larval fish – NOAA Teacher at Sea Blog

August 17, 2023August 18, 2023

Gail Tang: Contemplating the Enormity of the Minuscule, August 14, 2023

NOAA Teacher at Sea

Gail Tang

Aboard NOAA Ship Oscar Elton Sette

August 4, 2023 – September 1, 2023

Mission: Hawaiian Islands Cetacean and Ecosystem Assessment Survey (HICEAS)

Geographic Area of Cruise: Hawaiian archipelago

Date: Tuesday August 8, 2023

Weather Data from the Bridge

Temperature: 27.06° C

Latitude: 29°53’0” N

Longitude; 174°24’0”W

Science and Technology Log with Career Highlights

Previously, I wrote about the day-time operations focused on surveying whales, dolphins, and birds. Through the 25-powered binoculars (big eyes), the large mammals in the distance look microscopic. Now, the sun has set and I take us underwater to learn about the tiny world of ichthyoplankton, magnified to reveal intricate details of their exquisite structures.

Weather permitting, Nich Sucher (Survey Technician) works with the deck crew to deploy the CTD, which measures conductivity, temperature, and depth. This information is used to help scientists understand the physical, chemical, and biological changes of the ocean to help inform them of environmental changes. For example, Nich explained that data from CTDs are used to better understand why tuna were migrating away from Hawaii and towards California. The data can help answer whether the tuna are moving north for access to more oxygen in the water or for cooler temperatures. On our project, we deploy the CTD down to 1000m because that is where some of our deep diving cetacean species feed. Also, the temperature & pressure affects how sound travels through the water. This information can be used to calculate the speed of sound at different depths.

a view down the starboard rail of NOAA Ship Oscar Elton Sette. We see Logan, wearing a hard hat and life vest and facing away from us, lean his right arm over the rail. He looks down at the water as the CTD apparatus descends below the purple-blue surface of the water. In the distance, the sun has just set over the horizon, leaving orange, yellow, pink, purple skies dotted with a few scattered clouds. — Logan Gary (Able-bodied Seaman) deploys the CTD at sunset. Photo Credit: Gail Tang

Nich wanted to work for NOAA since he was in middle school! In high school he fell in love with fish. Initially he went to college in Iowa for soccer and then transferred to Carthage College, in Kenosha, Wisconsin to study environmental science, conservation and ecology. Nich did an independent study with his aquatic ecology professor on a coral reef project in Roatan, Hondurus. His senior thesis investigated the feasibility of releasing captive-bred axolotl (an adorable salamander that’s critically endangered and possibly extinct in nature) into the wild. After college, he had a job at an aquarium, and while he temped at US Fish and Wildlife studying chub and salmon, NOAA reached out about his job application. He started in January 2022 on the NOAA Ship Oscar Elton Sette!

Nich, wearing a hard hat, life vest, and an illuminated flashlight attached to his vest, looks straight at the camera as he holds up with both hands a styrofoam head decorated with marker designs and compressed (by water pressure) from its original size. — Nich Sucher (Survey Technician) with recently pressure-shrunken styrofoam head. Photo Credit: Fionna Matheson (Commanding Officer)

Since the CTD is deployed to 1000m, a common extracurricular activity is to attach styrofoam objects to the instrument because they shrink as a result of the pressure! On a previous leg, Commanding Officer Fionna Matheson shrunk a styrofoam head, which can be seen in the picture of Nich above. A few of us shrunk decorated styrofoam cups.

photo of a hand holding up a full-size styrofoam cup, upside down. it's decorated with many triangles drawn in black marker. the rim of the cup reads HICEAS 2023. we can see a view of a deck beyond. — Regular-sized styrofoam cup with Sierpiński’s Triangle Design

photo of a hand holding up a compressed styrofoam cup, upside down. it's decorated with many triangles drawn in black marker. the rim of the cup reads HICEAS 2023. we can see a view of a lab beyond. — Regular-sized styrofoam cup with Sierpiński’s Triangle Design

a hand holds up a stack of four upside-down compressed styrofoam cups, decorated, top to bottom, as purple design, smiley face, triangles, orca with hearts. — Artist of the cup from top to bottom: Jennifer McCullough (Lead Acoustician), Erik Norris (Acoustician), Gail Tang (Teacher at Sea), Alexa Gonzalez (Acoustician). Photo Credit: Gail Tang

The whole process of the CTD deployment and retrieval takes about an hour to an hour and a half. The Isaacs-Kidd Midwater Trawl (IKMT) net tow usually follows. Jessie Perelman and Dre Schmidt are the plankton researchers on board this leg of HICEAS. Most nights, we do 2-3 tows of the net. (They are affectionately called a “tow-yo” because the net gets towed in and out several times.) They use an inclinometer, a.k.a. angled angle, to measure the angle of the line (see picture below) and then confer with a chart to determine the length of the line needed to reach the desired depth. The chart is a good way to avoid on-the-spot trigonometric calculations. But it’s a good exercise to ask yourself anyway: if you know the desired depth and the angle, how would you calculate the length of the line needed?

Dre stands on deck at night, facing away from the camera, over the rail. She wears a jacket, a life vest, and a hard hat. Beyond her, we see a davit arm leaning over the water and a cable (attached to the net) extending at an angle off to the right. With her right arm, Dre holds out an angled angle - it's a metal semicircle, like a protractor, with a swinging arm attached at the center point of the straight edge. Dre holds it by a handle, lining the straight edge parallel to the extended cable. The swinging arm hangs straight down to the ship. Dre can read the resulting angle in the markings on the semicircle. — Dre Schmidt measuring with the angled angle. Photo Credit: Gail Tang

After the tows, we bring the larvae into the wet lab and the fun begins. The goal is to sort out the fish larvae from the other larvae. Truthfully, I am not very good at sorting the fish and I just like to look at the organisms under the microscope. The most awe-inspiring creatures I saw under the scope were the shelled pteropods (sea butterflies) and a juvenile sea star that, according to Dre, may have recently morphed from the larval stage. With the naked eye, they look like marks made with a sharp pencil, but under the scope, the enormity of their existence is profoundly moving. While I could not capture these beauties in a photograph, I was able to capture other creatures.

view through a microscope of a phronima animal living inside a (clear, jelly-like) salp. — Phromina living inside a salp. Photo Credit: Gail Tang

view through a microscope of a tiny squid and a polycheate worm. — Phromina living inside a salp. Photo Credit: Gail Tang

view through a microscope of a tiny squid surrounded by other, unidentified organisms. the squid's large purple eyes stand out. — Squid

Personal/Food Log with Career Highlights

As I fall into a daily routine, I periodically need small bits of irregularity for stimulation. This week, I was privileged enough to work with Chef Chris. Chef Chris is originally from north Philadelphia. In the absence of cable during childhood, he watched cooking shows like Yan Can Cook, Frugal Gourmet, and Julia Child on PBS. He started off cooking on NOAA Ship Rainier and now is the Chief Steward on NOAA Ship Oscar Elton Sette. We collaborated to make some pork dumplings and vegetable spring rolls for everyone. I cook at home often, but not for so many people, so Chris was essential in helping me scale up the dishes. We bonded over not measuring out ingredients so here is approximately the two recipes we used.

Chris, wearing a black chef's cap, stands at a large fryer in the galley. he's cooking three foods - eggs, pork, onions in large piles - and he reaches toward them with a spatula or perhaps a large knife. — Chief Steward Christopher Williams cooking the eggroll fillings. Photo Credit: Gail Tang

Pork Dumpling Filling

5 lbs of ground pork (when my mom makes these, we use a mix of lean ground pork and fatty ground pork)
Mirin (I use Shaioxing wine, but mirin is a good substitute!)
Soy sauce (we used Kikkoman; I like to use Pearl River Bridge Light Soy)
Green onions
Sugar

a plateful of prepared (but not yet friend) pork dumplings — The most gorgeous dumplings

a cafeteria-style pan of perfectly fried pork dumplings — The most gorgeous dumplings

Egg Roll Filling

Green cabbage
Red Cabbage
Carrots
Mushrooms
Soy sauce
Hoisin

a sheet pan of about 30 wrapped but uncooked egg rolls — Freshly wrapped vegetarian egg rolls

a cafeteria style pan of fried egg rolls — Freshly wrapped vegetarian egg rolls

Several of us worked together to help fold the dumplings and egg rolls. I delighted in the number of different hands that contributed to feeding our community. Chef Chris expertly cooked everything and it was all gobbled up!

Chris and Gail, sitting across from one another at a table, each hold up a freshly-rolled dumping to show off. we can see a large metal bowl of pork filling on the table between them. — Chef Chris Williams and Gail Tang

Four people around a table in the mess with a plate full of wrapped dumplings and dough circles and a bowl of pork filling. — Chef Chris Williams and Gail Tang

four people around a table wrapping egg rolls; there's a large bowl of filling, a tray of completed rolls, and two rolls in progress. — Gail Tang, Octavio De Mena, Jamie Delgado, Jessie Perelman rolling eggrolls

At night, I assist Jessie Perelman and Dre Schimdt with their plankton research. They were the first to come by to help fold dumplings. Jessie did her undergraduate work in biological science at University of Southern California (USC) with a plan to go to veterinary school. She worked in a marine science lab at USC, and then studied abroad in Australia to take more marine biology classes not available at USC. After she graduated, she got a job as research assistant at Wood’s Hole Oceanographic Institution, where she solidified her passion for research. She applied for graduate school and ended up at the University of Hawaii studying biological oceanography. Her dissertation focused on oceanographic influences on mesopelagic communities across eastern Pacific Ocean using insights from active acoustics, nets, and other sampling techniques. An interesting interdisciplinary part of her background includes learning about international policy on issues like deep sea mining. The international meetings with delegates were very informative for her. She’s also worked on science communication writing, such as science blogging. In Fall 2022, Jessie started as a Marine Ecosystem Research Analyst at NOAA!

Dre Schmidt received her bachelors in biology at Florida State University. She took Calculus, Mathematical Modeling for Biology, Analysis and Statistical Design, and Physics to supplement her biology degree. She volunteered at a research lab on campus and after college, took a couple of years off to work in marine science education for 5th grade to college level students. She went for her master’s degree in Kiel, Germany to study physiological effects of low-level warming on coral and their larvae. She has been at NOAA for 2 years, first as a research associate and now as an essential fish habitat coordinator. What she loves about her job is the variety of responsibilities. She keeps busy by sorting plankton, doing genetics lab work, analyzing data in R, writing up results, and going to sea! Engaging in these different tasks help to activate different parts of the brain, which I can totally relate to! Her advice to students is to know your worth and ask for what you deserve. Her favorite fish larva is the very ugly Centrobranchus andreae simply because her name is found within the name of the organism. I can’t blame her because my favorite flower is the Gaillardia for the same reason.

Andrea, wearing a mask, stands for a photo in front of a screen displaying a larval fish — Andrea with Andrea

Matt Benes (Able-bodied Seaman and Deck Boss) took a break in his duties to fold some dumplings with us. Though Matt declined to be interviewed, I can tell you we share a deep appreciation for food as a mechanism for cultural, historical, and political understanding.

Jamie Delgado (Medical Officer) joined in on the egg roll wrapping. Jamie received her bachelor’s in science and nursing at Rutgers University. She joined the Public Health Service (PHS), and worked at the Indian Health Service (IHS) in northern Arizona. Later, she worked at the National Institutes of Health (NIH) as a research nurse specialist. Jamie earned her Doctor of Nursing at University of Maryland before coming to NOAA as ship medical officer. Jamie has so much good financial advice about scholarships and loan repayments programs. Check out these links to learn more:

She also shared that you can retire in a total of 20 years with uniformed services, you get a pension, healthcare benefits, a housing allowance, a food allowance, 30 days paid leave, and unlimited sick leave. Jamie has been in service for 10 years, and with NOAA for 1 year and 5 months.

Jamie also helped me out during our in-port during Leg 1. Snorkeling had dislodged some ear wax and clogged my ear for a couple of days making daily life really uncomfortable. Jason Dlugos’s (3rd Assistant Engineer) “ear beer” helped, but I was still off balance. Jamie had to endure the task of flushing my ear out over the course of two days. Eventually, I did have to go to urgent care to get the rest out. Now I’m 100%!

Last but never least, Octavio De Mena, a.k.a OC, (General Vessel Assistant in the Deck Department) came by to roll some egg rolls. He is originally from the Republic of Panama and loves classic rock music. While we have no intersection in our movie tastes, we share some similarities in the food we ate growing up due to the large Chinese population in Panama. According to the Harvard Review of Latin America, the first Chinese immigrants arrived in Panama in 1854 to build the Trans-Isthmian Railroad. The inhumane treatment and disregard for the workers’ welfare is reminiscent of the situation a decade later with the Transcontinental Railway in the United States. This convergence of cultures led to haw flakes and dried plums in both our childhoods!

OC was an aircraft mechanic in the military reserves, and a security contractor in Latin America. He decided to come back to the U.S. to fulfill his dream job as a professional mariner. On his journey in pursuing his dream, he volunteered for the civil air patrol, and served as an auxiliary for search and rescue flying small Cessnas. He saw a NOAA ship at this job which prompted a search for a position within NOAA. He has been on the NOAA Ship Oscar Elton Sette since February 2023. On the ship, OC and I are regulars in the forward mess. Sometimes having opposite tastes works out in your f(l)avor, as I get to eat OC’s tomatoes and watermelon jolly ranchers.

Did you know?

You can track us! Visit this site to see where we currently are: https://www.windy.com/station/ship-wtee?26.549,-172.551,5

June 4, 2015August 21, 2021

Alex Miller: Working the Night Shift, June 3, 2015

NOAA Teacher at Sea
Alexandra (Alex) Miller, Chicago, IL
Onboard NOAA Ship Bell M. Shimada
May 27 – June 10, 2015

IMG_8309 (1) — The full moon lights up the night on top of the flying bridge.

Mission: Rockfish Recruitment and Ecosystem Assessment
Geographical area of cruise: Pacific Coast
Date: June 3, 2015

Weather Data:

Air Temperature: 13.3°C
Water Temperature: 14.8°C
Sky Conditions: Partly Cloudy, I could still see some stars
Wind Speed (knots/kts), Direction: 5.5 kts, NNE
Latitude and Longitude: 43°29’84”, 124°49’71”

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Later on Monday, once all the night-shifters had risen from their beds and were beginning to get ready for the bongos and mid-water trawls, I took a tour of the engines with marine engineer and NOAA crewmember, Colleen. We started in the control room. With up to four engines operating at any one time, Colleen says it’s a relief that computer systems help to automate the process. As part of her four-year degree program at Seattle Maritime Academy, she learned how to operate the engines manually as well, but I think we can all agree computers make life easier.

Before moving on to the actual engine room, Colleen made sure I grabbed some ear protection. For a one-time visit they’re probably more for my comfort than to protect from any real damage, but because she’s working with the engines every night, it’s important to protect against early-onset hearing loss. Once the plugs were in, we were basically not going to be able to talk so Colleen made sure that I knew everything I was going to see before we proceeded.

First, we made our way past the fresh water tanks. I was really curious about how we get fresh water on the ship, since we’re in the middle of the Pacific Ocean. The Shimada produces freshwater using two processes. Reverse osmosis produces most of the water, using high pressure to push the seawater across a membrane, a barrier that acts like a filter, allowing the water molecules to pass through but not the salt. This is an energy intensive process, but the evaporators use the excess energy produced by the engines to heat the seawater then pass it through a condensing column which cools it, and voilá, freshwater!

Next, we came to the four diesel engines. Four engines. These four engines are rarely all on at one time but never will you find just one doing all the work. That would put too much strain on and probably burn out that engine. While they burn diesel fuel, like a truck, instead of using that energy to turn a piston like the internal combustion engine of that same truck, they convert that energy to electricity. That electricity powers the two motors that ultimately make the ship go.

Panoramic view of the engine room, engines 1 and 3 can be seen in foreground and engines 2 and 4 in the background.

A ship the size of the Shimada requires a lot of power to get moving, but Colleen tells me it gets decent mileage. Though the ship’s diesel tank can hold 100,000 gallons, there’s only about 50,000 gallons in the tank right now and the ship only needs to refuel every couple of months.

After a quick pass by the mechanics for the rudder, the fin-shaped piece of equipment attached to the hull that controls the direction the ship is traveling we arrived at our last stop: Shaft Alley. Those two motors I told you about work together to turn a giant crankshaft and that crankshaft is attached to the propeller which pushes water, making the ship move. When I was down there the ship was on station, where it was holding its location in the water, so the crankshaft was only turning at 50 RPM (rotations per minute).

It was a pleasure getting a tour from Colleen!

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Throughout the night, the Shimada revisits the same transect stations that it visited during that day, but uses different nets to collect samples at each station. To the right, you can see a map of the stations; they are the points on the map. Each line of stations is called a transect. Looking at the map it’s easy to see that we have a lot of work to do and a lot of data to collect.

The transects and stations within them that the Shimada will survey at.

Why does this have to happen at night? At night, the greatest migration in the animal kingdom takes place. Creatures that spend their days toward the bottom layers of the ocean migrate up, some as far as 750 m (almost 2,500 ft)! Considering they’re tiny, (some need to be placed under the microscope to be reliably identified) this is relatively very far. And they do it every day!

To collect data on these organisms, three types of nets are used, two of which are not used during the day. Along with the surface-skimming neuston (which is used during the day), the bongo net, so named because it has two nets and looks like a set of bongo drums, and the Cobb trawl which is a very large net that needs to be deployed off the stern (back of the boat).

The operation of the bongo net is similar to the neuston, it is lowered off the starboard (when facing the bow, it’s the right side) side of the boat. Dropping down to 100 m below the surface and then coming back up, the bongo is collecting zooplankton, phytoplankton and fish larvae. The samples are poured from the cod-end into a strainer with a very fine mesh and since the water is full of those tiny bits, the straining can take a bit of time and some tambourine-like shaking.

The Cobb trawl on deck, waiting to be deployed.

These samples are then fixed (preserved) in ethanol and they will be analyzed for diversity (how many different species are present) and abundance (how many individuals of each species is present). The bongo is the net of choice for this survey because once scientists go to process the data, the double net provides a duplicate for each data point. This is important for statistical purposes because it ensures that the area that is sampled by one side of the net is similar enough to the area sampled by the other side of the net.

Below you can see video of the bongo net after it’s been hauled back. Scientists are spraying it down to make sure all organisms collect in the cod-end.

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Once the bongos are done, comes the real action of the night shift. The mid-water trawls take 15 minutes. I’ve become really great at communicating with the bridge and survey technicians who are operating the nets so that I can record data for the beginning and ending of the trawls. Once the catch is on deck, the survey technicians empty the cod-end into a strainer. The scientists prepare to sort, count and measure the species of interest. If the catch is large or particularly diverse, this can be a significant task that requires all hands on deck.

With four trawls a night, some with 30-50 minutes transit time with nothing to do in between, fatigue can set in and make the work hard to finish. To make it through the night, it takes great senses of humor and playful personalities. A little theme music doesn’t hurt either. The scientists of the night shift, under the direction of Toby Auth, a fisheries biologist with Pacific State Marine Fisheries Commission working as a contractor to NOAA and Chief Scientist Ric Brodeur, are Brittney Honisch, a marine scientist with Hatfield Marine Science Center, Paul Chittaro, a biologist with Ocean Associates working as a contractor to NOAA, Tyler Jackson, a fisheries science graduate student, and Will Fennie.

The data collected during these trawls provides a snapshot of the ecosystem. This data will help NOAA Fisheries Service understand the health of the ocean ecosystem as well as how large certain populations of commercially important fish are such as hake and rockfish.

In the meantime, it provides for some late night fun. Over the course of the nights that I’ve spent in the wet lab, we have uncovered some bizarre and fascinating creatures.

Clockwise from right: Mature hake, young lanternfish, King-of-the-Salmon, curlfin turbot, poacher.

Will holds a Pacific mackerel (Trachurus symmetricus)

The flat ones are larval Pacific sanddabs (Citharichthys sordidus) and the long skinny ones are larval anchovies (Engraulis mordax).

A Leptocephalus larvae of deep sea eel.

A Medusafish (Centrolophidae sp.)

Dungeness crab (Cancer magister) megalopae (larval)

Moon jelly (Aurelia labiata)

Krill (Euphausiids) with phytoplankton in their stomachs (green).

A tiny larval octopus (Octopus sp.)! I will call him Squishy and he will be my Squishy.

A heteropod (Pterotracheoidea sp.)

A Praya siphonophore.

Shortbelly (Sebastes jordani) and canary rockfish (Sebastes pinniger), actual rockfish! In juvenile form.

But in my opinion the real star of the trawls was the young female dogfish. A dogfish is a type of shark. I know what you’re thinking and no, she did not try to bite us. But dogfish do have two spines, one at the base of each dorsal (back) fin. We all fell in love, but, ultimately, had to say goodbye and return her to the sea.

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Thank you for your patience as I’ve gathered the images and video to make this and future posts as informative as possible. Stay tuned for Episode 5 coming soon!

Personal Log

First off, a heartfelt CONGRATULATIONS to the first 8th grade class at Village Leadership Academy. I wish I could be there when you walk across that stage on June 4th.

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Little did I know when I started hanging out with the scientists of the night shift that it would become a way of life. Each night I managed to stay up later and later and finally last night I made it through all four catches and almost to 0800, the end of the night’s watch. After dinner (some call it “breakfast”), I slept a full eight hours, and it felt completely normal to be greeted with “Good Morning!” at 3:30 in the afternoon.

Speaking of the night’s watch, I’m really grateful that someone was able to get one of my favorite TV shows last Sunday. And Game 7! The Blackhawks are in the finals! Even though I can’t call anyone back home to discuss my theories or that amazing goal by Seabrook in the third period, I can email and it feels like I’m missing less.

The only person I can’t email is my cat, Otto! I can’t wait to snuggle him until he scratches me.

output_GIG1yZ — Otto the cat. He loves snuggling.

Question of the Day:

Comment with answers to these questions and I’ll shout your name out in the next post!

What is your favorite animal we have seen so far?

Acknowledgements:

Thanks to Paul Chittaro for assisting in the use of iMovie for this post!

March 30, 2015August 21, 2021

Julia West: Science Is About the Details, March 29, 2015

NOAA Teacher at Sea
Julia West
Aboard NOAA ship Gordon Gunter
March 17 – April 2, 2015

Mission: Winter Plankton Survey
Geographic area of cruise: Gulf of Mexico
Date: March 29, 2015

Weather Data from the Bridge

Time 1600; clouds 35%, cumulus; wind 170 (S), 18 knots; waves 5-6 ft; sea temp 24°C; air temp 23°C

Science and Technology Log

We have completed our stations in the western Gulf! Now we are steaming back to the east to pick up some stations they had to skip in the last leg of the research cruise, because of bad weather. It’s going to be a rough couple of days back, with a strong south wind, hence the odd course we’re taking (dotted line). Here’s the updated map:

sampling stations 3/29/15 — Here’s where we are as of the afternoon of 3/29 (the end of the solid red line. We’ve connected all the dots!

I had a question come up: How many types of plankton are there? Well, that depends what you call a “type.” This brings up a discussion on taxonomy and Latin (scientific) names. The scientists on board, especially the invertebrate scientists, often don’t even know the common name for an organism. Scientific names are a common language used everywhere in the world. A brief look into taxonomic categories will help explain. When we are talking about numbers, are we talking the number of families? Genera? Species? Sometimes all that is of interest are the family names, and we don’t need to get more detailed for the purposes of this research. Sometimes specific species are of interest; this is true for fish and invertebrates (shrimp and crabs) that we eat. Suffice it to say, there are many, many types of plankton!

Another question asks what the plankton do at night, without sunlight. Phytoplankton (algae, diatoms, dinoflagellates – think of them like the plants of the sea) are the organisms that need sunlight to grow, and they don’t migrate much. The larval fish are visual feeders. In a previous post I explained that they haven’t developed their lateral line system yet, so they need to see to eat. They will stay where they can see their food. Many zooplankton migrate vertically to feed during the night when it is safer, to avoid predators. There are other reasons for vertical migration, such as metabolic reasons, potential UV light damage, etc.

Vertical migration plays a really important role in nutrient cycling. Zooplankton come up and eat large amounts of food at night, and return to the depths during the day, where they defecate “fecal pellets.” These fecal pellets wouldn’t get to the deep ocean nearly as fast if they weren’t transported by migrating zooplankton. Thus, migration is a very important process in the transport of nutrients to the deep ocean. In fact, one of the most voracious plankton feeders are salps, and we just happened to catch one! Salps will sink 800 meters after feeding at night!

Salp caught in the neuston sample. Salps are a colony of tunicates (invertebrate chordates for you biology students – more closely related to humans than shrimp are!)

Now it’s time to go back into the dry lab and talk about what happens in there. I’ll start with the chlorophyll analysis. In the last post I described fluorescence as being an indicator of chlorophyll content. What exactly is fluorescence? It is the absorption and subsequent emission of light (usually of a different wavelength) by living or nonliving things. You may have heard the term phosphorescence, or better yet, seen the waves light up with a beautiful mysterious light at night. Fluorescence and phosphorescence are similar, but fluorescence happens simultaneously with the light absorption. If it happens after there is no light input (like at night), it’s called phosphorescence.

An example of phosphorescence. We haven’t seen it yet, but I hope to! (From eco-adventureholidays.co.uk)

Well, it is not just phytoplankton that fluoresce – other things do also, so to get a more accurate assessment of the amount of phytoplankton, we measure the chlorophyll-a in our niskin bottle samples. Chlorophyll-a is the most abundant type of chlorophyll.

We put the samples in dark bottles. Light allows photosynthesis, and when phytoplankton (or plants) can photosynthesize, they can grow. We don’t want our samples to change after we collect them. For this same reason, we also process the samples in a dark room. I won’t be able to get pictures of the work in action, but here are some photos of where we do this.

chlorophyll lab — This is the room where we do the chlorophyll readings.

We filter the chlorophyll out of the samples using this vacuum filter:

chlorophyll filter — Each of these funnels filters the sea water through a very fine filter paper to capture the chlorophyll.

The filter papers are placed in test tubes with methanol, and refrigerated for 24 hours or so. Then the test tubes are put in a centrifuge to separate the chlorophyll from the filter paper.

filter paper for chlorophyll — Some of the test tubes for chlorophyll readings, and the filter paper. This box costs about $100!

The chlorophyll values are read in this fancy machine. Hopefully the values will be similar to those values obtained during the CTD scan. I’ll describe that next.

Fluorometer — This fluorometer reads chlorophyll levels.

While the nets and CTD are being deployed and recovered, one person in the team is monitoring and controlling the whole event on the computer. I got to be this person a few times, and while you are learning, it is stressful! You don’t want to forget a step. Telling the winch operator to stop the bongos or CTD just above the bottom (and not hit bottom) is challenging, as is capturing the “chlorophyll max” by stopping the CTD at just the right place in the water column.

Bongo graph — This is the graph that comes back from the SeaCAT on the bongo. We are interested in the green line, which shows depth as it goes down and comes back up.

The dry lab — Here I am trying my hand at the computers. The monitor on the left is the live video of what is happening on deck (see the neuston net?). Photo by A.L. VanCampen

CTD scan — This is the CTD graph after it has been completed. The left (magenta) line is the chlorophyll, and the horizontal red lines are where we have fired a bottle and collected a sample. Notice the little spike partway down. That is the chlorophyll max, and we try to capture that when bringing it back up. The colored chart shows columns of continuous data coming in.

Here’s another micrograph of larval fish. Notice the tongue fish, the big one on the right. It is a flatfish, related to flounder. See the two eyes on one side of its head? Flatfish lie on the bottom, and have no need for an eye facing the bottom. When they are juveniles, they have an eye on each side, and one of the eyes migrates to the other side, so they have two eyes on one side! Be sure to take the challenge in the caption!

Larval fish 2 — There is a cutlass fish just right of center. Can you find the other one? How about the lizard fish? Hint – look back at the picture in the last post. Photo credit Pamela Bond/NOAA

Personal Log

It’s time to introduce our intrepid leader, Commanding Officer Donn Pratt, known as CO around here. CO lives (when not aboard the Gunter) in Bellingham, WA. He got his start in boats as a kid, starting early working on crab boats. He spent 9 years with the US Coast Guard, where he had a variety of assignments. In 2001, CO transferred to NOAA, while simultaneously serving in the US Navy Reserve. CO is not a commissioned NOAA officer; he went about his training in a different way, and is one of two US Merchant Marine Officers in the NOAA fleet. He worked as XO for about seven years on various ships, and last year he became CO of the Gordon Gunter.

CO is well known on the Gunter for having strong opinions, especially about food and music. He loves being captain for fish research, but will not eat fish (nor sweet potatoes for that matter). A common theme of meal conversations is music; CO plays drums and guitar and is a self-described “music snob.” We have fun talking about various bands, new and old.

CO Donn Pratt — CO Don Pratt on the bridge.

One of the most experienced and highly respected of our crew is Jerome Taylor, our Chief Boatswain (pronounced “bosun”). Jerome is the leader of the deck crew. He keeps things running smoothly. As I watch Jerome walk around in his cheerful and hardworking manner, he is always looking, always checking every little thing. Each nut and bolt, each patch of rust that needs attention – Jerome doesn’t miss a thing. He knows this ship inside and out. He is a master of safety. As he teaches the newer guys how to run the winch, his mannerism is one of mutual respect, fun and serious at the same time.

Jerome has been with NOAA for 30 years now, and on the Gunter since NOAA acquired the ship in 1998. He lives right in Pascagoula, MS. I’ve only been here less than two weeks, but I can see what a great leader he is. When I grow up, I want to be like Jerome!

Challenge Yourself!

OK, y’all (yes, I’m in the south), I have a math problem for you! Remember, in the post where I described the bongos, I showed the flowmeter, and described how the volume of water filtered can be calculated? Let’s practice. The volume of water filtered is the area of the opening x the “length” of the stream of water flowing through the bongo.

V = area x length.

Remember how to calculate the area of a circle? I’ll let you review that on your own. The diameter (not radius) of a bongo net is 60 cm. We need the area in square meters, not cm. Can you make the conversion? (Hint: convert the radius to meters before you calculate.)

Now, that flow meter is just a counter that ticks off numbers as it spins. In order to make that a usable number, we need to know how much distance each “click” is. So we have R, the rotor constant. It is .02687m.

R = .02687m

Here’s the formula:

Volume(m³) = Area(m²) x R(F_e – F_s) m

F_e = Ending flowmeter value; F_s = Starting flowmeter value

The right bongo net on one of the stations this morning had a starting flowmeter value of 031002. The ending flowmeter value was 068242.

You take it from here! What is the volume of water that went through the right bongo net this morning? If you get it right, I’ll buy you an ice cream cone next time I see you! 🙂

sunset — Sunset from the Gordon Gunter as we are heading east.

June 30, 2011April 28, 2021

Jason Moeller: June 28, 2011

NOAA TEACHER AT SEA
JASON MOELLER
ONBOARD NOAA SHIP OSCAR DYSON
JUNE 11 – JUNE 30, 2011

NOAA Teacher at Sea: Jason Moeller
Ship: Oscar Dyson
Mission: Walleye Pollock Survey
Geographic Location: Whale Pass
Date: June 28-29, 2011

Ship Data
Latitude: 58.01 N
Longitude: -152.50 W
Wind: 23.95 knots
Surface Water Temperature: 9.4 degrees C
Air Temperature: 10.8 degrees C
Relative Humidity: 71%
Depth: 177.72 m

Personal Log

Welcome back, explorers!

Due to the injury to the deck hand, we are done fishing. Our trip has been cut a day short and we are now headed back to Kodiak. We should arrive tomorrow morning, and I will fly back home on the 30th.

The shortest route to Kodiak was through Whale Pass, a break in Kodiak Island. The pass made for some spectacular scenery.

The entrance to Whale Pass, from the back of the Oscar Dyson

Steep hills rolling down into the water were a common sight in the pass.

nav point — An island with a navigational marker in whale pass.

mountain 1 — There were some spectacular views of the mountains in the pass as well.

Mountains 2 — Another view of the mountains.

Mountain 3 — Another view of the mountains.

The coolest part of the pass, though, is definitely the wildlife. We saw sea otters everywhere! Unfortunately, they were so fast and at a great enough distance that the following shot is the only decent one I was able to take.

We also saw an animal that I have been hoping to see for a long time.

killer whales — Sorry about the grainy image, but it is the only one of the Orcas we were able to get.

We also saw a puffin, but it moved so quickly that there was no hope at a photo for it. Bummer. Several humpback whales were also spotted, along with numerous gulls and other seabirds.

Science and Technology Log

Today, lets talk about krill!

What are krill, you ask? They’re animals in the Phylum Arthropoda, which means they’re related to insects, spiders, crabs, lobsters, etc. They have jointed legs and an exoskeleton, are usually a couple of centimeters in length, and are reddish/orange-ish in color. They can often be found in dense schools near the surface of the water, and play an important role in the ecosystem as a source of food for lots of larger animals (like fish, whales, & penguins).

I’ve mentioned the two types of trawl gear that we use to catch fish, but if we want to catch smaller things like plankton, the mesh on those nets is way too small. Therefore, we use a third type of trawl called the Methot which has very fine mesh to corral the plankton down into a collection container at the end of the net. In addition to having a hard container at the end — as opposed to just a bag/codend that you see in the fish trawls — the Methot trawl also has a large metal frame at the beginning of the net. Check out the photos below.

The Methot trawl being taken from the water. Note the square frame.

After the net is brought back on deck, one of the fishermen or deck hands brings the container of krill into the fish lab. The first thing we do is dump the container into a sieve or a bucket and start picking out everything that isn’t krill. The two most common things that are collected (besides krill) are gelatinous animals (like jellyfish & salps) and larval fish. The fish get weighed (as one big unit, not individually) and then frozen for someone to look at later on.

After sorting the catch, we’re left with a big pile of krill, which gets weighed. We then take a small subsample from the big pile of krill (it’s a totally random amount depending on how much we scoop out!) and then weigh the subsample. Then the fun begins, as I’m the one that does this job; I get to count every single individual krill in the subsample. Tedious work. All of the data is then entered into the computer system, and the krill and anything else that we’ve caught (besides the larval fish) are thrown back into the water.

counting krill — How many individual krill are in this picture?

Species Seen

Northern Fulmar
Gulls
Puffin
Humpback Whales
Killer Whale!!!
Sea Otters!!!

Reader Question(s) of the Day!

Q. What has been your favorite thing about this trip so far?

A. I’ve been asked this question several times over the course of the last few weeks, but I’ve waited until the end to answer it.

Truth be told, it’s almost impossible to pick a favorite thing that I’ve seen or done. There are so many candidates! Exploring the Buskin River and seeing bald eagles before we set sail was a blast! Eating fresh caught salmon for the first time was a great experience, as it just melted in my mouth. Leaving shore for the first time was a lot of fun, as there is no feeling like the salt air blowing past your face at the front of a boat. Trying to take pictures of flying birds with a digital camera was a challenge, and we all had a good time laughing at the blurred images. Getting better at photography is something I’ve always wanted to do, and I feel like I have improved that. The first fish lab with the sleeper shark was great! Working in the fish lab, as messy as it was, was also a lot of fun! The XBT prank that was pulled on me was one of the best executed pranks I’ve ever seen, and it was hilarious! Hanging out and reading Martin’s Game of Throne series during breaks with my fellow scientists was a lot of fun as well, as it was just like a book club. Today’s ride through Whale Pass with the otters, whales, and mountains was exactly what I dreamed Alaska would be like.

The scientists sense of humor also made it an enjoyable trip. For example, this is what happens when you play around with the net camera for too long.

That being said, if I was absolutely forced to pick a favorite memory, it would probably the impromptu fishing trip at Sand Point. You know you love your job when you decide to keep going at it on your day off.

There will be one last log posted, so if you have questions please send them to me at jmoeller@knoxville-zoo.org!