tiger shark – NOAA Teacher at Sea Blog

August 26, 2025August 28, 2025

Robert Markuske: Starting to Untangle the Lines of Science and Policy, but Not Finished… August 26, 2025

NOAA Teacher at Sea

Robert Markuske

Aboard NOAA Ship Oregon II

August 13 – 29, 2025

Mission: Long Shark and Snapper Survey

Geographic Area of Cruise: Gulf of America

Date: August 26th, 2025

Greenwich mean Time: 5:52 PM

Data from the Bridge:

Latitude: 29 degrees 22.755’N
Longitude: 83 degrees 37.314’W
Relative Wind speed: 5.42 Knots
Wind Direction: Southeast
Air Temperature: 32.8 Celsius
Sea Surface Temperature: 30.3 Celsius

close-up photo of Rob, wearing a hard hat, life vest, reflective sunglasses, and a serious expression; in the distance, across a span of blue water, is the full view of NOAA Ship Oregon II. the sky is blue with a few wispy clouds. — Had a chance to ride the small boat, and really see the *Oregon II*

Ahoy from the Gulf!

This first paragraph was written in worse weather. Today the sun has come out and the calm waters are back. But previously, I was editing this blog as we floated around in storms in the Gulf. They finally dissipated and we had a chance to score stations with a snakefish, sandbar, and a tiger shark. Probably one of the higher-wave days on the Beaufort scale since we left the port of Miami. Today’s prediction from the bridge is west-southwest winds at 5–10 knots and wave heights of about 1 ft, with scattered showers. The Oregon II is rolling, and swaying to the beat of the Gulf.

What number do we fall on the Beaufort scale? Right now, we’re sitting at about a 2—depending on the moment. But it can change quickly.

Video from the galley. What’s our Beaufort Reading?

a table explaining the Beaufort Scale (Estimating Wind Speed and Sea State with Visual Cues.) Beaufort numbers range from 0 (calm) to 12 (hurricane.) — Beaufort Scale

Just like our environment speaks to us about what’s happening around us, the ship communicates with other seafarers. The Day Shapes on the Oregon II mean something. Different shapes, and combinations of shapes, signal the level of awareness and caution other vessels need to have when approaching.

Different shapes, and combinations of shapes, signal the level of awareness and caution other vessels need to have when approaching.

view up the mast of a line with metal shapes suspended from it — Shapes are tied to Foremast to communicate with other vessels

closer view of three metal shapes suspended in a line from lines against a blue sky. — Shapes are tied to Foremast to communicate with other vessels

Our Day Shapes mean we’re restricted in our ability to maneuver – especially when we are deploying the CTD (conductivity, temperature, and depth) instrument. Since late in the evening on August 13th, we’ve been laying long lines and conducting CTD’s in 12-hour watches, usually 3-4 sets per watch.

meteorologica map of the Gulf of America from the Windy App showing some storm clouds toward Florida — We are currently the white dot inside the white circle in the storm front.

So those shapes have been up for a while. Other than our current status, wading in the not so velvet Gulf, we’ve been consistently living those shapes.

I already blogged about how we fish using bottom longline gear—I’m going to dive a little deeper into why we do it, what happens after the fish are caught, and what happens after we release them.

I just want to preface this by saying: this is by far one of the most complicated topics I’ve ever tried to teach high school students. Part of my work out here is learning from the people who do this everyday, so I can simplify it and make a complex system of natural resource management engaging for my students—and make it make sense.

Everything I’m sharing below is based on my personal experience learning from the fisheries biologists aboard the Oregon II—whom I’ll introduce in another blog post—as well as digging through NOAA Fisheries and academic resources to add to my understanding. Some of those resources were created with input from the very fisheries biologists on this ship, using the science and data collected during surveys like the one I’m on.

Enjoy.

Fish Hauled – New additions are in red, since last blog post.

As of August 17th As of August 25th
Silky Shark – Carcharhinus falciformis
Sandbar Shark – Carcharhinus plumbeus
Barracuda– Sphyraena barracuda
Speckled hind– Epinephelus drummondhayi
Yellowedge grouper – Hyporthodus flavolimbatus
Red Porgy – Pagrus pagrus
Tiger Shark– Galeocerdo cuvier
Sharpnose shark– Rhizoprionodon terraenovae
Gulf Smoothhound – Mustelus sinusmexicanus
Snakefish – Trachinocephalus myops Great Hammerhead shark – Sphyrna mokarran
BlackTip shark – Carcharhinus limbatus
Spotted eel –
Lemon Shark – Negaprion brevirostris
Nurse Shark – Ginglymostoma cirratum
Blacknose shark – Carcharhinus acronotus
Scallaoped Hammerhead – Sphyrna lewini
Click Common Name for for more info

beautiful photo of sunset over the ocean, with streaks of blue and orange — Whats beneath the water and beyond that horizon?

Science and Technology Blog

Often overlooked, forgotten, Oceans and waterways are a massive source of “wild food,” a popular recreational playground, spiritual engagement, an epic research zone, and home to endless stakeholders. What I find most captivating about our ocean—and the complicated relationship humans have with it—is that you can’t see what’s below the surface without incredible precision, science, and a bit of luck and/ or chance.

a view of NOAA Ship Oregon II underway, at a distance, such that the length of the ship is visible. the sky is bright blue with wispy white clouds, and the ocean is glassy enough to reflect the images of the ship and the sky — Oregon II Underway to next fishing station.

The vast ocean covers 70% of Earth, and it’s deeply intertwined with our food, culture, oxygen, weather and climate, the water cycle, and life itself—the mystical, the economical, the spiritual, the recreational, and the scientific—right down to our land. How we manage and use it is vital to us all.

There are endless trenches I could dive into, but I’ll do my best to keep a steady progression in these blogs, cater to the students who will likely be reading this once school starts, and hopefully inspire some of them to explore deeper depths. I know I will—both during this trip and when I return to Brooklyn.

What is a “stock,” and how is it assessed?

First and foremost, a “stock” refers to the population demographics of a species of marine life. Stock assessments are conducted to check abundance and respond accordingly if needed with management strategies.

These assessments are built on the ABCs of a stock: Abundance, Biology, and Catch.

How do you collect data for the ABCs of fisheries science?

There are two types of data collected to assess a stock: fishery-dependent and fishery-independent.

Fishery-independent	Fishery-dependent
Fishery-independent data are collected by biologists on at-sea surveys that keep sampling time, area and gear consistent to gather information on fish stock abundance, biology, and their ecosystem.	Fishery-dependent data are collected directly from recreational and commercial fisheries, and provides landings information (total numbers caught), bycatch (catch that is incidentally caught), and biological details about the fish.

I am currently on a Fishery-Independent survey.

photo of a screen displaying planned ship transects overlaid on a nautical chart filled with depth readings — This a sample of what the day will look like.

Where is Oregon II going?

Being on the open water can get you all spun around. Now add zig-zagging across the Gulf nonstop for 18 days, 24 hours a day—baiting, setting, hauling, and doing science in the blistering heat. It helps that we have charts all over the “dry lab” and around the ship to show us where we are and where we’re headed.

I’m currently on Leg 2 of the survey. This survey has four legs. A leg is a separate time at sea within the overall survey. On each leg, different stations are worked to meet the objectives. The survey runs down the Atlantic Coast from North Carolina to West Palm Beach, FL, then transits back around past the Florida Keys and into the Gulf to begin sampling again north of the Dry Tortugas. In the Gulf, data is collected at three different depth strata: the shallowest and closest to the coast (9–55 m), midway (55–183 m), and farther out on the continental shelf (183–366 m)—bouncing back and forth along the shelf as we move up the western coast of Florida.

On my leg, we fish at different stations throughout the eastern Gulf, moving between these depth strata. I wasn’t too far from the coast where some families live. These stations are selected at random, with some structure like the depth strata and geographic areas to help ensure adequate spatial coverage. .

black and white line map of the eastern Gulf of America with green dots showing the sample stations, and a few black square outlines; also bathymetric lines; the sample sites are all in the contours along the coast of Florida, not in the deep Gulf — Green Dots represent areas surveyed, and black squares represent MPAs (Marine Protected Areas)

What is collected and how is it collected?

Catch is identified, measured, weighed, sexed, and often a fin clip is taken. Not all sharks are tagged, but every single one is identified. This part is the hardest for me—accurate identification is critical for collecting data used to assess the stock.

Even though we’re sailing in the Gulf of America, we use meters and Celsius. Standardization across datasets—as well as consistency in methods and results—is essential in science. Accessibility and transferability of data are key for making accurate determinations and ensuring the longevity of the dataset. I often forget that the rest of the world uses the metric system!

See a list of Atlantic and Gulf Sharks NOAA Fisheries.

There are lots of shark species that are easy to tell apart—and others, not so much. For example, there isn’t just one type of hammerhead.

Rob and another member of the science team, both wearing life vests, gloves, and hats, crouch on deck to hold a small shark on a measuring board — Smoothhound Shark ID

I find it so impressive when the fisheries biologists can identify them and then explain the differences to people who aren’t trained in fisheries biology. Major and subtle differences exist, and it takes a trained eye to spot them. The more you see it, the more you can’t unsee it.

a poster of shark anatomy - shared here at a size too small to read - developed by Shark Trust. — Basic Shark anatomy for reference.
Credit Shark Trust.

a line drawing of a generalized finfish showing different standard length measurements — Basic Shark anatomy for reference.
Credit Shark Trust.

To figure out the sex of sharks you look for claspers—males have them, females don’t. Males use their claspers during the reproductive process. And that’s the story of the birds and the fish.

visual guide to identifying male v female sharks with both illustrations and photos of the anal regions. — Identification of sex

We weigh them using a scale, placed in the mouth.

Finally, we remove the hook and let them go. All of this has to be done quickly, and once all the data is collected, we gently return the shark to the water and watch it swim away.

Rob, wearing a life vest, sunglasses, and a hat, poses for a photo holding a roughly 3 foot shark in two hands. he stands on deck. — Ready to release

view over the railing of the ship into dark water; the cradle is just below the water's churning surface, lifting a large shark in motion — Ready to release

Larger sharks are brought up in a cradle on the side of the vessel.

I got to see up close and personal what a hammerhead looks like—and had the privilege of participating in the tagging of this incredible animal. I have to say, I always knew they were real—a sort of mystical sea creature I thought I could only dream of seeing. Well, they’re real, and just as beautiful as I imagined.

Bringing a shark up in the cradle is always an exhilarating experience—being so close to these animals while contributing to both commercial and conservation efforts.

a great hammerhead swimming near the surface of bright blue water — Great Hammerhead we took samples and tagged and released.

great hammerhead swimming near the surface of bright blue water (different direction) — Great Hammerhead we took samples and tagged and released.

Rob sits and a computer desk with a row of small blue-capped sample vials — Processing fin clips

Genetic samples (fin clips) are taken to a lab back on shore, where Texas A&M geneticists catalog and store them for future use and species-specific research projects.

For other fish, we collect eye lenses, fin clips, and otoliths.

All of these methods—and the data collected—help inform the preservation, conservation, and management of these species for both commercial and recreational purposes.

Retrieving samples from Red Grouper
inside the eye lies a lenses
close up of red grouper eye lenses
Preserving eye lenses from red grouper
Sample of Fin Clip
Otolith is the ear bone from fish
Ear bone from fish can help age it
Close up of Otolith
Preserving Otoliths
Red Grouper; eye lenses, fin clip, and otolith.

But why is this collected?

A colleague and mentor from New York Harbor School—a Teacher at Sea alum on NOAA Ship Oscar Dyson years ago— told me he was confused about what I was doing; what is the research question he asked?

The research questions can change depending on the needs of a particular species and or direction of particular research bodies. This data is collected to help manage the stocks of shark species and red snapper. The fisheries data collected on the Oregon II is included in regional stock assessments. After the stock assessment team reviews all the available data for a given species, scientific models can be developed which can then contribute to federal stock management in the region.

This survey has been happening year after year—for more than 25 years.

So, what’s going on with sharks today?

The famous summer blockbuster based on the book the Peter Benchley, Jaws Novel, instilled fear among people about sharks and was a catalyst to increased fishing for sharks – specifically white sharks – contributing to overfishing. For two decades following the release, lack of knowledge and fear, led to effects on the shark fishery.

a gif from the movie Jaws, when the shark jumps up on the back of the insufficiently large boat — “Think we are gonna need a bigger boat?”

“Jaws spearheaded a “collective testosterone rush” among fishers in the East Coast of the United States, leading thousands to hunt sharks for sport, as George Burgess, former director of the Florida Program for Shark Research, told the BBC in 2015. In the years following the film’s release, the number of large sharks in the waters east of North America declined by about 50 percent. “

Sharks are fished for several reasons: sport, commercial products, food, and scientific research.

Over the course of this immersion with scientists aboard the Oregon II, I’ve grown to love these animals and feel far less fear around them. Now, does that mean I’m going to go swimming with sharks off Long Island or in NYC? Not without a trained biologist like the ones I’m working with on the Oregon II!

A long time fear of these apex predators, has been sort of a commercial enterprise. Go to any water park and you will see a shark necklace. I think I even swam with sharks at Disney World Blizzard Beach, now that I think about it, sort of a weird thing. Baby shark is all over the airwaves and streaming services. I think we underestimate how cultural influences affect our view of our environment and its inhabitants. Sometimes, culture seeps into our consciousness.

top-down view of a sandbar shark swimming away from the shark cradle in bright blue water — Sandbar shark swimming after being tagged.

top-down view of a sandbar shark swimming away in bright blue water — Sandbar shark swimming after being tagged.

I’ve stayed humbled and fascinated by these animals every single day of this experience.

Keep in mind, I’m just talking about federally managed fish in federal waters. To further complicate the matter there are also, States and/ or international law involved too. Sharks are managed federally under the Highly Migratory Species (HMS) classification.

Fishing and other human activities have influenced the species started in these fisheries, and the data has helped show these shifts over time. Hence the complicated, but necessary interconnections of science, policy, conservation, economics and stewardship. What adds to more a complicated scenario, generally sharks (relative to say many bony fish) are longer lived, take longer to mature and reproduce fewer young so that overfishing can have larger deleterious effects on their populations.

black and white photo of two men in suits sitting at a desk and conversing with one another. nameplates identify Mr. Stevens on the left and Mr. Magnuson on the right. — *U.S. Senators Ted Stevens (R-AK) and Warren Magnuson (D-WA), 1973. Credit: Ted Stevens Foundation*

The primary law that manages fisheries is the Magnuson Stevenson Act. The main purpose of the act was to establish sustainable and economically viable U.S. fisheries. Major components to establish this directive are as follows; Preventing overfishing, Rebuilding overfished stocks, Increasing long-term economic and social benefits, Ensuring a safe and sustainable supply of seafood, Protecting habitat that fish need to spawn, breed, feed, and grow to maturity.

NOAA Fisheries graphic on Science-Based Management Tools: Stock Assessments, Annual Quotas, Size Limits, Retention Limits, Gear Restrictions, Area Closures, Retention Bans, Reporting Requirements, Naturally Attached Fin Requirement, Strong Enforcement. — Science-Based Management Tools

Much of the management of sharks in the Gulf are in line with the Magnuson Stevenson Act. There are a variety of methods that contribute to managing a species.

Due to surveys such as the one I am sailing on, and a science-based management approach, some shark stocks have even experienced population growth including:

Atlantic sharpnose
Atlantic blacktip
Sandbar
Spiny dogfish
Tiger
White

However, there are some species that aren’t as positive a story and need protection. Below is a list of sharks that are Prohibited from being caught in the U.S Atlantic, the Gulf, and Caribbean. Moreover, there are tools to help mitigate harm to these animals if an unintended catch (bycatch) occurs.

Below is a list of Prohibited Sharks in U.S Atlantic, the Gulf, and Caribbean. Moreover, there are tools to help mitigate harm if bycatch occurs. Bycatch occurs when you catch something that wasn’t what you are targeting.

Prohibited Shark ID Placard Download

It’s important to note that regulations exist for both commercial and recreational fisheries. However, in all fisheries that harvest sharks, no fins can be harvested at sea. Animals must come intact (fins naturally attached) to shore then can be harvested along with the entire animal. Finning has been illegal in US waters since 1993, with further protection enacted in 2000 and 2010.

Fin-Sales-Act-FAQsDownload

Commercial Regulations

Recreational Regulations

Fin-Sales-Act-FAQs Download

Commercial Regulations

Recreational Regulations

Over time, if stocks replenish, species can be removed from the “no-fish” list. Conversely, if stocks dwindle, actions will be taken. Data is critical for making these decisions. It’s common for people to think that “overfished” means extinct. There are actually different classifications for fish populations. There’s a difference between extinction and being threatened, based on definitions in the Endangered Species Act.

An important concept for fisheries management and stock assessment is maximum sustainable yield—the maximum catch a species can sustain over time. It’s the amount of fish that can be harvested from a source, which will allow adequate reproduction and replacement. This is why research is done like the stuff down on the Oregon II and other ships in the NOAA fisheries fleet, the data helps make that decision. Fishermen need fish to make money, folks want fish to eat, and the environment needs to have the fish. Complicated.

Although complicated, data driven management has been proved to support growth of some shark species. Check out the cool story of the white shark slowly making a comeback after years of overfishing: White Shark Recovery.

In addition look at the timeline of shark fisheries; fishing, science, conservation, and policy.

two maps of the waters south of Long Island. the top map shows trajectories of 8 tagged white sharks, represented as dots (location pings) connected by straight lines. the bottom map replaces the individual pings with a heat map color-coding areas by ping frequency. there is a red hot spot adjacent to the eastern end of Long Island — First insights into the movements of young-of-the-year white sharks (*Carcharodon carcharias*) in the western North Atlantic Ocean Scientific Reports ( 2018)

What’s even more delicate and fascinating, the white shark nursery is in waters not far from NYC. Several researchers are tracking white sharks and their nursery habitats and juvenile behavior. They tagged and tracked 8 sharks and tracked their movement. You can see from their data where they are most frequent; red being the highest concentration, and light blue being the least during the months of August to October. This really shows the interconnection between the Hudson canyon, Long Island and our coastal harbors of NYC. All happening under the nose of the big city. The sharks are making it to the Hudson Canyon, which is approximately over 100 miles from NYC and filled with biological diversity.

Link to full paper.

Personal Log

We started talking today about when we’ll head back to port, and honestly, it made me a little sad that this trip is almost over. I had one day where I got really homesick—started missing Clara and the cat. A quick FaceTime fixed that and reminded me to stay present. Lately, school emails have started coming in too, so I guess I finally get what people mean by the “dog days of summer.”

The past few days have been a mix. Some hauls were pretty boring, and the weather’s been rough. But I don’t mind rough seas—kind of makes me feel salty, like a real mariner. Plus, the clouds have been a blessing, giving us some relief from the heat. And then came the set that changed everything: we brought up a tiger shark and a big sandbar in the cradle. That got my energy back in a hurry.

a person kneels near a fish measuring board to grasp the head of a tiger shark with two gloved hands safely behind its jaws — Taking hook out of Tiger Shark

Rob, wearing a life vest and gloves, looks on as two other science team members work together to weigh a tiger shark on a hanging fish scale — Taking hook out of Tiger Shark

Even on slow days, there’s a silver lining—it gives you time to really talk to people. Lately, we’ve been making our own fun with games like “find the rubber sharks” and a ship-wide murder mystery. I’ve already been “killed” and found 3 out of 20 sharks. When I’m not blogging or doing science, we’re in the lab playing Overcooked or Mario Kart. I wish I could say I’m crushing it, but that’d be a lie—at least for now. Maybe my luck will turn around. Out here, you need fun built in. Otherwise, the downtime will drive you nuts.

I’ve been working on listening more. It’s been cool. Folks here are curious about the Teacher-at-Sea guy from Brooklyn, and I’m just as curious about people from Mississippi doing shark stuff. The deck crew and engineering crew seem to be from all over, its awesome how all these people are on this ship to participate in this work. Clara would be proud—I’ve been asking more questions than talking about myself.

We’ve been sharing music too, and jamming during sets/ hauls. These folks are definitely not Phish fans, so I’ve had to dig into my youth and other playlists. I got one Phish studio track played—just one. Our watch leader Kristin was taking requests, and when I said Five Years, she laughed and asked, “Is it five years long?” It’s been fun shaking up my musical listening. New Orleans came up in convo, I forgot the geography of the Gulf area to NOLA—and that I actually lived and taught there in a season of my life. I have found memories of the food and culture of this area, it’s nice to relate to folks that enjoy it more frequently. One of these days, I’ll be back. Moe. is playing Halloween, Clara—what do you think?

I’ve also started talking to folks outside my watch crew. Turns out, it’s a small world out here. Some of these people are just a few degrees away from me in the environmental education world. We even know some of the same people. A couple of us have been in the same place at the same time before and didn’t even know it. One guy almost went to Harbor School but chose another path—still ended up working on ships like he wanted. Wild how that happens. The more I think about it, the more I realize: there are a lot of people out there doing wild things, and somehow, you bump into each other.

This blog was tough to write. There are so many directions to go. But at its core, it’s simple: people do science, and policymakers use that science to make decisions—especially about natural resources. Moreover, fingers crossed . For me, these blogs and this whole experience are filling in gaps in my own learning. They’re helping me figure out how to teach this stuff to my Harbor students in a real, meaningful way. Honestly, every paragraph here could be a lesson. Some could even turn into a whole unit. Maybe even a year-long course. The gears are turning.

Who knew I’d get this into sharks? It’s crazy how much we know—and how much we don’t—at the same time. A teacher at school is always saying playing science vs. real science, I wonder what he classifies this as. This experience makes me feel special, it’s been nice to see all the comments and folks have been reaching out to see how it’s going. It’s a good feeling when people are interested in what you are doing. I am glad to be tagging along with the crew on this ship, and it’s nice to highlight what they do is important and special. Waiting on the students to be interested, maybe I will let them have the dog days of summer. I see some of my students doing things like this in their future.

Animal Sighting:

view up at a brown bird flying overhead through bright blue sky — Brown Booby flying over the deck

Brown Booby ( Sula leucogaster)

Brown Booby flying over the deck

Brown Booby ( Sula leucogaster)

Seabirds that don’t nest in the U.S. but are seen flying in the gulf and visiting Caribbean and Florida.

Natty Brown, with yellow-bill, white underneath its wings. This one is a juvenile, as it hasn’t developed its color yet.

I thought this was a frigatebird at first, they are very different. Especially, the wings on the Booby are smooth, where is the wings on the frigatebird are sharp and lines.

Did you know?

photo a rusted plaque that reads R.V. Oregon II. Designed by R. H. Macy for U.S. Department of Interior Bureau of Commercial Fisheries. Built by the Ingalls Shipbuilding Corp. A Division of Litton Industries. Pascagoula, Mississippi 1967. — Once Built for Bureau of Commercial Fisheries

Prior to the National Oceanic and Atmospheric Administration (NOAA) there was the Bureau of Commercial Fisheries. The National Oceanic and Atmospheric Administration (NOAA) is part of the Department of Commerce and was created in 1970.

Early on the director of the National Oceanic and Atmospheric Administration (NOAA) had a contest of what the logo should be. Below are the candidates from 1970.

The candidates for NOAA

Dr. Robert White, NOAA’s first administrator, gave employees a choice. A year after they all were introduced, number one was chosen to show the interconnections between Earth, ocean, atmosphere, and ecosystems.

Dr. White stated: “A white, gull-like form links the atmosphere to the sea or Earth. The Earth and atmosphere and the interrelationships between the two are, of course, major concerns of NOAA. The line defining the top of the gull’s wings also resembles the trough of a foaming ocean wave against the blue sky. A creature of sea, land, and air, the gull adds an ecological touch to the Earth-sky motif.”

NOAA emblem; dark blue sky, white seagull, light blue water. — Winning Logo from 1971, still used today.

References

Cornell Lab of Ornithology. (2025). Brown Booby overview. All About Birds. https://www.allaboutbirds.org/guide/Brown_Booby/overview

Cornell Lab of Ornithology. (2025). All about birds. Cornell Lab. https://www.allaboutbirds.org/guide/Magnificent_Frigatebird/overview

Curtis, T. H., Metzger, G., Fischer, C., et al. (2018). First insights into the movements of young-of-the-year white sharks (Carcharodon carcharias) in the western North Atlantic Ocean. Scientific Reports, 8(10794). https://doi.org/10.1038/s41598-018-29180-5

Germain, J. (2022, December 20). Steven Spielberg regrets how Jaws impacted real-world sharks. Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/steven-spielberg-regrets-how-jaws-impacted-real-world-sharks-180981335/

JetStream Max: Wind and sea scales. (2023, September 22). National Oceanographic and Atmospheric Administration.

National Weather Service & National Oceanographic and Atmospheric Administration. (n.d.). Estimating wind speed and sea state: Beaufort scale.

NOAA Fisheries. (n.d.-a). Atlantic highly migratory species. https://www.fisheries.noaa.gov/new-england-mid-atlantic/atlantic-highly-migratory-species/shark-identification-cooperative-shark-1

NOAA Fisheries. (n.d.-b). Atlantic shark fisheries management highlights: A timeline. National Oceanic and Atmospheric Administration. https://www.fisheries.noaa.gov/sustainable-fisheries/atlantic-shark-fisheries-management-highlights-timeline

NOAA Fisheries. (n.d.-c). Endangered species conservation. National Oceanic and Atmospheric Administration. https://www.fisheries.noaa.gov/topic/endangered-species-conservation

NOAA Fisheries. (n.d.-d). Population assessments and fish stocks. https://www.fisheries.noaa.gov/topic/population-assessments/fish-stocks

NOAA Fisheries. (n.d.-e). Shark management laws. National Oceanic and Atmospheric Administration. https://www.fisheries.noaa.gov/national/laws-policies/shark-management-laws

NOAA Fisheries. (n.d.-f). Understanding Atlantic shark fishing. National Oceanic and Atmospheric Administration. https://www.fisheries.noaa.gov/insight/understanding-atlantic-shark-fishing

NOAA Fisheries. (n.d.-g). Understanding population assessments. Population assessments. https://www.fisheries.noaa.gov/insight/understanding-population-assessments

NOAA Fisheries. (2014, September 7). White shark recovery [Podcast]. In On the Line. NOAA Fisheries. https://www.fisheries.noaa.gov/podcast/white-shark-recovery#!

NOAA Fisheries. (2020, August 7). Are all U.S. sharks overfished? NOAA Fisheries. https://www.fisheries.noaa.gov/feature-story/are-all-us-sharks-overfished

NOAA Fisheries Outreach and Education & Northeast Fisheries Science Center. (2025, August 11). Fun facts about shocking sharks. NOAA Fisheries. https://www.fisheries.noaa.gov/national/outreach-and-education/fun-facts-about-shocking-sharksNOAA Office of Communications. (n.d.). About the NOAA emblem and logo. National Oceanic and Atmospheric Administration. https://www.noaa.gov/office-of-communication/about-noaa-emblem-and-logo

August 4, 2023August 6, 2023

Martin McClure: Let’s Talk Sharks, August 4, 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: August 4, 2023

Latitude: 33°47.753′ N

Longitude: 78°13.019 W

Air Temperature: 22.3 kph

Wind Speed: 26° Celsius

Science and Technology Log: Meeting the tiger shark

Let’s face it, sharks are cool! They are an apex predator of the ocean. They are hunters and capture our imagination. Like most people, sharks are fascinating creatures if you take the time to get to know them.

Sharks are an ancient group of fishes. They have been on Earth since before there were any trees. They are intelligent and can be are very curious creatures that want to investigate new objects. Some species have social structures and recognize each other, and form relationships that last over many years. Some sharks have been observed hunting in groups. Personality, or should I say “sharkonality,” wise, individuals have been observed to be more assertive or more timid. They have sensory organs called ampullae of Lorenzini that sense electricity to help them find prey.

Sharks are quite varied. Some sharks must keep moving to breathe, while others can sit on the sea floor for hours at a time. Some sharks lay eggs, while others have live pups.

view from above of a tagged tiger shark in a sling net suspended on the outside of the ship's railing, above the water. three crewmembers stand on deck near the rail. they are wearing hard hats, life vests, and gloves. — A tiger shark in the sling ready to be released. Notice the tag by its dorsal fin.

So far we have caught sandbar, Atlantic sharpnose, tiger, scalloped hammerhead, and great hammerhead sharks. The Atlantic sharpnose, sandbar, and tiger sharks all belong to the family Carcharhinidae, or requiem sharks. They have a flattened but not wide snout. In many species teeth are similar because in the top row the teeth are triangular and serrated (like a saw) and in the bottom row they are narrow and smooth-edged. Their eyes have a nictitating membrane that functions like an eyelid, but they can see through it. Interestingly, reproduction varies within this family of sharks.

two gloved hands hold a small tiger shark up for a photo; only the middle of the shark, from the base of the caudal fin to the gills, is visible (tail and head are out of view.) This close-up shows the black and white markings on the shark, more like spots than tiger stripes. — Markings on a tiger shark pup. (ba-by shark doo doo doo doo doo doo)

Tiger sharks are striking to see up close. Their markings on their skin gives them their name and makes them easy to identify, even for a novice. Young tiger shark markings tend more toward spots that can grow into bars or stripes as they age. The bars will fade as the shark grows older.

The teeth of a tiger shark are easily identifiable as they are curved with a notch in it. Unlike other sharks in the Carcharhinidae family, the bottom row of teeth has the same triangular, serrated teeth as the top row. They eat a variety of food including crabs, squid, bony fishes, turtles, rays and birds as well as many other animals even other sharks. They have also been known to eat boat cushions, tin cans and even license plates.

They are one of the larger sharks, often growing 11 – 14 feet long and up to 1400 pounds. In the United States, tiger sharks are found from Massachusetts to Florida and the Gulf of Mexico.

Tiger Sharks have live babies called pups. They are ovoviviparous, and young develop inside their body before giving birth to live young. It is common for them to bear between 35 and 55 pups but have been known to have as many as 104. Because they bear so many pups, and the gestation is between 15 to 18 months, it is believed that they reproduce every three years.

Depredation: When a shark takes your fish

Depredation is when a fish has been hooked by a fisherman and is then attacked and eaten or partly eaten by another marine animal. This is obviously a problem for the fisherman because the fishermen cannot use the fish. According to Dr. William Driggers, Chief Scientist on the Oregon II Longline Shark and Snapper survey, depredation is on the increase in U.S. waters because shark populations are increasing. Shark populations are increasing because of good management of the shark populations. The most likely shark species to take a hooked fish is the whatever shark species is most common in that area. In other words, no one species is the worst offender. We have witnessed this at least six times on this survey leg.

A sandbar shark biting a red snapper on a fishing line at the surface of the ocean — A sandbar shark takes a bite out of a red snapper.

Caitlin, wearing fish gloves and a life vest, holds up only the front half of a red snapper. Just below the dorsal fin, ragged edges of the fish reveal a shark bite. Caitlin stands on the aft deck, and we can see obscured views of other crewmembers behind her, plus a cloudy sky. — Graduate student Caitlin Retzlaff shows the results of depredation.

Meet the Crew: Fisherman/Deckhand Josh Cooper

Josh is a professional fisherman aboard the Oregon II! Yup, one position on this crew is to be a professional fisherman.

The responsibilities of a fisherman are many. Everyone on the boat has very well defined duties and must be flexible and a good team member. He helps load the ship before it leaves the dock. He helps with docking by handling the lines. There are many duties once underway. There is painting and cleaning to be done, preparing gear and running the machinery used for fishing.

Then there is the fishing. Josh loves fishing. The fishermen are on board to help handle the big sharks and other large fish. Josh has done a lot of fishing. He sometimes operates the crane when the cradle is needed for a big shark. In emergency situations Josh is on the fire team and operates the small rescue boat that is aboard the Oregon II.

Josh running the crane to use the cradle.

Josh graduated from the University of Alabama, but a degree from a university is not required to be a fisherman/deckhand. After earning a dual major in biology and marine biology, he went to Alaska as a fisherman on commercial fishing vessels.

After that, he joined NOAA as a fisheries observer. In this job, he was on commercial fishing boats. He would be assigned to join a fishing boat, usually a small boat with two to three fishermen. It was his job to collect data on the fish caught. This would include species, length and weight. After doing this for two years in Alaska, he moved to do the same job in the Gulf of Mexico. Josh continued to do this work for six more years.

He first came to the Oregon II as a contractor working with Artificial Intelligence (AI) teaching the computers to recognize fish species. He was doing this when a position opened up as a part of the deck/fisherman crew. He has been on the Oregon II for two years. He likes that the accommodations are better than many of the other boats that he has lived on and he likes the people that he works with.

Being a fisherman is a big commitment. Josh says that he is out to sea about 140 days a year. When the ship is docked there are many maintenance tasks to be done.

Josh sits on a bench on the aft deck of NOAA Ship Oregon II. It's a bright, clear day. He's spreading his arms about as wide as they can go and smiling at the camera. A pair of yellow fish gloves rests on the bench beside him. — Josh telling a fish story. He was not exaggerating, by much.

Personal Log: Schedules

NOAA Clock

Life on the Oregon II is dictated by schedules, until it’s not. My basic schedule is dictated by my shift. I am on the day shift, which means that I work from noon until midnight. The night shift is midnight until noon. We use a 24 hour time schedule to avoid any confusion about which 8:00 or 10:30 we are referring to. So I am working from 12:00 – 0:00. During that time we might set and haul as many as three stations, or as few as one, so far.

Many factors might impact this schedule, including transit time between stations, as well as weather. I usually wake up some time between 7:00 and 8:00. Breakfast closes at 8:00 and I do like breakfast. On those mornings that I do not make it to breakfast, there is always fruit, cereal, and a variety of leftovers available. The rest of the morning I can use to exercise, write, read and relax. I like to enjoy a few minutes up on the flying bridge watching the ocean or observing a haul below. Lunch begins at 11:00 and I like to get in there fairly early to be sure that I am ready for my shift at 12:00. Our shift simply takes over where the last one left off. Sometimes we are in transit, but we might take over with the set or haul. We continue for the rest of the shift with the station schedule until midnight. Dinner is scheduled from 17:00 – 18:00. If we are not able to make it to the galley due to working, they will hold a dinner for us.

The ship operates and holds to schedules 24-7 unless there is a problem with the weather or mechanical problems. It has taken a while, but I have adjusted to this schedule and it feels pretty normal. Currently, we are taking shelter near shore to wait out a storm. We are expecting a 24 hour delay with no fishing stations.

A photo of just the moon - orange, but with some topography visible - against a completely black background — The Sturgeon Supermoon

One of the real treats is the natural beauty. The ocean is not just a repetitive body of water, but an everchanging montage of colors and shapes. Sometimes a light green, to deep blue at other times. At night, the blanket of black is broken by the white foam of the bow waves and whitecaps. There are dolphins, sea turtles, sea birds, not to mention all of the interesting creatures that come up on the longline. Sunsets never fail to disappoint, and then of course, the moonrises. We were lucky enough to be hauling in the longline when the Antares rocket was launched from Wallops Island, Virginia. We watched as the orange glow slowly receded into the clouds. Just a few minutes later, the Sturgeon Supermoon rose behind the clouds on the horizon. That was an incredible experience. There is always some new natural beauty to be found out here. Nature may be beautiful but it is not subject to our schedules.

Animals seen: spotted dolphins, laughing gulls, gag grouper, scamp grouper, oyster toadfish, bonita, great hammerhead, scalloped hammerhead, sucker fish

We had been watching these dolphins coming to the surface. This is the video we got when we retrieved the CTD.

oyster toadfish, photographed head-on, in a white plastic bin. — Oyster toadfish, watch out for those venomous spines.
Photo credit: John Brule

Did you know?

Have you ever had someone wish you “fair winds and following seas?” Josh explained this saying to me. While we were talking, the boat was rocking back and forth in 3-5 foot waves. Not a particularly smooth ride. He commented that, “It seems like we always find the trough.” I asked him what he meant. He explained that when waves are coming from one side or the other, this is said to be “in the trough.” The low point between waves is called the trough. The smoothest ride on a boat comes when the waves are coming from the stern, following the ship, so to speak. That would be the seas following the boat.

August 19, 2019August 19, 2019

David Madden: Tiger Shark! Fish Trap Footage, August 19, 2019

NOAA Teacher at Sea

David Madden

Aboard NOAA Ship Pisces

July 15-29, 2019

Mission: South East Fisheries Independent Survey

Geographic Area of Cruise: Atlantic Ocean, SE US continental shelf ranging from Cape Hatteras, NC (35°30’ N, 75°19’W) to St. Lucie Inlet, FL (27°00’N, 75°59’W)

Date: August 19, 2019

Tiger Shark! NOAA Ship Pisces Underwater Camera Action (video has no dialogue, only music)

This video is a collection of fish trap camera footage recorded during my NOAA Teacher at Sea adventure aboard NOAA Ship Pisces. Very special thanks to the NOAA science team: Zeb Schobernd – chief scientist and especially Mike Bollinger and Brad Teer – camera and gear experts.

September 28, 2018

Kristin Hennessy-McDonald: Nurse Sharks, Tiger Sharks, and Sandbars, Oh My, September 27, 2018

NOAA Teacher at Sea

Kristin Hennessy-McDonald

Aboard NOAA Ship Oregon II

September 15 – 30, 2018

Mission: Shark/Red Snapper Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: September 27, 2018

Weather Data from the Bridge

Latitude: 2840.20N

Longitude: 8439.79W

Sea Wave Height: 0m

Wind Speed: 2.2 knots

Wind Direction: 39.04 degrees

Visibility: 10 nautical miles

Air Temperature: 30.045

Sky: 75% cloud cover

Science and Technology Log

We have moved from the coast of Texas, past Louisiana, Mississippi, and Alabama, to the coast of Florida. When watching the video from the CTD, we have seen the sea floors go from mostly mud to sand. The water has decreased in turbidity, and the growth on the sea floor has increased. The make-up of our catches has changed too. We moved outside of the productive waters associated with the Mississippi River discharge, so our catch rates have decreased significantly.

Yesterday, we had a fun day of catching sharks I had never seen. Our first catch of the day brought up a juvenile Tiger shark (Galeocerdo cuvier). I was excited to be able to see this shark, which is listed as near threatened by the International Union for Conservation of Nature. On our later catch, we brought up three sharks large enough to require the cradle. First, we brought up a Sandbar shark (Carcharhinus plumbeus). Then, we were lucky enough to bring up a Nurse Shark (Ginglymostoma cirratum). The mouth of the nurse shark has barbles, which it uses to feed from the sea floor. Our final shark of the evening was a much more developed Tiger Shark. I was lucky enough to help with the tagging of the animal.

Last night, we set a line at the end of day shift, and night shift brought it in. A few of the day shift science team members decided to stay up and watch some of the haul back, and were rewarded with seeing them bring in, not one, but two Silky sharks (Carcharhinus falciformis), back to back. From the upper deck of the ship, so that I was not in their way, I was able to observe the night shift work together to bring up these two large animals.

The night shift has gotten some pretty amazing catches, and they have enjoyed sharing them with us at shift change. The two shifts spend about half an hour together around noon and midnight sharing stories of the time when the other shift was asleep. The other day, the night shift caught Gulper Sharks (Centrophorus uyato) and Tile Fish (Lopholatilus chamaeleonticeps). These are two species we have not seen on the day shift, so it was fun to look at their pictures and hear the stories of how they caught these fish.

Gulper Shark Photo Credit: Gregg Lawrence

tilefish — Tilefish Photo Credit: Gregg Lawrence

Personal Log

When we have a long run between stations, once I have gotten done sending emails and grading student work, we will spend some time watching movies in the lounge. The ship has a large collection of movies, both classic and recent. Watching movies keeps us awake during the late night runs, when we have to stay up until midnight to set a line.

The day shift has started to ask one another riddles as we are baiting and setting lines. It’s a fun way to bond as we are doing our work. One of my favorites have been: “1=3, 2=3, 3=5, 4=4, 5=4, 6=3, 7=5, 8=5, 9=4, 10=3. What’s the code?”

Did You Know?

Sharks don’t have the same type of skin that we do. Sharks have dermal denticles, which are tiny scales, similar to teeth, which are covered with enamel.

Quote of the Day

Teach all men to fish, but first teach all men to be fair. Take less, give more. Give more of yourself, take less from the world. Nobody owes you anything, you owe the world everything.

~Suzy Kassem

Question of the Day

I have a lot of teeth but I’m not a cog
I scare a lot of people but I’m not a spider
I have a fin but I’m not a boat
I’m found in the ocean but I’m not a buoy
I sometimes have a hammerhead but I don’t hit nails

What am I?

August 31, 2018August 31, 2018

Stephen Kade: Shark On! August 29, 2018

NOAA Teacher at Sea

Stephen Kade

Aboard NOAA Ship Oregon II

July 23 – August 10, 2018

Mission: Long Line Shark/ Red Snapper survey Leg 1

Geographic Area: Southeastern U.S. coast

Date: August 29, 2018

Scientific Journal

“Shark On!” was the shout from the first person that sees a shark hooked to the long line that was being hauled up from the floor of the ocean. I heard this phrase often during the first leg of the long line Red Snapper/ shark survey on the NOAA ship Oregon II. We began fishing in the Northwest Atlantic Ocean, off the coast of West Palm Beach, Florida. We traveled north to Cape Hatteras, North Carolina, and back south to Port Canaveral over 12 days this summer.

Oregon II scientific crew, Chief Boatswain, and skilled fishermen hauling in the long line.

During our long line deployments each day, we were able to catch, measure, tag and photograph many sharks, before returning them to the ocean quickly and safely. During these surveys, we caught the species of sharks listed below, in addition to other interesting fish from the ocean. This blog has scientific information about each shark, and photographs taken by myself and other scientists on board the Oregon II. The following information on sharks, in addition to scientific data about hundreds of other marine wildlife can be found online at the NOAA Fisheries site: http://fisheries.noaa.gov.

Great Hammerhead Shark- Sphyrna mokarran Hammerhead sharks are recognized by their long, strange hammer-like heads which are called cephalofoils. Great hammerheads are the largest species of hammerheads, and can grow to a length of 20 feet. The great hammerhead can be distinguished from other hammerheads as they have a much taller dorsal fin than other hammerheads.

When moving through the ocean, they swing their broad heads from side to side and this motion provides them a much wider field of vision than other sharks. It provides them an all around view of their environment as their eyes are far apart at either end of the long hammers. They have only two small blind spots, in front of the snout, and behind the cephalofoil. Their wide heads also have many tiny pores, called ampullae of Lorenzini. They can sense tiny electric currents generated by fish or other prey in distress from far distances.

Male Great Hammerhead 10. 5 ft.

Great Hammerhead cephalofoil

The great hammerhead are found in tropical and temperate waters worldwide, and inhabiting coastal areas in and around the continental shelf. They usually are solitary swimmers, and they eat prey ranging from crustaceans and squid, to a variety of bony fish, smaller sharks and stingrays. The great hammerhead can bear litters of up to 55 pups every two years.

Nurse Shark- Ginglymostoma cirratum Nurse sharks are bottom dwellers. They spend their life in shallow water, near the sandy bottom, and their orangish- pinkish color and rough skin helps them camouflage them. At night they come out to hunt. Nurse sharks have short, serrated teeth that can eat through crustaceans such as crabs, urchins, shrimp, and lobsters. They also eat fish, squid, and stingrays. They have two feelers, or barbels, which hang from either side of their mouth. They use their barbels to search for prey in the sand. Their average adult size is 7.5- 9 feet in length and they weigh between 160-230 lbs. Adult females reach a larger size than the males at 7- 8.5 feet long and can weigh from 200-267 lbs.

Nurse sharks are common in the coastal tropical waters of the Atlantic and also in the eastern Pacific Ocean. This species is locally very common in shallow waters throughout the Caribbean, south Florida to the Florida Keys. Large juveniles and adults are usually found around deeper reefs and rocky areas at depths of 10-250 feet during the daytime and migrate into shallower waters of less than 70 feet deep after dark.

Nurse shark in cradle

Juveniles up to 6 feet are generally found around shallow coral reefs, grass flats or mangrove islands in shallow water. They often lie in groups of forty on the ocean floor or under rock ledges. Nurse sharks show a preference for a certain resting site, and will repeatedly go back to to the same caves for shelter or rest after leaving the area to feed.

Tiger Shark- Galeocerdo cuvier Adult Tiger sharks average between 10 -14 feet in length and weigh up to 1,400 lbs. The largest sharks can grow to 20 feet and weigh nearly 2,000 lbs. They mature between 5 and 10 years, and their life span is 30 years or more. Tiger sharks are named for the brown stripes and patches they have on their sides when they are young. As they get older, they stripes eventually fade away.

juvenile tiger shark

They will eat almost anything they come across, and have been referred to as the “garbage cans of the sea”. Their habitat ranges from shallow coastal waters when they are young, to deep waters over 1,500 feet deep. They swim in shallow waters to hunt lobster, squid, fish, sea turtles, birds, and smaller sharks.

They migrate with the seasons to follow prey and to give birth to young. They swim in cool waters in the summer, and in fall and winter they migrate to warm tropical waters. Their young grow in eggs inside the mother’s body and after 13 months the sharks hatch. The mother gives birth to a litter of 10 – 80 pups. Their current status is currently Near Threatened.

TAS 2018 Stephen Kade returning sharpnose shark to ocean.

Sharpnose Shark- Rhizoprionodon terraenovae Atlantic sharpnose sharks are small for sharks and have a streamlined body, and get their name from their long, pointy snout. They are several different shades of gray and have a white underside. Atlantic sharpnose sharks can grow to up to 32 inches in length. Atlantic sharpnose sharks have been observed to live up to 18 years. Females mature at around 2 years old in the Atlantic when they reach approximately 24 inches in length. Atlantic sharpnose sharks are commonly found in the western Atlantic from New Brunswick, Canada, right through the Gulf of Mexico. They are commonly caught in U.S. coastal waters from Virginia around to Texas.

Atlantic sharpnose sharks eat small fish, including menhaden, eels, silversides, wrasses, jacks, toadfish, and filefish. The lower and upper jaws of an Atlantic sharpnose shark have 24 or 25 rows of triangular teeth. Atlantic sharpnose sharks mate annually between mid-May and mid-July in inshore waters, and after mating, they migrate offshore to deeper waters. They also eat worms, shrimp, crabs, and mollusks.

Sandbar Shark on long line

Sandbar Shark in cradle

Sandbar Shark- Carcharhinus plumbeus. The most distinctive feature of this stocky, grey shark is its huge pectoral fins, and long dorsal fin that increases its stability while swimming. Females can grow between 6 – 8.5 feet, and males grow up to 6ft. Its body color can vary from a blue to a light brown grey with a pale white underside. The sandbar shark lives in coastal waters, living in water that is 20 to 200 feet deep. Rarely is its large dorsal fin seen above the water’s surface, as the sandbars prefer to remain near the bottom. It commonly lives in harbors, lagoons, muddy and sandy bays, and river mouths, but never moves into freshwater. The sandbar shark lives in warm and tropical waters in various parts of the world including in the Western Atlantic, from Massachusetts down to southern Brazil.

The sandbar shark spends the majority of its time near the ocean floor, where it looks continuously for prey, such as small fish, mollusks, and various crustaceans. Their main diet consists largely of fish. Sandbar sharks give birth to between 1 and 14 pups in each litter. The size of the litter depends on the size of the mother, with large females giving birth to larger litters. Pregnancy is estimated to last between 8- 12 months. Females move near shore to shallow nursery areas to give birth. The females leave coastal areas after giving birth, while the young remain in the nursery grounds until winter, when they move into warmer and deeper water.

remora sucker pad

remora being weighed

Fun Fact- Remoras, or shark suckers, live in tropical oceans around the world. They have a rigid oval- shaped sucker pad on top of their head that it uses to attach itself to sharks and rays. It is symbiotic relationship where both animals gain something from their temporary union. Remoras mouths are at the top front of the body so while attached to a shark’s body, they do their host a favor by nibbling off skin parasites. They can also eat scraps of leftover food the shark leaves behind while they also enjoy a free ride. The shark gains a day at the spa for a body scrub, and can rid itself of parasites in a way it couldn’t have before!

Personal Journal

It was certainly an unforgettable experience being able to work with the scientific and fishing team for this shark survey. The opportunity to see and handle these sharks up close for two weeks has informed me of so many interesting things about these wonderful and vital members of the ocean. I can now take this information and share it first hand with students in my classroom, and members of my community. I also want to work to bring a positive awareness to these vital members of the ocean food web so they can thrive well into the future. As an artist, this trip has been invaluable for me, as now I’ve seen the how colorful and varied sharks are and other various anatomy details you just can’t see in books or television. This new awareness will help to make my future paintings more accurate than before.