Tag: trawl net

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Germaine Thomas: What Does Acoustic Trawl Sampling Really Tell Us? August 13, 2023

NOAA Teacher at Sea

Germaine Thomas (she/her)

Aboard NOAA Ship Oscar Dyson

August 7 – August 21, 2023

Mission: Acoustic Trawl Survey (Leg 3 of 3)
Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska
Date: Sunday, August 13, 2023

Weather Data
Lat 59.12 N, Lon 150.11 W
Sky condition: Partly Cloudy
Wind Speed: 13 knots
Wind Direction: 330°
Air Temp: 14 °C

Science and Technology blog

The ocean is a really big place. We have really only mapped about 5% of the ocean bottom. How do we manage fisheries if we have to count fish in an area that is overwhelmingly large? This is where the genius of acoustics and trawl sampling complement each other. The scientists aboard NOAA Ship Oscar Dyson use the echo sounders to find fish or other animals lurking in the ocean and then they can extrapolate and upscale that data to a much larger area which is covered by their transects.

Wait! That is a lot of information using language that folks don’t really use at the dinner table. Could you please explain this in more basic terms? You bet, as a matter of fact in the last couple of days I have been swimming in a sea of new vocabulary, talking to really smart people and trying to keep up with the conversation that it almost makes my head explode. Don’t worry, I am safe. But it’s really impressive how scientists have developed ways to accurately know fish and marine organism populations in the ocean with out having to sample all of it.

Acoustics

Acoustics uses the echo-sounders a lot like a fish finder, but the ones on NOAA Ship Oscar Dyson are much more capable than the type you would find on your boat. The echo-sounders are attached to the bottom of a lowered centerboard—essentially a large keel—in the center of the boat, and they measure five different frequencies with different wavelengths.

A photo of a computer screen displaying five echograms (graphs of recorded echoes) in a row. Germaine has added annotation: a black arrow points at the top of the echogram with the label "Top of the ocean," and another points to a solid, dark red bar midway down the echogram with the label "bottom of the ocean." Dashed marks, angled up or down, are scattered across the echograms, concentrated in upper portions. Germaine has drawn a black circle around some of these, with the label "The colored marks in the oval indicate "backscatter," which could indicate fish or other marine organisms." At the top of each echogram, in its title, Germaine has circled the frequency measured, but they are difficult to read.
View of the 5 different frequencies measured by the echosounders, one in each frame. The darker marks on the screen could be fish, jellyfish, krill or other marine organisms, this is referred to as “backscatter.” The red circles show the different frequencies used to measure the backscatter.

So, if we can see the fish using acoustics, why do scientists need to sample using a trawl net? As you can see above, the marks in the backscatter can show the depth and the approximate shape of objects, but there is not enough detail to tell exactly what kind of organism is present. Most of the scientists on board have a pretty good idea what kind of fish or organisms are present, but the most definitive way to know is to take a trawl sample.

Trawl Sampling

The trawl net as seen in the picture below is being set off the aft deck.

A crewmember wearing a hard hat, life vest, and heavy work overalls stands off to the side as the trawl net is lowered off the aft deck from a large yellow A-frame.
The part that is in the air is called the codend. That is the section of the net where the specimens are ultimately collected.
view of two rollers - like large spools - containing rolled up fishing nets. the net on the right is orange. the net on the left is white and partially paid out.
The trawl is a about 172 meters long and it stored on these rollers on the back deck.

When the trawl is deployed to the depth that the scientists want to sample, the net will funnel fish and other organisms into it. This is called flying the net.

A photo of a monitor screen displaying information about the position of a deployed trawl net. There are three different views, represented by simple line drawings of a boat followed by diagrams of the trawl net and attached lines. In the Top View, we see the shape of a boat from the sky. A straight red line measures the distance between the boat and the opening of the net as 210 m. The net is being dragged at an angle 13 degrees to the right of center. For the side view, there's the shape of a boat on a horizontal line representing the water's surface. A straight red line measures the distance from the water's surface to the top of the net as 21.5 m. There's also a front view, showing the net as a narrow set of lines extending below the front profile of a boat. At top, the screen notes the course at 158 degrees and speed at 4.3 Kn.
The screen above diagrams three different views of the net as it is pulled through the water. You can see that the trawl net was not directly behind the boat and went to a depth of 21.5 m.
photo of a computer screen displaying data about the position of the net, along with a more detailed diagram. Germaine has added arrows to label "The doors help open the net" and "the codend at the end of the net that collects the sample." We can see that the set length measures 457 meters.
In this image you can see the net and how far back it trails behind the Oscar Dyson.

I just have to include one more view of the trawl net from the bridge as it is pulled behind the boat.

A photo of a computer screen showing a 3-d rendering of the deployed trawl net and the following measurements: door depth port - 16.5 m. door depth starboard.- 15.7 m. door spread - 59.4 m. door pitch port - 4.7 degrees. door pitch starboard - 6.1 degrees. headrope horizontal range - 204 m. headrope true bearing - 326.0 degrees. depth - 21.0 m. change meters/minute - -0.2 m.
This image was taken when the crew was bringing the net back into the boat, so the depth is shallower.

The next image shows the path that the net was pulled through the water.

photo of a computer screen displaying an echogram (graph of recorded echoes.) This echogram shows the returns from a single frequency. Germaine has annotated it with arrows pointing to: Header rope or top of the trawl path, and Footer rope or bottom of the trawl path. Another arrow points to colored specks and reads: The echosounders show backscatter, which could be fish or other organisms.
The acoustics show the backscatter which the scientists make the trawl target. The next step is to process what is captured in the codend of the trawl and see exactly what is present.

Because the trawl is dragged through the water, it catches different organisms at different times. The scientists want to know when the different organisms were caught so they have cleverly attached a camera to the side of the net. Through the camera they can see which type of fish came into the trawl. Ultimately, this links the kind of acoustic backscatter viewed in the echograms recorded during the trawl to exactly the type of organism caught by the trawl.

view of a trapezoidal metal apparatus, containing underwater cameras and floats, attached to a blue trawl net, spread out on deck
The camtrawl: a camera that records the type of fish entering the net and when they enter.

Below is a picture of some fish as they enter the trawl net and move towards the codend.

a photo of a computer screen displaying a black-and-white underwater camera feed. a few fish (pollock) are visible swimming by the net.
The camera is looking across the net as the fish move past. The fish in the picture are pollock, the type of fish we are looking for on this leg of the cruise.

Transect Lines

So how do scientists take this information and extrapolate the data to a broader area? While the Oscar Dyson is out at sea they run transect lines while recording acoustic data. Transect lines are specific paths in the ocean. The picture below shows the transect lines that we plan to do and have done on this leg of the cruise.

a screenshot of an electronic nautical map of the Gulf of Alaska. straight lines extending toward and away from the coast are superimposed across the map.
The red lines are the transects we have done and the blue lines are the transects scientists plan to do in the remainder of this leg of the cruise. If you look closely there are pictures of fish symbols on the transect lines where the ship has made trawl samples.

Using the acoustic data that the echo-sounders provide and verifying the types of fish and other marine organisms through the trawl sampling allows the scientists to predict, with a high level of certainty, the amount and types of marine organisms that are present along the transect lines that were not trawl-sampled. Thus saving the taxpayers money, and allowing fisheries managers to use good data, keeping the fishery viable, and allowing commercial fishing boats to have reasonable catch limits.

Scientist in the Spotlight

Honestly it takes a team to make all of this happen. But, half of our team is sleeping at the moment, I have the night shift from 4pm to 4am, so I am going to introduce one fabulous expert in acoustics and fisheries:

Abigail, wearing a blue hoodie featuring a drawing of a salmon, sits back from a long computer desk with eight computer montiors mounted above and to the side. She smiles at the camera.
Abigail McCarthy in the Acoustics Lab

Abigail McCarthy has been working for MACE: Midwater Assessment and Conservation Engineering Program since 2007. She received her undergraduate degree in Biology from Wellesley College and then obtained a Masters in Fisheries from Oregon State University.

For fun, she surfs and enjoys long-distance prone paddle board races. She has recently found a new love with fly fishing.

Aboard the Ship Oscar Dyson, she is working as a specialist helping to run the acoustics lab.

I asked Abigail what she thought of about her educational experience? She immediately said, “I love learning! High school and college were both a lot of fun.”

What would be a good suggestion for a young aspiring high school student pursuing a degree related to ocean studies or science in general?

Her response was great: “Being curious and working hard is more important than being brilliant. Persistence and determination will get you where you want to be in the future.” Finally, “Learn to code! Become familiar with programing languages like Python and R.”

Hopefully, I answered your burning questions about the use of acoustic trawl sampling, and surveys. Yet, there is so much more to learn. Why not take a trip yourself? Check NOAA’s website out and just apply.

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George Hademenos: A Day in the Life…of a Marine Science Researcher, August 25, 2022

NOAA Teacher at Sea

George Hademenos

Aboard R/V Tommy Munro

July 19 – 27, 2022

Mission: Gulf of Mexico Summer Groundfish Survey

Geographic Area of Cruise: Eastern Gulf of Mexico

Date: August 25, 2022

In this post, I would like to walk you through my interactions and observations with the science research being conducted aboard the R/V Tommy Munro, in particular, the steps that were taken during a trawling process. The entire process involved three stages: Preparing for Sampling, Conducting the Sampling, and Analyzing the Sampling with each stage consisting of six distinct steps.

View the following steps in an interactive tour here: Trawl Sampling Process (Genially)

I. Preparing for Sampling

Step 1: The ship travels to designated coordinates for sampling sites as determined for the particular leg of the Survey by SEAMAP (Southeast Area Monitoring and Assessment Program).

screenshot of a computer screen showing the path that R/V Tommy Munro traveled among sampling sites. The ship's path is a bold blue line connecting sample sites marked in yellow. It's superimposed on an electronic nautical chart. This survey occurred southeast of Florida's Apalachicola Bay and St. George Island.
Ship Transport to Sampling Site

Step 2: Once the ship reaches the site, a Secchi disk is attached to a cable and lowered into the water off the side of the ship to determine visibility. When the disk can no longer be seen, the depth is recorded and the disk is raised and secured on ship. 

a scientist wearing a life vest stands on a small grated platform that has folded down off the fantail of R/V Tommy Munro. With his left land, he grasps a cable hanging from an A-Frame that extends out of the photo. The cable is attached to a white disk, about the size of an old record, with a weight underneath.
Deployment of Secchi Disk

Step 3: A CTD (Conductivity, Temperature, and Depth) unit is then prepared for deployment. It is a rectangular chamber with sensors designed to measure physical properties of the water below including dissolved oxygen, conductivity, transmissivity, and depth. 

a conductivity, temperature, and depth probe, mounted inside a rectangular metal cage about 1 foot square and about 3 feet high, sits on deck. a crew member wearing white shrimp boots hooks a cable onto the top of the CTD frame. Another person, mostly out of frame, touches the CTD frame with their right hand, covered in a blue latex glove.
Preparation of CTD Unit

Step 4: The CTD unit is powered on and first is submerged just below the surface of the water and left there for three minutes for sensors to calibrate. It is then lowered to a specified depth which is 2 meters above the floor of the body of water to protect the sensors from damage. 

the CTD unit, attached to a cable, sinks into dark blue water.
Deployment of CTD Unit

Step 5: Once the CTD unit has reached the designated depth, it remains there only for seconds until it is raised up and secured on board the ship.  

a science team member, wearing a blue hat, a blue life vest, and blue latext gloves, stands on the deployment platform out the back of R/V Tommy Munro. He grasps the top of the CTD frame as a cable lifts it back out of the water.
Recovery of CTD Unit

Step 6: The CTD unit is then turned off and the unit is connected through a cable to a computer in the dry lab for data upload. Once the data upload is completed, the CTD unit is flushed with deionized water using a syringe and plastic tubing and then secured on the side of the ship.   

the CTD unit sits on deck, now connected to a computer via a cable to upload the data it collected.
Data Upload from CTD Unit

II. Conducting the Sampling

Step 1: The trawling process now begins with the trawl nets thrown off the back of the ship. The nets are connected to two planks, each weighing about 350 lbs, which not only submerges the nets but also provide an angled resistance which keeps the nets open in the form of a cone – optimal for sampling while the ship is in motion.

a view of the fantail of R/V Tommy Munro, from an upper deck. we are looking through the rigging of the trawl frames. two large planks rest on the lower deck, connected to ropes and lines. the trawl net, connected to the planks, extends out the back of the fantail. It is just visible below the surface, a turquoise-colored cone submerged in a blue sea.
Preparation of the Trawling Process Part 1
another view of the fantail of R/V Tommy Munro from an upper deck, through extensive rigging and frames. the trawl net is further extended; now the large planks are lowering off the back deck as well, suspended by lines connected to a pulley in an A-frame. it is a clear day and the water is very smooth.
Preparation of the Trawling Process Part 2

Step 2: Once the trawl nets have been released into the water from the ship, the ship starts up and continues on its path for 30 minutes as the nets are trapping marine life it encounters.

a view of the fantail of R/V Tommy Munro from an upper deck. the trawl net is fully deployed and no longer visible. a crew member sweeps the deck.
Onset of the Trawling Process

Step 3: After 30 minutes has transpired, a siren sounds and the ship comes to a stop. The two weighted planks are pulled upon the ship followed by the trawl nets.

a view of the A-frame at the fantail R/V Tommy Munro as the trawl net rises from the ocean. The two spreader panels are suspended from separate lines running through the central pulley. behind those, the top of the trawl net is visible above the water. a crew member guides the spreader doors with his left hand, holding the lines with his right hand.
Conclusion of the Trawling Process Part 1
the spreader doors are now resting on the fantail deck again. two crewmembers, wearing life jackets, pull the trawl net back on board.
Conclusion of the Trawling Process Part 2

Step 4: The trawl nets are raised and hoisted above buckets for all specimens to be collected. Then begins the process of separation. In the first separation, the marine life is separated from seaweed, kelp and other debris. The buckets with marine life and debris are then weighed and recorded.

a crewmember (only partially visible) empties the contents of the trawl net into a blue plastic basket. it looks like it's mostly sargassum.
Content Collection from the Trawl Part 1
four plastic baskets on deck hold the sorted contents of the trawl. one has larger fish; another contains only a single fish; a third is a jumble of seaweed and sargassum, and may represent the remainder to sort; the contents of the fourth are not visible. a crewmember wearing a life vest and gloves leans over the baskets. another crewmember, only partially visible, looks on.
Content Collection from the Trawl Part 2

Step 5: The bucket(s) with marine life are emptied upon a large table on the ship’s stern for separation according to species.

a pile of fish on a large metal sorting table. we can see snappers, a trigger fish, and many lionfish. a stack of white sorting baskets rests adjacent to the pile.
Separation Based on Species Part 1
a gloved hand reaches toward the pile of fish on the metal sorting table. (this photo was taken from the same vantage point as the previous one.)
Separation Based on Species Part 2

Step 6: Each species of marine life is placed in their own tray for identification, examination, and measurements inside the wet lab. 

two gloved crewmembers sort fish into smaller white baskets on a large metal sorting table. the table is on the back deck of the ship, and we can see smooth ocean conditions in the background. the crewmember in the foreground considers a small fish he has picked up from the remaining unsorted pile. the other crewmember looks on.
Species Sorted in Trays Part 1
a close-up view of the sorting basket containing only lionfish.
Species Sorted in Trays Part 2

III. Analyzing the Sampling

Step 1: After all species were grouped in their trays, all trays were taken into the wet lab for analysis. Each species was positively identified, counted, and recorded.  

a direct view of three fish of different species, lined up on the metal sorting table. the third is a spotfin butterflyfish.
Tray Transport to Wet Lab

Step 2: Once each species was identified and counted, the total number of species was weighed while in the tray (accounting for the mass of the tray) and recorded on a spreadsheet to a connected computer display system.   

a view of a scale.
Total Weight Measurements

Step 3: For each species, the length of each specimen was recorded using a magnetic wand with a sensor that facilitated the electronic recording of the value into a spreadsheet.   

two hands, wearing latex gloves, measure a small lionfish on the electronic measuring board. the scientist holds the fish against the board with his left hand and with his right hand marks the length with the magnetic stylus.
Individual Length Measurements

Step 4: Weights of the collected species were recorded for the first sample and every fifth one that followed.   

the gloved arm places the small lionfish on the scale behind the fish measuring board.
Individual Weight Measurements

Step 5: If time permitted between samplings, the sex of selected specimens for a species was determined and recorded.   

gloved hands cut into a small lionfish to remove the fish's gonads.
Individual Species Sex Identification

Step 6:Once the entire sampling was analyzed, selected samples of specimens were placed in a baggie and stored in a freezer for further analysis with the remaining specimens returned to a larger bucket and thrown overboard into the waters. The separation table was cleaned with a hose and buckets were piled in preparation for the next sampling. 

view out the fantail of R/V Tommy Munro from the lower deck. the trawl net and spreader doors lay on the deck, not currently in use. the sun shines on calm seas.
Finalize Process and Prepare for Next

In this installment of my exercise of the Ocean Literacy Framework, I would like to ask you

to respond to three questions about the fifth essential principle (The ocean supports a great diversity of life and ecosystems.), presented in a Padlet accessed by the following link:

https://tinyurl.com/427xp9p3

Remember, there are no right or wrong answers – the questions serve not as an opportunity to answer yes or no, or to get answers right or wrong; rather, these questions serve as an opportunity not only to assess what you know or think about the scope of the principle but also to learn, explore, and investigate the demonstrated principle. If you have any questions or would like to discuss further, please indicate so in the blog and I would be glad to answer your questions and initiate a discussion.

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Allison Irwin: Trawling for Fish, July 13, 2019

NOAA Teacher at Sea

Allison Irwin

NOAA Ship Reuben Lasker

July 7-25, 2019


Mission: Coastal Pelagic Species Survey

Geographic Area: Northern Coast of California

Date: July 13, 2019

Weather at 1600 Pacific Standard Time on Thursday 11 July 2019

Happy to report we’re back to a much calmer sea state! I finally made it up to the flying bridge again since it isn’t raining or choppy anymore. It’s the first time in two days I’ve needed to wear sunglasses. The ocean looks almost level with scattered patches of wavelets which indicates about a 5 knot wind speed. It reminds me of the surface of my palms after I’ve been in the water too long – mostly smooth but with lots of tiny wrinkles. Check out this awesome weather website to look at what the wind is doing in your area!

weather conditions
A weather map from Windy.com


PERSONAL LOG


Stretch everyday. I should stretch everyday. I do not. On the ship it’s even more of a necessity. One of the scientists calls it “Boaga” – like mixing “boat” with “yoga.” Try doing yoga on the ship and the rocking might cause you to tumble, but I enjoy a good challenge. Fitness requires strength and flexibility, so if I do some yoga and have to work harder to stay balanced since the ship is rocking, all the better.

A combination of the good food, constant access to homemade snacks, and lack of natural ways to burn calories on the ship, I need to turn to deliberate exercise. I just haven’t started that routine yet. The ship does have a nice, albeit small, gym on the same floor as my stateroom. It includes free weights, kettlebells, a treadmill, and a few other pieces of equipment. Now that our first week is coming to a close, my goal for today – and everyday forward – is to develop a routine for stretching and cardio. Sigh. Otherwise the five pounds I’ve already gained will turn into fifteen. And I have no desire to work off fifteen pounds of belly fat when I get home.


THE SCIENCE


“Trawl” has its origins in Latin. The original word meant “to drag” and it still carries a similar denotation. Fishermen use trawl as a noun, verb, and adjective. On NOAA Ship Reuben Lasker we use a Nordic 264 Surface Trawl to conduct the Coastal Pelagic Species Survey each night. The trawl is spooled onto a giant iron net reel which connects to the deck with sixteen 2.5 inch bolts and is securely welded.  We try to get three trawls in per night, but sometimes we don’t quite make it. Poor weather, issues with the net, or sighting a marine mammal can all put a quick end to a trawl.

Now let’s use it as a verb. The origin “to drag” deals more with how you operate the net than the construction of the net itself. To trawl for fish like we do each night means to slowly unravel 185 meters in length of heavy ropes, chains, and nylon cord mesh into the water off the stern with an average of 15,000 pounds of tension while the ship steams at a steady rate of about 3 knots. Getting the net into the water takes about 15 minutes.

Scott Jones, Chief Bosun, took me on a tour of the equipment. Two reels below deck spooled with cable the diameter of my forearm, one even larger reel on the fantail to house the net and ropes, a winch to lift the weight of the trawl as it transitions from deck to water, plus two work stations for the Chief Bosun to manually monitor and control all those moving pieces. There are three additional nets on board in case they need to replace the one we’ve been using all week, but the deck crew are pretty adept at sewing and mending the nets as needed.

As I stand on the bridge watching the net snake its way into the water behind the ship, everything pauses for a brief moment so the deck crew can use daisy knots to sew floatable devices into the kites. Later, they attach two more of these floats to the headrope (top line). The floats keep the mouth of the net open vertically.   A couple minutes later they stop to attach 250lb Tom weights to the footrope (bottom line) of the trawl opening. When fully deployed, this roughly 25 meter vertical opening is as tall as an 8-story building!

It’s like watching choreography – every detail must be done at exactly the right moment, in the right order, or it won’t work. The Chief Bosun is the conductor, the deck crew the artists. Hollow metal doors filled with buoyant wood core – together weighing more than a ton on land – are the last to enter the water. Each hangs on large gallows on the starboard and port side of the ship, just off stage, until they’re cued to perform. These doors are configured with heavy boots and angled in the water to act as a spreading mechanism to keep the net from collapsing in on itself.

largemouth bass

If unspooled properly, the net ends up looking like an enormous largemouth bass lurking just under the surface.

photo from http://www.pixabay.com

Commercial fishermen use all kinds of nets, long lines, and pots depending on the type of catch they’re targeting, fishing regulations, and cultural traditions. But if we use “trawl” as an adjective, it describes a specific kind of net that is usually very large and designed to catch a lot of fish all at one time. It looks like a cone with a smaller, more narrow section at the very end to collect the fish.

I imagine something like a cake decorating bag that’s being used to fill a mini eclair. Except, instead of squeezing delicious icing into the pastry, we’re funneling a bunch of fish into what fishermen call a “codend.” This codend (pronounced cod-end, like the fish) houses the prize at the end of the trawl! When they haul everything back in – taking a little longer, about 45 minutes to complete the haul back – they end up with (hopefully) a codend full of fish to study.

mini eclairs
Two Mini Eclairs Filled with Pastry Cream

A trawl net can either be used like we are to collect fish close to the surface or it can be weighted and dropped to the sea floor in search of groundfish. We’re searching for pelagic fishes that come up to the surface to feed at night, so it makes sense for us to trawl at the surface. Think of pelagic fish as the fishes in the water. Sounds funny to say, but these fishes don’t like to be near the seabed or too close to the land by the coast. They like to stay solidly in the water. Think of where anchovies, mackerel, tuna, and sharks like to hang out.

To catch groundfish on the other hand, we’d need to trawl the bottom of the ocean since they prefer to stay close to the ocean floor. Trawling the seabed in the Northeast Pacific Ocean would bring in flavorful rockfish and flounder, but we’re not looking for groundfish during this survey. One very lucrative and maybe less known groundfish in this area is the sablefish. In commercial fishing, they use bigger nets, and a trawl can bring in tens of thousands of pounds in just one tow. When I spoke to someone on board who used to work on a commercial trawl boat, he said catching sablefish are a pain!  They live in very deep waters. Plus, the trawl must hit the seabed hard and drag along the bottom in order to catch them. This causes huge tears, many feet wide, in the mesh. He said they used to keep giant patches of mesh on the boat deck so they could patch up the holes in between trawls. When I get home, I’m definitely going to purchase sablefish and try it for dinner.

  • Trawl Net Spooled
    Trawl Net Spooled on the Net Reel on the Fantail
  • Chief Bosun Scott Jones
    Chief Bosun Scott Jones at a Control Station
  • Trawl Entering the Water
    Trawl Entering the Water
  • Codend Floating in the Water
    Codend Floating in the Water
  • Trawl Net Snaking off the Stern
    Trawl Net Snaking off the Stern
  • Floats Sewn into the Kites
    Floats Sewn into the Kites
  • Floats
    Floats When They’re Not Sewn In
  • Daisy Knot
    Daisy Knot
  • Getting Ready to Add Tom Weights
    Getting Ready to Add the Tom Weights (chains)
  • Hauling the Net back on Deck
    Reversing the Process – Hauling the Net back on Deck
  • Prepping the Codend
    Prepping the Codend before Emptying the Catch
  • Emptying the Catch
    Emptying the Catch


TEACHING CONNECTIONS


I’ve never once wondered how the fish I buy at the grocery store ends up on my plate. Now I can’t seem to stop asking the scientists and deck crew questions. There are all these regulations to follow, methods to learn based on what type of fish you’re targeting, and so much that someone would need to understand about traveling in the ocean before even attempting to fish commercially. I’ve been immersed in a world I don’t recognize, and yet the fishing industry impacts my life on a daily basis. We are so far removed from what we eat.

The other aspect to the trawling topic that interests me is just how effortless it looks. The deck crew make such an intricate task look, truly, easy. An article on BBC News called Can 10,000 Hours of Practice Make You an Expert? does a nice job of summarizing how this might be possible. Of course, it doesn’t hurt that I’m currently reading Grit: The Power of Passion and Perseverance by Angela Duckworth, that I’ve already read Outliers: The Story of Success by Malcolm Gladwell and Mindset: The New Psychology of Success by Carol Dweck, and that as a teacher I’m familiar with Ericsson’s work on deliberate practice. I know how many years and cumulative hours they each must have put in to make it appear seamless.

Like most teachers, I want my students to find a career that they love enough to practice with such diligence. I want them to find a vocation instead of just work to pay the bills. I feel very much led to making sure my students have access to as much information as possible about post-secondary career and training options. For that reason, I’m glad to have met these folks and learn from them so I can share their practice with the hundreds, possibly thousands of teenagers I’ll teach over the course of my career.

It’s easy for me to do this as a reading specialist since I can read career profiles with students, let them annotate the text, and then engage them in a discussion on a regular basis. Reading, analyzing, and discussing text are kind of my bread and butter. For other disciplines, it might take a bit of a re-work to fit this in, but certainly not impossible. A science, math, art, STEM, you-name-it teacher could post a career profile specific to their discipline to their digital classroom space each week for students to read at their leisure. Or you could bring discipline specific literacy skills into your classroom by incorporating short texts into your lessons a few times each quarter.

I’m planning now to read a career profile with my students one time per week. I’ll keep the texts short so that reading, annotating, and discussing the text will stay under 15 minutes.  Some careers from the ship they might find interesting are the Chief Bosun position or a NOAA Corps Officer, but I’ll share a wide variety of career profiles from many disciplines based on the students’ interests once I meet them this year.


TEACHING RESOURCES

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Erica Marlaine: One Fish, Two Fish, June 26, 2019

NOAA Teacher at Sea

Erica Marlaine

Aboard NOAA Ship Oscar Dyson

June 22 – July 15, 2019


Mission: Pollock Acoustic-Trawl Survey

Geographic Area of Cruise: Kodiak Island, Alaska

Date: June 26, 2019


Weather Data from the Bridge:

Latitude: 58º 33.15 N
Longitude: 152º 58.87 W
Wind Speed: 17.5 knots
Wind Direction: 229º
Air Temperature:  13º Celsius
Barometric Pressure: 1020.2 mb


Science Log

Today we did our first two trawls of the trip. According to Webster’s dictionary, trawl is defined as the act of fishing with a trawl net, which is a large conical net dragged along the sea bottom in order to gather fish or other marine life. It can also mean the act of sifting through something as part of a search.  Both definitions are accurate for what is done on the NOAA Ship Oscar Dyson.

The Oscar Dyson uses a variety of nets to catch the fish being studied. One net that has been used for many years is called an Aleutian Wing Trawl (or an AWT). The mesh size of the AWT is ½ inch.  Attached to the AWT net are smaller nets (called pocket nets) which also have a ½ inch mesh size.  The new net being used this year is an LFS 1421, which has a 1/8 inch mesh size. It has 9 pocket nets, also with 1/8 inch mesh size. It is thought that fewer fish will escape the LFS net because the mesh size is smaller, in turn allowing the scientists to get a more accurate picture of the fish and other creatures living in the areas they are trawling.  Trawls are being conducted using both nets (back-to-back) to determine the extent to which the new net is more efficient and provides a more accurate measure.

AWT and LFS nets
The older AWT net is on the left. The newer LFS 1421 net is on the right.

Once the nets are pulled in, the processing begins. The main net (i.e., codend) is emptied onto the large processing table in the fish lab.

catch on the processing table
One catch on the processing table.

Each pocket net is emptied into a separate plastic bin.  The fish are then identified, weighed, measured, and sometimes dissected in order for us to accurately determine the age and sex of each fish.

Evan with plastic bin
Volunteer Biologist Evan Reeve with a pocket net bin.

Otoliths (ear bones) and ovaries are collected from a sample of the walleye pollock caught in the codend of the net. Otoliths allow scientists to determine the age of the fish.  Over time, ridges form on the otoliths, and are indicative of age in much the same way a tree’s age can be determined by counting the rings of its trunk. 

Ovaries are collected to be sent back to the lab as part of a long-term histology study which hopes to determine whether walleye pollock experience multi-batch spawning events (i.e., do pollock spawn more than one time) within or between seasons. Histology, also known as microscopic anatomy or microanatomy, uses a microscope to study the anatomy of biological tissues. In contrast, gross anatomy looks at structures without a microscope.

After a trawl, scientists onboard the NOAA Ship Oscar Dyson examine the ovaries with the naked eye to determine the reproductive stage of the walleye pollock that has been caught. There are 5 stages: Immature (not yet capable of spawning, typically age 0-2); Developing (beginning to develop the ability to spawn) Pre-spawning, Spawning, and Spent (completed spawning).  Once a pollock spawns, it begins the cycle again beginning at step 3 (pre-spawning). Additionally, the histology study also hopes to determine whether the spawning stages being designated by scientists during the cruise are in fact accurate.

Elementary Math Fun

Let’s say 200 total fish were caught in the new LFS 1421 net, including the nine pocket nets attached.

Pocket nets 1, 2 and 3 each had 20 age-0 pollock in them.

Pocket nets 4, 5 and 6 each had 13 lantern fish in them.

Pocket net 7 had 3 small herrings  in it.

Pocket nets 8 and 9 each had 2 age-1 pollock in them.

How many fish were in the codend or main part of the net?


Personal Log

As a Southern Californian, I imagined Alaska to be cold even in the summer, and packed sweaters and a big puffy winter coat.  Apparently shorts and t-shirts would have been more appropriate! The weather in Kodiak has been warm and beautiful, with the sun shining until midnight.

Barometer Mountain
Barometer Mountain, Kodiak, Alaska

My first day in Kodiak was a free day, so I joined the science team on a hike up Barometer Mountain, which many say is the most difficult hike in Kodiak.  It is 2100 feet straight up a very steep, rocky, brush-filled path, and then 2100 feet down that same, steep path.  It was quite the challenge, but the view from the top was magnificent.

NOAA Ship Oscar Dyson
My home for the next three weeks!

At present, there are 31 people onboard the NOAA Ship Oscar Dyson, including NOAA corps officers, engineers, deck personnel, cooks, scientists, interns, and me, the NOAA Teacher at Sea. The ship, which was originally launched in 2003, and commissioned into service as a NOAA ship in 2005, is named for Alaskan fisherman and fishing industry leader Oscar E. Dyson. It is one of the most advanced fisheries research vessels in the world, due in part to its acoustic quieting technology.  This allows scientists to monitor fish populations without concern that the ship’s noise will affect the behavior of the fish.

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Justin Garritt: Paired Trawling, X-raying, and The Galley Master: September 11, 2018

NOAA Teacher at Sea

Justin Garritt

NOAA Ship Bell M. Shimada

September 1-14, 2018

Mission: Hake Research

Geographical area of cruise: Seattle, Washington to Newport, Oregon

Date: September 9-11, 2018: Day 7-9

Location: West of the Columbia River and Astoria, Oregon

 

Where Are We? After fishing off of the Straits of Juan de Fuca on Friday and Saturday, we headed south.  We ended up west of the Columbia River off the coast of Astoria, Oregon and continued to fish for a few days.

Heather and I with a large hake
A canary rock fish
Hello Sunday morning!
A chilly morning aboard the Shimada outside the Oregon coast
Beautiful cloudy evening
Cruise ship
Lots of krill

 

The fishing and sampling continues: A typical day consists of the scientists waking up before sunrise to begin scouting for fish. We use the information from the acoustic transducer to find fish.

Chief Scientist Rebecca Thomas
Chief Scientist Rebecca Thomas spots signs of fish on the sonar

sonar from the acoustic transducer
The sonar from the acoustic transducer showing signs of fish

Paired Trawling: Last week I wrote about our goals of the cruise. One of them was to perform paired trawls to determine net size impact to evaluate the differences between the US 32mm net liners and the Canadian 7mm net liners. A paired trawl is when we fish approximately the same location and depth two times using two different size liners. Data is collected on the size, characteristics, and species of fish being caught to eliminate the possibility that there is bias in the data between the two liners. Below are pictures of the nets being sent in and brought back based on information from the sonars. This typically happened 2-4 times per day (1-2 paired trawls).

The net out
The net getting pulled back in
The catch
The catch being dumped in the hopper
The catch being dumped in the hopper
The catch in the hopper

 

Sorting the Fish Aboard:

The fish coming down from the hopper
The fish coming down from the hopper
The fish coming down the conveyor belt
Rebecca sorting the fish by species
A yellow rock fish is sorted
The hake continues down the belt
Dr. Dezhang Chu inspects the different species
A rockfish covered with krill
Jellyfish covered in krill
A small squid
Sorting the rockfish
One of numerous hake baskets
Lampreys
Rockfish
Charlie and Heather sorting the catch

rockfish photo shoot
A rockfish photo shoot 🙂

How We Collect Data:

When fish come aboard we follow this flow chart to determine what analysis needs to be done on the catch.

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Our instructional chart for how we analyze the hake and other species

Hake is the majority of the fish we catch. It is also the main species we are researching this cruise.

A random sample of 250 are set aside and the rest are sent back in to the ocean. Of the approximately 250 random hake, 30 are dissected for enhanced sampling (length, weight, sex, maturity, and other projects).

220 are set aside for sex/length analysis. All other species of fish must be logged into the computer and some are kept for special research projects. See pictures below:

Male vs. female hake distinction:

A Pacific hake
Determining the sex of the hake
A male hake
A female hake

Determining the length of the hake:

Determining the length of rockfish
Determining the length of each hake
Determining the length of hake

Enhanced sampling (length, weight, sex, maturity, and other projects):

Dr. Melanie Johnson dissects a hake
Scientist Steve de Blois measuring hake
Scientist Steve de Blois plus in data from his station

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Dissecting the hake to enhance sample

Special Projects: There are also a number of special projects going on aboard:

Fish X-ray: Scientist Dezhang Chu x-rays samples of fish occasionally. The x-ray is used to determine the volume of the swim bladders in certain species of fish (see picture below). The volume of different species’ swim bladders affects the observed acoustics. I spoke to him about the purpose of this study. He said that the present acoustic transducers are great to capture whether fish are present below the ship’s surface but are still not able to classify the type of species being observed. He is working on a team that is trying to use x-ray’s from multiple species to solve that problem. When asked how long he thought it may take for there to be an acoustic system advanced enough to better predict the species onscreen, he said, “People have and will continue to spend their entire careers on improving the system.” If we have more scientists like Dr. Chu on this project, I predict it will be much sooner than he leads on.

X-ray of a rock fish
Dr. Dezhang Chu teaching me about the x-ray project
Dr. Dezhang Chu x-raying a rockfish
Dr. Dezhang Chu x-raying another rockfish

"Super Chu"
“Super Chu” and I with his new apron I made him for x-raying

Filming the Catch: Melanie Johnson leads the science team’s visual analysis. During each trawl a camera is placed securely on the net. The purpose of the net is to analyze approximately which depth and time certain fish enter the net.

Cameras being detached from the net for analysis
Scientist Melanie Johnson collects data from the camera that was in the fishing net

fish entering the net
Camera footage of fish entering the net

———————————————————————

Getting to know the crew: As promised in other blog posts, here is another interview from the incredible crew aboard  NOAA Ship Bell M. Shimada who continue to make my journey such a rich experience:

Mr. Arnold Dones, Head Chef

Arnold Dones is our head chef or what I like to call him, “Master Chef.” Since the minute I’ve been aboard I quickly noticed the incredible work ethic and talent of our chef. To be clear, every meal has incredible! When I spoke to my mom a few days into the cruise my exact words were, “The food aboard is better than a buffet on a cruise ship. I expected to come aboard for two weeks and lose a few pounds. Well that’s not going to happen!”

Chef Arnold
Chef Arnold and his incredible food artwork

Arnold was born in the Philippines and his family migrated here when he was twenty. When he first got here he knew very little English and worked hard to learn the language and the American culture. He worked a few odd and end jobs until he joined the United States military as a chef. During his first years in the military, he showed so much promise as a chef that he enrolled in “A School” which allowed him to learn how to be a master chef in the military. He spent more than a decade working on military vessels. His last ship placement was aboard the USS Ronald Reagan where he and his team prepared meals for 6,000 soldiers per meal. Two months ago he joined the NOAA Ship Bell M. Shimada family as head chef.  Arnold has two children and a wife who live back in San Diego.

After a tour of the galley with Arnold, I learned how much work it takes to pull 42 meals in 14 days for over 40 crew members without a supermarket nearby. A few weeks out, Arnold has to create his menu for the next cruise leg (typically two weeks). He then has to order the food required to make the meals and do so by staying under a strict budget. When the ship ends a leg and pulls in to port, a large truck pulls up and unloads all his ordered food in large boxes. He then organizes it in the order he plans to prepare it in his large freezer, refrigerator, and store rooms. The trick is to be sure his menu is organized so nothing spoils before it is used.  Arnold’s day begins at 05:00  (5am) and goes until 19:00 (7pm) with a short break after lunch. The only days off he has is a day or two once every two weeks when the boat is in port.

Master Chef Arnold showing me his organized refrigerator
The mess hall
The menu is posted for every meal
An amazing buffet is served three times a day at 7am, 11am, and 5pm.
Salad is available 24 hours a day
Arnold’s art work
Lunch one day
Dinner one night

Here is a sample menu for the day:

Breakfast (7-8am)- Eggs benedict, blueberry pancakes, french toast, hash browns, scrambled eggs, oat meal, cut fresh fruit, and breakfast danish.

Lunch (11-12pm)- Bacon wrapped rockfish, chicken wings, Chinese noodles, brussel sprouts, bread, a large salad bar, homemade salads, avocado, bean salad, homemade cookies, and ice cream.

Dinner (5-6pm)-  Stuffed pork chops with spinach and cheese, fine braised chicken thigh, baked salmon, Spanish rice, oven potatoes, peas, dinner rolls, a large salad bar, homemade salads, homemade apple pie, and ice cream.

Snack (24/7)- Soup, crackers, ice cream, and salad/fruit bar

King crab legs!
Crab legs and t-bones at sea 🙂

We dock in Newport, Oregon on Friday, September 14, 2018. My final post will be on Friday. Thank you for continuing to follow along in this journey. I am grateful for your support and for the amazing people I have met aboard.

Justin

 

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Kimberly Godfrey: Night time..Day time! June 10, 2018

NOAA Teacher at Sea

Kimberly Godfrey

Aboard NOAA Ship Reuben Lasker

May 31 – June 11, 2018

 

Mission: Rockfish recruitment and ecosystem assessment survey

Geographic Range: California Coast

Date: June 10, 2018

Data from the Bridge

Latitude: 36° 39.980′ N

Longitude: 122° 33.640′ W

Wind: 30.87 Knots from the SE

Air Temperature: 12° C

Waves: 2-3 feet with 6-8 foot swells

Science Log

As you may have gathered from my previous blogs, I spent my time working with the night scientists. However, there was a lot happening during the daylight hours that I would like to highlight. There was a separate team assigned to the day shift. Some of their tasks included analyzing water samples, fishing, and surveying marine mammals and seabirds.

Catching fish during the day allowed them to see what prey were available to diurnal predators, and they could also compare their daytime catch to the evening catches. They used a different net called a MIK Net, which is a smaller net used for catching smaller and younger fish.

MIK Net
The MIK net used by the day time scientists to catch juvenile fish.

The day shift is also the best time for spotting seabirds and marine mammals. Some of the bird species spotted included brown pelican, common murre, terns, black-footed albatross, shearwaters, and at least 1 brown booby. The marine mammals we spotted included humpback whales, fin whales, blue whales, common dolphins, and sea lions.

I had an opportunity to speak with Whitney Friedman, a postdoctoral researcher with NOAA, and she explained to me some of the goals of their marine mammal survey. Many may recall that there was a time when whale populations, especially humpback whales, were in significant decline. Today, humpback whales are considered a success story because of rebounded populations. The concern now is monitoring the success of their food sources. Humpback whales feed on krill and fish like anchovies. However, it is possible that when these sources are less available or as competition increases, they may feed on something else. The question is, what is that something else? During this survey, one goal was to collect whale scat for analysis. Studies have found that some seabirds feed on juvenile salmon incidentally when their preferred local prey is limited, and they move inshore to feed on anchovy. Is it possible that whales might do the same? What else might they be foraging on? Unfortunately, we did not have much luck catching whale scat this time around, but they will try again in the future, and hopefully will find the answers they are looking for.

As previously mentioned, we also did water quality tests and took water samples using the Conductivity, Temperature, and Depth (CTD) Rosette. This instrument has multiple functions. As the initials suggest, it detects conductivity (the measure of how well a solution conducts electricity) and temperature at any given depth. Salinity (the amount of dissolved salts and other minerals) and conductivity are directly related. By knowing the salinity and temperature, one can determine the density. Density is one of the key factors that drives the ocean currents. Many species depend on the ocean currents to bring in nutrients and food. It all comes full circle.

CTD
CTD Rosette used to capture conductivity, temperature, and depth. We also used this to take water samples at specified depths.

CTD
The CTD is lowered into the water by a winch with the assistance of the deck crew.

When we lowered the CTD we could also take water samples at any given depth. This allowed scientist to test for various parameters. For example, we filtered various water samples to determine the amount of chlorophyll at certain depths. This can help scientists estimate the growth rates of algae, which in the open ocean are called phytoplankton. One of the scientists collected water to analyze for environmental DNA (eDNA). This is DNA that might be left in the air, soil, or water from feces, mucus, or even shed skin of an organism. In her case, she was trying to find a way to analyze the water samples for sea turtle DNA.

I’ve heard of eDNA, but I have never actually understood how they collected and analyzed samples for this information. My understanding is that it can be used to detect at least the presence of an extant species. However, when collecting these samples, it is likely to find more than one species. Scientists can use previously determined DNA libraries to compare to the DNA found in their samples.

Personal Log

We started trawling again on the evening of June 7th. By then we settled ourselves into the protection of the Monterey Bay due to the weather getting bad. While we still had some off-shore stations, we tried our best to stay close to the bay because of the wind and swells. We had some interesting and challenging trawls in this area: lots of jellyfish. Some of the trawls were so full we had to actually drop the catch and abort the trawl. If not, we risked tearing the net. We tried to mitigate the overwhelming presence of jellies by reducing our trawls to 5 minutes instead of 15 minutes, and we still had similar results. One night, we had to cancel the final trawl to sew up the net. I’ve been told that sewing a fish net is an art form. Our deck hands and lead fisherman knew exactly what to do.

Let me tell you my experience with jellyfish during the survey. As you may recall, someone must be on watch for marine mammals on the bridge. This is the ship’s control room that sits on the 5th level above water.

Reuben Lasker
The Bridge of the Reuben Lasker is where we do inside Marine Mammal Watch. This is where the main controls of the ship are located.

From here you can see the surface of the water quite well, which makes it a great spot for the marine mammal watch. It was also great for watching hundreds of moon jellies and sea nettles float right by. It was one of the coolest things to watch. It was somewhat peaceful, especially hanging your head out of the window, the cool air blowing against your face, and the occasional mist of sea spray as the ship’s hull crashes against some of the larger swells. However, that same peaceful state disappears the moment you realize, “I’m gonna have to lift, count, and sort all those jellies!” I wasn’t too concerned about being stung; we had gloves for the sea nettles and the moon jellies were no real threat. However, the sea nettles (Chrysaora fuscenscens) smelled AWFUL, and the moon jellies (Aurelia spp.) are quite large and heavy. I’m honestly not sure how much they weighed; we did measure up to 20 per haul, some of them measuring over 400 mm. Even if they weighed about 5 pounds, lifting 50-60 of them consecutively until the count is complete is enough to get the muscles burning and the heart rate elevated. It was a workout to say the least. I was literally elbows deep in jellyfish. I also wore my hair in a ponytail most of the time. Anyone that knows me knows well enough that my hair is long, and definitely spent some time dipping into the gelatinous goop. I smelled so bad! HAHAHAHA! Nonetheless, it was still one of the most intriguing experiences I’ve had. Even though the jelly hauls proved to be hard work, I enjoyed it.

In those last few days, I felt like I became integrated into the team of scientists, and I felt comfortable with living out at sea. I had a few moments of nausea, but never really got sea sick. I still couldn’t walk straight when the ship rocked, but even the experts wobbled when the ship hit the big swells. Then, that was it for me. By the time I got the hang of it all, it was time to leave. I wish there were more hours in the day, so I could have experienced more of the day time activities, but I still got to see more than I thought I would, and for that I am grateful.

Did you know…

NOAA offers many career options. As a scientist, here are some things one might study:

  • track and forecast severe storms like hurricanes and tornadoes; monitor global weather and climatic patterns
  • Research coastal ecosystems to determine their health, to monitor fish populations, and to create policies that promote sustainable fisheries
  • Charting coastal regions and gathering navigational data to protect the ship from entering unsafe waters

NOAA Corps allows one to serve as a uniformed officer, commanding a ship or piloting aircraft. On NOAA Ships, they need engineers, technicians, IT specialists, deck hands, fishermen, and even cooks (The Reuben Lasker had two of the best, Kathy (Chief Steward) and Susan (second cook)). There are many opportunities available through NOAA, and there is a longer list of amazing experiences one can have working for this organization. If you want to explore in more detail, visit http://www.careers.noaa.gov/index.html

 

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Amanda Dice: Fish Sticks with a Side of Science, August 29, 2017

NOAA Teacher at Sea

Amanda Dice

Aboard NOAA Ship Oscar Dyson

August 21 – September 2, 2017

 

IMG_1553
We have made it to the most northern point on the survey.

Mission: Juvenile Pollock Fishery Survey

Geographic area of cruise:
Western Gulf of Alaska

Date: August 29, 2017

Weather Data: 10.2 C, rainy/stormy

Latitude: 59 20.0 N, Longitude: 152 02.5 W

 

 

Science and Technology Log

The main focus of this survey is to gather information about juvenile walleye pollock, Gadus chalcogrammus. Juvenile pollock less than 1 year of age are called young-of-the-year, or age-0 juveniles. Age-0 walleye pollock are ecologically important. Many species of birds, mammals and other fish rely on them as a food source. Adult pollock have a high economic value. Pollock is commercially fished and commonly used in fish sticks and fish and chips. This study is interested in learning more about the size of current juvenile pollock populations, where they occur, and how healthy they are.

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An age 0 juvenile pollock is shown below an adult pollock.

In order to collect a sample, a trawl net is lowered into the water off of the back of the ship. The deck crew and bridge crew work together to release the right amount of wire and to drive the ship at the right speed in order to lower the net to the desired depth. The net is shaped like a sock, with the opening facing into the water current. In order to keep the mouth of the net from closing as it is pulled through the water, each side is connected to a large metal panel called a “door”. As the doors move through the water, they pull on the sides of the trawl net, keeping it open. When the doors are ready to be put in the water, the fishing officer will instruct the winch operator to “shoot the doors”!

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The deck crew bring the trawl net back on deck. One of the metal “doors” can be seen hanging off of the back of the ship.

Sensors help monitor the depth of the upper and lower sides of the net and relay a signal to computers on the bridge, where the data can be monitored.

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Sensors on the trawl net relay data to computers on the bridge which show the position of the net in the water.

Once the net is reeled in with a large winch, the catch is placed on a sorting table, in a room just off of the back deck called the fish lab. Here, the science team works to sort the different species of fish, jellyfish, and other kinds of marine animals that were caught.

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Crew members stand below a winch and empty the catch from the trawl net into a large bin.

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The catch is then sorted on the sorting table in the fish lab.

Juvenile pollock are sorted into their own bin. If it is a small catch, we weigh, count, and measure the length of each one. However, if it is a large catch, we take a smaller sample, called a subsample, from the whole catch. We use the weight, lengths, and count of animals in the subsample to provide an estimate count and average size of the rest of the fish caught at that station, which are only weighed. This information is compiled on a computer system right in the fish lab.

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Here I am measuring some fish.

 

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Data from the catch is collected on computers in the fish lab.

 

The focus of this study is juvenile pollock, but we do catch several other species in the trawl net. The presence of other species can provide information about the habitats where juvenile pollock live. Therefore, data from all species collected are also recorded.

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Here are some other interesting species we caught: 1. jellyfish (with a partially digested pollock inside it!) 2. lumpsucker 3. herring 4. spider crab

A small sample of juvenile pollock are frozen and saved for further study, once back on land. These fish will be analyzed to determine their lipid, or fat, content and calorie content. This data reveals information about how healthy these fish are and if they are getting enough food to survive through the cold Alaskan winters.

Other agencies within NOAA also conduct scientific surveys in this area. These studies might focus on different species or abiotic (non-living) properties of the Gulf of Alaska marine ecosystem. The data collected by each agency is shared across the larger NOAA organization to help scientists get a comprehensive look at how healthy marine ecosystems are in this area.

 

Personal Log

As we move from one station to the next, I have been spending time up on the bridge. This gives me a chance to scan the water for sea birds and marine mammals, or to just take in the scenery. Other members of the crew also like to come up to do this same thing. I have really enjoyed having this time every day to share in this activity (one of my favorite past-times) with other people and to learn from them how to identify different species.

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Here I am outside of the bridge, posing with some glaciers!

 

Did You Know?

You can find the exact age of many fish species by looking at a bone in their ears! Fish have a special ear bone, called an otolith. Every year, a new layer will grow around the outside of this bone. As the fish ages, the otolith gets larger and larger. Scientists can find the exact age of the fish by cutting a cross section of this bone and counting the rings made from new layers being added each year.

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A small otolith of an age 0 juvenile pollock

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Larger otoliths from an adult pollock

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Anna Levy: First Day of Fishing! July 12, 2017

NOAA Teacher at Sea

Anna Levy

Aboard NOAA Ship Oregon II

July 10 – 20, 2017

 

Mission: Groundfish Survey

Geographic Area of Cruise: Gulf of Mexico

Date: July 12, 2017

 

Weather Data from the Bridge

We’re traveling through some mild rainstorms. Nothing extreme, but we do feel a little more side to side rocking motion in the boat (which makes me feel sleepy!)

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Mild rainstorms on the horizon

Latitude: 29 degrees, 56.2 minutes North

Longitude: 86 degrees, 20.6 minutes West

Air temp: 24.7 degrees Celsius

Water temp: 30.1 degrees Celsius

Wind direction: light and variable

Wind speed: light and variable

Wave height: 1 foot (about 0.3 meters)

Sky: overcast with light rain

 

Science and Technology Log

Today I completed my first shift on the science team and we surveyed 3 complete stations. At each station, we carried out a multi-step protocol (or procedure). Here are the steps:

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The Depth Contour Output graph displays data collected from one station.

Before we begin fishing, the ship conducts a transect (or cross-section) of the survey area, using multiple pieces of equipment to observe the ocean floor. This tells us if it is safe (for both ship operations and for fragile coral that may exist) to trawl here. If a coral reef or other large obstacle was present, we would see significant variation in the depth of the ocean floor. This “depth contour output” graph shows the data we collected at one station. How deep is the water at this station? Is it safe to trawl here?

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The CTD collects information about water chemistry

We also use a collection of instruments called a “CTD” to collect information about the chemistry of water itself at different depths. This information is called the water’s “profile.” For fisheries studies, we are most interested in the amount of dissolved oxygen and the temperature at different depths. Why might this information be relevant for understanding the health of fish populations?

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Forel-Ule color scale

We also measure the water color using the Forel-Ule color scale by matching it to the samples shown in this photo. This gives scientists an indication of the amount of particulates, chlorophyll, and nutrients are in the water.

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Trawl Net being lowered into water

Once we determine it is safe to trawl, the ship returns to the starting location. We will trawl along the same path that we observed. Here’s the trawl net before it is lowered into the water. It will be pulled just along the bottom of the survey area, using tickler chains to agitate the ocean floor for benthic organisms for 30 minutes, and collecting whatever crosses its path!

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The catch is emptied into baskets

Once the trawl is finished, the deck crew uses a large crane to pull the trawl on board. We all help to empty the net and place everything into baskets. Most of what we catch are biological organisms, but small amounts of non-living material (like shells, dead coral, and even trash) come up as well.

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The Wet Lab

We then bring the baskets into the wet lab.

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Baskets are emptied into a long trough with a conveyor belt

We dump the baskets into a long metal trough that has a conveyor belt at the bottom.

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The catch is sorted into baskets by species

Next we sort the catch. Each species gets its own basket and we count the number of individuals for each species.

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Identifying organisms

Then, it’s time for the tough part (for me at least) – every organism has to be identified by its scientific name. That’s a lot of Latin! Fortunately, Andre and the senior scientists are very patient and happy to help those of us who are new. It’s amazing how many species these experienced scientists recognize off the top of their heads.

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Field Guides

We also have many field guides, which are books containing photos and descriptions of species, to help us.

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For each species, we record the total number of individuals and total mass

We are interested in how much of each species are present, so we record both the total number of individuals and total mass of each species.

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TAS Anna Levy measures the length of a flatfish using the Limnoterra Board

We also measure the length and mass of a sample of individuals. A handy device called a Limnoterra Electronic Measuring Board makes this process easy.  We place the mouth of the fish on one end of this board and then touch its tail fin with a pen-like magnetic wand. The board then automatically sends the fish’s length to the computer to be recorded.  We use an electronic balance that is also connected to the computer to measure and record mass.

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A computer screen displays FSCS software

All of the information is recorded in a database, using software called FSCS (pronounced “fiscus”).

Many of the specimens we collect are saved for use in further research on land.   Scientists at NOAA and other research institutions can request that we “bag and tag” species that they want. Those samples are then frozen and given to the scientists when we return to shore.

Any organisms or other material that remains is returned to the sea, where it can be eaten or continue its natural cycle through the ecosystem. The conveyor belt, conveniently, travels to a chute that empties back into the ocean. Now all that’s left is to clean the lab and wait for the process to begin again at the next station!

Our goal is to complete this process 48 times, at the 48 remaining stations, while at sea. 3 down, 45 to go!

Personal Log

IMG_1048
Sometimes the work is high-paced…

This work has real highs and lows for me, personally. There are dramatic, hold your breath, moments like when equipment is lifted off the deck with cranes and lowered into the water. There is the excitement of anticipating what data or species we will find. My favorite moment is when we dump the buckets and all of the different species become visible. I’m amazed at the diversity and beauty of organisms that we continue to see. It reminds me of all of the stereotypical “under the sea” images you might see in a Disney movie.

The more challenging part is the pace of the work. Sometimes there are many different things going on, so it’s easy to keep busy and focus on learning new things, so time passes quickly. Other times, though, things get repetitive. For example, once we start entering all of the data about the individual fish, one person calls out the length and mass of a fish, while the other enters it into the computer – over and over until we’ve worked through all of the fish.

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… but sometimes the work even stops altogether, especially when whether interferes.

Sometimes, the work even stops altogether, especially when the weather interferes. There have been mild rainstorms coming and going continually. It is not safe to have people on deck to deploy the CTD and trawling equipment when there is lightning in the area, so there is nothing for the science team to do but wait during these times.

Because the pace of the work is constantly changing, it’s difficult to get into a groove, so I found myself getting really tired at the end of the shift. However, an important part of collecting data out in the field is being flexible and adapting to the surroundings. There is a lot to accomplish in a limited amount of time so I keep reminding myself to focus on the work and do my best to contribute!

Did You Know?

When working at sea, scientists must use special balances that are able to compensate for the movement of the ship in order to get accurate measurements of mass.

To ensure that we are accurately identifying species, we save 1 individual from each species caught at a randomly selected station. We will freeze those individuals and take them back to NOAA’s lab in Pascagoula, where other scientists will confirm that we identified the species correctly!

Questions to Consider:

Review: Look at the “depth contour output” graph above: How deep is the water at this station? Is it safe to trawl here?

Research: What does “CTD” stand for?

Research: For fisheries studies, we are most interested in the amount of dissolved oxygen and the temperature at different depths. Why might this information be relevant for understanding the health of fish populations?

Reflect: Why might scientists decide to use three different pieces of equipment to collect the same data about the ocean floor? And, why might they have several different scientists independently identify the species name of the same individuals?

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Sian Proctor: Nothing But Net!, July 12, 2017

NOAA Teacher at Sea

Sian Proctor

Aboard Oscar Dyson

July 2 – 22, 2017

Mission: Gulf of Alaska Pollock Survey

Geographic Area of Cruise: Gulf of Alaska

Date: July 12, 2017

Me next to chafing gear from AWT. Image by Meredith Emery.

 

Weather Data from the Bridge

  • Latitude:   56° 46.8 N
  • Longitude: 154° 13.7 W
  • Time: 0800
  • Sky:Clear
  • Visibility: 10 nautical miles
  • Wind Direction: 279
  • Wind Speed: 9 Knots
  • Sea Wave Height: 1-2 foot swell
  • Barometric Pressure: 1019.9 millibars
  • Sea Water Temperature:   11.1°C
  • Air Temperature:   12.0°C
  • Sunrise: 0531
  • Sunset: 2300

Science and Technology Log: Nothing But Net!

Once the scientists determine where and how deep they want to fish, based on analyzing the echogram, then the boat moves into position and the net is deployed. Safety is the top priority when working on the vessel. The deckhands all have to wear life jackets, hard hats, and good boots when working on deck because the conditions can be sunny one moment and stormy the next.  There is some serious hardware at the back of boat. There are cranes, winches, and spools of wire ropes & chains. The Chief Boatswain is responsible for all deck operations and deploying any gear overboard. The following video illustrates the sampling process using an Aleutian Wing Trawl net.

There is a camera (aka camtrawl) attached to the net along with a small pocket net. The pocket net is designed to catch tiny animals that slip through the AWT meshes. The pocket mesh only catches a small amount of escaping animals which can then be used to determine what was in the water column with the bigger pollock. The camtrawl has a pair of cameras that shoot stereo images of what is entering the net. The camtrawl was developed by NOAA scientists and its goal is to estimate the size and identify the species that enter the net using visual recognition software from University of Washington. The ultimate goal of the camtrawl is to be able to identify everything entering the net without ever having to actually catch the fish.

 

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A limitation of the AWT is that it can’t go closer than a few meters from the sea floor. Pollock are semi-pelagic so they are sometimes down at the sea floor and a different net is used. The Poly Nor’Easter (PNE) is used to trawl along the bottom of the Gulf of Alaska because the bottom can be rocky. The PNE has roller gear along its bottom to keep it from getting stuck. The opening of the PNE is 6 meters tall and 15 meters wide and also funnels to a codend.

There is a third net on Oscar Dyson called the Methot and it is used to catch large plankton such as krill. The Methot is so small that it sits on the deck and is easily lifted and put into the water. The net you use is determined by what you are trying to catch and where they are located in the water column.

Interview with Ryan Harris

Chief Boatswain

Chief Boatswain Ryan Harris managing Oscar Dyson crane.

  • Official Title
    • Chief Boatswain
  • Normal Job Duties
    • I am in charge of the deck operations on board the ship from deploying gear over the side to up keep of the ship.
  • How long have you been working on Oscar Dyson?
    • 15 months
  • What is your favorite thing about going to sea on Oscar Dyson?
    • I get to see things normal people do not.
  • When did you know you wanted to pursue a career in science or an ocean career?
    • 11 years ago I fell in love with the excitement of travel.
  • What are some of the challenges with your job?
    • Trying to keep all the gear working to complete the mission.
  • What are some of the rewards with your job?
    • I get to serve my country and leave something behind that me and my family can be proud of.
  • Describe a memorable moment at sea.
    • Seeing killer Whales 5 feet away.

Interview with Tom Stucki

Lead Fishermen

Lead Fishermen Tom Stucki on the NOAA ship Oscar Dyson. Image by Matthew Phillips.

  • Official Title
    • Lead Fishermen
  • Normal Job Duties
    • I run the winches for trawls, Maintain and fix the nets, help with maintenance of our equipment. Paint and preserve the ship when time and weather allows, clean up inside of ship.
  •  How long have you been working on Oscar Dyson?
    • 2 months this time and a month long trip last year. I am a relief pool employee. I fill in where the fleet needs me.
  • Why the ocean? What made you choose a career at sea?
    • I grew up on the coast in a fishing community.
  • What is your favorite thing about going to sea on Oscar Dyson?
    • The crew and work we do.
  • Why is your work (or research) important?
    • Our work is translated back to the commercial fleets so we don’t end up overfishing.
  • When did you know you wanted to pursue a career in science or an ocean career?
    • Once I got out of the Army and went on my first successful Salmon fishing trip.
  • What part of your job with NOAA (or contracted to NOAA) did you least expect to be doing?
    • Traveling as a relief pool employee.
  • What are some of the challenges with your job?
    • Working 12 hour days for months at a time.
  • What are some of the rewards with your job?
    • Knowing that the work I am helping with actually matters and hopefully will have positive implications down the road.
  • Describe a memorable moment at sea.
    • There are lots but its always nice in the middle of a trawl when you look up the sun is setting the water is flat calm and you think to yourself “yeah, I get paid for doing this.

Interview with Jay Michelsen

Skilled Fisherman

  • Official Title
    • Skilled Fisherman
  • Normal Job Duties
    • Operations of equipment to facilitate the needs of the science party.
  •  How long have you been working on Oscar Dyson?
    • two years
  • Why the ocean? What made you choose a career at sea?
    • I love the challenge of creating something stable from something so uncertain and ever changing as the ocean.
  • What is your favorite thing about going to sea on Oscar Dyson?
    • Seeing some of the creatures that the ocean has living in its depth.
  • Why is your work (or research) important?
    • My work is important more for personal reasons, I am able to support my family and make their lives more comfortable. My work on the ship is nothing special besides understanding the rigging and being able to trouble shoot issues that arise just as quickly as they show up.
  • When did you know you wanted to pursue a career in science or an ocean career?
    • I have wanted to pursue a career on the water for as long as I can remember, however it was my mother five years ago who pushed me to follow that desire.
  • What are some of the rewards with your job?
    • I enjoy seeing the creatures that we pull up from the ocean. The pay isn’t bad. If you are able to stay in for a long period of time, you can get a stable retirement.
  • Describe a memorable moment at sea.
    • There was a time that we brought up a salmon shark in the net and I was able to get it back into the water by cutting a hole in the net and pulling it out with the help of another deckhand. It was exhilarating!

Personal Log

Me in the survival suit.

I will admit that my biggest concern with going to sea was the thought of falling overboard. Now that I have been on Oscar Dyson I have learned that safety is a top priority and there are a lot of procedures for keeping everyone productive yet safe. Every week there are safety drills such as fire, abandon ship, and person overboard. The one I like the most is the abandon ship because I get to try on the survival suit. The waters here are so cold that survival overboard is unlikely without the survival suit.

It is comforting to know that the crew of Oscar Dyson work hard to keep themselves and everyone on board safe. I am no longer afraid of falling overboard because I’ve learned to be safe when navigating around the vessel and I have finally developed my sea legs – well sort of! The weather has been amazing with smooth sailing almost everyday. We did have a few days with some rolling seas and I had to put a seasickness patch behind my ear.

 

Education Tidbit: NOAA Fisheries Website

Another cool NOAA website that lets you explore deeper into fisheries and this video shows you how to find information for educators and students.

Did You Know?

The average size of a Bering Sea commercial fishing net is 60m tall by 120m wide.

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Dana Chu: May 17, 2016

NOAA Teacher at Sea
Dana Chu
On Board NOAA Ship Bell M. Shimada
May 13 – 22, 2016

Mission: Applied California Current Ecosystem Studies (ACCESS) is a working partnership between Cordell Bank National Marine Sanctuary, Greater Farallones National Marine Sanctuary, and Point Blue Conservation Science to survey the oceanographic conditions that influence and drive the availability of prey species (i.e., krill) to predators (i.e., marine mammals and sea birds).

Geographic area of cruise: Greater Farallones, Cordell Bank, and Monterey Bay National Marine Sanctuaries

Date: Tuesday, May 17, 2016

Weather Data from the Bridge
Clear skies, light winds at 0600 increased to 18 knots at 0900, 6-8 feet swells

Science and Technology Log

Ahoy from the Bell Shimada! Today, I will explain three of the tools that are deployed from the side deck to obtain samples of the water and the ocean’s prey species.

First off we have the Harmful Algal Bloom Net, also known as the HAB Net, which is basically a 10-inch opening with a 39-inch fine mesh netting attached to a closed end canister. The HAB net is deployed manually by hand to the depth of 30 feet three consecutive times to obtain a water sample. The top fourth of the water collected is decanted and the remaining water (approximately 80ml) is transferred to a bottle which is then sealed and labeled with the location (latitude, longitude), date, time, vertical or horizontal position, and any particular comments. The samples will eventually be mailed off to California Department of Health Services lab for analysis for harmful toxins from algae that can affect shellfish consumers.

Next we have the hoop net, which is pretty much similar in design to the HAB net, except for a larger opening diameter of 3 feet (think hula hoop) and a net length of nine feet. The net tapers off into a closed container with open slits on the sides to allow for water drainage. The purpose of the hoop net to collect organisms that are found at the various depth levels of the deployment. The hoop net is attached to a cable held by the winch. The hoop net is lowered at a specific angle which when calculated with the speed of the vessel equates to a certain depth. The survey crew reports the wire angle sighting throughout the deployment.

Every time the hoop net is brought back up there is a sense of anticipation at what we will find once the canister is open. Coloring is a good indicator. Purple usually indicates a high concentration of doliolids, while a darker color may indicate a significant amount of krill. Phytoplankton usually have a brownish coloring. Many of the hoop net collections from today and yesterday include doliolids and colonial salps, neither are very nutrient dense. Yesterday we also found pyrosomes, which are transparent organisms that resemble a sea cucumber with little bumps and soft thorns along their body. The smallest pyrosome we came upon was two and a half inches with the largest over six inches long. A few small fish of less than one inch in length also showed up sporadically in these collections as well.

The Scientific team is looking for the presence of krill in the samples obtained. The Euphausia pacifica is one of the many species of krill found in these waters. Many tiny krill were found in the various hoop net deployments. On the last hoop net deployment for today and yesterday, larger sized krill of approximately 1 inch) were found. This is good news because krill is the dominant food source for marine mammals such as whales. Ideally it would be even better if the larger krill appeared more frequently in the hoop net samples.

Finally, we have the Tucker Trawl, which is the largest and most complex of the three nets discussed in today’s post. The Tucker Trawl consists of three separate nets, one for sampling at each depth: the top, middle, and bottom of the water column. Like the hoop net, the tucker trawl nets also have a canister with open slits along the side covered with mesh to allow water to drain. All three nets are mounted on the same frame attached to a wire cable held by the winch. As the Tucker Trawl is towed only one net is open at a time for a specific length of time. The net is closed by dropping a weight down along the tow. Once the weight reaches the net opening, it triggers the net to shut and sends a vibration signal up the cable line back to the surface which can be felt by the scientist holding the cable. The net is then towed at the next depth for ten minutes. Once the last net tow has been completed, the Tucker Trawl is brought back up to surface. Similar to the hoop net, the survey tech reads the wire angle throughout the deployment to determine the angle the cable needs to be at in order for the net to reach a certain depth. This is where all the Geometry comes in handy!

As mentioned already, with three nets, the Tucker Trawl yields three separate collections of the nutrients found within the top, middle and bottom of the water column. Once the nets are retrieved, each collection container is poured into a different bucket or tub, and then into a sieve before making it into a collection bottle. If there is a large quantity collected, a subsample is used to fill up a maximum of two bottles before the remainder is discarded back into the ocean. Once the samples are processed, an outside label is attached to the bottle and an interior label is dropped inside the bottle, formalin is added to preserve the sample organisms collected so that they can be analyzed later back in the lab.

Personal Log

It is so good to finally get my sea legs! I am glad I can be of use and actively participate. Cooperative teamwork is essential to getting everything to flow smoothly and on time. The Bell Shimada’s deck crew and NOAA team work hand in hand with the scientists to deploy and retrieve the various instruments and devices.

In the past two days I am getting a lot of hands on experience with deploying the HAB net to assisting with processing samples from the HOOP Net and Tucker Trawl. It’s always exciting to see what we might have collected. I can’t wait to see what the rest of the week may bring. I wonder what interesting finds we will get with the midnight Tucker Trawl samples.

Lesson Learned: Neatness and accuracy are imperative when labeling samples! Pre-planning and preparing labels ahead of time helps streamline the process once the samples are in hand.

Word of the Day:        Thermocline – This is the depth range where the temperature of the water drops steeply. The region above the thermocline has nutrient depleted waters and while the region below has nutrient rich waters.