Tag: trawl net

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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.

img_11131
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

IMG_1251
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