Allison Irwin: The Otolympics, July 20, 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 20, 2019

Weather at 1300 Pacific Standard Time on Friday 19 July 2019

We’re rockin’ and rollin’ out to sea. This transect carries us 138 miles off the coast, and the winds are steady at 35-40 knots. Waves keep slapping up over the deck outside our lab. I’m watching it through a window. As the boat rocks back and forth, the full frame of the window alternates between powder blue sky and foamy, purple blue sea. We’ve started tacking (zig-zag) through the water so we can minimize the effect of the roll. But with 12 foot waves, it’s only a minimal aide to our comfort. We’ve rolled a full 35° and pitched about 15° throughout the day. Though I haven’t been outside to compare it to other days, the temperature on the monitor reads 17° Celsius. With the strong breeze, I must assume it feels colder than that outside.

PERSONAL LOG

Let’s talk about seasickness.  It rattles everyone from the novice to the career fisherman. It depends on sea state and state of mind. The rougher the weather, the more people seem to feel woozy and nauseated. There’s no pattern I can see between people who are new versus people who have been at this a while. It doesn’t seem to get any better with experience. Almost everyone I’ve talked to has taken some sort of motion sickness medication at some point over the last three weeks for some reason. I’d like to believe that the more healthy you are going into it – physically fit, decent diet – the more stoic your stomach will be, but I haven’t seen a connection in that respect either.

All I know, is that some people are sick and some are not.  Differences? Medication is one. We’re all taking different types. Of those I’ve seen wearing a patch, they are not feeling well. I’ve been taking Bonine and I’ve felt great the whole trip. Bonine is a chewable tablet that you only need once each day. I took it for the first few days, stopped taking it, then started again when the weather forecast looked bleak. I’ve found that if it’s in my system before the waves get choppy, then I fair well through the storm.

Another difference is attitude. Of the people who are not feeling well, those who smile and take it in stride are able to spend more time out of their staterooms focused on the task at hand – whatever their role may be. Distraction is a bonus. It’s not like you have a virus that is running its course. If you can get yourself good and distracted, it eases the symptoms and provides some relief.

And also, sleep. There is a definite connection between quality of sleep and symptoms of sea sickness. I’ve seen a solid nap cure a couple people of their ails. Thankfully, due to a little bit of luck and a little bit of Bonine, the waves lull me to sleep each night so I wake feeling rested and I do not contend with nausea during the day. All in all, the best combination I could have hoped for.

And then there are the folks who need no meds at all and they feel fine. Lucky ducks.

THE SCIENCE

Jack Mackerel Otolith Under a Microscope
photo taken by Bryan Overcash, Fisheries Biologist

Fifteen hundred years ago, a thousand years before Magellen’s crew successfully sailed around the world, sailors used otoliths to divine whether rough or fair seas awaited them on their journey. During the era of John Smith and Peter Stuyvesant, some Europeans recognized the otolith as medicinal with the ability to cure colic, kidney stones, and persistent fevers. If you’re truly interested in the legends associated with the otolith, you should read the brief and probably only account of Fish Otoliths and Folklore ever published.  Though primarily informative, it reads with a touch of humor and it’s easy to tell that Christopher Duffin enjoyed researching the topic. As did I!

The science of otoliths as they’re used in the modern era is even more incredible than the folklore. You can determine the age of a fish by reading the annuli on its otolith under a microscope just as a botanist might count the rings on a tree to determine its age. The bands themselves can tell scientists how fast a fish grew and whether it went through periods of slower growth or not. The unique chemistry in each ring can also be studied to learn just about anything you’d want to know from that year – water temperature, migration patterns, what the fish ate, and how healthy it was. Since the shape of an otolith is unique to its species, we can even study the stomach contents and feces of other animals like sea lions or predatory fish to build a picture of their diets. Scientists use this information to craft complex food webs.

Anthropologists find otoliths in ancient scrap food piles called middens that are still intact and can shine light on the diets of bygone cultures. On this trip we’re saving fish for scientists at the San Diego Natural History Museum so they can compare bones from the coastal pelagic species with bones that they’ve excavated from archaeological expeditions.

Jack Mackerel Otolith on my Keyboard

But what is an otolith? Some call it an earstone. The otolith is a small structure of calcium carbonate that accumulates throughout a lifetime.  Where humans have an ear canal, fish have an otic capsule that houses, actually, three symmetrical otoliths on each side of its head.  When people say otolith though, they’re typically referring to the sagitta which is the largest one (in most fish) and is usually situated just behind the stem of the brain. Those are the ones we’re collecting during the Coastal Pelagic Species Survey. It takes such a concerted effort to collect them each night that one of the interns, Hilliard Hicks, started calling it the Otolympics!

To get to it is not pretty. The otoliths are situated within the brain cavity, posterior and ventral to the brain itself. The easiest way to get to them in a Jack Mackerel without breaking the otoliths is to first make a vertical incision where the base of the fish’s head meets its body. Then, turning the fish onto its side, you make another cut across the top of the fish’s head from one eye to the other. You’re essentially cutting off and removing a rectangular section at the top of the head to reveal the brain cavity.  Then, after removing the brain, you get easy access to the otic capsule where the otoliths sit. Using small forceps or tweezers, we pull them out, dry them off, and encapsulate each fish’s sagittae in a vial for further study back on land. Multiply that process by about 75-100 and add weight and length measurements, and you get a sense of what our routine is after each trawl. We usually have 3-5 people attending to the task and it takes us roughly 45 minutes.

If you’d like, you can try determining the age of a fish without all the mess. This interactive Age Reading Demonstration website from NOAA is a great one for someone interested in the topic. It can also be used with students. New technology for aging otoliths seems to be on the horizon for scientists as well.

The main component of an otolith, calcium carbonate, is used today for lots of familiar medicines. While not derived from an otolith itself, it is still notable that calcium carbonate is a very common substance in pharmacology. We use it in antacids to neutralize the acid in our upset stomachs, to boost calcium thereby warding off osteoporosis, and to save us from enduring heartburn. It’s no wonder people used to pop otoliths in their mouth to cure what they identified as kidney stones. Maybe on some level, it really did help to assuage pain associated with their stomachs and digestion. In 2015, a team of scientists published a study in the Journal of Chemical and Pharmaceutical Research to share how they’ve been researching the use of otoliths with diabetes. There are far easier ways to collect stores of calcium carbonate, but the study shows that interest in otoliths stems not just to ichthyology, but also to climatology, anthropology, and pharmacology. It is an important little item.

Don’t have diabetes or an upset stomach? Not looking to see what the folks were eating in your neighborhood 500 years ago? Maybe you’d like to add an otolith to your wardrobe instead. In Alaska there are a couple of different places you could stop to purchase otoliths as jewelry.  When used in earrings they look like tiny little feathers. A unique gift item for sure.

TEACHING CONNECTIONS

Stick with me for a minute while I get to my point. Earlier this week one of the scientists taught me about ctenophores (pronounced teen-a-fours with emphasis on the first syllable). They’re a type of zooplankton that look like translucent globes. If you’ve ever blown a bubble and watched it shimmer in the sunlight, that is exactly what they look like under a microscope. Except now visualize that bubble with eight longitudinal stripes lined with hundreds of little hairs. This orb is a living creature called a ctenophore.

Later, while I was reading on my own to research otoliths, I stumbled across the word ctenoids. A ctenoid scale on a fish has many little cilia (tiny hairs or spikes) all around its edge. “Cteno-“ can be traced back to Latin or Greek origins to mean “little comb” and I was able to use that understanding to help me visualize a ctenoid fish scale. So, here’s my point. If it weren’t for that short exchange with the scientist earlier this week about ctenophores, I would have breezed right past the word ctenoid while reading without ever having paused to visualize what the fish scale looked like. I would not have learned as much while I was researching on my own.

As teachers, we can’t possibly know all the things our students will come across in a day. By teaching them Latin and Greek word parts that align to our curriculum, they stand a better chance of connecting their lives outside the classroom to our class content.

Prefixes, suffixes, and root words are used in every discipline to help identify concepts and patterns. Don’t teach them in the abstract, instead teach them in word groupings so our students’ brains have something to latch onto. I particularly enjoy using root word tree images. Spending 15 minutes per week going over a root word tree with students, and providing them a digital link so they can look over it again at their leisure, is an excellent way to ignite a conversation in your discipline. 

Sharing a root word tree with students can be a powerful way to solidify abstract concepts.

taken from https://membean.com/treelist

If I were a history teacher for example, I might choose to start a unit on modern democracy by passing out copies of the “dem: people” root word tree, telling each student to write a paragraph at the bottom of the page with whatever comes to mind while they’re looking at the tree. Then they could walk around the room sharing their writing with their classmates and highlighting patterns they find in the responses. They’ll hopefully never forget that a democracy is a government built of the people, by the people, and for the people (as the famous saying goes). At the very least, they’ll understand why the first three words of the preamble are “We the people…” and how a democracy is different from other forms of government like a monarchy, theocracy, and dictatorship.

TEACHING RESOURCES

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