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
  • Chief Bosun Scott Jones
  • Trawl Entering the Water
  • Codend Floating in the Water
  • Trawl Net Snaking off the Stern
  • Floats Sewn into the Kites
  • Floats
  • Daisy Knot
  • Getting Ready to Add Tom Weights
  • Hauling the Net back on Deck
  • Prepping the Codend
  • 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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