Weather Data
WX Cloudy, fog
Wind NW 20 kts
Sea 6ft
Temp 50’s
The Shumagin Islands’ spectacular scenery
Science and Technology
For the past 30 hours the FAIRWEATHER has been on route back to port. We had beautiful weather most of the way back, which made it perfect for whale watching. Yesterday evening, many of the crew made their way out to the ship’s bow to watch at least 8-10 humpback whales swimming around the ship. It seemed like everywhere you looked, you saw another whale spout. It was quite exciting, as we all were snapping pictures trying to get the perfect shot. Unfortunately, they were just a little too far away. Later in the evening, the ship stopped to let some of the crew (those with valid fishing licenses) get a chance to do a little fishing. Several had good luck in catching halibut, before the ship had to continue on the voyage back to port. The FAIRWEATHER arrived back at port today at 11:00am. This gives the officers and crew time to prepare for tomorrow’s Fleet Inspection.
FAIRWEATHER Profile: Able Seaman Emily Evans
More spectacular scenery.
Emily works in the Deck Department where she is responsible for a variety of duties. She is in charge of cleaning and general maintenance of the ship as well as operates cranes, stands bridge and anchor watch, and pilots the small boats (she drove the survey launch I was on). Not a position you might expect from someone with a B.S. degree in Physics!
Emily grew up in New York, close to Lake Ontario, and raced sailboats competitively. After college, Emily soon realized she wanted to get back to what she loved doing – sailing. She spent the next five years working on sailboats, primarily teaching environmental science classes aboard educational vessels and sailing skills. But she wanted to work with serious boat people. After discounted shipping out commercially, feeling it wouldn’t be stimulating enough, she looked into NOAA. It became a perfect fit!
Able Seaman Emily Evans is relaxing in the ship’s mess hall.
Working for NOAA has everything Emily was looking for – a serious, science oriented experience that has a lot of variety and opportunities. She actually heard about NOAA through her older brother, Ben. Ben happens to be the Field Operations Officer on the RAINIER. So it is very comforting to know she has family close by. Emily loves being on the water and driving the small boats. She feels very fortunate to be able to see parts of the country like Alaska that very few people get a chance to see. For now, she is just savoring her time aboard ship. She is studying to get certified for the survey department which will provide many more opportunities for her in the future.
Personal Log
I’ve had a wonderful ten days in Alaska! I want to thank everyone at NOAA and especially the officers and crew of the FAIRWEATHER for allowing me to join them for this leg of their hydrography season. The knowledge I’ve gained from this experience will be shared with my students for years to come!
The NOAA Ship FAIRWEATHER off the coast of the Shumagin Islands.
NOAA Teacher at Sea
Heather Diaz
Onboard NOAA Ship David Starr Jordan July 6 – 15, 2006
Mission: Juvenile Shark Abundance Survey Geographical Area: U.S. West Coast Date: July 12, 2006
Science and Technology Log
There was no swordfish, set done last night because of our excursion to Catalina Island. Instead, we set our first line (shark line) at 6am. We hauled in the line around 10am. We caught 10 makos, 4 blues, 1 lancetfish, 3 pelagic rays, and 2 molas. I had the opportunity to videotape the entire haul, which turned out to be one of our most productive. 1 mako died today during the haul because it had swallowed the hook and most likely suffered an internal injury. He was measured, weighed, and dissected for further research. One of the makos we caught during this set was among the largest three we caught during this entire leg, and it was really interesting to see such a large shark, so close! We set our second line at around 12 noon. We hauled it in around 4pm. We caught 7 makos and 2 blues. Two of the makos we caught during this set were among the largest three we caught during this entire leg.
This Mako shark didn’t survive being on the longline. The coloring of the shark is truly beautiful, and their skin is very smooth in one direction, and like sandpaper in the other. If you look closely, you can see little spots on his nose, which are actually part of his hunting and defense mechanism, and he is able to “detect” things in the water from a long way. Makos don’t have a protective “eyelid”, unlike Blue sharks. Karina and João have helped to preserve the jaw, and I cannot wait to show it to my students!
Personal Log
With our first set, things started off right off the bat with several makos. Then, we got 2 humongous Sunfish (mola-mola)…and I mean they were huge! Then, we got a huge mako. He was almost 2 meters long. It was as long as the cradle itself! I couldn’t believe it. Everyone was super excited and at that point. During the whole commotion, one mako was pulled over the side nearly dead.
We also had a lancet-fish which they hauled over the side while we were dealing with the monster mako in the cradle….and that was very much alive. It was flipping all over the place. Sean picked him up, took the hook out, and tossed it overboard. After we were all done and all the animals had been processed, we went over to look at the mako that they had brought on deck. Although the mako was near death, it appeared to be still breathing a little, though it might have been a lingering reflex reaction. After examining him on the deck, they weighed him and then started to dissect him. I have most of the dissection on tape. It was very interesting to see where all the internal organs are located and to see how their muscle tissue is designed. Dr. Heidi Dewar explained how they use their muscle tissue design to actually preserve body heat. It was really fascinating. I am excited to show my students her “lecture” on the muscles, and to share with them the dissection video, so that they can see what a shark looks like on the inside. I think they will enjoy it.
During the second set, I was allowed to get down on the platform with the first two sharks…the first one, Dr. Suzy Kohin, Chief Scientist just explained everything. The second one, I was able to get in there and actually do the stuff! I collected the DNA sample of his dorsal fin…I put the tag in his dorsal fin…and, I gave him a shot of OTC in the ventral area. I also got to take its length measurement, which was freaky because I had to grab its tail and pull it straight. I don’t think the shark appreciated that much, and he squirmed a bit. He was also bleeding. Dr. Suzy Kohin, the Chief Scientist, said that he was bleeding a bit because he had swallowed the hook. I opted not to do the spaghetti tag (which involves shoving this metal tip into their skin) and I opted not to cut the hook out of its mouth,.…it just seemed really, really, really REAL…and I didn’t want to mess up and come out of it missing a hand or something…or worse, having unintentionally hurt the animal.
Anyhow, I gave my kneepads over to Daniele who jumped in and finished the haul for me on the platform while I did the gangions. Which, turned out to be too bad, since we got some really huge makos on this haul…everyone was very excited about them. I think the largest was about 197cm. They put special tags in the really large makos, which they called a PAT (Pop-Up Archival Tag). They explained that these tags, which look more like turkey basters, are used to report data on temperature, depth, and even longitude so that they can better track the makos and learn more about their behaviors. They are especially looking for information about diving behaviors and their temperature and depth preferences. I would love to see what they find out from these fish!
They also use a SPOT (Smart POsition and Temperature) tag. This is almost translucent and is bolted the dorsal fin (only on larger sharks). It looks a little like a computer mouse and is oval shaped. This tag sends radio signals to a satellite whenever the animal is near the surface, and they can use this information to track precisely where the animal is in the ocean.
NOAA Teacher at Sea
Dena Deck
Onboard NOAA Ship Hi’ialakai June 26 – July 30, 2006
Mission: Ecosystem Survey Geographical Area: Central Pacific Ocean, Hawaii Date: July 12, 2006
Integrating backscatter with bathymetry, showing the seafloor in rich detail
Science and Technology Log
When soldiers from Napoleon’s army found the Rosetta Stone, it was a breakthrough discovery. Carved in ancient Egypt, it contained pieces of a message in known languages and also a language that had been dead for centuries. Without any link to other known languages, historians had been unable to decipher this language until the stone was found, which provided the necessary clues to translate it. Modern day ocean mappers are looking for their own Rosetta Stone that will allow them to link backscatter data to other ecological information.
A backscatter map, indicating substrate characteristics. Dark areas represent a harder seafloor, while lighter areas are indicative of a soft, sandy bottom.
Our ship, the NOAA ship Hi`ialakai, has a set of three sonars that, when used in conjunction, can provide accurate data about the seafloor. When emitted by a sonar, a “ping” comes back bringing two pieces of information with it: travel time and strength. The two-way travel time (the time it took from emission, bouncing off the seafloor and return back to the ship), coupled with the measured velocity of sound in the specific water location where the ship is traveling in, gives mappers a bathymetric view of the seafloor, revealing the depth of each of its points. (See “Painting the Seafloor” article.)
A second piece of data obtained from each ping is the strength of the signal. When sound hits a surface, above water or below, some of it is absorbed and the rest bounces back in what we experience as an echo. The strength of this echo depends on the hardness of the material that the sound is bouncing from. This is a very convenient fact of nature that is used when mapping to compliment the bathymetric map that provides the depth. The acoustic hardness of a substrate, or ocean bottom, affects the strength of the ping coming back to the sonar. In a real sense, the loudness of the echo changes if it is bouncing off sand or rock. Sand, being soft and full of small holes in between grains, will absorb quite a bit of sound. A more solid surface like a rock will provide a bigger echo for each ping that hits it.
A diver armed with a camera is towed from a boat, obtaining many pictures that will be used to groundtruth mapping data.
This strength of the signal coming back is called “backscatter” and provides mappers with a second view of the seafloor. While bathymetry is a measure of the depth, backscatter gives us a clue about the nature of the seafloor being mapped. Since coral reefs, with their calcium carbonate, provide a much harder surface than a sandy sea bottom, the two will appear differently in the backscatter map. Values of intensity range from low intensity, showing up as white and representing soft, sandy bottom, to high intensity, represented as dark areas for harder substrate in the backscatter gray scale map.
When the backscatter map shows up binary data – white and black – it is easy to infer on the type of substrate being mapped. The challenge is presented with all of the gray areas in the map. Does light gray represent coarse sand? Is dark gray indicative of sand over rocks, or thousands of coral polyps? Or maybe just rock covered by sand? Every shade of gray has a value that can indicate a type of substrate.
Mapping
Backscatter alone cannot give you these answers. With so many variables present in the mapping process, data needs to go through a “ground-truthing” process, or compared to visual observations of the sites. To do this, researchers collect video, photographs and perform actual dive observations of many of the sites that are mapped. These video and images need to be analyzed by a person. It’s a tedious process that cannot be automated – it requires having a person able to classify types of substrate from watching hour after hour of video data or many photographs. And all of these data needs to be “geo-rectified,” or coupled with GIS information to know exactly where each video segment and photograph was taken. Sometimes the payoff for “groundtruthing” backscatter is unexpected: wrecks or rich coral beds can be discovered.
We do not have yet a backscatter “signature” for each type of substrate, or sea bottom, yet. This would be the Rosetta Stone of mapping, a development which will allow mappers to correctly identify some of the ecological characteristics of each area mapped. For instance, mappers are working towards refining their backscatter analysis to allow them to tell apart live coral from bleached ones.
The NOAA Coral Reef Conservation Program has built a pilot data set from the French Frigate Shoals, consisting of large amounts of video footage, observations, and other data. They are in the process of compiling all of this information with their backscatter maps they have for the area, and study how they relate, trying to find meaning to each gray area in these maps.
When mapping, additional and unexpected discoveries can take place. Sometimes what we think of as featureless terrains are revealed to have rich topographies. In 2004, an ocean area off the island of Oahu in Hawai`i, thought to be featureless and plain, was discovered to have sand dunes and ridges, providing important habitat to the marine fauna. Interpretation of backscatter data has improved in quality over the years, and when combined with videos and photographs, remote characterization of sea floor habitats becomes possible.
Weather Data
WX Cloudy, fog
Wind NW 25kts
Sea 8ft
Temps 50’s
The Ambar boat leaves the FAIRWEATHER for the shore.
Science and Technology
Today was the last full day of hydrography before heading back to port. The ship planned to take full advantage of the time. Starting off at 8:15, the small Ambar boat aboard the FAIRWEATHER was launched. The Ambar is about 20 feet long with a shallow reinforced hull to make it ideal for getting even closer to shore than the survey launches. The Ambar’s mission is to check for hazards close to shore that were previously detected. While the Ambar is out working the coastline, the FAIRWEATHER continued surveying in the deeper water, making it a very productive day.
The Ambar boat heads out to see if certain hazards detected by LIDAR were accurate. Several days ago, the FAIRWEATHER welcomed aboard a senior hydrographic surveyor, James Guilford, from the Tenix LADS Company. He was here to support his product – LIDAR. NOAA works with several independent companies that uses a different hydrographic technology called LIDAR. LIDAR is a laser that is used from planes rather than boats. These planes generally fly at between 1,200 and 2,300 feet along mainly coastline, to survey those difficult areas that are hard to reach by boat. The LIDAR can generally reach water depths of 20-25 feet and can be used 24 hours a day. The only drawback is that the LIDAR has trouble penetrating the water surface when there are obstructions like heavy kelp areas or whitewater. However, between data collect from the boats and planes, NOAA can create a very complete survey of an area.
Commander Beaver stands next to a coast guard rescue helicopter at their base in Kodiak, Alaska.
Personal Log
I have been amazed at how smoothly the ship operates 24 hours a day. It can be a bit overwhelming watching the crew head to their posts and rotating through the mess hall throughout the day. At first, I found life at sea a bit of an adjustment, but then you fall into a routine and it becomes easier. As a visitor to the ship, it can be a bit hard because you have no set role. Those crew members new to the ship that have a specific job seem to quickly adjust. I don’t know if I would ever make a very good sailor, but it is fun to get a little taste of what it is like at sea.
FAIRWEATHER Profile: Commander Andrew Beaver
The FAIRWEATHER recently underwent a change of command. Commander Andrew Beaver officially took command in June of 2006. The FAIRWEATHER is fortunate to have been assigned such an experienced commander. However, you would never have expected it based on his upbringing. Commander Beaver was born and raised on a 180 acre farm in Iowa, where his family raised corn, soybeans, and pigs. In fact, he could easily have followed his father’s footsteps and become a farmer. However, he went on to Iowa State where he graduated from Agriculture Engineering. After graduating, jobs were not readily available, so Commander Beaver pursued the NOAA corps. It provided many unique opportunities and he took to life on a ship right away.
Before joining the FAIRWEATHER, Commander Beaver was assigned to a variety of posts including service with the NOAA Diving Program office, Navigation, Field Operations and Executive officer of the WHITING, and also Commander of the NOAA ship RUDE. Commander Beaver and his family are delighted to be here in Alaska. Everyone is very nice and his home port in Ketchikan even reminds him of the small towns in Iowa where he grew up. His family loves the beauty and wildlife of Alaska. He feels it’s a wonderful place to bring up a family.
He is enjoying the new challenges of his new job and getting to know the ship’s crew. The surveying has been different because the coastline is more sheer in Alaska, whereas on the east coast it tends to be more gradual. He loves the fact that there is a lot less boat traffic on the water and that the remoteness of his survey work forces the ship to be more self-sufficient.
NOAA provides employees a variety of opportunities. Commander Beaver always enjoyed knowing that every 3-4 years he can move on and try something different. He would encourage any student interested in the math and sciences to look into employment opportunities like those found with NOAA. NOAA allows you to “make a difference in the world” and you would be “doing something that your parents and grandparents would be proud of”!
NOAA Teacher at Sea
Dena Deck
Onboard NOAA Ship Hi’ialakai June 26 – July 30, 2006
Mission: Ecosystem Survey Geographical Area: Central Pacific Ocean, Hawaii Date: July 2, 2006
A NOAA ship using the sonar system.
Science and Technology Log
The first part in appreciating what we have is to know exactly what we have to begin with. Biologists conduct species census in both terrestrial and marine environments, and spend a great deal of time studying each species. But to gain a fuller understanding of an ecosystem, it is also necessary to know the physical characteristics of the environment that provides the foundation for these ecosystems. This is one of the main reasons why we map the seafloor.
The primary goal, as far as mapping is concerned, is to have 100% of all shallow coral reefs mapped. The group mapping the Northwestern Hawaiian Islands is a large team comprised of staff from NOAA Fisheries Coral Reef Ecosystem Division, and the University of Hawai`i. They have an exemplary set of tools at their disposal to do their work. Aboard the NOAA shipHi`ialakai, they employ two sonar systems. Used in conjunction, these sonar systems are slowly giving us a detailed account of the submerged geological features that make up the Hawaiian archipelago.
A bathymetry map showing a 15-meter drop off from several angles. Colors indicate relative depth
The primary objective of this mission is to produce benthic (sea bottom) habitat mapping of Kure and Pearl & Hermes Atolls. We are filling in a doughnut-shaped gap on both Kure and Pearl & Hermes Atolls, finishing a painting of the seafloor that started several expeditions ago. Coral reefs around the world are receiving increased attention because of the many threats that they face (coastal development, overfishing, climate change), and the U.S. Coral Reef Task Force has produced a number of goals and mandates relating to these ecosystems in America. Among these goals is a call for better management of these resources, and to learn more about them. Mapping all U.S. coral reefs puts Hawai`i at the center stage of this effort with its large chain of islands and atolls stretching across vast distances and volcanic islands found at every stage of geological development, from birth to eventual demise.
The research vessel operating in Kure atoll.
The two sonars that we have aboard the ship perform the same task, but each is best suited to work in different conditions. That is because they employ different frequencies which have different rates of penetration. Let’s go back to the analogy of painting a wall. If you have a large wall to paint, you can use a broad brush (or even better, a roller), to cover large areas at every stroke. But within this wall you also have edges that need to be painted more carefully. Let’s say there is a light switch placed in the middle of the wall. Using a painting roller will invariably leave white spaces in between (either that, or you end up also painting the light switch!). So for this light switch, you would use a smaller brush, allowing you to carefully get close to it, eventually covering the entire surface of the wall without painting over it. In this analogy, each light switch in the wall represents an atoll of the archipelago.When a ship maps the ocean floor, it needs to slowly cover swath areas under it. The process is very much like painting a wall with a brush. A wall cannot be painted all at once, of course. The painting is accomplished one stroke at a time, where each passing of the brush needs to slightly overlap the previous one, as to not leave any white spaces in between. When mapping the seafloor, the ship, with its sonar as a giant brush, needs to carefully cover every bit of seafloor surface, as to not leave any area between passes, or swaths, blank and unmapped.
A completed bathymetry map superimposed with satellite imagery of Kure atoll. Red indicates lowest depth, and blue deepest. White indicates exposed reef ring.
I am going to use the example of sunlight traveling through water to illustrate the way that the ship’s sonar works, both light and sound are waves. Sunlight has many frequencies, frequencies that readily break out into all colors by raindrops or a prism. Red color has the highest frequency and, much like the 3002 kHz sonar, is the first absorbed by water. The color red is the first one to disappear underwater. Take anything cherry-colored down a few meters of water, and it will quickly loose all its brilliance, turning into a dull-looking color, an effect that is magnified with the scarcity of light at nighttime. Fish also know this very well. Many fish which are active at night tend to have a red color. Soldierfish, with their large eyes and flame-red color, are perfectly suited for the night environment.Painting over a light switch would mean running the ship into the reef! So mappers have a set of “ paint brushes” in the form of three sonars that allow them to carefully map each area. There is one low-frequency sonar (using a 300 Kilohertz (kHz) frequency) that has a long wavelength that can map between 100 meters (about 328 feet) and 4,000 meters (about 13,421 feet) – this is the ship’s big roller. There is another, high-frequency sonar (using a frequency of 3002 kHz) that can map when the seafloor is less than 100 meters (about 300 feet) from the surface – this is like a mid-sized brush. There is a third sonar, mounted on a smaller, 25-foot research vessel Ahi (which stands for Acoustic Habitat Investigator), with a sonar working at an even higher frequency, which can get really close to the reef – up to places which are 10 meters in depth (quite shallow, at 30 feet). This little boat is like the small brush used to cover areas right at the edge of what needs to be mapped.
Blue, at the other end of the visible light spectrum, has a low frequency. Its large wavelength is the last one to be absorbed by particles in the water, and penetrates deep in the ocean. If you are able to go down deep enough, say 100 meters (328 feet), all around you will look blue. I once went on a submarine ride with my sister, and when we reached 45 meters (150 feet) in depth, the entire inside of the submarine was bathed by blue light. I took her picture and, with no camera tricks, it showed how everything had acquired a sapphire hue (see picture).
When the pings return back to the ship from their very quick trip to the ocean floor, the sonar measures (or “listens”) to how long it takes for them to return, and how strong their signals are. To do this accurately, there are over 100 arrays of receivers in the sonar on the bottom of the ship, each carefully calibrated to listen carefully to each echo of a new ping. The pings coming back carry with them two bits of important information: how long they take (known as the “Two-Way Travel Time”) and the strength of the signal. The time it takes for the ping to return depends on how far it needs to travel (of course!) and how fast sound is traveling in the water.Now, how exactly does sonar work? The sonar unit emits sound, actually given the descriptive term of “ping.” This ping can be at either the low or high frequency described above. After the ping is emitted the sonar unit “listens” for it to come back. Sonar, therefore, has two essential components: the first one that emits the ping, and the second one that listens for it coming back from the seafloor. This is because when sound hits a surface, some of it is absorbed while the rest bounces back. (If you have many large walls around you, you can hear almost all of your sound coming back at you, this is the echo you hear.) The denser, and flatter the surface, the more of the sound that bounces back.
Adding a bit of complexity to this process, the speed of sound is not immutable like the speed of light. In water, it depends on the temperature of the water, its salinity, and depth (all of them affecting the density of water), so careful and constant measurements need to be taken regularly. A large array of devices, collectively known as CTD, are routinely lowered from the main ship into the water. Armed with this information, and by carefully measuring the time it took for the ping to complete its travel, we can know how far each ping had to go. If you do this many times over, you have something called “bathymetry,” a picture of the seafloor.
Putting together shallow and deep water mapping, we soon end up with a seafloor that has been completely painted, full of colors representing depths. An accurate map is essential as a base layer upon which other information can be overlaid, such as bottom cover type – coral, rocks, sand, etc. Mapping, combined with bottom characterization allows us to monitor long-term trends and changes in the marine habitat. This long-term observation is an essential tool for management of the resources. It can serve as one of the indicators for the effectiveness of the conservation efforts, allowing us to make “sound” management decisions.
