Service to provide a more accurate weather forecast for this geographical region by providing local data to plug into the weather prediction models.

Weather in the Shumagin Islands could be very different from that of the nearest permanent weather station, so this can be valuable information for mariners. In our time out here, we have experienced a lot of fog and cool temperatures (although the spectacular sunshine and sunsets of the past few days make that seem like a distant memory). One reason for this is our simultaneous proximity to a large land mass (Siberia, in far-east Russia) and the ocean. Cool air from the land collides with warm waters coming up from Japan, which often leads to fog.

Currents of the Pacific — Currents around Alaska

However, because we are pretty far north, we also experience a lot of daylight (although not the 24-hour cycles so often associated with Alaska). At this time of the year, even though the Earth is farther away from the sun that it is in our winter season, the axis of the Earth is tilted toward the sun, leading to more direct sunlight and longer hours of illumination.

Earth's orbit around the sun — Earth’s orbit around the sun

One slightly bizarre fact is that all of Alaska is on the same time zone, even though it is really large enough to span several time zones. Out in the west, that means that sunset is in fact much later than it otherwise should be. Our last few spectacular sunsets have all happened around 11pm and true darkness descends just past midnight. I have on several occasions stayed up several hours past my bedtime fishing on the fantail or getting distracted wandering around the ship because it is still light out at 11pm!

Rosalind and Avery at sunset — Rosalind and Avery (with Van de Graaf generator hair) at sunset

Personal Log:

Well friends, I said a bittersweet goodbye to the Rainier and its incredible dynamic crew. I am sad to have left but am also excited to return home to the Oregon Coast to begin planning for this school year. I look forward to incorporating my newfound knowledge and unique experience at sea into the classroom. I am still amazed at the breadth and diversity of information that I learned in just under 3 weeks. From learning how to steer the ship to acquiring and processing survey data to puffin reproduction, the list goes on. I never stopped asking questions or being curious. And the Rainier crew was always there to graciously answer my questions. I am grateful for all that they taught me and for the kindness and patience they consistently showed me.

When I asked Rick Brennan, the Commanding Officer, what he most enjoyed about his job, he responded “The people.” He said he enjoys seeing the personal and professional growth of individual crew members. It is not hard to see that the Rainier crew is pretty amazing. They are an extremely dedicated group of individuals whose passion for their profession supersedes living a “normal life”. Each one of them has an interesting story of how they got to the Rainier and many of them sacrifice family time and personal relationships to be aboard the ship for months at a time.

Beyond the scientific knowledge attained, I leave this ship with a few important life reminders.

1) Be patient with yourself, your own learning style, with others around you and the task at hand. Authentic science is messy and exhausting. Ship life attracts unique personalities.

2) Don’t forget about the big picture and why you are here in the first place. “Mowing the lawn” day in and day out can seem mundane but all of those data points together will compromise the updated nautical chart which will ensure safe mariner travel for a multitude of ships.

3) Teamwork is key to any complex operation. This not only means working together but always being willing to lend a helping hand and sharing your particular knowledge with fellow crew members.

4) Appreciate, observe and protect the natural beauty that surrounds us. Cultivate this awareness in others. Our livelihood as a species depends on our interaction with the environment.

This is my second to last blog post. Stay tuned for an exciting last entry about my extended stay in Kodiak, Alaska (post Rainier) where I explored the unique cultural and historical facets of this vibrant fishing port. Note: This next post will involve bears, a seal skin kayak, a behind the scenes fish factory tour, orcas, reindeer sausage and fossils!

For now, I leave with fond memories of a truly unique 18 day voyage aboard the most productive coastal hydrographic survey platform in the world: her majesty, the Rainier. Thank you lovely lady and thank you Rainier crew for making this Teacher at Sea adventure so magical!

July 24, 2013August 13, 2021

Avery Marvin: Sound Off! From Noise to Nautical Charts, July 22, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier (NOAA Ship Tracker)
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 22, 2013

Current Location: 54° 55.6’ N, 160° 10.2’ W

Weather on board: Broken skies with a visibility of 14 nautical miles, variable wind at 22 knots, Air temperature: 14.65°C, Sea temperature: 6.7°C, 2 foot swell, sea level pressure: 1022.72 mb

Science and Technology log:

“Teamwork, Safety First”, is inscribed boldly on the Rainier stern rafter and after being aboard for more than 2 weeks, it is evident this motto is the first priority of the crew and this complex survey operation at hand.

Rainier launch — This is one of the survey launches that we use to gather our survey data. In this case, the launch is shown approaching the Rainier, getting ready to tie up.

It’s a rainy overcast morning here in SW Alaska and we are circled around the officers on the fantail for the daily safety meeting. Weather conditions, possible hazards, and the daily assignment for each launch are discussed. Per the instructions on the POD (Plan of the Day), handed out the previous evening, the crew then disperse to their assigned launches. The launches are then one-at-a-time lowered into the water by the fancy davit machinery and driven away by the coxswain to their specific “polygon” or survey area for the day. A polygon surveyed by a launch on average takes 2-3 hours at 6-8 knots to survey and usually is an area that is inaccessible by the ship. Many polygons make up one large area called a “sheet” which is under the direction of the “sheet manager”. Several sheets make up an entire survey project. Our hydrographic project in the Shumagins has 8 sheets and makes up a total of 314 square nautical miles.

This is a chart of the Shumagin Islands showing the 8 sheets (highlighted in green) that we are surveying.

Polygons — East side of Chernabura Island divided into survey “polygons”, each labeled with a letter or word. Notice how each polygon is a small subset of the larger sheet.

On board each launch we have a complex suite of computer systems: one manages the sonar, another manages the acquisition software, and the third records the inertial motion of the launch as it rocks around on the water (pitch, heave, roll). The acquisition system superimposes an image of the path of the launch and the swath of the sonar beam on top of a navigational chart within the polygon. Starting at one edge of the polygon, the coxswain drives in a straight a line (in a direction determined by the sheet manager), to the other end of the polygon, making sure there is some overlap at the boundaries of the swaths. He/she then works back in the other direction, once again making sure there is some overlap with the adjacent swath. We call this “mowing the lawn,” or “painting the floor” as these are visually analogous activities. Throughout the day, we pause to take CTD casts so that we have a sound velocity profile in each area that we are working.

Typical launch dispersal for a survey day. Launches are signified by “RA-number”. You can also see the location of our tide measurement station and GPS control station, both of which we use to correct our data for errors.

Mowing the lawn — This image shows the software tracking the path and swath of the launch (red boat shape) as it gathers data, driving back and forth in the polygon, or “mowing the lawn.” The darker blue shaded area shows overlap between the two swaths. The launch is approaching a “holiday”, or gap in the data, in an effort to fill it in.

You might be wondering, why the swath overlap? This is to correct for the outer sonar beams of the swath, which can scatter because of the increased distance between the sea floor and the sonar receiver below the hull of the boat. The swath overlap is just one of the many quality control checks built into the launch surveying process. Depending on the “ping rate”, or the number of signals we are able to send to the bottom each second, the speed of the boat can be adjusted. The frequency of the sound wave can also be changed in accordance with the depth. Lower frequencies (200 khz) are used for deeper areas and higher frequencies (400 khz) are used for shallower areas.

Rosalind working the surveying computers in the launch

Despite what might seem like mundane tasks, a day on board the launch is exhausting, given the extreme attention to detail by all crew members, troubleshooting various equipment malfunctions, and the often harsh weather conditions (i.e. fog, swells, cool temperatures) that are typical of southwest Alaska. The success of the ship’s mission depends on excellent communication and teamwork between the surveyors and the coxswain, who work closely together to maximize quality and efficiency of data collection. Rain or shine, work must get done. But it doesn’t end there. When the launches arrive back at the ship, (usually around 4:30 pm), the crew will have a debrief of the day’s work with the FOO (field operations officer) and XO (executive officer). After dinner, the survey techs plunge head first (with a safety helmet of course) into the biggest mountain of data I have EVER witnessed in my life, otherwise known as “night processing”. We are talking gigabytes of data from each launch just for a days work. It begins with the transferring of launch data from a portable hard drive to the computers in the plot room. This data is meticulously organized into various folders and files, all which adhere to a specific naming format. Once the transferring of data has finished, the “correction” process begins. That’s right, the data is not yet perfect and that’s because like any good science experiment, we must control for extraneous factors that could skew the depth data. These factors include tides, GPS location error, motion of the launch itself, and the sound velocity in the water column.

Plot room — Our chief surveyor works in the plot room cleaning and correcting data.

Data cleaning. — Data showing the consequences of the tide changing. The orange disjointed surface shows the data before it was adjusted for the tide changing. You can see how the edges between swaths (i.e. red and olive green) do not match up, even though they should be the same depth.

Sound speed artifact — This image shows the edge effects of changing sound speed in the water column. The edges of each swath “frown” because of refraction owing to changing density in the water column. This effect goes away once we factor in our CTD data and the sound speed profile.

In previous posts, I discussed how we correct for tides and the sound velocity. We also correct for the GPS location of the launch during a survey day, so that any specific data point is as precisely located as possible. Although GPS is fairly accurate, usually to within a few meters, we can get even more precise (within a few centimeters) by accounting for small satellite errors throughout the day. We do this by determining the location of a nearby object (our Horizontal Control, HorCon, Station) very precisely, and then tracking the reported position of this object throughout the day. Any error that is recorded for this station is likely also relevant for our launch locations, so we use this as the corrector. For example, if on July 21, 2013, at 3pm, the GPS location of our Bird Island HorCon station was reported 3cm north of its actual location, then our launches are also probably getting GPS locations 3cm too far north, so we will adjust all of our data accordingly. This is one of the many times we are thankful for our software. We also account for pitch, heave, and roll of the launch using the data from the inertial motion unit. That way, if the launch rolled sideways, and the center beam records a depth of 30 meters, we know to adjust this for the sideways tilt of the launch.

HorCon station — This shows the set up of our Horizontal Control and tide gauge station. The elevated rock position was chosen to maximize satellite visibility.

After all correctors have been applied (and a few software crashes weathered), the survey technicians then sort through all the data and clean out any “noise.” This noise represents sound reflections on sea life, air bubbles, or other items that are not part of the seafloor. Refraction of sound waves, as mentioned in the last post, is caused by density changes in the water due to changes in the temperature, pressure, or salinity.

Dirty data — This shows sonar data with “noise”. The noise is the seemingly random dots above and below the primary surface. On the surface itself, you can see data from four different swaths, each in a different color. Notice the overlap between swaths and how well it appears to be matching up.

Cleaned surface — This shows sonar data after the “noise” has been cleaned out. Notice how all data now appears to match a sea floor contour.

Many of the above correctors are applied the same day the data is collected, so the sheet manager can have an up-to-date record of the project’s progress before doing final planning for data collection the next day. After a sheet has been fully surveyed and ALL correctors applied, the sheet manager will complete a “descriptive report”, which accompanies the data and explains any gaps in the sonar data (“holidays”) and/or other errors present. This report, along with the data, is sent to the Pacific Hydrographic Branch for post-processing, and in 1-2 years, we will have a corrected and updated navigational chart. During this time the data is reviewed for quality and adherence to hydrographic specifications and then is distilled into a cartographic product (nautical chart) consisting of points, lines, and areas.

Personal Log:

So I am going to hold off in talking about an animal that has recently fascinated me and instead devote this personal log to some cool things I have been doing on the ship.

Most recently I got to be the helmsman and steer the ship. This involved me following orders from the “conning officer” who told me various steering commands such as: “Left ten degrees rudder”, “steady on course 167°”, “ease 5° right”, “helm in auto” (auto-pilot). To acknowledge the command, I repeated what the conning officer said followed by “aye”. For example: “Left ten degrees rudder, aye” or “course 167°, aye”. When the boat is actually on the course that was requested by the conning officer, I repeated the command with the word “steady”. For example: “Steady on course 167°”

You might be wondering why all of the commands involve degrees. Well that is because this ship is steered by the rudder, similar to how you manually steer a small sailboat. So changing the angle of the rudder will change the direction of the ship. To change this angle, you turn the steering wheel a desired amount of degrees beyond zero in the direction the conning officer instructed. So if he said “right 5 degrees rudder”, I would turn the steering wheel right, and stop at the 5 hash mark.

Once the boat actually turns 5°, I will make sure I am at the correct “heading” or degree mark that the conning officer instructed. A heading can be any number between 000-360 (where 000-deg = North, 045 = Northeast, 090 = East, etc.) as this boat can turn in a complete circle and be navigated in any direction. (There is 360° in both a compass and a circle.) Once I am steady at the correct heading, I will put the steering wheel back to 0° which means the rudder is completely straight and parallel with the boat. At this point the boat is going straight. If this were a car, you could just stay straight no problem.

But because this boat moves in water and is affected by ocean conditions such as swells, it is easily knocked off course of the heading. So as helmsman I am constantly making tiny adjustments with the steering wheel by a few degrees in either direction to maintain my heading. This adjustment is done using the steering wheel if I am driving manual, or using a dial on the gear panel if the boat is in “auto” (auto-pilot). Because the ship rudder must “push water out of the way” in order to steer the boat, there is a delay between when I turn the steering wheel to when the ship actually moves that amount of degrees. This is not a car which turns instantaneously by the movement of axles. So I need to account for that “lag time” as well as ocean conditions and the speed of the boat when turning the ship. For example, if the boat is going slow (3 knots) and I need to turn quickly, I will have to use a greater rudder angle. Throughout this process I have several digital screens that show me my current position and course, current heading and desired heading as well as other navigational aides. When I was helmsman, I was closely monitored and assisted by Jason, a former Navy Chief Boatswain, who is one of the best helmsman on the ship. To be a good navigator you need to know the fundamentals but you also need a lot of practice and exposure to various navigational situations.

Yesterday, Rosalind and I got to work on deck and help the Chief Boatswain with various deck tasks such as lowering the anchor and assisting with the davit to hoist the launches from their day of surveying out on the water. Assisting with the job of lifting a 16,000 lb launch with 3 people aboard using the davit winch was by far the most exhilarating experience thus far on the ship. I handled the task with extreme caution. As with being a helmsman, there are many factors I must consider as a davit operator. For example, if there is a significant swell, I need to be more aggressive with the davit movements to get the boat lifted fast to avoid any excessive swaying in mid-air. Most importantly, I must attentively follow the gestures of the deck boss below who is able to see the launch very clearly and is directing me on every davit movement. Even an experienced davit operator like Jason, who probably can predict the next davit movement in his sleep, must never assume and then act. He ALWAYS follows the exact orders of the deck officer below because he never knows what they are seeing that he cannot from the above deck. Overall, with Jason’s close attention and assistance, I think I did a good job of assisting with the davit. The boat made it safely aboard, and my heart returned to a normal beating pattern. 🙂

Operating the crane to get the davit ready to lift the launch out of the water — Getting the davit positioned and ready to lift the launch out of the water.

On a lighter note I learned how to play the good ole’ mariner pastime favorite, Cribbage. Rosalind (the other Teacher at Sea and my delightful roommate) taught me how to play. We had a cribbage tournament here aboard the ship in which about 12 people competed. I did not advance to the finals but had a lot of fun nonetheless. I am looking forward to gaining more Cribbage strategies so I can be a more competitive player for future matches.

First round of Cribagge tournament — First round of Cribbage tournament

Just for fun:

An adorable sole I caught on the fantail of the Rainer (I released him/her). 🙂

Fun factoid: A fathom which is a maritime measurement equal to 6 feet, was originally based on the distance, fingertip to fingertip of a man’s outstretched arms. Fathom that!

July 22, 2013August 13, 2021

Avery Marvin: Beaming With Excitement – Sound Waves and the Sea Floor, July 19, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier (Ship Tracker)
July 8-25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 19, 2013

Current Location: 54° 49.684 N, 159° 46.604 W

Weather Data from the Bridge: Foggy and overcast, wind 21 knots, air temperature: 11.5° C

Science and Technology Log:

As the fog horn sounds every two minutes and we sail solitary through the ocean, we are now in full swing surveying the Shumagin Islands, between and around Nagai, Bird, and Chernabura Islands. Unlike the old-time surveyors who used lead lines (lead weight attached to a long string), we are using a multibeam sonar system, which enables us to gather a large quantity of very accurate data in a more efficient and timely fashion.

3D sea floor — Processed sonar data showing 3D image of the sea floor.

Sonar, (SOund Navigation And Ranging) uses the principle of sound wave reflection to detect objects in the water. Just as our eyes see the reflection of visible light off of the objects around us to create a visual image, when a sound wave hits something, it reflects off that “thing” and returns to its starting point (the receiver). We can measure the time it takes for a pulse to travel from the Sonar device below the boat to the ocean floor and then back to the receiver on the boat. Using a simple distance=speed * time equation, we can get the water depth at the spot where each beam is reflected.

The skiff that we use for the shoreline activities discussed in the last post has a single-beam sonar system that directs a pulse straight down beneath the hull to get a rough depth estimate. However, for our hydrographic work on the ship and launches, we use a multibeam system that sends 512 sound pulses simultaneously towards the sea floor over a 120° angle. When many sound waves or “beams” are emitted at the same time (called a pulse) in a fan like pattern (called a swath), the reflected information creates a “sound picture” of the objects or surface within that swath range. The actual width of this swath varies with the depth, but with 512 beams per pulse, and sending out between 5-30 pulses every second, we acquire a lot of data. If you piece together many swaths worth of data you get a continuous topographical or physical map of the ocean floor, and thus the depth of the water. For more information about the specific sonar system used aboard the Rainier and its launches, check out the ship page or the NOAA page about their hydrography work.

Multibeam — Graphic showing an example of the multibeam swath below a launch. Notice how the swath gets wider as the depth increases.

Multibeam data — Cross section of sea floor data showing dot or “ping” for each multibeam measurement. Notice how many individual measurements are represented in this one section.

Swath data — Cross section of sea floor data. Each color represents data from one swath. Notice the overlap between swaths as well as the width for each one.

3D floor image — Processed sonar data showing 3D image of the sea floor.

In order to understand the complexities of sonar, it is important to understand the properties of sound. Sound is a pressure wave that travels when molecules collide with each other. We know that sound can travel in air, because we experience this every day when we talk to each other, but it can also travel in liquids and solids (which whales rely on to communicate). As a general rule, sound travels much faster in liquids and solids than in air because the molecules in liquids and solids are closer together and therefore collide more often, passing on the vibration at a faster rate. (The average speed of sound in air is about 343 meters every second, whereas the approximate speed of sound in water we have been measuring is around 1475 meters every second). Within a non-uniform liquid, like saltwater, the speed of sound varies depending on the various properties of the saltwater at the survey site. These properties include water temperature, dissolved impurities (i.e. salts, measured by salinity), and pressure. An increase in any of these properties leads to an increase in the speed of sound, and since we’re using the equation distance = speed * time equation, it is crucial to consistently measure them when seeking depth measurements.

CTD Data — Data from CTD showing temperature vs. sound speed from one data set. Notice how the temperature and sound speed seem correlated.

To measure these properties, a device called a CTD (Conductivity-Temperature-Depth) is used. Conductivity in this acronym refers to the free flowing ions in salt water (Na and Cl, for example), which are conductive and the concentration of these ions determines the salinity of the water. The CTD measures these three properties (Conductivity, Temperature and Depth) so the speed of sound in the water can be calculated at every point in the water column

To use the CTD, lovely humans like Avery and I will drop it into the water (it is attached to a winch system) at the area where we are surveying and as it travels to the sea floor, it takes a profile of the three saltwater properties mentioned before. Back in the computer lab, software takes this profile data and calculates the sound velocity or speed of sound through the water in that region. As a crosscheck, we compare our profile data and sound velocity figures obtained at the site to historical measured limits for each property. If our measurements fall significantly outside of these historical values, we might try casting again or switch to a different CTD. However, because we are surveying in such a remote area, in some cases, data outside historical limits is acceptable.

CTD graphs — Graph of our sound speed vs. depth data showing comparison to historical data.

Given that we are trying to determine the water depth to within centimeters, variations in the sound speed profile can cause substantial enough errors that we try to take a “cast” or CTD reading in each small area that we are gathering data. The software the survey team uses is able to correct automatically for the sound velocity variations by using the data from the CTD. This means that the depth profile created by the sonar systems is adjusted based on the actual sound velocities (from the CTD data) rather than the surface sound speed. We are also able to account for speed changes that would cause refraction, or a bending of the beam as it travels, which would otherwise provide inaccurate data about the location of the sea floor.

Avery lowers the CTD into the water for a “cast”. The CTD needs to sit in the water for a few minutes to acclimate before being lowered for a profile.

Avery successfully hauls in the CTD out of the water.

Personal Log:

You can’t go to Alaska without fishing its waters, rich with a variety of delectable fish species. So I decided to get my Alaskan recreation fishing license and try my hand at it on the fantail (stern) of the Rainier, while we were anchored in Bird Island cove. Carl VerPlanck, an experienced fisherman with arms like Arnold Schwarzenegger, had coached me on the best jigging techniques for catching a halibut and with my eyes (and mind) on the prize I followed his instructions diligently. It paid off as I landed several fish my first night on the fantail, with one halibut being a true keeper. John Kidd, NOAA Corps. Officer, gaffed my meaty fish over the steep rail of the Rainier and hauled it aboard. He was impressed with my catch (and hidden fishing talent), stating “This is the biggest fish caught so far this season.” Woohoo! Most impressive was the amount of meat the fish yielded (4 large filets) which I proudly donated to the kitchen and John. (Three big filets to the kitchen and one filet to John for his camaraderie, the use of his high-tech rod set-up and filleting skills). The following night, we all ate delicious baked Pacific Halibut filets, coated in a creamy Caesar glaze, prepared by chef-extraordinaire, Kathy. It’s pretty cool that I got to feed the ship!!

Avery's meaty catch, a Pacific Halibut. — Avery’s meaty catch, a Pacific Halibut.

John Kidd (NOAA Officer) filleting my halibut — John Kidd (NOAA Corps. Officer) filleting my halibut

This was my first time catching a halibut and after close examination (and dissection) of this large, rather bizarre looking flatfish I became very intrigued and had several questions: How and why do the eyes migrate to one side? How do you tell the age of a halibut? What does the word “halibut” mean?

Like any good scientist, I proceeded to find the answers to these questions, and in doing so, learned many more interesting tidbits about Halibut. (The other species of halibut is the Atlantic Halibut which is very similar to the Pacific Halibut and is named as such for the ocean it occupies.)

So lets start with the name “halibut.” It’s origin is Latin (hali=haly=holy, but=butt=flat fish) and literally translates to “holy flat fish” because it was popular on Catholic holy days. Now what’s with the eye migration and why are both eyes on the same side? Well to understand this question thoroughly we must look at the conditions under which the halibut is born. Female halibut are sexually mature at age 12, spawning from November to March in deep water (300-1500 feet). Depending on their size, females release several thousand to several million eggs which are fertilized externally by the males. After the eggs are fertilized by the males, they become buoyant and start to float up the water column, hatching into free floating larva at about 16 days. As the larva mature, they continue to rise to the surface. At this larval stage they are upright, like any other “regular” fish, with one eye on each side of their head. This eye placement makes sense, considering they are in the open ocean with water on all sides of them. When at or near the surface, the larvae drift towards shore by ocean currents. As they get closer to shore and at about 1 inch in length, they undergo a very unique metamorphosis in which the left eye moves over the snout to the right side of the head. At the same time their left side fades in color eventually becoming white and their right side becomes a mottled olive-brown color. By 6 months, they are ready to settle to the bottom in near shore areas, hiding under the silt and sand, with just eyes exposed. Their mottled side will be face up, blending into their surrounds and their white side will face down, creating a “countershading” coloration, which helps keep them hidden from predators.

From halibut larvae to adult halibut. Notice the migration of the left eye to the right side and the pigmentation at the last stage. — Halibut development: from halibut larvae to adult halibut. Notice the migration of the left eye to the right side and the pigmentation at the last stage.

The Pacific Halibut I caught was by no means a monster or “barn door” as the huge ones are called. But it also was not a “chicken”, slang for a small halibut. Female halibut can reach lengths of 8 feet and a weight of 500+ pounds. Males rarely exceed 100 pounds. Halibut are generally not picky eaters and will pretty much eat anything that lives in the ocean. Carl joked that a halibut would even eat an old shoe dangling from a fishing pole.

I was surprised to learn that halibut can live as long as 55 years. Scientists can accurately age a halibut by counting the rings in their ear bone or “otolith”, similar to dating a tree using its annual growth rings. So next time you catch a halibut and plan on keeping it, try to find the ear bone, grab a microscope and age the fish. If that fails, don’t forget to cut the cheeks out of the halibut (along with the 4 regular meaty fillets), for I am told that is the best part to eat. 🙂

Halibut otolith or ear bone that can be used to age the fish by counting the rings under a microscope — Halibut otolith or ear bone that can be used to age the fish by counting the rings on the otolith (under a microscope).

Fun factoid: Sonar works a lot like the echo sounding of a bat, and its development was partially prompted by the Titanic disaster.

July 17, 2013August 13, 2021

Avery Marvin: Is it an Island or Just an Ink Blot? July 16, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier (NOAA Ship Tracker)
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 16, 2013

Current Location: 54° 55.8’ N, 160° 09.5’ W

Weather on board: Overcast skies with a visibility of .5 nautical miles, South wind at 18 knots, Air temperature: 10°C, Sea temperature: 7.2°C, 1-2 foot swell

Science and Technology log: Shoreline Verification

When you think of a shoreline, you might think of a straight or curved “edge” made of sandy beaches that gradually retreat into deeper and deeper water. In the Shumagin Islands, a sandy cove is a rare occurrence and a place for a beach party! Towering, jagged cliffs patched with Artic moss and blanketed by a creeping fog are the typical “edges” here. Below the cliffs in the water, lie sporadic toothed rocks and beds of dense rooted bull kelp, swaying with the current. As I sit on the edge of the skiff (small dingy-like boat), which gently trudges along the outside of the protruding rocks, I think to myself “Is this what Ireland is like?” or is this a world unto its own-untouched and solitary? Whatever it is, this place evokes an ethereal mood and you really feel like you are in one of the most remote places in the world.

Navigating through Bull Kelp bed — Navigating around Bull Kelp bed

Remote it is and that is why we are here. These are for the most part, uncharted or poorly documented waters and shorelines and in this post, I am going to talk about the shoreline aspect. Besides taking bathymetric data (depth data), hydrographic ships like the Rainier must also verify that the shorelines of various land-masses are portrayed accurately and that all necessary “features” are documented correctly on nautical charts. Features include anything that might be a navigational hazard such as rocks, shoals, ledges, shipwrecks, islets (small islands) and kelp beds. For shoreline verification, a 19 foot skiff is used for maneuverability and shallow water access. This boat will go out during the “shoreline window”, when the tide is the lowest, with the hopes that if there is a dangerous feature present, it will be visible above the water. In the best case scenario, we can investigate the shoreline fully with the skiff before sending in the bigger launches to survey the area with the sonar, so that we know they won’t hit anything.

Shoreline verification crew. From left: Randy (Coxswain), John (NOAA Corps. Officer), Chief Jacobson (Chief Survey Tech), Avery (Teacher at Sea)

Shoreline verification crew hard at work. From left: Randy (Coxswain), John (NOAA Corps. Officer), Chief Jacobson (Chief Survey Tech), Steve (NOAA Corps. Officer)

The main goal of the scientists aboard the skiff is to establish a “navigational area limit line” (NALL). This is a boundary line delineating how far off shore the launch boats should remain when they are surveying. This boundary line is obtained in one of three ways:

1) presence of a navigational hazard such as a dense kelp bed or several protruding rocks

2) a depth of 4 meters

3) distance of 64 meters to shore

Whichever of these is reached first by the skiff will be the navigational area limit line for the launches. Here in the Shumagins, kelp beds and rocks have been the boundary line determinant and often these hazards are in water that is deeper than 4 meters because we have been encountering these before we get within 64 meters of the shoreline.

While scientists are determining the NALL, they are also verifying if certain features portrayed on older charts are in fact present and in the correct location. Using navigational software on a waterproof Panasonic Toughbook, they bring up a digitized version of the old chart of a specific survey area. This chart depicts features using various symbols (asterisk=rock above water, small circle=islet). This software also overlays the boat’s movement on top of the old chart, allowing the boat to navigate directly to or above the feature in question.

Shoreline map 1 — Shoreline map showing course of skiff, shoreline buffer, and feature for examination.

Shoreline map 2 — Shoreline map showing charted location of islet and the actual location of islet determined by the skiff.

If the feature is not visually seen by the human eye or the single beam sonar on the skiff, it will be “disproved” and a picture and depth measurement will be taken of the “blank” location. If the feature IS seen, more data will be recorded (height of feature above the water, time of day observed, picture) to document its existence. This same verification procedure is used for newfound features that are not present on the old charts. All of this data is written on a paper copy of the chart and then back in the “dry lab”(computer lab), these hand-written notes are transferred to a digital copy of the chart.

Section of shoreline showing data and notes about specific features in question

Digitized version of notes and data taken at field site Note: Kelp buffer are the large shaded red areas and the smaller red circle is the actual position of the islet — Digitized version of notes and data taken at field site. The black box corresponds to the area from the previous picture above.
Note: Kelp buffers are the large shaded red areas and the smaller red circle is the actual position of the islet. The three southernmost rocks (marked by red asterisks) inside the black box were disproved.

On the two shoreline verification adventures I went on, many rocks and islets were disproved and several new features were found. Most of the new features were rocks, islets or large kelp beds. It is important to note that if scientists find a new feature which is a serious present navigational hazard (ex. Shipwreck, huge jutting rock or shoal far offshore) it will be marked a DTON (Danger to Navigation) and communicated to mariners within a short time frame. Other less significant features take 1-2 years to appear on updated nautical charts.

For some survey areas, the Rainier uses aircraft-acquired LiDAR (Light Detection And Ranging) to get an initial idea of various features and water depths of a shoreline area. (This is a service that is contracted out by NOAA.) LiDAR data is obtained by a plane flying over an area at 120 mph, emitting laser beams to the water below. Like SONAR, LiDAR measures the time it takes for the laser beam to return to its starting point. Using this measured time and the speed of light, the distance the light traveled can be obtained, using the equation distance = speed*time, accounting for the fact that it travels through air and then water. Because light travels much faster than sound, the plane can travel significantly faster than a boat and a large area can be surveyed faster. Unfortunately LiDAR can only be used in clear, calm water because light is easily reflected by various solids (silt in the water, floating wood), specific color wavelengths (ex. White foam on ocean surface) and absorbed by biological specimens for photosynthesis (ex. Surface bull kelp). LiDAR surveys do reduce the time hydrographers spend at a shoreline site thus increasing the safety and efficiency of an operation. As with any data acquisition method, it must be cross-checked by another method and in this case because of the obvious downsides, it is used as a guide to shoreline verification.

Map of island showing LIDAR data. — Map of island showing LiDAR data. The skiff does shoreline verification outside the orange line that outlines the island. Everything inside this orange island was surveyed by the LIDAR airplane. The three orange features circled in red on the southeast section of the island, need to be re-surveyed by the skiff. Different colors show various depths. (Green is more shallow than light blue.)

After spending several days “disproving” a lot of rocks and islets that were clearly not present in their identified location, we started to wonder why someone would have thought there was a specific feature there. One possibility is that it was just an ink blot on the original chart, made by accident (from a fountain pen), and then interpreted as a rock or islet in the process of digitizing the chart. It’s better to be safe than shipwrecked! Another possibility is that these features were “eyeballed” in their documented location, and thus were present but just in the wrong spot. Lastly because of limitations previously mentioned, LiDAR occasionally mis-reports features that are not present. Fortunately, our current survey methods use sophisticated navigational technology and several cross-checks to minimize data errors.

After shoreline verification has been completed, launches can survey the ocean floor (using SONAR) outside the boundary (NALL) that was established by the skiff. Each launch will be in charge of surveying specific polygons (labeled by letters and names). The picture above shows the polygon areas which are outlined in light orange (most are rectangles). I will talk more about SONAR and surveying on the launch in my next post. 🙂

Personal log:

I have been on the skiff two times now helping with the shoreline verification process. After the second time around and a chat with the XO Mike Gonsalves, my understanding of this process is more fine-tuned. It feels good to reach this point and it reminds me of the need to be patient, diligent and okay with the unknown when learning something new. I, like my students, often seek answers and a deep understanding of complex topics immediately and if this doesn’t happen I can get frustrated with myself. I have been more self-forgiving aboard the Rainier because I know I will be exposed to the same topic or process once again either in a different format or with a different set of crew members. I am also surrounded by a group of tolerant people who continually answer my questions with grace and peak my interest with new ideas. This repetition of content and supportive network is crucial for any learning environment, whether it be on a ship or in a classroom. Additionally, I have been given several small but important tasks which make me feel like a part of this group and complex operation. This empowerment inspires me to learn more and continue contributing. Building a successful classroom community is no different than what is going on here on the Rainier. All students need to have a stake in their learning and a purpose for coming to class each day.

One of my small tasks aboard the skiff during the shoreline verification was to take pictures of the various features (rocks, islets etc.) that needed to be examined. In some cases, it was important to photograph specific biological features that had an effect on navigation. For example, when rounding the SE side of Chernabura Island we came across a large Stellar Sea Lion rookery inhabiting a small rocky islet. The male proudly stood in the center, surrounded by about 50 females. As seen in the picture, this was a hefty male who easily weighed upwards of 1200 pounds. (Males can get as big as 2,500 pounds.) During the breeding season (June-August), the male will fast and often won’t leave his reproductive rookery site. His primary focus is to defend his territory and spread his genes! Even though male Stellar Sea Lions are polygamous, they do not force the females into a harem but rather control the boundaries around their physical territory where within, the females reside. The most successful rookery territories, not surprisingly are small rocky islands which can remain stable and productive for up to two months.

After researching about the Stellar Sea Lion, I learned that the western stock which resides in the Aleutian Islands is listed as an endangered species (since the 1970’s populations have declined by 70-80%). The cause for this is complex and has been attributed to a range of factors including: overfishing of sea lion prey (ex. Herring, Pollock), predation by Orca whales, shooting by fisherman, and disease. Interestingly, a few native Alaskan communities are still permitted to hunt Stellar Sea Lions for subsistence (survival) purposes.

Stellar Sea Lion Range Note, the two different stocks (Western and Eastern) — Stellar Sea Lion range

Fun factoid: The Stellar Sea Lion was named after the naturalist, George Wilhelm Stellar who first discovered the species in 1741 while part of Bering’s tragic voyage across the uncharted North Pacific.

July 15, 2013August 13, 2021

Avery Marvin: Ebbs and Flows and Puffins! July 11, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier
July 8 — 25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 11, 2013

Current Location: 54° 49.6 N, 159° 46.6 W

Weather data from bridge: 8.7°C, good visibility (6-8 miles), light and variable wind, overcast

View of Bird Island Cove from tide gauge installation point

Science and Technology Log:

Today, Rosalind and I were scientists in the field, helping the ship’s crew install tidal equipment in preparation for ocean floor survey work. This was a complex process, so we decided to walk you through it in a step-by-step question format.

What does a navigation chart show you?

The image below shows a chart of the area that we are in right now. Our first anchor point was off the north coast of Bird Island in a cove. On the chart, you can see many tiny numbers in the water areas, which represent various depths. These depths are measured in fathoms (1 fathom=6 feet). This depth information helps mariners stay in safe areas that are not too shallow. The charts also show known hazards such as sub-surface rocks and ship-wrecks. This chart clearly has a lot of white space, signifying many areas were never surveyed.

Shumagin survey area — Part of our survey area. Notice the white spaces around Bird and Chernabura Islands!

But wait, why are the depth numbers “fixed” on the charts? Doesn’t the water level change with the tides?

Yes! It sounds easy to say, “the water is 10 fathoms deep at this point”. However, water is subject to the gravitational pull of the moon and sun, resulting in various water levels or tides throughout the day. So the water will not always be “10 fathoms deep at this point.” For navigational purposes, the most hazardous water level is the lowest one, so nautical charts show the depth at the low tide water level. Depending on the location, some places have two high tides and two low tides per day (semi-diurnal) and some places have one high tide and one low tide per day (diurnal). Here in the Shumagin Islands we are on a semi-diurnal mixed tide schedule (meaning that the two highs and two lows are not the same height).

How do you measure the tides each day?

shumagin_tide_zone — Map of the Shumagin Island-Sand Point Tide Zones. Notice how the eastern Shumagin Islands are 6 minutes ahead of Sand Point.

There are permanent tide measuring stations all over the globe that provide information on how to “correct for” and figure out your local tide conditions. For our case, there is a tide station at Sand Point on Popof Island, which is west from our survey area. Our survey area is in two zones, one which is in the same zone as Sand Point and the other which is in a different zone. Therefore, we installed a tide gauge in the latter to verify that the tidal times and heights of this zone are accurately predicted by the Sand Point values. According to the current information, it says that in the different zone the tides should occur 6 minutes before the tides in Sand Point and to multiply the heights by 0.98.

A tide gauge is a pretty cool device that works by the laws of physics. It is installed (by divers) on the sea floor near a coast-line, in relatively deep water, so that it will always be covered with water. The tide gauge uses the water pressure above to determine the depth of the water column (density of water and gravity are the important factors in making this calculation). The tide gauge stays in place for at least 28 days (one full tidal cycle), after which there is a record of the water level throughout that time period (as we were gathering data), as well as a rough idea of the tidal cycle each month, ready for comparison to the Sand Point data.

How do you know if the tide gauge is working?

To verify that the tide gauge is working, humans (i.e.: Rosalind and I), take water level measurements (in an area close to the tide gauge) using a giant meter stick or “staff”. In our case, we recorded the average water level height every 6 minutes for 3 consecutive hours. This 3-hour data set can then be compared to the tide gauge data set for that same time period, and hopefully they will show similar trends.

Geiger_IMG_1279 (25) — Mike (XO) and Avery, taking water level data using the staff (big meter stick)

Tide staff — This is the tide staff we used to gather water level data for comparison to the tide gauge.

Map of the Shumagin Island-Sand Point Tide Zones. Notice how the eastern Shumagin Islands are 6 minutes ahead of Sand Point. — Graph showing the water height measurements from the tide staff and the tide gauge. Notice how they appear to be increasing at the same rate! That’s good.

What happens if the survey terrain changes over time? Will that affect the water depth?

The ocean floor is above a liquid mantle, so it is possible for there to be terrain changes and this would affect water depth measurements. Thus, as scientists, we must make sure the location of our survey area is “geologically stable”. To do this, we installed “benchmarks”. If you’ve ever been to the highest point on a mountain in the United States, you might have already seen something like this: they are bronze disks that mark important places, used by NOAA as well as other agencies. We stamped our benchmarks with the year and our station data, letter A-E (by hand! with a hammer and letter stamps!), and installed them at roughly 200-foot intervals along the coastline in what we hope is bedrock. Once they were cemented in place, we determined each benchmark’s relative height in relation to the staff using a survey instrument called an optical level – this process is also called “leveling.” At the end of the survey season, the ship will come back and re-level them. If the area is geologically stable, the benchmarks should all be at the same relative heights to one another as they were when they were initially installed. More so, the scientists will also be very pleased because their ocean depth measurements will be reliable going forward in time.

Cemented benchmark — A benchmark firmly cemented in place.

Avery cements her first benchmark :) — Avery next to her first cemented benchmark 🙂

Rosalind measuring distance between benchmarks — Rosalind measuring the distance between benchmarks

So what next?

Now that we have completed all necessary pre-survey measurements and research, we are ready to begin surveying the coastline and ocean floor. Happy Hydro!

Personal log

It’s a pretty cool feeling to know that you stepped foot on an island that hasn’t seen human visitors in 20+ years. It was also refreshing to get off the big boat and head to shore for some science fieldwork. I learned all about tide gauge and benchmark installation. I had several small but important tasks:

stamp each bronze benchmark with year and appropriate code using hammer and metal letter stamps
mix up cement batter and add to drilled rock hole and under benchmark disc to secure it in place for years to come (much harder than it looks because the cement was like “oobleck” and not very cooperative)
measure distance between each benchmark using extra long tape measure
take water level data using staff (big meter stick) in water every 6 minutes

Cool anemome I found! — Cool sea anemone I found!

In between tasks, I perused the tide pools for various critters. I saw a few new anemones and got a great shot of one with my new underwater camera. I absolutely love tide pooling and could spend most of the day doing it. I also enjoyed observing the puffins flying in and out of their cliff-side home. They tended to leave the cliff in packs probably to do some offshore fishing for herring and capelin. Upon return, presumably with a belly full of fish, some puffins would fly in large circles near their dwelling a few times before finally landing. This bewildered me. I thought, what a waste of energy! So I researched this and found out the following: Puffins are much better swimmers than flyers and have poor maneuverability while in the air. They sometimes are involved in mid-air collisions or crash landings into rocky slopes. Thus, they “size up” their landing a few times by circling near it before finally flying directly into their vertical burrow entrance.

Their body is mostly adapted for swimming, with short rigid wings helping them to “fly” underwater, to 30+ ft. depths! They have durable bones that endure pressure changes while diving and their body tissues store oxygen. They use anaerobic respiration for long dives. To waterproof their wings, puffins rub their bill on their oil gland several times and then smear this oil all over their feathers. How cool!

We are seeing a lot of Tufted Puffins out here in the Shumigans because it is breeding season (June-August), the time when they return from lonely open waters to rocky islands to mate and raise young. Puffins are monogamous, usually having one partner for many years. Interestingly, a female puffin only lays one egg, which is incubated for around 45 days! Both parents share incubation and feeding duties. Right on! The chick then stays in the nest for around 45 days until ready to fly. I love puffins! They are not only adorable but very well-adapted creatures.

Fun/sad factoid: Alaskan and Canadian natives made reversible parkas out of puffin skin. When it was rainy out, they wore the feathers on the outside and in cold dry weather, they wore the feathers on the inside. It took 45 puffins to make one parka!

July 11, 2013August 13, 2021

Avery Marvin: Discovering Ship Life En Route to the Shumagin Islands, July 9, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier
July 8–25, 2013

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 9, 2013

Current Location: 54° 49.6 N, 159° 46.6 W

Weather data from bridge: Broken clouds, no wind, 12° C

Orientation to Ship Life: NOAA Ship Rainier motto: “Teamwork, safety first.”

First view of the Rainier in the Kodiak Port — First view of the Rainier in the Kodiak port

Science and Technology Log

Greetings from the NOAA Ship Rainier! It has been a whirlwind two days since we departed from our docking station at the Coast Guard base in Kodiak, AK and Oregon seems a world away here in the remote Shumagin Islands. The trip over took roughly 32 hours and during this time we had the chance to see the many facets of ship life. The crew on board the Rainier have been incredibly welcoming, enthusiastically answering even the most basic questions (of which we Teachers at Sea have many), and have made both myself and the other Teacher at Sea onboard, Rosalind Echols, feel very comfortable.

In this blog post, I’d like to talk about getting acquainted with life on a ship. The Rainier is a complex operation, and each person on the ship wears many hats (which is very much like being a teacher) depending on what is happening on the ship each day. One person might man the bridge (front command center of the ship) in the morning, be part of the dive team in the afternoon, and at night, take the role of the on-call medical officer.

Our course leaving our docking point in Kodiak

Rosalind and I have both spent considerable time on the bridge in the last two days, watching the navigation process, from “threading the needle” between the red and green buoys in Woman’s Bay where our ship was docked to plotting out the course many hours ahead. We both noticed how important communication is in this process, specifically making sure that everyone is on the same page all the time. Thus there is specific ship language that is used and repeated for every activity. For example: when acknowledging a change of duty, everyone on the bridge responds with “Aye.”

Being a newcomer on a ship can be daunting. My first day on the ship, before we set sail, the only thing I could reliably find was my own stateroom (which has our bunkbed, or “rack”, and bathroom, or “head”). One of the many things the Rainier crew has done for us is to take us on a very thorough tour of the ship, showing us everything from the engine room to the flying bridge (the highest point on the ship outside of the mast, which offers a great view of what is going on). It is important to know how to get around in case of an emergency, so you can get to your assigned “muster” point quickly, and take an alternate route if necessary.

Avery in her "survival suit" — Avery in her “survival suit”

This actually came up not long after we got underway! In the spirit of safety, the whole ship regularly does emergency drills, so once we were in open water, we had a fire drill which was signaled by one loud long horn. Since we’re on a ship, this isn’t like a school fire drill where everyone leaves the building as fast as possible and waits for the experts to show up. The ship is a self-contained community and it is in everyone’s best interest to keep the ship afloat and functional. Therefore, when the fire drill sounds, everyone heads to their muster station, is checked in (to make sure you are not trapped in the fire!), and then either carries out or is assigned a fire fighting duty such as: attending to the injured, manning the fire hose, preparing to mop up the water, “de-smoking” the area etc. Shortly after the fire drill, we had an abandon ship drill, which again involved us meeting at a specific “muster” station. In this case, we were preparing to abandon ship, so we quickly slipped into our bulky, waterproof, self-inflating “immersion” or “survival” suits and then prepared to exit the ship. We didn’t actually exit the ship but envisioned such a next step. After the two drills, the crew met in the “galley” (eating area) for a debrief of the two drills led by the XO (Executive Officer) where we discussed what had gone well, what hadn’t and what we should improve upon for next time. It made me feel like I am in very good hands here on the Rainier. In the end, this complex ship operation relies on a dedicated crew who works and communicates well as a team, keeping safety as the number one priority.

Our Geographical Area

Survey area — Part of our survey area, around Bird and Chernabura Islands

While on board, we will be working primarily as part of the Survey Team, the people taking the hydrographic measurements. I will get into much more detail about how this all works once we delve into our first project, but for today, I want to focus on why this work is important and why we are in the Shumagin Islands specifically. When navigating, ships use charts, either electronic or paper, to plot a safe course through an area. In open ocean, you typically don’t have to worry about navigational hazards (rocks, shoals, ship wrecks), but as you get closer to land, these are more and more common, and ships need to be able to avoid them.

Approaching the Shumagins — The Rainier approaches the Shumagin Islands

If you look at a chart of the Shumagins, you can see that there is a lot of “white space”: empty areas with no depth soundings. Most often, we see a string of measurements in a straight line, fairly regular but also fairly sparse. Our CO (Commanding Officer) said that these were most likely done with a lead line, where someone literally took a lead weight on the end of string and dropped it down to the seafloor over the side of the ship, and measured how deep it was in that spot. While very accurate, it is hard to collect a lot of data about one entire area, and therefore there are many blank spaces.

In deciding where to survey, NOAA creates a priority list. You can find the complete list and list of factors on the Nautical Charts site, but our CO said it comes down to three main factors: age of the last survey, commerce in the area, and recent natural disasters (like Hurricane Sandy, for those of you on the East Coast: the shoreline and sea floor look very different now). As I said earlier, the Shumagins have very sparse data, and it’s old (the most recent survey in the area we are looking at was 1969, at best). Some of the measurements could be from when the Russians surveyed the area, 100+ years ago. Because the Shumagins are en route from Asia to some North American ports, updated nautical charts are vital for safe mariner travel.

Speaking of remote, the CO said that it might have been 20 years since someone set foot on one of the Shumigan islands. That seems incredible to me! Living in a big city, there are always people around. What about you? What’s the most remote place you’ve ever been? Leave me a comment below to let me know.

Personal Log:

Hi friends!

I have been on lots of boats in my life: canoes, kayaks, rowboats, sailboats, small fishing boats, large fishing boats, a live aboard scuba diving boat in Australia and I even was the sole operator of the Soundkeeper boat one summer in high school. My duties on this boat were unique and environmentally important for I was transferring sewage from large vessels to the hull of my small vessel and at the end of the day this sewage was transferred via a vacuum system to a large holding tank on land. It was both a smelly and fun job! Never though have I lived on a boat quite as large or complex as the Rainier. And it really isn’t that large (Length: 231 ft, breadth: 42 ft., draft: 14.3 ft) in comparison to freight-liners or huge Carnival cruise ships but what’s impressive is the use of space and it’s scientific capabilities. Hallways are narrow, ladders (stairs) are steep and storage space is maximized. Everything is bolted down to the ground or secured with a bungee cord, which is essential when the boat is in motion. Besides the normal rooms and amenities you would expect on a live-aboard, the Rainier has several labs, a bridge (front command center) with several hi-tech navigational aides, a technology room (with terabytes of storage), 4 launch boats, 2 skiffs (dingy type boat), 1 rescue boat, 3 cranes and a fancy hydraulic system that puts the launch boats in the water.

On the food side, there are two 24- hour coffee stations, a fully stocked ice cream freezer (dangerous!) and a big snack basket. The actual meals are pretty darn good and nutritious too. For example, tonight the menu was: stuffed bell peppers, cucumber salad, homemade minestrone soup, halibut, broccoli and coconut cream pie.

I write this post to you in the mess (eating area) as the boat is anchored in the cove of Bird Island which is one of the Shumigan Islands. I am quite happy we are anchored for many reasons:

1) I have trouble not bumping into things on a moving ship

2) Turns out I am prone to seasickness (Thankfully, anti-nausea pills prevent me from meeting the true Ralph.)

3) I can safely go to the bathroom without injuring myself.

4) I get to go on daily research excursions on the small boats.

5) I get to see many more adorable Puffins!

6) I get to wake up and see the rising sun glisten off the water.

It’s been a good few days so far. I am thrilled there is another Teacher at Sea onboard (Rosalind Echols) with whom I can directly relate and who shares many of the same questions and curiosities about this complex scientific operation as myself. I though, tend to ask more questions (both inane and profound) which in the end helps us both learn more. We are now getting into the interesting Hydrographic science so the next post will be quite informative and science-y.

Fun factoid: In the 1800’s, the Aleut people of the Aleutian Islands, covered the outside of their homemade sea kayaks with sea lion skin which is both flexible and water repellant.

Have any questions about life at sea or the research I’ll be doing? Leave me a comment below!

July 2, 2013August 13, 2021

Avery Marvin: Excited for this upcoming adventure! July 1, 2013

NOAA Teacher at Sea
Avery Marvin
(Almost) Onboard NOAA Ship Rainier
July 8–25, 2013

Mission: Hydrographic Survey
Geographical area of cruise: Shumagin Islands, Alaska
Date: July 1, 2013

Greetings from the Oregon Coast! Thank you for visiting my blog, and I hope you continue to follow me this summer throughout my 18-day Alaskan adventure aboard the NOAA ship Rainier. I am elated and honored to be a NOAA Teacher at Sea—an experience that will undoubtedly shape me and my classroom instruction for years to come.

My name is Avery Marvin and I am a middle school General Science and high school Biology teacher at Taft 7-12, a mid-size public MS/HS in Lincoln City, on the Oregon coast. I moved here just one year ago, and have been discovering the unique facets of living and teaching in a coastal community ever since. I continue to be amazed and inspired by the natural surroundings and marine resources (i.e. the NOAA base in Newport, Hatfield Marine Science Center) at my fingertips. Knowing I am New York native, many of my students have quizzically asked me, “Ms. Marvin, why did you move here?” My hope, then, is that through this NOAA experience, I will be further able to inspire and show kids that “here” is a pretty amazing place to be—not just in terms of its natural beauty but its ecological and research significance moreover. With this awareness and education, students hopefully will feel a greater sense of ownership of—and thus appreciate and actively protect—the greatest resource in their very backyard: the ocean.

Diving in Tasmania — Avery dives in the chilly waters of Tasmania, Australia

As an avid adventurer and ocean-goer, I have explored many waters both as a conservationist and a recreationist (i.e. scuba diver, fisherwoman). Yet Alaska is a place I have dreamed of visiting for most of my life, and to be able to combine my experience with like-minded scientists conducting vital ocean research is truly awesome to me. The Rainier, homeported at the NOAA Marine Operations Center – Pacific in Newport, Oregon, is a hydrographic surveying ship whose primary focus is mapping the sea floor in coastal areas. The depth data collected on the Rainier is used to update nautical charts. This is crucial work as commercial shippers, passenger vessels and fishing fleets rely on accurate nautical maps to safely traverse various ocean passages. In the case of Rainier’s work in Alaska, some of the terrain is being surveyed for the first time. Rear Adm Gerd Glang, director of Coast Survey, sums it up best, “Simply put, we have better maps of the moon than of our oceans.” Several multi-beam sonar systems located on the Rainier as well as on a few smaller launch boats are employed to acquire this mapping data. This six-minute video gives a good overview of the mission and daily operations of the Rainier.

My 18-day journey begins on July 8, 2013 in Kodiak, Alaska, where I will be meeting up with the Rainier. From Kodiak, we travel southwest to the Shumagin Islands, where the majority of the research on this leg of the trip will be conducted. We will then conclude our journey back in the Kodiak port. (Track Rainier’s movement here.) I can’t wait to dive in and absorb all that I can. I am particularly looking forward to working with and learning from all the scientists onboard, seeing the majestic Alaskan landscape and understanding how survey data can be used for mapping vital fisheries habitats.

I hope you will ‘virtually’ join me aboard the Rainier, this summer, and be a witness to some incredible scientific research. This blog will be updated weekly with interesting stories, pictures and lots of newfound information about our mission at sea. So check back often and feel free to leave comments and questions for me. If I don’t know the answer, I will ask a brilliant scientist to help me.

“For most of history, man has had to fight nature to survive; in this century he is beginning to realize that, in order to survive, he must protect it.” -Jacques-Yves-Cousteau