Stacey Morris: Show me the Fish! August 7, 2026

NOAA Teacher at Sea

Stacey Morris

Aboard NOAA Ship Reuben Lasker

July 26 – August 10, 2026

Mission: Integrated West Coast Pelagics Survey

Geographic Area of Cruise: West Coast Pacific Ocean

Date: August 7, 2026

Weather Data from the Bridge

Latitude: 45°00.923°’N

Longitude: 124°27.721’W

Wind Speed: 14 kts

Air Temperature: 17.5°C

Science and Technology Log

My mother just texted me, “So, what do you do with the fish that you catch?” Great question!

view of the metal door attached to the lines and the trawl net designed to keep the mouth of the net open as it is deployed into the water. it is nighttime, and the water is dark and foamy.
Door used to hold open net

We do three trawls every evening, based on what the acoustic data shows us from moving our ship along our transect lines during the day. We do a marine mammal watch for 15 minutes before we cast the net. If everything is clear, we drop the net into the water. We then put two large metal “doors” into the water, that support the mouth of the net opening. The net has been specifically designed for the fish survey, to catch even the smallest fish larva and krill. Towards the end of the net, called the “codend,” there is a metal grate that is sewn into the net with a slit above it. This grate not only keeps larger species out of the net, like sharks, dolphins, and sea lions, but it  also allows them to escape if they do swim into the net. There are sensors at the top and bottom of the net that show its position so we know that it is in the right position.  Here is a photo of the monitor that can “see” the net:

photo of a screen display showing readings about the net: measurements of door spread, footrope depth, port and starboard doors, vessel speed, depths over time
This image shows how wide the net is open and its depth

We fish for thirty minutes, and then we hear “haul back!” which signals the net is being reeled back in. They use a large industrial spool to wind the net and the deck crew makes sure that it doesn’t get tangled, plus they stop if they see anything caught in the lines, such as mola mola (ocean sunfish) that like to hitch a ride in the net.

Stacey, wearing orange rain gear, orange life vest, orange hard hat, and teal gloves, holds up a smaller mola mola in two hands for a photo. she is standing in the wet lab.
Stacey with a mola mola… this is a baby one!

When we reach the back of the net, this is where we focus for our survey. If there are any protected species, like salmon, we measure, weigh, and take a quick photo record before we toss them back into the water. We put hardy fish that are not part of our survey into a saltwater bucket and also toss them over the side once we collect data.

We focus mainly on our target species, Northern Anchovies, Pacific Sardines, Pacific Mackerel,  and Jack Mackerel, and separate them out from the rest of the catch. From these, we take a random sample to measure and weigh, and then we remove their otoliths (ear bones) which can be used to determine their age. We document all the species we find, and if there are any sample requests (from universities or marine labs) that we can fulfill, those fish are put into the freezer.

Once we are done sorting, documenting, and data collecting, everything goes back to the sea and we clean up before the next trawl comes in. We always randomly sample five baskets from a catch, no matter how big or small it is. A “water catch” is if we don’t pull up any of our target species, but we’ve been lucky enough to have at least one in each of our trawls on this leg of the trip. I’ve been amazed at how different each of our trawls have been, and it’s changed quite a bit as we go north, with different species being more prevalent. 

Here are the fish that we have seen between San Francisco and Florence, OR :

English Common NameSpanish Common NameScientific Name
Northern anchovyAnchoveta del PacíficoEngraulis mordax
AnimaliaAnimalesAnimalia
Jack mackerelJurel del PacíficoTrachurus symmetricus
Whitebait smeltPez lápizAllosmerus elongatus
Pacific hake (whiting)Merluza del PacíficoMerluccius productus
Pacific herringArenque del PacíficoClupea pallasii
Coho salmonSalmón cohoOncorhynchus kisutch
Chinook (King) salmonSalmón chinook/reyOncorhynchus tshawytscha
Pacific sardineSardina del PacíficoSardinops sagax
Pacific (chub) MackerelCaballa del PacíficoScomber japonicus
EulachonEulacónThaleichthys pacificus
SteelheadTrucha arcoírisOncorhynchus mykiss
Whiptail ribbonfishPez listónDesmodema lorum
American shadSábal americanoAlosa sapidissima
Abraliopsis felisCalamarAbraliopsis felis
Aequorea spMedusa cristalAequorea sp
Amphipods (order)AnfípodosAmphipoda
Wolf eelPez lobo moteadoAnarrhichthys ocellatus
Sablefish (blackcod)Bacalao negroAnoplopoma fimbria
Pacific argentineArgentina plateadaArgentina sialis
Greater argonaut – paper nautilusArgonautaArgonauta argo
Shiny (shining) loosejawPez dragón luminosoAristostomias scintillans
Moon jellies (genus)Medusa lunaAurelia sp
Deepsea smelts (family)Peces de aguas profundasBathylagidae
Carinariid heteropod (shell)CarinariaCarinaria japonica
Heteropods (shell)CarináridosCarinariidae
Ocean WhitefishBlanquilloCaulolatilus princeps
Chiroteuthis calyxCalamar de cristalChiroteuthis calyx
Pacific sanddabLenguado del PacíficoCitharichthys sordidus
Speckled sanddabLenguado manchadoCitharichthys stigmaeus
Pacific sauryPaparda del PacíficoCololabis saira
Spectacular corolla (Sea butterfly)SalpaCorolla spectabilis
Sandpaper (tennis ball) squidCalamar de cristalCranchia scabra
Comb jellies (phylum)CtenóforosCtenophora
Crabs – Shrimps (order)DecápodosDecapoda
California headlightfishPez linternaDiaphus theta
Humboldt squidCalamar gigante de HumboldtDosidicus gigas
Northern anchovy larvaeLarvas de anchoveta del PacíficoEngraulis mordax larvae
Striped (luminous flying) squidCalamar luminosoEucleoteuthis luminosa
Pacific KrillKril del PacíficoEuphausia pacifica
Euphausiids (order)KrilEuphausiacea
Soupfin sharkCazónGaleorhinus galeus
Rex solePlatija del PacíficoGlyptocephalus zachirus
Hardtail (catalina) congerAnguila serpienteGnathophis cinctus
North Pacific armhook squidCalamar borealGonatopsis borealis
Gonatus spCalamar GonatusGonatus sp
Seven armed octopusPulpo siete brazosHaliphron atlanticus
Hormiphora spCtenóforoHormiphora sp
Diamond turbotPlatija diamanteHypsopsetta guttulata
MedusafishPez medusaIcichthys lockingtoni
RagfishPez ragfishIcosteus aenigmaticus
Pacific blackdragonPez dragón negroIdiacanthus antrostomus
Cookie cutter sharkTiburón cigarroIsistius brasiliensis
Glass squidCalamar LeachiaLeachia pacifica
Bay gobyGobio escamosoLepidogobius lepidus
Pacific staghorn sculpinCharrasco costeroLeptocottus armatus
Slender barracudinaPez lagartoLestidiops ringens
California smoothtonguePez plateadoLeuroglossus stilbius
Eared (popeye) blacksmeltPez gelatinosoLipolagus ochotensis
California market squidCalamar de CaliforniaLoligo (Doryteuthis) opalescens
Slender solePlatija finaLyopsetta exilis
Dover soleSolla dl PacíficoMicrostomus pacificus
Ocean sunfishPez lunaMola mola
Robust clubhook squidCalamar robustoMoroteuthis (Onykia) robusta
Octopus squidCalamar pulpoOctopoteuthis deletron
Tuberculate pelagic octopusPulpo pelágicoOcythoe tuberculata
Boreal clubhook squidCalamar garfioOnychoteuthis borealijaponicus
Ocean (pink) shrimpCamarón rosadoPandalus jordani
California Spiny lobsterLangosta de CaliforniaPanulirus interruptus
Barracudinas (family)Peces lagartoParalepididae
Purple striped jellyMedusa pelágicaPelagia colorata
Pacific butterfish (Pompano)Palometa del PacíficoPeprilus simillimus
Egg-yolk jellyMedusa huevo fritoPhacellophora camtschatica
Phronima spPhronimaPhronima sp
Pelagic red crab (tuna crab)Langostilla rojaPleuroncodes planipes
Plainfin midshipmanPez sapo luminosoPorichthys notatus
Praya spSifonóforoPraya sp
Blue sharkTiburón azulPrionace glauca
Pelagic stingrayRaya violetaPteroplatytrygon violacea
Heteropods (no shell)Caracoles pelágicosPterotracheidae
Jewel fire squidCalamar luciérnagaPterygioteuthis gemmata
PyrosomePirosomaPyrosoma atlanticum
Salps (order)SalpasSalpida
Pacific bonitoBonito del PacíficoSarda chiliensis
California scorpionfishPez escorpión manchadoScorpaena guttata
CabezonCabrilla marmoleadaScorpaenichthys marmoratus
Brown rockfishRóbalo orejónSebastes auriculatus
Rockfishes (genus)RóbaloSebastes sp
Sergestid shrimps (family)Camarones pelágicosSergestidae
Northern lampfishPez linterna norteñoStenobrachius leucopsarus
Blackbelly dragonfishPez dragónStomias atriventer
California lanternfishPez linterna de CaliforniaSymbolophorus californiensis
Kelp pipefishPez pipa de CaliforniaSyngnathus californiensis
Blue lanternfishLinternilla azulTarletonbeania crenularis
Smalleye SquaretailPez cuadradoTetragonurus cuvieri
Common salpSalpa giganteThetys vagina
Pacific torpedo (electric) rayRaya eléctrica de CaliforniaTorpedo californica
Jack mackerel larvaeLarvas de jurel del PacíficoTracharus symmetricus larvae
King-of-the-salmonPez cintaTrachipterus altivelis
Mexican lampfishPez linterna mexicanoTriphoturus mexicanus
Panama lightfishPejecito punteadoVinciguerria lucetia
Vinciguerria spPez linternaVinciguerria sp
Longspine combfishPez peineZaniolepis latipinnis

While northern anchovy, Pacific and jack mackerel, whitebait smelt, and Pacific herring make up most of the fish we catch during our survey, California smooth tongue fish are our most common non-target species. Most of our target species are included in federal fisheries management plans, which means scientists regularly monitor their populations to help ensure they are harvested sustainably.

Understanding how fish populations change from year to year is essential for assessing the health of fish stocks and managing fisheries responsibly. Some species are especially important to the West Coast ecosystem and economy. Pacific sardines, for example, once supported a major fishery, but their population has declined dramatically in recent decades. Northern anchovies may not have the same economic value, but they play a critical role in the marine food web by serving as prey for many larger fish, seabirds, and marine mammals. Jack mackerel are also ecologically important and support commercial and bait fisheries that extend from state waters into federally managed waters.

Whitebait smelt and Pacific herring are unique to our survey because they are detected not only in our net catches but also in our acoustic data. Comparing the two datasets helps scientists validate survey results and improve estimates of fish abundance.

Did You Know?

FishBase is a website where you can look up 36500 different fish species, their common names, and pictures to help you identify something that you see or catch. You can even find out what they are called in other countries where they are found, which is tremendously helpful when you are working with fisheries that expand beyond U.S. waters or with migrating fish.

screenshot of the heading of the FishBase website with totals listed across the top: 36500 species, 333000 common names, 65800 pictures, 68300 references, 2570 collaborators, 700000 visits/month

Personal Log

We are now located off of Newport, and I realize we are getting to the end of our trawling survey. I’m excited to get back home and see my family and friends, but I know I’ll miss the adventure of being on a scientific expedition with experts in the field. I love asking questions about the fish we are seeing, the nautical gauges on the bridge, and what all the equipment is down below in the labs and engine room. The wind has died down, and it’s easier walking around the ship. I’m sleeping very well, better than at home, which must be due to the rocking or the physical labor of processing the fish trawling. My favorite activity is mammal watch, making sure none are close to our boat before we put the net into the water. Seeing whales with the moon over the water was a beautiful sight!

view of the moon over the ocean, where the water is reflecting the moonlight
Full moon at mammal watch

Cheyanne Vanderdonckt: In Which I Learn How to Tag a Shark, August 4, 2026

NOAA Teacher at Sea

Cheyanne Vanderdonckt

Aboard NOAA Ship Oregon II

July 27 – August 12, 2026

Mission: Shark/Red Snapper Bottom Longline Survey, Leg 1

Geographic Area of Cruise: Western North Atlantic Ocean

Date: August 4, 2026

Latitude: 34° 20.659’ N

Longitude: 76° 35.444’ W

Weather Data from the Bridge: Southwest winds 5 to 10 knots becoming 10 to 15 knots in the afternoon. Seas 3 to 4 feet. Showers with a chance of thunderstorms in the morning, then a slight change of showers and thunderstorms in the afternoon.

Science and Technology Log

The survey is in full swing. Every day during our 12-hour shift we will arrive at 2-3 stations, and the night shift will do the same. The exact number depends on how far apart the day’s stations are, as well as weather conditions and how long haulbacks take. We work in the rain, but not if there is lightning. The distance between stations varies from about 10 to 50 nautical miles. (A nautical mile is approximately 1.15 miles on land.) Our exact speed varies with current and wind, but we generally travel at about 11 knots, which means 11 nautical miles per hour. We begin to bait the hooks for the next station about 15-20 minutes before we arrive. Then it takes about 20 minutes to deploy the line off the ship’s stern. As soon as we are done with that, a few members of the science team will go to the bow with the deck crew to deploy a device that collects data about the water column (more on that below). An hour after the line was set, we will begin to haul in the line. 

What are we hauling in? In this part of the Atlantic Ocean, we are mostly catching sandbar sharks (Carcharhinus plumbeus). Other species include tiger sharks (Galeocerdo cuvier), nurse sharks (Ginglymostoma cirratum), and Atlantic sharpnose sharks (Rhizoprionodon terraenovae). As explained in my previous post, most sharks are hauled up using the cradle. In the cradle, length measurements are taken.

Why more than one measurement? Before this trip, I always heard about, say, a “six foot shark.” I knew that scientists use the metric system so we wouldn’t be measuring in feet and inches, but we are also taking 3-4 length measurements for each fish. These measurements have been standardized using parts of the shark’s anatomy as endpoints. This allows scientists to make comparisons across different specimens and field studies, but it also helps them check for accuracy. It can be challenging to get accurate measurements on a living, moving shark. In addition, some species do not have a fork in the tail or a pre-caudal pit. The measurements generally taken are the pre-caudal length (from the tip of the snout to the point where the caudal fin meets the body), the fork length (from the snout to the fork in the tail), and the total length. You can see these lengths on this helpful diagram from the Florida Museum of Natural History. As a scientist takes the measurements, a recorder stands by with a data sheet to write them down.

simple diagram of a shark (possibly a sandbar shark) with 10 different length measurements denoted by horizontal blue lines extending from the left side (length = 0) to specific body features. they are: pre caudal length, pre second dorsal length, pre first dorsal length, head length, pre orbital length, pre pectoral length, pre pelvic length, pre anal length, fork length, total length (tip of caudal fin)
A diagram showing how to take different length measurements of a shark (Image credit: Florida Museum of Natural History)

When we catch a small shark, we can measure and weigh it on the deck. However, there isn’t a practical or safe method for weighing a large shark in Oregon II’s cradle. Instead, weights can be estimated based on length. If you are interested in how much a shark of a specific length might weigh, you can use this handy calculator from NOAA: https://apps-nefsc.fisheries.noaa.gov/shark/ This could be a great activity for having a little fun with measurement for students! After using good measurement practices to get your height, type your height in inches or centimeters into the calculator to see how much you would weigh if you were a shark. (If I were a sandbar shark, I would weigh about 95 pounds.)

The most exciting part of a shark catch is getting to tag the shark. Shark tagging helps scientists study shark behavior, populations and migration. If somebody catches a tagged shark, they can provide updated information on its location using a phone call or a website with a form. The tags we are using look like a piece of yellow coated electrical wire rather than a big plastic tag. They are inserted into the body right alongside the shark’s dorsal fin. After making a short (less than an inch) incision in the skin, the tagger inserts the tip of the tag with a device that resembles a large metal hypodermic needle. It’s important for everyone to work carefully but quickly to reduce stress on the animal and the chances of anyone being injured. After tagging, the hook is cut from the shark’s mouth and it is lowered back down to the water to be released. I have been allowed to tag three sandbar sharks so far and it is awe-inspiring to be so close to these amazing creatures. 

top-down view of three people wearing hard hats and gloves leaning over a shark in a cradle. Most of the shark is obscured by the crewmembers. Cheyanne, in the center with a yellow hard hat, rests on hand on the shark's back. another crewmembers stands off to the side partially out of frame.
Cheyanne Vanderdonckt (in yellow hardhat) tags a sandbar shark in the cradle while science party chief William Driggers and lead fisherman Sean Gronquist control the head and tail (Photo credit: Masyn Douglas)

This is the first leg (of four) of the Shark/Red Snapper Bottom Longline Survey. On this leg, we are fishing off the east coast of Florida, Georgia, South Carolina, and North Carolina. On the next legs, they will be in the Gulf and will likely catch much more red snapper. Red snapper has been fished commercially in the Gulf since the 1840’s and by the 1920’s there were already signs of overfishing that led to regulation. Today, it is considered a sustainable seafood choice because it is responsibly managed in the United States. The annual survey conducted by NOAA Fisheries helps inform the process of establishing catch limits. 

Gretchen, wearing a life vest and fish gloves, squats next to a wooden fish measuring board on the deck floor. She uses two hands to line a large orange-red snapper along the board and read its length.
Survey technician Gretchen Arndt measures the length of a red snapper (Lutjanus campechanus)

When a red snapper is caught, length and weight measurements are taken. Then the otoliths (ear stones) are retrieved. Otoliths are structures made of calcium carbonate that help the fish with balance and determining their position in the water. Otoliths of different species develop new layers at different rates. Marine scientists use the layers of the otolith to determine the age of a fish — much like counting the rings of a tree’s trunk. The fish is also examined to determine its sex and other tissue samples may be taken.


Maritime Career Focus: Survey Technician

Senior Survey Technician Gretchen Arndt is responsible for the scientific survey equipment on Oregon II. She has a bachelor’s degree in biological sciences with a marine focus from Florida Atlantic University.  She worked as a field biologist and a field operations manager in the Florida Everglades. Marine biology is a competitive field that attracts many talented individuals. Gretchen says that driving and maintaining airboats and other equipment in the field helped give her the technical experience that led to her being hired by NOAA. 

One of the pieces of survey equipment that Gretchen is responsible for is known as the CTD (for conductivity, temperature and depth). CTDs come in various designs and they are integral to the science of oceanography. The CTD can be used to retrieve samples of water for further analysis, as well. This device is deployed off the bow deck after each line is set. Getting the CTD into and out of the water is a coordinated effort between the bridge, the science team, and the deck crew. Gretchen also equips Oregon II’s CTD with a light and camera so that the science team can visually evaluate the seabed.

Gretchen, wearing a hard hat, life vest, and rubber boots, poses for a photo with one hand on a large scientific instrument. a round metal cage houses an array of narrow vertical gray water sample bottles. beneath that array is the conductivity, temperature, and depth probe. Gretchen and the CTD apparatus and photographed in front of a railing on NOAA Ship Oregon II and we can see blue water and blue sky behind them.
Gretchen Arndt with the “CTD”

Personal Log

sunset seen over the ocean. the water is dark blue and choppy. at the horizon, thin bands of yellow, orange, and pink peak out behind low gray clouds.
Another beautiful sunset, viewed from the stern deck.

I feel like I could just look at the sea and the sky all day and night. Fortunately, we do have transit time between stations so I am able to spend some time gazing. At first I just see blue everywhere, but the longer and closer I look, the more colors I can pick out. In the reading curriculum we use in my school district we have lessons in which students spend time silently observing a work of art. They aren’t allowed to speak for at least a minute because it’s important to let everyone form their own impressions before they hear others’ ideas. I will definitely share some of my sea and sky photos with my class to have them look for as many colors as they can see. 

view of the horizon over the ocean. the water is blue-gray with some chop. the sky is light blue, with hints of pink toward the horizon, obscured by wispy white and gray clouds at different heights.
A view of the Atlantic Ocean from Oregon II. How many colors can you see?

Occasionally I see other ships on the horizon and sometimes I can make out some features on shore. When we passed by the Kennedy Space Center at Cape Canaveral, I could see the massive Vehicle Assembly Building. My favorite view, however, is when dolphins swim alongside the ship. Dolphins follow boats and ships for many reasons. They can ride the bow wave to conserve energy. As the ship moves through the water, it can also disorient smaller fish, making them easier to catch. It is very hard to catch the exact moment a dolphin leaps to the surface, but I took a video one night while a spotlight was being used to illuminate the water for hauling back the longline. 

One thing I enjoy about being a teacher is that people often tell me what they were like as children at school. At least a couple of people working aboard Oregon II have told me tales of having trouble at school because they didn’t like to sit still or got bored easily. Like many teachers, I always loved school. But I know this is not the case for everyone. In education circles, we talk about the “hidden curriculum.” Success in school requires a set of skills and traits that have nothing to do with the academic content being taught and which can be really challenging for neurodivergent students, students with disabilities, and many others. But this does not mean they lack the intelligence or drive to learn. In fact, many of them have the type of insight and creativity that is needed to drive innovation. If schools can’t support them, we are all losing out on the unique gifts and talents they have to share. To that end, I am always trying to find ways to make learning hands-on and connected to the real world. Although there is time for quiet and reflection, most of the day should be active and even a little loud. I try to highlight ways that my students’ character traits and interests might lend themselves to different career paths. I’m getting so many ideas from watching people work aboard Oregon II.  

In my opinion, one of the coolest jobs on board is that of Fisherman. Fishermen handle lines and operate equipment, including cranes (I’m jealous!), winches, and the anchor windlass. They work with the scientists during fishing operations and maintain the fishing equipment. On this survey we are using a longline, but the ship is also equipped with trawling nets. (In fact, the ship’s design is basically that of a fishing trawler). When a shark is in the cradle, fishermen operate the crane to haul it up, handle the lines on the cradle to help guide it into place, and help control the shark. 

Lead Fisherman Sean Gronquist shared one of his hobbies with us after we caught a red snapper. He paints one side of the fish with a biodegradable ink and stamps it onto canvas to make a print. This preserves the size and details of the fish, and makes a beautiful piece of art. The Japanese name for this art is gyotaku. In my classroom, I use arts integration a lot in science and math. Arts integration is a method in which a lesson addresses both academic content standards and fine arts standards. It has been shown to increase student engagement and improve retention of learning. It’s also great fun. I’m really excited to share this cool art form with my students. It has a physicality to it that makes it more interesting than a photograph. It will also be a great starting point to talk about texture. If you’re interested in educational uses for fish printing, here is an article from Smithsonian Museum of Natural History: https://ocean.si.edu/conservation/get-involved/educational-uses-gyotaku-or-fish-printing

We have about a week to go in our survey and I am still enjoying every minute of my time on board. We had a couple of windy days that tested my sea legs, as well as my ability to sleep. Ships are very noisy in the first place, but the sounds increase as things start to slide around and doors knock around in their frames. Fortunately, I’ve got old hands to teach me tricks like stuffing bits of paper towel into drawers and doors to stop them from rattling. Nothing is as simple on a ship as it is on land, but that’s all part of the adventure.

Did You Know?

Although they are fish, many sharks give live birth. This means that some sharks have “belly buttons” that remain for a few months after birth. (If we come across a shark belly button I promise to share a picture!) Sharks also have two uteri. This year, one of my students was very excited to tell me that sand tiger shark embryos eat their siblings in utero and that checks out too. Although it may seem a little gruesome as a “fun fact,” it also helped us put things into perspective one day when he shared that he was in a bad mood because he had a fight with his sister. You never know when some scientific knowledge will come in handy!

Stacey Morris: MVP & Investigating the Acoustic Trawl Method, August 3, 2026

NOAA Teacher at Sea

Stacey Morris

Aboard NOAA Ship Reuben Lasker

July 26-August 10, 2026

Mission: Integrated West Coast Pelagics Survey

Geographic Area of Cruise: West Coast Pacific Ocean

Date: August 3 , 2026

Weather Data from the Bridge

Latitude: 43° 06.4 ‘N

Longitude: 124°52.3 ‘W

Wind Speed: 25 kts

Air Temperature: 14.9 °C

Science and Technology Log

To understand more about the acoustic study component of our fish survey, I sat down with Kevin Stierhoff, Chief Scientist and Primary Investigator, and Brad Erisman, marine biologist, to see how our sonar mapping efforts integrate with the nightly trawling operations.

Interview Discussion with Kevin Stierhoff, Chief Scientist:

The Acoustic Trawl Methodology

Kevin: The acoustic trawl method is a globally recognized technique for surveying coastal pelagic species. By utilizing sonar, the ship can efficiently map expansive stretches of the seafloor and record precise echoes from fish populations. These instruments are highly calibrated and sensitive, providing us with accurate data on the biomass below. However, acoustics alone cannot identify the specific species creating the signal. To solve this, we conduct sonar surveys during the day when fish are schooling at depth, and then perform net trawls at night as they rise toward the surface. This nocturnal sampling allows us to determine the species and size composition without the fish avoiding the net as easily. By combining these datasets, we can apply the ratios found in our catches to the sonar echoes gathered during the day. This robust method is the primary tool for managing sardine and anchovy stocks along the West Coast.

photo of a screenshot of the display of the SX90 sonar readings with arrows labeling a bright red blob as a school of fish and a squiggly line as a fish track; this image may be in a textbook
Sonar image of fish school: Image credit NOAA

Historical Context

While simpler sonar and net surveys were conducted as early as the mid-1970s, the modern integrated approach used by the NOAA Southwest Fisheries Science Center in San Diego began in 2008. Since 2012, we have maintained a consistent schedule, performing these surveys at least once annually.

Observing Ecosystem Shifts

The marine environment has changed significantly since the surveys began. In 2012, sardines were the dominant species, but their numbers plummeted leading to the fishery’s closure in 2015. Conversely, northern anchovy and jack mackerel populations have surged, with anchovies remaining the most prevalent species we encounter today. Sardines have yet to show signs of a rebound following their crash a decade ago.

a metal tray filled with thin, silver fish all arranged to face the same direction
Anchovies brought up in one of our trawls this week

Environmental Drivers

There is much discussion regarding why these shifts occur. While fishing pressure reduced stocks in the past, current low levels are likely driven by environmental and biological factors, rather than active overfishing.

Leadership Roles at Sea

The structure of the scientific team ensures the integrity of the data collected. The Principal Investigators (PIs) are responsible for the overall coordination and quality of the long-term survey. On the ship, the Chief Scientist manages daily operations and leads the scientific party, coordinating with the PIs to ensure the survey’s objectives are met successfully.

Advanced Sonar Systems

photo of an illustration printed in a book or on a brochure of a white ship, its centerboard, and swaths of color emanating from the ship or the centerboard representing sound waves. printed on the image is this paragraph: "Multibeam Sonar System provides information on the biomass within the water column and on the type and topography of the seafloor. Drawing courtesy of Kongsberg-Simrad."
Acoustic sonar system under NOAA Reuben Lasker

The ship’s acoustic “eyes” are located on a retractable centerboard, or keel, beneath the hull. While in port, this keel is flush with the ship, but it is lowered once we reach deep water. The Reuben Lasker is equipped with an impressive array of six different sonar frequencies. Low frequencies, like the 18 kilohertz signal, penetrate deep into the ocean to map the seabed, while higher frequencies are better for detecting smaller organisms like krill in the upper water column. We primarily use the 38 kilohertz frequency to measure fish echoes. Anything in the water column with a different density than the surrounding seawater—whether it be a fish, squid, or the ocean floor—reflects sound waves that our instruments carefully measure.

six vertical panels showing backscatter readings at each depth over time, with each panel using a different frequency
Different sonar frequencies used to find fish

Omnidirectional and Multi-beam Sonars

Beyond the downward-looking sonar, we utilize an omnidirectional sonar mounted forward that scans in a radius around the ship. This helps us see fish near the surface that might be missed by the keel-mounted sensors. We also have multi-beam echo sounders, like the ME70 and MS70, which provide detailed three-dimensional views of fish schools and behavior. While these are invaluable for observing marine life, they are more difficult to calibrate for the precise biomass estimates provided by our primary systems.

photo of a computer screen displaying output from the ME70 - backscatter at different frequencies, and a sonar image
sonar image from ME70
photo of an illustration printed in a book or on a brochure depicting a ship at the surface and soundwaves emanating out from its hull; the waves surround a school of fish.
Image credit: NOAA

Survey Transects and Navigation

The survey follows a series of transects that span the U.S. continental shelf from Mexico to Canada. These lines generally extend at least 35 miles offshore to ensure we capture the full range of the species we are monitoring. Each transect provides a localized estimate of biomass, and by repeating these measurements across the entire coast, we can calculate a mean population estimate with statistical confidence. The spacing between these lines—currently 12.5 nautical miles—is a careful balance between our available time at sea and the need for scientific precision. While navigating perpendicular to the coast can sometimes lead to a rougher ride in the troughs of the waves, it remains the most efficient and scientifically sound way to sample across the varying densities of marine life.

simple political map of the west coast of the continental United States, ranging from the border of California and Mexico to Vancouver. small black lines extend out perpendicular to the coastline. each is labeled with a code.
transect lines for the Integrated West Coast Fisheries Survey:
Image Credit: NOAA

Did you Know?

The sonar system on the Reuben Lasker is so sensitive it can detect individual organisms based on their density relative to the water.

two side by side political maps of the western continental United States shown side by side to graph two different types of data by latitude: on the left, density of biomass fish species along the survey transect lines; on the right, proportions of species at sample locations along the transect lines
Density of biomass of fish species (left) and species proportions (right) –Image credit: NOAA

Interview with Brad Erisman, marine biologist about the use of the MVP 

Brad: The precision of our acoustic survey relies heavily on the physical properties of the water we traverse. Factors such as temperature and density significantly influence the strength and travel speed of sonar echoes. While we calibrate our instruments in San Diego, the conditions change as we move north along the coast. To maintain the accuracy of our biomass estimates, we must continuously adjust our parameters to account for variations in sound absorption and velocity within the water column.

The Moving Vessel Profiler (MVP)

This is where the MVP, or Moving Vessel Profiler, becomes indispensable. We deploy this specialized probe to capture a comprehensive temperature profile of the water column. These real-time measurements allow us to calculate essential coefficients for our acoustic data. Along every transect, we perform multiple deployments to ensure we have representative environmental data. This constant fine-tuning allows us to produce the most reliable estimates of fish populations possible.

a woman wearing a float coat and a hard hat and holding a radio in her right hand reaches her left hand up to a control on a large blue piece of scientific equipment mounted on the deck of the ship. the equipment, the moving vessel profile, includes a metal arm that extends over the water and a cable that it is using to pull the sensor behind the ship
MVP is deployed via crane

Environmental Sensors

The MVP is a sophisticated tool, far more capable than a simple surface drifter. It is equipped with an array of sensors that measure salinity, chlorophyll levels, oxygen concentration, and sound speed. While a drifter only provides a surface snapshot, the MVP reveals the three-dimensional structure of the sea, highlighting fascinating features like thermoclines where warm, shallow water meets the colder, deeper ocean water.

Correlating Fish Patterns with Ocean Data

These environmental datasets help us explain the spatial and vertical distribution of the species we monitor. By collecting in situ data at the same fine scale as our sonar and trawl operations, we can identify correlations between habitat conditions and fish behavior. While satellite data provides a broad overview, the MVP gives us the high-resolution evidence needed to understand why schools appear in certain areas or why species patterns shift across different oceanographic breaks.

photo of a computer screen displaying output from the moving vessel profiler
MVP screen

Efficiency at Sea

The beauty of the Moving Vessel Profiler is in its name—it allows us to sample while the ship is in motion. A traditional Conductivity, Temperature, and Depth (CTD) cast involves a large cage lowered from a stationary ship, which would force us to halt our acoustic sampling. The MVP allows us to gather the necessary data without sacrificing valuable time. Although it doesn’t collect water samples or reach the extreme depths of a stationary cast, it provides exactly what we need to keep the survey on schedule.

A Three-Dimensional View of the Habitat

Oceanographers use these data points to build complex 3D models of the marine environment. These models are vital for understanding fish preferences; for instance, if sardines migrate further north, we can often trace that movement to a specific temperature preference, such as 15-20 C°-degree water, shifting with the currents. This helps us distinguish between a population decline and a simple change in habitat location.

Climate Signals and Regional Patterns

While large-scale climate signals like El Niño or La Niña are often monitored via satellite, our shipboard data helps define how these patterns manifest regionally. By looking at the data across the entire coast, we see the localized reflections of these massive basin-wide shifts, providing a clear picture of how the changing climate impacts our West Coast ecosystems.

close-up photo of a pile of dice of different numbers of sides
D & D dice

 Personal Log

We’ve run into windy conditions after we crossed over the border into Oregon. We only were able to do one trawl last night before we had to call it a night due to rough waters. Tonight, we were on watch until midnight to see if things would calm down but it’s still too rocky. To fill the time, we are discovering the delightful world of Dungeons and Dragons, led by the artful storytelling of the Operations Officer, Mike Fuller.

It’s challenging walking down the hallways, and a large wave can scatter anything that isn’t well secured. Luckily the Dramamine is doing its trick and I haven’t felt queasy at all this week. 

View of ocean swells out a porthole window

Jo Slavitz: Expect the Unexpected, July 30, 2026

NOAA Teacher at Sea

Jo Slavitz

Aboard NOAA Ship Oscar Dyson

July 19th – August 10th

Mission: Summer Pollock Acoustic-Trawl Survey, Leg 3

Geographic Area of Cruise: Bering Sea, Alaska

Date: July 30, 2026

Weather Data from Bering Sea

Latitude: 58° 38.303’  N

Longitude: 176° 17.674’ W

Winds: SW at 9 mph

Air Temperature: 46.94° F (8.3° C)

“It is that range of biodiversity that we must care for – the whole thing – rather than just one or two stars.” – David Attenborough

Science and Technology Log

NOAA scientists conducting the Acoustic-Trawl survey are skilled at finding pollock, but even, so tiny amounts of other species also sometimes slip into the net. These unexpected creatures are called “bycatch.” Although not targeted, it doesn’t mean that these species are not important. A healthy pollock population depends on a complete and healthy ecosystem, so the science team also measures and takes data on these creatures before releasing most of them back to the water. Sometimes, the science team also gathers information about these species for other scientists on land conducting special projects for other programs. Here are some of the interesting fish that came in with trawls aboard Oscar Dyson on Leg 3.

Jellyfish

Outside of pollock,  jellyfish have been the most frequent visitor to the trawl. Existing before dinosaurs, jellyfish trace their origin back over 500 million years, their closest relatives being corals and anemones. They are invertebrates (meaning they do not have a backbone) in the phylum Cnidaria, subphylum Medusozoa. Jellyfish are found around the planet in the world’s oceans and even in some fresh water ponds/lakes. Not a fish at all, jellies contain no brain, bones, gills or hearts. They are considered a keystone organism, one that holds the ecosystem together because it interacts with so many other species within the food web. Jellyfish’s main diet consists of tiny animals and plankton. They serve as food for sea turtles, fish, crabs, birds and even humans. Even though they can often sting, small animals will swim among jellies to hide from predators. So far we have seen 3 species of jellyfish in the trawls in the Bering Sea:

Chrysaora: The most common jellyfish found in the trawls this trip are by far Chrysaora. These stunning animals get their name from mythology. Chrysaor was the warrior child of Poseidon the sea god and Medusa, and his name means “adorned in gold” or “golden warrior.” It’s the perfect name for this golden beauty. Chrysaora are in the family commonly referred to as sea nettles. They can grow to reach up to 2’- 3’ in diameter. Chrysaora is typically found at depths up to 100 meters in the Bering and Arctic Seas. Since the 1990’s the total biomass of this species has been increasing. Biomass is the total amount of mass of an animal population in a specific area.

Jo, wearing overalls, long yellow gloves, and sunglasses, leans forward over a sorting table in the wet lab. On the table in front of her is a yellow-orange jellyfish that may be 3 feet in diameter.
Chrysaora Jellyfish

Aequorea: Less showy and bright than Chrysaora, Aequorea jellies are predominantly clear with a flat smooth disk-shaped bell. Its name is taken from the Latin words aequor “from the sea” and aequus “even, flat or level.” Their family is commonly known as crystal jellies. This family of jellyfish fascinates scientists because they contain photoproteins that allow them to fluoresce with bioluminescence. Bioluminescence is the ability for animals to create their own light. Animals such as backyard lightning bugs and deep-sea fish are also capable of this unique adaptation.

close-up view of a completely translucent jellyfish spread out on a white plastic measuring board. we can read the measuring line through the jellyfish; it extends from about 2.5 cm to about 13.5 cm.
Aequorea Jellyfish
close-up view of a brown jellyfish on a metal table. looks like a blob.
Aurelia Jellyfish

Aurelia: Aurelia or moon jellyfish are one of the most widely distributed family of jellies.  A. limbata, or brown moon jellies are native to the Bering Sea and coastal Alaska. They range in size from about 9 to 12 inches in diameter. They have a clear cup-shaped bell with brown to orange organs arranged in a circle around the center.


Fish

Pacific Cod: A relative of the Alaskan pollock, Pacific cod are also a cold water whitefish. Also similar to pollock, many people like to cook and eat cod, so this fish ended up as our guest in the mess later that night for dinner.

A Pacific cod in sample basket; later, plated for dinner in the mess hall

Northern Rock Sole: As a bottom dweller, the northern rock sole has both eyes on a single side of its head. His topside is a splotchy brown color, while his underside is a translucent white.

mottled brown right-eyed flatfish laid out against a white surface
Northern Rock Sole


Chum Salmon: Though this one is not so big. Chum salmon are the second largest pacific salmon after chinook. Males of this species develop large canine-like fangs

one salmon in a green plastic basket
Chum Salmon

Smooth Lumpsucker: A deep-sea fish, the smooth lumpsucker has a slippery, scaleless skin. Look closely to see the circle on its underside. The pelvic fins in this species are modified to form a disk used to help secure the fish to ocean surfaces in fast moving waters.

a remarkably round fish held up in someone's glove hand tilted toward the ceiling to reveal the suction disk on its underside
Smooth lumpsucker


Try It on Dry Land

Although you may not be able to hitch a ride out to the Bering Sea for the pollock acoustic survey, you can create your own trawling simulation with a box of Trix cereal and a few kitchen materials.

Trix Trawl

Materials:

  • 1 box Trix Cereal 
  • 1 cookie sheet or shallow baking pan
  • A ruler
  • Tape
  • 1 Tbs measuring spoon or scoop 
  • Data chart (downloadable pdf)

       * Optional small kitchen scale

Instructions

  1. Use ruler to measure and mark with tape both long sides of the cookie sheet in 2” segments. These are your transects lines that you will sample from.
  2. Drag the tablespoon from the mark on one side to the corresponding mark on the opposite side. This is your trawl net. You may not touch the cereal with anything but the spoon.
  3. Sort the cereal into groups of the same shape/color type and record on data sheet.
  4. Repeat until all steps until transects are complete. 
  • Did you get the same number for each shape/color?
  • Do you feel like it was an accurate representation for all the cereal in the box? 
  • Did you find anything unexpected in the cereal box?
  • NOAA scientists also gather the weight for each species group. If you have a small kitchen scale you can weigh each shape/color group and record. Is the set with the most individual pieces also the heaviest? 

Happy Sampling!

Jo, wearing overalls, yellow gloves, and sunglasses, stands in the wet lab in front of stacks of plastic sample bins. She stretches her arms toward the camera to show off a large, yellow-orange chrysaora jelly. a few pollock are visible on the sorting table off to the side.
Jelly Love

Stacey Morris: Get my Drift? August 2, 2026

NOAA Teacher at Sea

Stacey Morris

Aboard NOAA Ship Reuben Lasker

July 26-August 10, 2026

Mission: Integrated West Coast Pelagics Survey

Geographic Area of Cruise: West Coast Pacific Ocean

Date: August 2, 2026

Weather Data from the Bridge

Latitude: 42°29.6 ‘N

Longitude: 125°11.9’W

Wind Speed: 27 kts

Air Temperature: 15.8°C

Science and Technology Log

The day before I left for my trip aboard NOAA Reuben Lasker, I received an exciting email from the Teacher at Sea program. I was going to have the opportunity to participate in NOAA’s Adopt-a-Drifter Program, and I would be getting three drifter buoys that I would be releasing along our journey north along the coastline. 

three drifting buoys sit on a metal table in the wet lab. each drifting buoy's surface float rests on its coiled up drogue. the surface float portions are covered in stickers and decorated with marker. we can see NOAA Teacher at Sea stickers, stickers from Churchhill High School, and drawings of octopus.
Three Drifters ready for deployment

A drifting buoy, frequently called a “drifter,” is designed primarily to track sea surface temperatures. They can also capture data on everything from winds and atmospheric pressure to salinity and wave height. As these buoys meander across the ocean, pushed along by currents, their internal sensors beam this information up to satellites circling overhead. By mapping their journey over time, scientists can piece together a detailed profile of how our oceans move.

screenshot from the Global Drifter Array world map showing the current position of 1,126 drifting buoys, color coded by deploying country. U.S. buoys are bright blue and the most numerous, especially in the Pacific Ocean.
Map of drift buoys and their respective deploying countries

To ensure it stays on track with the water rather than the wind, a drifter utilizes a “drogue,” which acts as an underwater sea anchor extending down about 20 meters (or 65 feet). This drogue is tethered to the surface float, ensuring they travel in tandem with the near-surface currents. Without that heavy drogue to steady it, a drifter would just be tossed about by the wind and waves, much like a beach ball skittering across the top of a swimming pool. 

illustration of a drifting buoy above and below the surface of the ocean. arrows label: Surface Float - designed for moving on the surface with the currents, Antenna - The drifters transmit the data they collect as well as their position via satellite, Sensors - Sea Surface Temperature sensor and various measuring systems, Drogue - The buoys have some for of subsurface drogue or sea anchor
Drifting Buoy diagram. Image Credit: NOAA

Drifter information is vital for mapping worldwide ocean currents and eddies, validating satellite readings, and constructing complex weather and climate models.  These sensors also help predict where pollutants might travel after a spill, how garbage moves through the ocean,  and even help track the path of approaching hurricanes. 

This data isn’t just for scientists—the general public and students have full access to it. Through the Global Drifter Program, classes can follow their own adopted buoy or any others in the fleet in near real-time. Students can retrieve and plot coordinates, time stamps, and Sea Surface Temperature (SST) to create their own time series or map their drifter’s journey over a day, a month, or even a full year. 

map of GOES Sea Surface Temperature readings in the northern Atlantic Ocean on August 3, 2026 at 0655 GMT.  we can see where cold water and warm water collide along a horizontal sweep easy of New Jersey.
Sea Surface Temperature: Image Credit – NOAA

This is why I have this opportunity to be part of this amazing study. It was suggested I personalize the buoys, so I reached out to a local print shop to see about getting Churchill High School stickers made, although I felt it was a long shot due to the short turnaround time. Luckily, QSL Printing saved the day, and all they wanted for compensation was a picture of the buoys covered with their stickers. I was so thankful for their help! 

close up view of a drifting buoy, drogue folded; the surface float has been decorated with Teacher at Sea stickers, Churchill High stickers, an octopus, and the name ZOE
Drifter Zoe–decorated with an octopus and various NOAA & Churchill stickers

I named the buoys after my two sons and a family friend’s daughter: Otto, Nicolai, and Zoe, respectively. Shaun Dolk at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami let me know that the best location to drop the drifters would be off the coast of Eureka, California. The ship’s chief  scientist, Kevin Stierhoff, and I decided that deploying them every ½ hour would give some spacing between buoys, thereby decreasing the chance they would drift together. 

We dropped Otto overboard first, and I realized it was a little odd dropping something named after my child into the ocean. He quickly bobbed away into the distance and I hoped that he would have a safe passage to wherever he might end up. Nicolai and Zoe met a similar fate soon after, although Zoe was greeted by whales that were traveling alongside the ship. 

Drifter Deployment–Stacey (Teacher at Sea) & Melissa (marine biologist)

The expected/average lifetime of a drifter is around 450 days. Each drifter has a full identifier number, and the IMEI numbers are preprogrammed into each transmitter. The IMEI number is sent as a “signature” within each data message received. With nearly 1300 drifters transmitting every hour, it is essential to differentiate messages and separate them accordingly. 

Should you happen to encounter one of these drifting buoys, you should  reach out to the Global Drifter Program team with the details displayed on its surface float. In cases where the instrument is still functional and powered, they will coordinate its redeployment to continue its mission. While most of these instruments have a much shorter lifespan, the most resilient drifter ever documented managed to send back signals for an incredible 10 years, 4 months, and 21 days. It’ll be interesting to see how long my kiddos will be afloat! 

a map of a drifter trajectory in the Pacific Ocean, showing a red line squiggling around the water west of California and then extending over to Japan
Longest drift ever! : Image credit–NOAA

When the drifters start transmitting, I will share a link with you all to see where they are out in the world! (UPDATE: click here to see their progress https://adp.noaa.gov/trackadrifter/churchill-high-school/ )

Personal Log

Switching to working in the evening has been tiring, and it’s sometimes unclear what day it is. I now have pork chops for breakfast, and french toast for dinner which hasn’t been such a bad thing. We’re settling into our daily routine onboard. We haul up three trawls of fish every evening, as weather allows it. We’ve had great weather, and only a couple days of rougher seas. Speaking of which…have you ever used a treadmill on a ship? You don’t need to use the incline function, as you’ll be going up and down with the waves. You definitely need to hang on and it adds an extra work out element to your exercise routine. 

Between trawls, the scientists have some downtime and we’ve learned how to felt sea creatures. Here are some examples of their creations:

Felted ray, crab, and jellyfish

Did you Know?

screenshot of sonar display on computer
sonar used to detect dolphin echolocation signals

Before we do any trawl for fish, we do a mammal watch 15 minutes before we put the net into the water. The net has a metal grate that is designed to keep any large creatures from entering, but it’s possible for dolphins or sea lions to get entangled in the mesh. We scan the water for any splashing, sounds, or spoutings. It’s difficult to discern in the dark, however.

This year, the science team has acquired infrared binoculars, which helps tremendously. You can see almost as well as daylight viewing, and I was able to see whales that were in the distance very easily. There is also a sonar that can show dolphin echolocation soundings, which also assists crew in checking if they are in the area. We had to cancel a trawl this past week due to dolphins hanging around the ship, even after we tried moving to another area. Last night, a sea lion followed us a bit, but we were able to do our trawl after it lost interest. 

Pacific white-sided dolphins playing in our wake