NOAA Teacher at Sea: Tammy Orilio NOAA Ship Oscar Dyson Mission: Pollock Survey Geographical Area of Cruise: Gulf of Alaska Date: 25 June 2011
Weather Data from the Bridge:
Latitude: 54.91
Longitude: -161.27
Wind Speed: 13.80 knots
Surface Water Temp: 7.9 degrees C
Water Depth: 113.78 m
Air Temp: 8.3 degrees C
Relative Humidity: 97%
Personal Log:
Unfortunately, it’s been another day of no fishing for me đ My shift just ended, and we’ve only seen small, scattered groups of fish on the acoustic displays today- not enough to put the nets into the water. Yesterday was nearly the same as today, but we did do a plankton trawl to sample the krill in the water. I’ll write more about that in another post.
From what I’ve heard from other Teachers at Sea, I expected to be working in the fish lab pretty much the entire duration of my 12 hour shift. Unfortunately, this hasn’t been the case! But, there’s not much I can do if there are only a scattering of fish in an area. Even the scientists are saying that they’re surprised by the lack of fish on this leg of the survey. I still have another 5 days or so (depending on when we start heading back to port, and if we’re working on the way there, or just straight sailing), so hopefully I’ll see some more action over the last few days of the trip. However, I know that we can’t control whether the fish are here or not- it’s all part of the science process!
The science team will be disembarking on Thursday June 30 and heading home, but the trip is definitely not over for the rest of the crew and NOAA officers. Another group of scientists and two more Teachers at Sea will be boarding the ship, and then they’ll set sail for another 3 weeks, doing the same thing we’ve been doing, just in a different part of the Gulf of Alaska. Then, the original group of scientists (that are on board now) and two more teachers will come back for the last leg of the trip. This method of switching people every few weeks is advantageous so that no one gets too run down or antsy to get off the ship. However, most of the deck crew, engineers, and NOAA officers stay onboard for all 3 legs of the trip- I don’t know if I could do that! I’ve been on board for 2 weeks now, and I’m doing fine, but I couldn’t imagine being on here for 9 or 10 weeks!
Lastly, here are a few photos of the area we’ve been in the last two days. Looking at our digital map, we’ve got nothing to look at but open water for the next 10 hours or so, but we’re moving into an area filled with lots of little islands in the next day, so I’m sure I’ll get some photos!
I can see Russia from my house!! (kidding, of course)
NOAA Teacher at Sea: Margaret Stephens NOAA Ship: Pisces Mission: Fisheries, bathymetric data collection for habitat mapping Geographical Area of Cruise: SE United States continental shelf waters from Cape Hatteras, NC to St. Lucie Inlet, FL Dates of log: Thursday, 19 May through Saturday, 21 May, 2011
Here I am with the CTD equipment
Weather Data from the Bridge
Position: Latitude 27.87, Longitude -80.16
Wind Speed 11.06 kts
Wind Direction. 131.46 Âș
Surface Water Temperature 26.88 ÂșC
Surface Water Temperature
Air Temperature 27.10 ÂșC
Relative Humidity 78.00 %
Barometric Pressure 1015.50 mb
Water Depth 28.05 m
Sky conditions: clear
Science and Technology Log
General Description of the Scientific Work Aboard Pisces
While at sea, the shipâs operations and scientific crews work in shifts 24/7 â yes, thatâs twenty-four hours, every day, with ship operations, maintenance, data collection and gear deployment continuing day and night.
The scientific team, headed by Chief Scientist, Dr. Nate Bacheler, includes researchers who are mostly marine biologists specializing in fisheries. Each team member has complementary specialized skills such as acoustics (use of sonar for sea floor mapping), physical or chemical oceanography, underwater video camera operations, data management and analysis, and many aspects of fish biology.
The main mission of this research cruise is to study red snapper and related grouper species, fish that are of great importance economically and to the marine ecosystem in near shore areas off the southeastern coast of the United States. In particular, the team is studying where the fish are likely to be found (their spatial distribution patterns) and their numbers, or abundance, and population dynamics (how the populations change over time).
This work expands the knowledge needed to guide decisions about how to protect and manage fisheries in a sustainable manner. Healthy, sustainable fish populations are essential to the economy, to the function of healthy ecosystems, and as high-protein (and tasty) food sources. In the past, many fish species have been overfished, resulting in dangerous declines in their populations.
The scientific work on board Pisces for this project is divided into three main areas. This log entry gives an overview of each of the three main areas of work, with a more detailed account of the acoustics, or mapping portion. Upcoming logs will describe the other phases in more detail.
Acoustics â Using the science of sound with advanced sonar and computer technology, the acoustics team maps the sea floor and identifies areas likely to be good fish habitat.
Fish survey â The survey team sets baited traps to catch fish, then collects them, identifies the species, and records essential data about the species of most interest.
Underwater videography â The video team attaches cameras to the traps to view the kinds and activities of fish in the water and assess the type of sea bottom, such as sandy or hard, flat or âbumpyâ, regular or irregular.
After all this information is collected in the field, much of the painstaking, detailed analysis takes place back in the home labs and offices of the researchers.
Acoustics Work
Since acoustics is the first step used to identify specific sites to set traps for the fish survey, weâll start here.
Throughout a long night shift, from 6 p.m. until the work is complete, often 7 a.m. or later the following day, the acoustics team uses sonar (SOund NAvigation and Ranging) and computer analysis to map the sea floor and identify promising areas to set traps for the fish survey. See a detailed description of the sonar equipment and procedures below.
Investigator Jennifer Weaver showing GIS model of sea floor contours
At 5 a.m., the acoustics team meets with Chief Scientist Nate to report any sites they identified overnight and select the stations to sample with fish traps and underwater cameras during the day. The team then converts their data into a kind of route map that the helmsman (the shipâs âdriverâ) uses to steer the ship along the designated survey route.
The acoustics team members possess extensive knowledge about fish habitats, geography and geology of the sea floor, and computer and sonar technology. They also need to be aware of the interactions among wind, weather and currents and understand charts (marine maps) and shipâs navigation. They constantly communicate with the shipâs bridge via the internal radio network.
Fish survey team prepares baited traps at dawn
The acoustics lab houses work space large enough for five to ten people, banks of computer screens, servers, and large-scale display monitors projecting images from the sonar devices, real time navigation, and views from cameras positioned in work areas on deck.
Once the now-very-sleepy acoustics lab team wraps up its nocturnal work, the team members turn in for a dayâs (or nightâs?) sleep, just as the other teamsâ daylight tasks begin in earnest.
Fish Survey Work
By 6 a.m., in the predawn darkness, the rear deck becomes a hub of concentrated activity, with sounds muffled by the early ocean haze and drone of the engines and generators. The four or more members of the fish survey team, still rubbing sleep from their eyes, assemble on the stern deck (rear of ship or fantail) to prepare the traps to catch fish for the day. Before the sun rises, floodlights illuminate the work of cutting and hanging menhaden, whole fish bait, in the traps, securing the underwater cameras in place, tagging each piece of equipment carefully and checking that everything is ready for deployment.
Chief Scientist Nate Bacheler directs trap deployment from the dry lab
Chief Scientist Nate directs the deployment of the traps from the dry lab, where he faces a bank of computer screens displaying maps of the identified sampling route, the shipâs course in real time, and camera shots showing the personnel and operations on deck. By radio, Nate directs the deck crew to lower the traps at each of the designated sites.
The ship is steered along the sampling route, dropping traps in each of six locations. Each trap is left in place for approximately ninety (90) minutes. Once the last trap is lowered, the ship returns to the first location and raises the traps, usually following the same order. The deck crew members, together with the fish survey team, empty any catch and ready the traps for redeployment.
Chief Scientist Nate Bacheler directs trap deployment from the dry lab
Then the fish survey team, coordinated by Investigator Dave Berrane, sets to work sorting, weighing and measuring any catch and immediately releasing any fish not needed for further study.
Investigator Christina Schobernd views underwater video with Chief Scientist Nate Bacheler
Videography Work
As soon as the traps are hauled aboard by the deck crew, the wet lab team detaches and dries the cameras and hands them to the dry lab, where the videography team, headed by Investigator Christina Schobernd, removes the memory cards and transfers and makes duplicates of the video files on computer drives. All the teams take extreme care to label, catalog and back up everything carefully. Data management and redundancy are essential in this business. The scientists view some of the footage immediately to see if the cameras are working properly and to make any adjustments necessary. They also look for anything unusual or unexpected, any fish captured on camera other than those that made it into the trap, and they assess how closely the sea floor type matched what was expected from the acoustic teamâs mapping work.
Christina works well into the night to back up and catalog all the dayâs video recordings.
Detailed Description of Fisheries Acoustics Surveys
Multibeam sonar mapping the seafloor. Image courtesy of Jill Heinerth, Bermuda: Search for Deep Water Caves 2009.
Fisheries Acoustic Surveys: Acoustic surveys help determine the relative abundance of target species and provide information to determine catch rates and guidance for fisheries management.
The equipment aboard Pisces includes two types of sonar devices that use sound waves to measure the water depth, shape or contours of the sea floor, and to a limited extent, fish groupings, or aggregations. Sonar operates using established knowledge about how fast sound travels in water under different conditions to develop a three-dimensional image of the shape of the sea floor. The first type is known as split-beam sonar, which uses sound waves at different frequencies to provide a picture of the underwater environment. Pisces has a Simrad EK60 echosounder.
The second, more sophisticated and expensive system involves Multibeam sonar mapping. Aboard Pisces is a Simrad ME70 device. Multibeam devices emit sound beams that forms an inverted cone, covering a larger area and providing a more complete picture of the sea floor than the series of vertical or horizontal sound signals that the split beam sonar provides. As described above, the bathymetric mapping surveys are conducted primarily during the night, from sundown until dawn, when fish sampling and other ship operations are not taking place. Ideally, this allows the science team to map out a route of sampling sites for the next dayâs fish trapping work. At the end of the overnight shift, the acoustics team presents its findings to the Chief Scientist, who then coordinates the dayâs activities with the fish team, the shipâs bridge, and the deck crew headed by the chief boatswain.
Itâs called âmultibeamâ because unlike the first single-beam sonars, which sent out one signal or ping, multibeam sonar sends out a whole group of pings at once. Multibeam sonar can cover a larger area than a single beam can. Hereâs a Quicktime movie of multibeam sonar: http://oceanservice.noaa.gov/education/seafloor-mapping/movies/multi_240.mov
Personal Log
I cannot say enough about how friendly and helpful everyone on board has been to this neophyte. It takes a while to adjust to any new environment, but being on a ship at sea has its own learning curve. Pisces, at 209 feet long, operates like a small town. Because it is out at sea for weeks at a time, all supplies and systems must be operating 24/7 to keep the ship and crew focused on the appointed mission and keep everyone on board safe, comfortable, and able to do their jobs.
I spent the first two days getting acclimated to the layout of the ship, safety practices, meeting the members of the scientific crew, adjusting to the rigorous schedule, and doing my best not to commit any grave offenses or make big mistakes that would make the work of this very patient group of dedicated professionals any more difficult than it is already.
Sleep Time Because the shipâs work continues round the clock, sleep time varies, depending on the personâs position and duties. It is important for everyone aboard to be mindful that at any hour of the day or night, itâs likely that someone is sleeping. The mapping crew began a 6 p.m. to 6 a.m. shift (or later, until the work is finished) on our second day at sea, and most of them will keep that difficult schedule for the entire cruise. Since Iâm the lucky one to experience every aspect of the work, Iâll rotate through the various jobs and schedules. For the first few days, Iâll work with the fish survey team, from 6 a.m. until their work is completed, which may mean a break for supper at 5 p.m. followed by a few more hours of lab work to process all the dayâs catch. My first day on the acoustics team, Iâm scheduled to start at 4 a.m. assisting their nightly wrap up, as by the last few hours of their shift, they are quite tired.
Dining and Comforts Aboard Ship
Chief Steward/Chef Jesse Stiggens with a Pisces creation, a vegetable quiche.
Chief Steward Jesse Stiggens and Assistant Steward Michael Sapien create a terrific, appetizing menu for the three main meals and plenty of extras and snacks available at any hour.
The stewards are very accommodating, so anyone who will miss a main meal because of their work or sleep schedule can sign up in advance for the stewards to set aside a full plate of delicious food for them. The mess (dining room on a ship) is open all day and night, with coffee, cold beverages, an array of sandwich fixings, cereals and assorted leftovers kept chilled for anyone to microwave anytime they get a hankering for a nibble or a bigger bite. AndâŠvery important for morale ⊠thereâs a freezer stocked with ice cream, even Blue Bunny (a favorite in the South that I had not seen before) and HĂ€agen-Dazs. Thereâs also a big screen television in the mess. The lounge area has computers, a conference or game table, a small library of books, a large screen television and several hundred movie titles, even new releases, for the crew to enjoy in their off time. Also available are wonderful reclining chairs, so comfortable, I wish I had time to use them. The one and only time I tried one out, the fire alarm went off for our first drill, and I havenât had a free moment since.
Doomsday Came and Went: Saturday, 21 May, 2001âŠ.and Pisces work continues
CNN reports: After months of warnings and fear, the Day of Rapture, as predicted by apocalyptic Christian broadcaster Harold Camping, passed without apparent calamity. Judgment Day was to have started at 6 p.m., but as darkness fell on many parts of the world, it appeared that heaven could wait. At this writing, there have been no reports of people soaring upward to the skies, but plenty of folks are talking about it.
That includes those of us on Pisces. The possibility that Doomsday was approaching generated some good-natured kidding and gallows humor. We had some debate about when the end would begin. Since most of the shipâs instruments use Greenwich Mean Time (GMT) as a reference, we speculated that our end time might occur four hours later than east coast Daylight Savings Time (DST).
Everyone had their eyes on the clock and the horizon as first, the predicted doomsday hour of 6 p.m. DST came and went, and then, four hours later, 6 p.m. GMT passed without incident. Any apprehensions were put to rest, and now we have new fodder for discussion.
Special Challenges for Research at Sea
Many people have the idea that science is neat, pretty and conducted in sterile lab environments by other-worldly thinkers in clean white lab coats. That is decidedly not the case in fisheries work at sea. This section lists the special challenges (or, as, some optimists would say, âopportunitiesâ) of conducting shipboard research. Each log will focus on or give examples of one or more challenges.
Limits of âshooting in the darkâ â Imagine a vast, dark, deep, ever-changing, difficult-to-penetrate area, with living organisms moving about in and out, with all kinds of surface, bottom, and in-between conditions. Thatâs what underwater research involves. Examples: The mapping team thinks it has found great habitat for red snapper and grouper, so the survey team expects a bountiful trap. But up comes nothing but a trap still full of untouched bait. Or, the habitat conditions look promising, but the current is too strong to set the traps safely.
The Unexpected â It is often said that the only thing predictable in field research of this kind is unpredictability! You just never knowâŠ.
Curiosity-seekers and just plain business – recreational and commercial boats – Not surprisingly, the areas of interest for NOAA fisheries research are often favorite fishing grounds for recreational fishermen, scuba divers, and active routes for commercial ships. Therefore, Pisces crew and helm (the person steering the ship) must always be on alert for other boat traffic. Example: On Saturday, a small recreational boat occupied by partiers pulled up nearly alongside Pisces. Despite polite cautions and requests from our bridge for the small boat to move away to a safer distance, the visitors just kept waving and cheering for a while.
Challenges to come in next logs:
Changing sea conditions, weather, waves and current
NOAA Teacher at Sea Donna Knutson NOAA Ship Oscar Elton Sette September 1 â September 29, 2010
Mission: Hawaiian Islands Cetacean and Ecosystem Assessment Survey Geograpical Area: Hawaii Date: September 24, 2010
I Hear Them!
I am in the stateroom writing.
I Hear Them!
September 24, 2010
Teacher at Sea:Â Â Donna Knutson
Ship Name:Â Â Oscar Elton Sette
Mission and Geographical Area:Â Â
The Oscar Elton Sette is on a mission called HICEAS, which stands for Hawaiian Islands Cetacean and Ecosystem Assessment Survey. This cruise will try to locate all marine mammals in the Exclusive Economic Zone called the “EEZ” of Hawaiian waters. The expedition will cover the waters out to 200 nautical miles of the Hawaiian Islands.
Data such as conductivity, temperature, depth, and chlorophyll abundance will be collected and sea bird sightings will also be documented.
Erin, Sussanah, and Kim working on the array.
Science and Technology:
Latitude: 25â 13.6â N
Longitude: 168â 23.7â W Â
Clouds:Â Â 4/8 Cu, Ci
Visibility:Â Â 10 N.M.
Wind:Â Â 8 Knots
Wave height:Â Â 2-3 ft.
Water Temperature: 28.2â C
Air Temperature:  25.6â C
Sea Level Pressure:Â Â 1021.6 mb
Of the five senses, hearing is the most important sense to cetaceans.  Sea animals depend on hearing to feed and communicate.  In water it is impossible for whales see long distance, their sense of smell is not as developed as in sharks, their sense of taste and touch will not help in traveling through the water seeking food, so therefore the sense of sound has become the most developed.
“Guts” of the array.
Cetaceans whether odontocetes, the âtoothed whalesâ such as the sperm whales and dolphins, or Mysticetes, the baleen whales such as the Brydeâs or humpback whales, have different ways of producing sound.  Because their methods and mouths are different, different kinds of whales produce different kinds sounds with varying frequencies.
Frequency is the number of waves or vibrations that pass a certain point in one second.  People have a hearing range of approximately 150 â 20,000 Hz.  Hertz or Hz is the unit for frequency meaning how many waves are reaching a destination in one second.   People talk within this frequency range and can hear slightly above and below this range.
Cetaceans have a much broader frequency range.  The âtoothed whalesâ produce rapid bursts of high frequency clicks and whistles.  Their hearing range is 250 â 150,000 Hz.  Single clicks are used for echolocation and a collection of clicks for are used for communication.
Erin, Sussanah, Yvonne, Nicky and Kim checking the connections.
The baleen whales have a lower frequency range of about 10 â 31,000 Hz.  They too use sound for echolocation and communication, but the âwhale songâ often associated with humpback whales is primarily for sexual selection.
When comparing whales to other land animals, they even have a higher frequency range than dogs or bats.  The bat has a hearing range of 10,000 â 100,000 Hz and the dogâs range in 15,000 â 50,000 Hz.  In whales and bats the higher frequencies are used for echolocation.
 Another difference between the land and aquatic animals, is where their sound is transmitted.  Land animals send and receive sound through the air and cetaceans do both through water.  Sound travels almost four times faster through the water. That is the reason whale noises can travel thousands of kilometers.
Listening in.
Whale noise is not the only noise in the ocean. People are making a lot of noise themselves.  With increased noise from ships, sonar, and seismic surveys the ocean is becoming a noisy place. Environmentalists and cetalogists are concerned with the added noise.
Noise may be one of the factors in animal strandings.  The strandings may due to stress from noise, but in some cases cetaceans have had damaged ears.  It is unknown if increased noise levels have caused the ear damage or it is only old age.  This is definitely an area which could use more study.
Personal Log:
A group of sperm whales sound like the patter of rain.
It has been through my observations aboard the Sette, the acousticians have a challenging job! They of course have a love of cetaceans like all marine biologists, and want to locate and study these animals, but they need to work with very sophisticated electronic equipment rather than be out on the flying bridge looking through the âbig eyesâ. If the equipment is not designed properly, whale and dolphin sounds cannot be detected.
Yvonne, Sussanah and Nicky are the acousticians on the ship.  These young women have had additional adventures over and above others on the cruise, and adventures that they would probably wish they didnât have to experience.  I am very impressed with their trouble-shooting abilities, their patience and their tenacity!
Each dot is a click, every color is a different animal.
At the beginning of the cruise the acousticians were gifted with a brand new array!  An array is a long clear soft plastic tube containing all the electronic equipment needed to absorb and transmit sound to the sound equipment back in the ships lab.  The array had (notice I said had â past tense) hydrophones and transmitting boards throughout its 50 foot length.  In order for the sound to travel through the water and be received by the array, the entire electronic circuitry inside the array needed to be immersed in a liquid similar to salt waterâs density.  If the electronics were exposed to sea water there would be too much corrosion for the system to work properly. So, they chose a colorless oil to fill the array. The array is laid out on the fantail (back deck) bridge and is connected to a spool of power and relay cords (ok, you realize by now I know virtually nothing about electronics) and then the cords are slipped into the lab and connected to the sound equipment.  I know that last part for certain, because I helped Nicky wire tie them together at the beginning of the cruise.
All was done that could be so it was decided to put it back together, and try it again.  It worked!  I wasnât surprised but rather amazed!  Unfortunately two of the four hydrophones stopped working.  Each hydrophone picks up different frequencies so if they donât all work.  The array doesnât work. Drat! Not to be overcome with minor setbacks.  (Minor to them, Iâm thinking definitely Major if I had to work on it!) The acousticians set to work making an entirely new array!  One day I decided to stop down in the lab to check things out and see what new adventures they were presented with.  As Sussanah sat and stripped wires, I asked Yvonne and Sussanah how much electronic background they had to have for this job because I was clearly impressed.  Neither of them has had any classes, only the experience of working on similar equipment in the past.
Sperm whales use echolocation to find food. This is what you see before they make their vertical dive.
None of them had an electronic background, but they decided to make a new array themselves with the left-over parts. They were determined to become an active part of the survey team!   And they did it!  They built their own array!  It was (yes drat, past tense again!) working great until one day it was getting progressively worse. When the girls pulled it in, they noticed it had been bitten!  Some fish came up behind it and bit the newly fabricated array!  What kind of luck was that!   Salt water was leaking in.  âHow can you fix that?â I asked Sussanah at dinner.  She said, with her British accent, (which is so much fun to listen to, and one of the reasons I like to ask her questions) the kevalar material inside the device, which is giving the new array strength and structure, is acting like a wick and soaking up the salt water.  So they split the kevalar and it is being held together with a metal s-connector to try and stop the wicking.
Ernesto, Adam and Juan Carlos gave a valiant effort. Unfortunately no biopsy samples were collected.
It will hold for the next six days until we can get back to port.  Wow, for all the adventures/troubles they are picking up some good information!  The array will receive the sounds from the âtoothed whalesâ but to pick-up the lower frequencies from the baleen whales, the acousticians send out a sonobuoy.  A sonobuoy  is an independent device that is dropped over board, and floats on the surface while sending the signals back to the ship. As I am writing this I am told the acousticians are hearing pilot whales!  They can not only hear them, but can also tell where the whales are at!  I need to go check it out!  They are truly an amazing group of young women.  Even though I have known them for only for a short time, I am truly proud.  Their hard work has definitely paid off.  Their determination is to be admired
Acoustician, Sandra Parker-Stetter on the Bridge preparing to fish..
When you walk into the acoustics lab you are greeted with an impressive display of primary colors and fascinating images. Sandy, our Acoustician is also there to greet you and help explain the science behind the images of sound. She explained not only the basics of acoustic science; but also shared some fascinating biological phenomena that can be witnessed with this technology.
So first some basics about the acoustics.  (Hoping BTW to make Sandy proud about her skills in teaching a physics phobic..  She only made my head hurt a few times..) When you walk in the Acoustics Lab on the Oscar Dyson you will see there are six different acoustic displays in the lab:
18 kHz & 38 kHz on one display  (These are more common to fishing vessels to distinguish larger fish from jellies, zooplankton and juvenile fish)
70 kHz, 120kHz, 200kHz and a 70 kHz with a sideway view from the ship.
The acoustic sounders positioned on the ship’s centerboard emit a ping that is transmitted directly downward from the boat (except one 70kHz pointed sideways).
These pings each have a set characteristic frequency designated by the unit of a kiloHertz (kHz).  A kilohertz simply is the thousands of cycles per second that the wave is transmitted. Frequency is indirectly related to wavelength. So if you think about what will fit in-between the waves in the left image it will make sense that lower frequency acoustics are used to identify larger things, while higher frequency captures images of much smaller species or individuals.
Acoustics have the potential to not only identify schools of fish, but also discriminate between species types as well. A characteristic scattering is observed from different types of fish depending on their internal structure (morphology) and composition. For example, whether or not a fish has a swimbladder can be used for identification. A swimbladder will cause a greater acoustic scattering. In terms of composition, jellyfish are over 99% water.  The more like the composition of water, the less the sound bounces off the specimen. Therefore, the scatter from the ping of the acoustics is weak and difficult to see on the monitor.  However, the jellyfish signature is shows up quite strong on the acoustic monitors. In this case, the size and shape of the jellyfish causes the sound to scatter regardless of its’ composition. So acoustic analysis is not always as straight-forward as the scientists (and fishermen) would like. So how do the scientist tell a jellyfish from a juvenile salmon? Trawling data..  Part of the acoustic’s mission on our BASIS cruise. The scientists would like to develop patterns to match trawls with acoustic signals. Therefore, acoustics can be used in the future more effectively to track and monitor pelagic populations.
Biological Phenomena Visualized with Acoustic Technology
Zooplankton MigrationÂ
Using the 200kHz acoustics, tracking the movement of the zooplankton is quite easy. In the image to the left, taken and archived during the evening hours you can literally see how the zooplankton migrate toward the ocean surface as the sun sets(Around 10PM in these parts..).  Trying to avoid their predators, the zooplankton stay near the ocean bottom during the daylight hours, but migrates upward toward their food source, the phytoplankton, once darkness begins to onset.
Riding the Pycnocline
Another interesting physical oceanographic feature you can observe with acoustics is the pycnocline. While you can’t literally see the density change of the water using the acoustics aboard this ship, you can watch the fish hover immediately above this feature.
18 kHz Acoustics38 kHz Acoustics
Personal Log:
Sunset
Yesterday morning’s sunrise was one for the books.. Tuesday was a glorious, sunny day aboard the Dyson.. (Uh.. the answer is YES.. apparently Alaskans do sunbathe in 50 degree weather. As long as the sun is out… I won’t mention any names.)  The daytime turned to an evening with a sky full of stars. We then were treated to a spectacular sunrise the next morning with beautiful calm seas. Thanks to Sandy, who captured the picture to the left that morning, while most of us were busy eating omelets and pancakes in the Mess Hall.
It’s fun sometimes when Sandy’s right….
Brian Beckman, Fish Biologist
After days of searching for the juvenile salmon, we finally found their playground. One of trawls yesterday brought us over 2,000 sockeye juveniles along with a mess of jellies… After accosting my colleagues with a few paparazzi moments, it was fun to join in to help sort out the catch.  And even sometimes when things don’t work out perfectly, finding what you’re looking for makes everything better. To the right is a snapshot of what happens when the bin doesn’t stop in time and the fish/jelly mess overtakes the belt and scientists. Now this is fishin’….
There are many different groups of people working aboard the ship, Oscar Dyson – Scientists, NOAA Corps officers, Deck Hands, Engineers, Survey Technicians, and Cooks. Within the science department, there are 12 members aboard and two Teachers at Sea which totals to 14 souls. For this third leg of pollock surveys, the chief scientist is Taina Honkalehto. Her job aboard the ship is to plan the scientific activities and make the decisions on how best to carry out that plan. Of the scientist crew, there are two Russian scientists that are conducting their own research in collaboration with NOAA.
This pollock survey, which focuses on determining abundance and distribution, is an important component of the fishing industry in the United States. According to The Bering Sea Project, âThe largest concentrations of pollock occur in the eastern Bering Sea,â and more specifically, âWalleye pollock support the largest single commercial fishery in the U.S., producing the largest catch of any one species inhabiting the 200-mile US Exclusive Economic Zone.â Additionally, the pollock industry is incredibly important to the people living in Dutch Harbor and Unalaska because pollock is one of the main fishes processed there and has helped classify Dutch Harbor as Americaâs #1 fishing port in the USA for fish landed (NOAA, 2009).
View of a spread out group of pollock as seen from the computer screen. Notice in the far right corner a red spot. That shows that at that location, the fish are densely packed. The red, yellow, and green-blue line represent the seafloor.
There are two summer surveys being conducted to estimate the Bering Sea pollock population: Acoustic-Trawl Survey and the Bottom-Trawl Survey. Currently on the Oscar Dyson we are conducting the Acoustic -Trawl Survey. After we catch the fish, we combine the acoustics, fish samples, and CTD deployment data, to draw conclusions that help us estimate population size and ecological factors of pollock. Remember, in order for pollock to live where they do, they need food and so when we extract stomach samples, we are looking for what pollock prey upon (mostly krill). Besides, food, other important aspects of their habitat must be in place for their survival. The CTD data – Â water temperature, salinity, nutrients, oxygen, and chlorophyll – help us understand how the distribution of pollock has changed in past years and may also provide information about how it could change in the future.
However, not all of the scientists on board are collecting data related to pollock. Currently we have two other subgroups with one observing seabirds and the other observing marine mammals. The crew observing seabirds have a goal of observing species seen during the tour to determine seabird species distribution and abundance. The marine mammal observers are working to obtain current data on cetacean species distribution and abundance.
The Teachers At Sea (TAS), which currently include Obed Fulcar (New York, New York) and myself (Dutch Harbor, AK) have an important role of working under the scientists and other crew members to learn about the research being conducted in an attempt to bring real science into the classrooms.
A large group of fish scattered about from the perspective of the transducer.
Because acoustics is a major tool used in pollock survey, I feel it would be beneficial to provide a few details on how it works. Remember, referring to Blog #2 âthe ship has Transducers that send pings of sound energy down through the ocean and when they hit some object, such as the bottom of the ocean or a fish, in this case they are hitting the swim bladders of the fish, some of the energy in the sound ping is returned to the ship and received by our echo sounding system in the acoustics lab of the ship.â It is important to note that the acoustics under the water are different than in the air because the pressure in each location is different. Inside the acoustics lab there are many different screens that display the pings at different frequencies of sound waves. We know that jellyfish tend to show up the best from the low frequencies. Acoustics is a good tool to use to study pollock because pollock is the primary fish species inhabiting the middle-waters of the Bering Sea shelf. For example, bottom fish are difficult to see because the acoustic signals from the seafloor are too strong and tend to hide the bottom fish signals. Acoustic signals that we see on the computer screen rely on the actual physiological make-up of the fish. Also, the behavior of pollock plays a role in how we can see them acoustically. For example, salmon do not swim in large schools like pollock. When we see large schools of pollock on the acoustic screens, density determines the color – blue usually is reflecting a couple fish whereas red represents a high density of fish – and the shape of the schools tend to be typical of pollock. Through acoustics, we are able to survey pollock over a wide area and gain information regarding their distribution and population.
Prior to fishing, we consistently monitor the screens as the ship travels up and down the rectangular transects you can see when you view the shipâs path on ShipTracker. When we observe schools of fish, we need to decide whether they are large enough to sample the fish with the trawl. Because we also want to target certain ages of fish, it is important to be able to estimate their size.
We can estimate size through a method using additional measurements from the acoustic data. We draw a box around an area that is not densely packed with pollock so it is easier to distinguish an individual acoustic image of a fish. The software we have gives us the average intensity of the acoustic pixels. We call this intensity target strength which translates to the size of the echo. Because the size of the swim bladder is proportional to the size of the fish, we can use the intensity of the echo off the swim bladder to estimate the size of the pollock. In short, target strength depends on the size of the swim bladder and features of the swim bladder can be used to predict fish size.
Acoustic image from the bridge. The bottom blue streak is a large group of fish that ducked under the net. The horseshoe shape is the net. The blue inside the horseshoe are the fish.
We can use an equation for calculating decibels to help us estimate the size of the fish in the school we might target. Â For my friends and students who are math gurus, the equation is TS = 20Log(length cm) + b20. The b20 variable is different for different fish species and so for Walleye Pollock in the Bering Sea, b20 is -66. Therefore, the equation for Walleye Pollock is TSpollock = 20Log(length cm) – 66.
To provide an example of how the equation works, lets say that the average length of a two year-old pollock is 25 cm and that is the size we want to target. We take that 25 centimeters and âplug itâ into the section of the equation that stands for length in centimeters. Scientific calculators are wonderful devices for logarithms as they have the Log function already installed, and if you plug in 20Log(25) – 66 into the calculator, the answer -38.4 translates into the target strength that would show up on the screen. So if we find schools of pollock and see that the target strength is close to -38.4, then we know the echosounder is observing two-year old pollock.
Once acoustics have determined that we need to fish, they send the coordinates they want the Officer of the Deck (OOD, a.k.a. the NOAA Corps officer on watch on the bridge) to follow and the officers drive the ship to the location. On the bridge of the ship, the scientists are able to see the acoustic screens and are able to keep an eye on the location of the fish, relative to the transducer underneath. From there the Lead Fisherman or Chief Bosun operates the machinery required to put the trawls in the ocean. After the large mesh net is placed in the ocean, the crew put on a sensor that measures water depth and temperature. They also install a tool, called a headrope unit, that is similar to a mini transducer which makes an image of the mouth of the net and allows the scientists to watch fish entering the net from the bridge.
Senior Survey Technician, Kathy Hough, and Ordinary Seaman, Frank Footman, installing the head-rope unit.
Once the fish are caught, the deck crew will draw the nets back onto the boat using hydraulics. From the stern (back of the boat), the fish go into the fish lab on a conveyer belt where we sort, sex, measure, and extract stomachs and otoliths. Since being on the ship, during my shift we have been averaging two trawls per day.
How is the information we collect used?
On the ship, we are collecting raw data, entering into our computers, and analyzing what we see. From there, we can draw conclusions based on what we have observed from our samples. However, there are other scientists at work here. For example, perhaps you are interested in working with computers and want to be involved with wildlife. Some of the scientists help design the computer programs we use and maintain them. Perhaps boat life is not your “cup of tea.” All the stomach and otolith samples we collect need to be sent into a lab to be analyzed by a stomach or otolith expert. The data they compile from the samples we collect get added into our publication at the end of the survey. There are also scientists that compile our conclusions about what we saw on the ocean and they create models to show population trends and predict future abundance. From that information, a council of scientists, industry representatives, and others of interest, get together and determine things such as fishing quotas. Also, don’t forget that there are teachers, like me, aboard who take some of the scientific information or scientific processes and educate students about real science in the real world.
If you want to obtain a job working in the sciences department of NOAA, some courses of study that will increase your chances of becoming involved include but are not restricted to: Marine Biology, Chemistry, multiple levels of mathematics, Computer Science, Writing. Versatility is another key factor to consider for any job you may want to pursue as the more background information you have, the more information you can “bring to the table.” For example, perhaps you love music. An understanding of decibels and how sound is carried at different frequencies is incredibly useful in acoustical sciences. Foreign Language is always beneficial as you will continually work with people from all over the world and remember, there are two scientists currently on the ship who are from Russia! Therefore, in my opinion, don’t forget about your electives when choosing your courses because the more rounded you are, the greater your chances are for success!
Personal Log:
My morning started off fantastic as I was able to launch an XBT into the water again. By the time I was beginning to type this blog we passed over a school of pollock and decided that we needed to turn around and go fishing. Approximately two hours of sorting commenced before I was able to return. I learned that acoustics is a very difficult concept to explain as there are many factors in mathematics and physics that are complicated to translate into laymanâs terms. I ended up spending a lot of time reading a textbook on the research the theories of using acoustics on wild fish. Please do not hesitate to ask in the comment box below this post if you have questions!!!
Overall, there was a good assortment of fish today and I stayed fairly busy in the fish lab collecting pollock sample data!
Me giving the fish a layer of water so that they slide down the chute and onto the conveyor belt easier.
Animals Seen Today:
Walleye Pollock
Silver Salmon
Northern Fulmar
Parakeet Auklet
Short-tailed Shearwater
Least Auklets
Tufted Puffin
Thick-billed Murre
Northern Fur Seal
Something to Ponder:
Life at sea can be an amazing experience but there are many things people may take for granted when living on land. For example, consider the possibility of becoming hurt on the job, or developing a medical condition such as a rash or appendicitis. From the middle of the ocean, it is very difficult to reach a doctor to get a diagnosis. On board the ship, we have some medical supplies but typically there is not a licensed doctor on board the ship. Would you know how to respond to an emergency if it were to happen? If you have taken a First Aid or CPR class, do you remember what you need to do? How would you react? What would you do to reach help? Who could respond to your call?
For the Oscar Dyson we have the following protocols:
1. Contact the medical officer on board for an initial diagnosis.
2. If the condition requires advanced medical care, he or she will contact the medical officer on call at the NOAA Marine Operations Center.
3. In the case of an emergency and when the Marine Center cannot be contacted, he or she will contact the Maritime Medical Assistance (MMA).
4. If needed, we will arrange for a medevac (medical evacuation) which could involve the US Coast Guard and/or head back to port.
