circle hook – NOAA Teacher at Sea Blog

August 7, 2025August 8, 2025

Cheryl Milliken: It’s a Great Day to Go Fishing, August 5, 2025

NOAA Teacher at Sea

Cheryl Milliken

Aboard NOAA Ship Oregon II

July 25 – August 10, 2025

Mission: Bottom Longline Survey, Leg 1

Geographic Area of Cruise: Atlantic Coast of Florida

Date: August 5, 2025 11:25 PM

Weather Data from the Bridge

Latitude: 34° 40.1455′ N
Longitude:075° 45.5686′ W
Wind speed: 8 kts
Wave height: 1 m
Air temp.: 29.4 C
Sky: Clear

Science and Technology Log

Yesterday we reached our northernmost station, off the coast of Cape Hatteras. These shark lovers were hoping to catch a great white there, and we had two lines that were bitten through, so there may have been one that escaped (his name was Winston, in case you were wondering).

a large tiger shark hooked (momentarily) on a line, swimming in the ocean. — Large tiger shark that bent the hook and swam away before we could cradle and measure her.

close up view of two hooks resting on a metal surface. the bottom hook is a standard "circle hook" - it curls now quite all the way around into a circle. the top hook is only slightly curved. — Large tiger shark that bent the hook and swam away before we could cradle and measure her.

During that station we caught two Atlantic sharpnose sharks, a large tiger shark (estimated to by 2.25 meters, or more than 7 feet long), a baby tiger shark (0.87 meters, or a little less than 3 feet), and a male great hammerhead shark that was 2.71 meters (almost 9 feet!) long.

view of a great hammerhead shark visible just below the surface of the water; it is attached to a line — Great hammerhead shark waiting to be hoisted alongside the ship for tagging and measuring.

I was so excited that I was able to tag and fin-clip the great hammerhead! From not really having much background experience with or knowledge of sharks beyond dogfish, I have had a tremendous exposure to these apex predators!

close up view of a round fiberglass buoy: white on top, blue on the bottom. the white section is decorated with stickers and marker drawings.

close up view of a round fiberglass buoy: white on top, blue on the bottom. the white section is decorated with stickers and marker drawings. this angle shows a drawing of a red snapper.

view from across the deck of three people wearing life vests carrying the drifter buoy

two men in life vests lift the drifter buoy (the buoy and its attached drogue) up toward the rail of the ship. it is nighttime.

two men wearing life vests toss the drifter buoy over the rail. it is night time.

Photos: decorations on Drifter #3, launched by Josh and Sean south of Cape Hatteras on Tuesday night.

Near the next station, we were able to launch the third drifter close to the Gulf Stream. I can’t wait to share the information about these drifters with my students! The Adopt a Drifter program has lesson plans that you can check out here: Adopt a Drifter Teacher Resources.

Here are links to see where our drifters are:

Our goal in launching these drifters was to put them into the Gulf Stream to see how they behave. Perhaps they will all stay in the Gulf Stream, or perhaps they will veer out because of eddies. We shall see!

Interview with Gretchen Kruizenga

Gretchen stands next to the CTD rosette on the deck of NOAA Ship Oregon II. the sky is blue with puffy white clouds, and the ocean is a very vivid blue. — *Gretchen Kruizenga, senior survey technician on NOAA Ship* Oregon II, explaining to new staff the purpose and procedure for launching the CTD (Conductivity, Temperature, and Density) apparatus.

Gretchen, the ship’s senior survey technician, always has a smile on her face. She has been so helpful and supportive to me as a newbie on this project, and I appreciate her level-headed guidance and patient encouragement as I learn all the new things. Gretchen’s high energy level and enthusiasm is appreciated. She works with the science crew to bait hooks, then she hustles to collect water quality data from the CTD (short for conductivity, temperature, and depth). Gretchen grew up in Walworth, WI (graduating from Big Foot High School!), then earned a degree in Biological Sciences (minoring in Environmental Science) from Florida Atlantic University (FAU). Her avid affection for sharks is contagious. She has had an amazing breadth of experiences so far, which led her to this job in January 2023.

Why is your work important?

“My job is vital for keeping the scientific operations running. For example, when a sensor breaks, I can replace it to keep them collecting water quality information for the survey.”

What are your responsibilities? This position is new to me.

“I am in charge of maintaining and operating scientific sensors and oceanographic sampling equipment. My job on this vessel is different than on other NOAA vessels because since this ship is small, I also stand a science watch.”

What do you enjoy most about your work?

“I love being able to work on my two biggest career passions: water quality data collection and scientific data collection. I consider myself to be the luckiest person on the ship.”

What tool do you use in your work that you could not live without?

“I’d have to say multimeter. It allows me to figure out if cables are broken or if sensors are getting enough power without having to bring the whole apparatus into the lab.”

When did you know you wanted to pursue a career in science or an ocean career?

“My dad took me to see the ocean for the first time at South Padre Island, TX, when I was 9 years old. I knew then that I wanted the ocean in my life in any capacity it could be. I originally wanted to work for National Geographic to write blogs about places around the world. I got an internship in South Africa with Oceans Research, where I fell in love with sharks. When I’m not on Oregon II, I work with American Shark Conservancy out of Jupiter, FL, to collect water quality data and shark information on recreational shark ecotourism diving boats. I gave a presentation at the American Elasmobranch Society in 2023 about that citizen science work. We collect data that would otherwise be missed.

“I found this job when I googled “NOAA shark research” and found out about this [bottom longline] survey. I’ve always wanted to work with Trey [Driggers] on this shark survey. Being able to contribute to the stock assessment data that I’ve been looking at for years is crazy.”

What is the toughest part of your job?

“The toughest part of my job is keeping a healthy work-life balance. The needs of the ship means being away a lot, which impacts maintaining social relationships.”

What part of your job with NOAA did you least expect to be doing?

“I do more electrical work than expected. I have to read a lot of manuals because there aren’t a lot of people who can answer those questions for me.”

How do you help wider audiences to understand and appreciate NOAA science?

“Coming from an outreach background, I love to share everything I learn with others. I share links and stories on Instagram to get the message out there to anyone who will listen. I do wish we had more outreach opportunities.”

Do you have any outside hobbies?

“I like to make epoxy waves (www.etsy.com/shop/GretchenEpoxSeas), kickbox, and scuba. I like to see my friends. I like to push myself out of my comfort zone. I love to travel (favorite place is Iceland).”

What do you think you would be doing if you were not working for NOAA?

“This is my dream job, but if I can’t work here anymore, I would try to do anything that combines my technical expertise with sharks.“

Personal Log

This time is flying by, and yet every day seems to blend into the next. We have a television on in the science lab while we are moving between stations, and yesterday a Meg (Megalodon) marathon was on… I I loved the quote from the movie, but the portrayal of a long-thought-extinct shark coming back to kill all the people was a little more than I wanted to think about (spoiler alert: especially when one megalodon launched itself out of the water and onto the research vessel in the movie…)

Although I am not going to officially interview her, I want to give a shoutout to Tera Winters, the other watch member who is affiliated with the University of Miami’s Cooperative Institute for Marine And Atmospheric Studies. Tera has been a veterinarian in Tallahassee and Panama City, FL, but has added marine science to her skill set. Tera takes pride in working efficiently, particularly when she is back in the lab processing otoliths (ear stones) from bony fishes to estimate growth rates and ages of individual fish. This information is a critical part of the stock assessment information, because managers need to know how long it takes (in addition to size) for fish of a certain species to reach sexual maturity. Tera has been responsible for FT-NIRS scanning, imaging, weighing, and ageing thousands of otoliths from red snapper. Without this information, the catch limits of red snapper may be miscalculated. I have been privileged to work with such amazing professionals.

Did You Know?

Sharks were around 200 million years before the dinosaurs, and they have persisted for 450 million years. Don’t you think it would be a tragic event if humans caused the extinction of any of the over 500 species of sharks that have been identified?

August 1, 2023August 2, 2023

Martin McClure: Starting the Survey, July 30, 2023

NOAA Teacher at Sea

Martin McClure

NOAA Ship Oregon II

July 25– August 9, 2023

Mission: Shark/Red Snapper Bottom Longline Survey

Geographic Area of Cruise: Gulf of Mexico/Atlantic Ocean

Date: July 30, 2023

Latitude: 31°21.967’N

Lonfitude: 80°12.135’W

Air Temperature: 27.5° C.

Wind Speed: 6.79 kph

Science and Technology Log: Longline Fishing

Teacher at Sea Stephen Kade created this graphic to help explain longline fishing.

We have started the longline survey and it is well organized and exciting. The first part of the process is called the set. We start the fishing process by baiting circle hooks. These hooks are attached to a 12 foot length of 3 mm line called a gangion (gan-jin). We use mackerel for bait. Each piece of fish is hooked through a circle hook.

Circle hooks ready for baiting

Next we drop over a buoy with a radar reflector on top called a hi flier. Attached to this is a 4 mm line called the main line. Then a weight is attached to the line and dropped. This anchors the beginning of the fishing line to the seafloor. Next, a numbered clip is attached to each gangion. The gangions are attached to the main line in order from 1- 50. A second weight is then attached to the main line and the process is repeated with gangions numbered 51- 100. A third weight is then attached to anchor this end of the line to the seafloor.

Tagging and attaching the gangions

Finally, a second hi flier buoy is attached and released to mark the end of the line. As each of these steps is done a member of the team records it on a computer. This gives a precise time that each baited hook went in the water as well as when and where the anchors and buoys were released.

Ready to drop the hi flyer

The next step is to take water measurements. This is done with a remarkable device called a CTD. CTD stands for conductivity, temperature and depth. Conductivity is related to how much salt is in the water (salinity) and is related to how well it will conduct electricity. It also measures the temperature and depth of the ocean at that spot. We attach a camera to it to see what the seafloor is made of at that spot. We want to know if it is a sandy bottom, sea grass, muddy, etc.

The CTD

Then we wait one hour.

The second part of the process is called the haul. The haul is simply the set done in reverse, except that we often catch fish. The fishermen use a grappling hook to retrieve the main line attached to the hi flier.

Grappling hook ready to thrown

When it is brought on board, the main line is attached to a winch. The winch is used to pull the main line up of the seafloor. As the main line is pulled in the gangions are detached and replaced in a barrel, the numbered clips are detached and kept on a line in number order. That way, everything is ready to be used for the next set. Whatever is on, or not on, the hook is recorded on the computer. If the bait is missing or damaged is noted.

Weighing a barracuda

Any fish caught is noted on the computer and the team jumps into action. For sharks there are several things that happen. They are identified by species. The hook is removed and the shark is weighed. It is then measured for three different lengths, precaudal (before the tail fin), fork (at the fork in the tail, and total (the end of the tail fin). The sex, male or female, and maturity is determined. Tissue samples are taken by cutting off a small piece of a fin. This tissue sample is placed in a small plastic vial and labeled. They are also often given a numbered tag. This information is all recorded and entered into the computer.

Me, tagging a sandbar shark.

Meet the Crew: Lieutenant James Freed

NOAA Corps Lieutenant James Freed is the operations officer for the Oregon II. He has many responsibilities as part of his job. Part of his job is to liaison, or maintain communication, between the science party and the ship’s commanding officer (CO). That means making sure that everything that the science team needs is on the ship. If the science team has needs then we would go through him and not directly to the CO. As Operations Officer he is also in charge of organizing materials when they come aboard the ship. He posts the Plan of the Day which lets everyone on board know what to expect that day. Lieutenant Freed coordinates port logistics for the ship. This means he coordinates the loading and unloading of materials. His duties also include acting as Officer of the Deck (OOD). During this 4 hour shift he is responsible for the ship’s navigation and safety. His emergency response assignments on the Oregon II include being the nozzleman on the fire team, launching life rafts for abandon ship and he goes out on the rescue boat for man overboard.
Lieutenant Freed grew up in Santa Rosa, California. He attended Santa Rosa Junior College and then transferred to University of California, Santa Cruz where he studied marine biology. During this time he worked as an intern on a fishing vessel and this is where he first heard about the NOAA Corps. He has now been in the NOAA Corps for 6 years. Before being assigned to the Oregon II he was first assigned to the NOAA Ship Bell M. Shimada in Newport, Oregon. He then moved to Seattle working with the Marine Mammal Laboratory at Alaska Fisheries Science Center. For this assignment his duties were quite varied. They included doing a lot of field work, flying drones, and doing whale biopsies.
Lieutenant Freed is clearly enthusiastic about his career in the NOAA Corps. He describes it as an “incredible career” that supports his growth with leadership and management training. The NOAA Corps is growing with new ships and aircraft and will need to recruit new members.. The ships participate in a wide variety of tasks including fisheries research, oceanographic and atmospheric data collection and hydrographic mapping.

Personal Log

Well these last few days have been quite a transition. After 2 1/2 days of transit from Pascagoula, MS to Miami. It was a bit shocking to see how the skyline has changed after 40+ years. It has grown, to say the least. We started fishing just north of Miami. The 10 person science team is split into two shifts. I am on the “day” shift. We work from noon to midnight. These long shifts are filled with alternating periods of activity and waiting. After the set we wait for an hour before the haul. Then, depending on where the next set is, there will be another wait of between two to three hours. The hauls seem to follow the same patterns. As the mile of line is reeled in, there are long periods with not much happening. Then, there might be three fish online within a few hooks. Last night it was two baby tiger sharks and a 1200 mm (3 ft. 11 in.) barracuda within about 5 minutes. When there is a shark too big to haul up by hand on the gangion, the crane is used. We all don hardhats, the crane is moved into place and everyone is busy taking measurements, preparing tags, and taking tissue samples. I was warned to bring a lot of reading material for the down time and I did that. However, with so many things to learn, interesting people to talk to, and beautiful scenery to watch, I have had little time for boredom to creep in.

Ready to release a baby tiger shark.

One of the most common questions that I had before I left concerned getting motion sick. Dare I utter the word… seasick. So far, I have been lucky… hmm, I can’t seem to find any wood around here to knock on. I started the voyage with what I consider to be a rational decision, take the Dramamine. We started with two days of beautiful weather. By the first sign of rough seas I had stopped taking the Dramamine so I went outside and watched the horizon for about an hour. I decided that watching the horizon on a beautiful day at sea had no drawbacks. I never did feel nauseaus. Some people recomended that I buy the accupressure bands which I did. When seas get rough and I am inside I will sometimes wear those. I have not been seasick, yet. I still take precautions like not doing computer work inside when in rough seas but so far I have been fine. In fact, as far as I know none of the volunteers or crew have been sick.

I cannot end this blog without acknowledging the stewards in the gally and the impressive menu available at each meal. I think that there are always three choices for a main dish and a variety of sides. Additonally, a salad bar is always available, snacks, and my favorite, ice cream.

Just one of three delicious options that night

Animals seen: sea turtle, dolphin, snake fish, spotted eel, barracuda, shark sucker. Sharks: sandbar shark, tiger shark, Atlantic sharpnose shark, scalloped hammerhead

shame faced crab

Did you know?

Most of the fish that we catch have parasites living in and on them?

July 28, 2014August 21, 2021

Lynn Kurth: Eagerly Waiting to Tag Sharks, July 28, 2014

NOAA Teacher at Sea
Lynn M. Kurth
Aboard NOAA Ship Oregon II
July 25 – August 9, 2014

Mission: Shark/Red Snapper Longline Survey
Geographical area of cruise: Gulf of Mexico and Atlantic
Date: July 28, 2014

Lat: 24 17.334 N
Lon: 082 30.265

Weather Data from the Bridge:
Wind: 7.52 knots
Barometric Pressure: 1017.85 mb
Temperature: 31.1 Degrees C

Science and Technology Log:

We have been traveling across the Gulf over the past two days and will continue traveling until Monday night when we will reach our first testing station. Wondering exactly where we are? You can see the ship’s location live at: NOAA Shiptracker

Our official survey has not begun but Dr. Jim Nienow, an instructor from Valdosta University, is aboard for the cruise and has been doing some basic plankton sampling while we are on the move. Dr. Nienow participated in his first shark longline survey back in 2008 and this is his sixth cruise aboard the Oregon II. He enjoys being part of the shark longline survey because it provides him with the opportunity to collect the samples that he analyzes with his students when he returns to the university. In the first few years that Dr. Neinow began collecting plankton samples he was interested in the overall biodiversity he found in the samples.

But over the past few years his work has evolved and he is currently focused on the distribution of diatoms. Diatoms are microscopic single celled photosynthesizing algae and are the most common type of phytoplankton found. Diatoms represent approximately half of the ocean’s production. In other words, these little buggers are important because they serve as the base of the food chain for the ocean. By studying diatoms scientists are able to study the overall health of the particular environment that they were collected from.

We have spent some time preparing the gear for the survey by getting the fishing lines ready. Circle hooks are used for the shark long line survey vs. J hooks so that the sharks are rarely hooked deep which makes the hook easier to remove and reduces the potential of harming the shark.

Did you Know?

Diatoms are used for the following:

as mild abrasives found in cleaning products and sometimes toothpaste
as filter material when making alcoholic/non alcoholic drinks, syrup and medicines
as insulation in sound proof or fire proof doors

Diatoms as seen through Dr. Nienow's scanning electron microscope Photo Credit: Dr. Jim Nienow — Diatoms as seen through Dr. Nienow’s scanning electron microscope
Photo Credit: Dr. Jim Nienow and The Deep C Consortium

Personal Log:

During our time traveling we had an abandon ship drill. If we were to abandon the ship we would put on a full neoprene survival suit before entering the water. The water temperature in the Gulf of Mexico is around 87 degrees Fahrenheit so the suit protects folks from hypothermia that would occur over time.

August 3, 2007April 1, 2021

Elizabeth Eubanks, August 3, 2007

NOAA Teacher at Sea
Elizabeth Eubanks
Onboard NOAA Ship David Starr Jordan
July 22 – August 3, 2007

Mission: Relative Shark Abundance Survey and J vs. Circle Hook Comparison
Geographical Area: Pacific Ocean, West of San Diego
Date: August 3, 2007

Weather Data from the Bridge taken at 1300 (5am)
Visibility: 10+ miles
Air temperature: 18.7 degrees C
Sea Temperature at surface: 21.9 degrees C
Wind Direction: 010N
Wind Speed: 5 kts
Cloud cover: partially cloudy– stratus
Sea Level Pressure: 1014.2 MB
Sea Wave Height: 1-2 ft
Swell Wave Height: <1 ft

Science and Technology Log

Cleaning – Cleaning – Cleaning. We fuel for 4+ hours – Amazing! We will be in port by 2pm today.

Personal Log

Thank you, thank you, thank you. I have been honored to be selected to participate in NOAA’s Teacher at Sea program. This has been a life-changing adventure. I am wiser and have so much to share with my students and community.

A huge thanks to all of the scientist for being so nice and so helpful. I feel honored to have worked with Dr. Suzi Kohin, Dr. Russ Vetter and Dr. Jeff Graham as well as grad students Lyndsay Field, Heather Marshall, Dovi Kavec (thanks for being my on board conscience!), Noah Ben Aderet, Alfonsia “Keena” Romo-Curiel, South West Fisheries staff (including Suzi and Russ), Anne Allen (thanks for taking me to the bow chamber), Eric Lynn, Monterey Bay Aquarium staff, Ann Coleman (thanks for teaching me how to set and haul and collect data), and my roommate Leanne Laughlin from California Department of Fish and Game. The crew has been awesome. I give you many, many thanks and wish you the best at sea. Chico – I am happy and I know it – so my face surely shows it! Jose – “any minute now” and you will catch a fish.

Peter good luck at the Maritime Academy and with the guitar.

LCDR Keith Roberts, thanks for your command. XO Kelley Stroud, thanks for your help with kids’ supplies. I am going to stop here, in case I forget someone, but please know I appreciate all of the folks on the deck, bridge, engine room (Great tour John!) and the galley (the food was amazing) so much. Thanks for your interviews – you will be famous. This trip has been amazing!

Questions of the Day

What sounds most interesting about the adventure at sea? Would you like to go to see to study sharks?

Question of the trip: Which hook, the J or Circle, will catch more sharks?

Please make a hypothesis. Utilize resources to justify your hypothesis. ———Yes, you get extra credit for this.

August 2, 2007April 1, 2021

Elizabeth Eubanks, August 2, 2007

NOAA Teacher at Sea
Elizabeth Eubanks
Onboard NOAA Ship David Starr Jordan
July 22 – August 3, 2007

Mission: Relative Shark Abundance Survey and J vs. Circle Hook Comparison
Geographical Area: Pacific Ocean, West of San Diego
Date: August 2, 2007

Weather Data from the Bridge
Visibility: 10+ miles
Air temperature: 20.3 degrees C
Sea Temperature at 500 m:
Sea Temperature at surface: 19.8 degrees C
Wind Direction: 280 W
Wind Speed: 17 kts
Cloud cover: partially cloudy–alto cumulus
Sea Level Pressure: 1015.7 MB
Sea Wave Height: 1-2 ft
Swell Wave Height: 2 ft

Science and Technology Log

The Bow Chamber! Wow! The Bow Chamber is in the bulbous bow. It is located in the very front of boat where the V hull is. Basically this area breaks up the water pressure to create less drag. The chamber is actually a little room about 20 feet down below the main deck. It has port holes/windows so you can see aquatic life. Currently the windows have a lot of algae on them so it is hard to see out of them during the day. A group of us went down after dark and we could see bioluminescent creatures zipping by. We were seeing things such as dinoflagelletes/ plankton and jelly fish. It was so beautiful to watch.

Personal Log

Doctoral student Dovi Kacev and NOAA Teacher at Sea Elizabeth Eubanks look down into the bow chamber.

Great day. I got up at 5:30am to watch and learn a little more about the CTD, which I wrote about yesterday. We completed our 2 final sets and I gathered goodies to bring back to school. We had the perfect ending to our last set. One of the very last hooks we pulled in possessed a huge, enormous Blue Shark. He was the biggest that we had caught so far, in length (229 cm) and girth. He gave a huge fight while in the water and even threw up a little (but thankfully not his stomach) before they got him onto the cradle. The best part of this was that the rest of the scientists could watch the people on the platform work with the shark, because the long line hauling was finished. It was truly the perfect ending to the perfect adventure.

Question of the Day

How do bioluminescent creatures shine?

Question of the trip: Which hook, the J or Circle, will catch more sharks?

Please make a hypothesis. Utilize resources to justify your hypothesis. ———Yes, you get extra credit for this.

A big Blue Shark. Graduate student Heather Marshall holds the tail while Dr. Jeff Graham helps Dr. Suzi Kohin with the bolt cutters as Dr. Russ Vetter retains the head.