#otoliths

Otoliths - Lithos

These are remains from a fish called the freshwater drum (sheepshead). They were found in a refuse pit at an Oneota site in Onalaska. At the left is a pharyngeal arch—part of two matched pairs of plates in the fish’s throat, used for crushing mussels. The other four are otoliths, or “ear stones.” An otolith in each ear helps the fish with balance and movement. Two of the otoliths are burned. The three otoliths in the center are all lefts, and the one at the right is a right, from smaller fish. These right and left otoliths came from four different fish, and the pharyngeal arch represents another, smaller fish, bringing the total to five. Different sides and sizes of fish bones help us figure out how many fish are represented—the Minimum Number of Individuals, or MNI.

Freshwater drum have the largest otoliths of our freshwater fishes. The shape of drum otoliths makes them easy to identify, and their composition allows for exceptional preservation at archaeological sites. Comparing measurements of archaeological otoliths to modern specimens from fish of known weights provides a way for biologists and archaeologists to estimate size- and the contribution of drum fish to the diet. Otoliths from drum weighing 40 pounds or more have been found at La Crosse area Oneota sites.

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See the Sky About to Rain

© GIF Poetry by hiromi suzuki, 2022

published in otoliths issue 67 (November 1, 2022)

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“In Texas some people carry a small bone from a fish’s head as a charm against evil. This charm is most effective after it has been lost” (Hendricks 5). 

This superstition comes from Lubbock, TX, but is echoed by another superstition from Fort Worth, TX: “Two little bones, found in the head of a certain fish, are called lucky stones; but the good luck comes only after they are lost” (Bergen 57). What is the fish bone referenced?

Welp, I’m having trouble uploading videos to tumblr.  Let me know in the comments if you know any tricks when it comes to working with tumblr’s video sharing, it would be much appreciated. 

So instead, today we are going to do “Life on a Research Vessel Part 1″. 

One of my more recent trips was aboard NOAA’s Oregon II for a shark and red snapper longline research trip.  You can read more about the specifics of that trip and learn more about longline fishing here: https://teenyfish.tumblr.com/post/622033107021873152/marine-biology-story-of-the-day.

So on this trip, I was on the night watch as a scientist.  We were going to stations in the Gulf of Mexico around the clock, 24 hours a day, catching sharks and collecting data.  Night watch was from Midnight to Noon, so I generally woke up around 11:30 pm to throw on some clothes and grab a bowl of blue bell ice cream (breakfast of champions) and meet everyone in the science lab.  There, we would wait until we reached a station to set out our first longline. Once the longline was out we would wait 1 hour for the sharks to come biting. 

About an hour later, it was time to haul our line back.  Our boat crewmen had a winch to reel in the line, and our job was to process sharks and take data as quickly as possible to get them back in the water.  

tiger shark on the line, ready to come up.

Measuring, tagging, fin clipping, and hook removal on an Atlantic sharpnose. Fin clipping involved taking a “biopsy” of fin tissue, and this tissue will be instrumental in a variety of shark population genetics projects. 

weighing the shark--And then would send the sharks on their way!  This took about 5 minutes total to ensure the shark’s survival.  Sometimes we would have multiple sharks going at once--it’s always important to keep a good head during this so you process the babies quickly and don’t get hurt or bit. 

Then we would go and process the red snapper--red snapper are a large recreational game fish that hang out offshore along reefs, and they were another target species of this survey.  We would take a few fish to process (yes, they are dead).  

We would determine the sex of the fish and take sections of ovaries to determine information about reproductive health of this particular population, and we would take otoliths to determine the fish’s age.  An otolith is the ear bone of the fish--and it grows much in the same way a tree ring does.  The fish lays down individual growth rings each year in this teeny tiny bone, and you can read them like tree rings!

This information is crucial for us to understand how long it is taking fish to mature (warmer waters from climate change = fish mature faster, at smaller sizes, which means they produce less offspring).  Also, sex data determines the ratio of males/females in the population and helps fisheries management make decisions about size limits for fishermen to prevent overfishing of mature females.  After we got the data, we would filet the fish for the galley to cook up later (sorry vegetarians and vegans).

Then we we would do this on repeat for 12 hours--with a break for real breakfast at about 7 am.  We had a galley on board the ship and breakfast was always my favorite because it meant biscuits, pancakes, or french toast.   I would also always make sure to catch the sunrise beforehand, at 6 am 

And then our watch would end at noon, and we would eat lunch as dinner.  Sometimes we would head out to watch the day watch pull in a longline, but usually we would go back to our bunks to crash.  Since we were only out on this trip for 2 weeks, our bodies were still not used to that time change, and working 12 hours in the Texas heat probably contributed to that as well. 

sometimes, if I caught a day watch longline though, we would get to see some different cool stuff, like this remora 

remoras are basically fish with big suction cups on their heads.  They attach to the bellies of sharks, whales, and other large ocean going critters and scavenge from the meals the sharks catch.  

Our rooms were maybe 6ft by 8ft, with two bunks, a wardrobe for storage, and a sink.  Each room had one person on the night watch, and one on the day watch, so each person could sleep in peace while the other was working.  Each chief scientist and the Captain had rooms to themselves. There were 2 showers for a boat full of 30+ ppl, and showering in rough seas can be difficult (sometimes you just fall butt ass naked out of the shower if you aren’t holding on tight).  There was also a lounge stocked with movies that the navy gets pre-released (so I got to watch the live action Aladdin movie before it came out in theaters), laundry machines, and a small gym (haha, there was no way I was going to work out).