sandbar shark – NOAA Teacher at Sea Blog

July 31, 2026August 3, 2026

Cheyanne Vanderdonckt: The Survey Begins, July 30, 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: July 30, 2026

Latitude: 27° 40.261’ N

Longitude: 80° 12.372’ W

Weather Data from the Bridge: Southwest winds 15 to 20 knots. Seas 2 to 3 feet.

Science and Technology Log

I promised more details of how the longline survey is carried out and I will do my best to describe it here. A long fishing line (about a mile long) is equipped with weights and buoys at each end, along with a weight in the middle. The buoys also have a “high flyer,” which is a marker that sticks up off of the buoy so that we can see where it is. Attached to this longline are 100 shorter lines called “gangions” (say “GAN-jin”) with a number and a baited circle hook. (Circle hooks are used because they cause less damage to fish than “j-hooks.”) The longline is deployed, then given about an hour to “soak,” before we go back and start reeling it in.

illustration of a fishing vessel setting a long line. each end of the line is attached to an anchor and a buoy. along the line itself, shorter lines connected to fishing hooks are attached at regular intervals. this illustration depicts a fish on one of the hooks. — Longline setup (Credit: NOAA)

How do you manage a mile-long line with 100 shorter lines attached without getting everything tangled? It’s a careful and orderly — albeit fast-moving — operation. The hooks are set up in barrels with notches that keep them lined up and ready to be attached to the longline as it is let out off the stern (back of the ship). Later when the line is hauled in, somebody will place them back in order to be ready for the next station. When every element of this set-up — high flyers, weights, and every single hook — is either deployed (thrown off the stern) or hauled in at the bow (front of the ship), somebody is ready at the computer to record the exact time, latitude, longitude, the state of the bait, whether there is a fish, weather conditions, etc. for each hook. Fortunately, the computer records most of this automatically so there are only a few keys to push when each piece is either deployed or hauled in.

a white plastic barrel lined with baited hooks attached to short fishing lines — Hooks baited with mackerel attached to the gangions ready to be clamped to the longline

At our first station we caught four sandbar sharks (Carcharhinus plumbeus). When a shark is caught, it is a carefully coordinated operation to haul it up in a “cradle” (a big net with a stiff metal frame) using a crane. There is an operator working the crane, two people holding onto ropes attached to each side of the cradle, and at least two people to manage the shark’s head and tail while measurements and samples are taken. They are also communicating with the bridge where the officers driving the ship have to maneuver it to help get the cradle into position. The shark’s length is measured in millimeters and a small tissue sample is taken from its fin. Most sharks are also tagged, which allows scientists to track movements and examine growth rates. When smaller fish are caught, they are brought onto a measuring board in the middle of the deck. (More pictures and information about all of this will be coming in future posts!)

three people work to hold a large sandbar shark still against a cradle made of teal mesh webbing. we can see part of the face of the man in the foreground and only the arms of the other two scientists. everyone wears fish gloves. — William “Trey” Driggers helps secure the tail of a sandbar shark while it is tagged

Wildlife Spotted

One afternoon when the skies cleared after some rain, a pair of brown boobies (Sula leucogaster) came to rest on the weather station. A fellow science volunteer alerted me to their presence and we spent some time watching them spin around. To my amazement, they were still there hours later. I spent some more time watching them with the nearly full moon behind them.

two birds with brown backs and white undersides perch on either side of a weather vane. the sky is light blue and cloudy.

two birds are visible perched on either side of the weather vane, photographed at a distance. we can see the moon shining through the clouds and reflecting on the water.

Two brown boobies (Sula leucogaster) perched on the ship for hours

Simple Machines on a Ship

I have a student who got really interested in simple machines this year after, so I thought I would investigate as many of the simple machines as I could find on the ship. Simple machines are devices with few or no moving parts that make work easier. There are six basic types: wheel-and-axle, inclined plane, lever, pulley, wedge, and screw. A good example that we have at my school is a ramp, which is an inclined plane. I couldn’t carry a shopping cart full of science supplies up the stairs, but the ramp — along with the wheels and axles on the cart — allows me to push a heavy load up to the second floor relatively easily. Likewise, you probably can’t pick up your best friend, but if you get on a see-saw (a type of lever), you can send him high up into the air. Simple machines can be used on their own or in combination to make work easier.

There are many pulleys on the ship. They help make it easier to lift heavy objects. Winches are used to make it easier to haul in lines and to adjust the length of cables on cranes. Winches are essentially made of a wheel and axle and a lever. The rope or line wraps around the wheel as it turns on the axle. The handle acts as a lever that makes it easier to turn the wheel. The reel on a fishing rod acts as a winch when you turn the crank to reel the line in. Motorized winches use motors to turn the wheel.

view of pulleys clearly visible against a blue sky — Pulleys on one of the outriggers

view of the winch mounted on deck — Pulleys on one of the outriggers

A screw is a simple machine that is basically an inclined plane that wraps around a cylinder. If you have a screw at home, you can put your finger at the tip and follow that one groove all the way to the head. Think about cars driving up a circular ramp in a parking garage: they move on a continuous inclined plane that spirals around from bottom to top. The ship has engines that turn a big propeller and that propeller is a giant screw that pushes against the water to make the ship move forward. Although the blades of a propeller are separate rather than one continuous plane, they operate on the same basic principle as a screw.

Obviously I can’t see the ship’s propeller because it is under the water, but I asked the crew to tell me more about it. Oregon II has a variable pitch propeller which means that they can change the angle of the propellers relative to the axis that they spin around. The angle of this pitch changes the amount of work the screw can do with one full rotation. So a 1-foot pitch means that turning the screw one full rotation would theoretically move the ship 1 foot (This can vary depending on the other forces acting on the ship, such as currents and wind). Oregon II’s propeller has a maximum pitch of 6 feet. Naturally, I had to ask why you wouldn’t just always use the maximum pitch to go as fast as possible. It is like the gears on a bike or a car. If you have a bike with gears, you have probably found yourself pedaling furiously at some point, wearing yourself out without going any faster. If you choose the right gear, your energy will not be wasted. The officer driving the ship determines which pitch is appropriate for the conditions and the desired speed.

These are some of the simple machines I’ve discovered so far. Look around you and see what simple machines you have at home, work, school, or in the community. How do they make work easier? Can you use some objects in your house to make a simple machine?

Resources from NOAA:

NOAA has a great handout for students on the six basic simple machines at https://oceanexplorer.noaa.gov/wp-content/uploads/2025/04/simple-machines-handout.pdf (Teachers and parents: After introducing the basics of simple machines, look up some “Rube Goldberg” machine videos and challenge students to identify the different simple machines involved!)
Here is a lesson from NOAA that is designed for middle schoolers but which could easily be adapted for other levels in which students use basic materials to design a robotic arm using simple machines: https://oceanexplorer.noaa.gov/lesson/underwater-robots-simple-machines/

Personal Log

I am settling into life aboard ship. Because I get off duty at midnight and still need time to shower and wind down a bit, I am waking up later in the morning than I am used to in order to get a full night’s sleep. (I always tell my students how important sleep is and I like to practice what I preach.) This means that I wake up after breakfast and just about an hour before lunch is served. At home I tend to eat something on the sweet side for breakfast, but I am getting used to starting my day with a hearty meal of pulled pork, cod, or fried green tomato sandwiches. I was told to expect good food and I have not been disappointed. Everything is fresh and delicious! As you can imagine, the people aboard all have great stories and interesting backgrounds. I hope to introduce you to some of them in future posts.

As we had three days of transit time without much for me to do, I got to spend a lot of time just looking at the water and the sky and this is truly a gift. Everyone should have the opportunity to see and experience this. Earlier this summer I participated in a teacher training course with the Chesapeake Bay Foundation. I enrolled thinking it would be another way to enhance my scientific understanding of our local watershed and it certainly did that. However, the instructors and community partners also took the time to let us simply experience being in nature and encouraged us to let our students do the same. We visited an urban farm with a summer camp (and soon to have an all-outdoor year-round preschool program!) and the staff talked about how they incorporate nature to help students with emotional regulation and other skills that develop the whole child. They emphasized that these are things we can do anywhere outdoors. We don’t need to go off to the wilderness or even a park. In fact, the more we can get children to pay attention to the nature that they see everyday in their yard, neighborhood, or schoolyard, the deeper their connection will be. This will in turn drive their curiosity and their desire to learn more.

I am experiencing this myself aboard ship. Although I have work to do, taking some time to just experience what is around me with all of my senses helps to calm me, refresh me, and make me even more eager to keep learning. Being at sea is a new experience for me, but I can tell that even the veterans aboard still carry that sense of awe. People still come out to watch the sun set over the water and they still get excited to see dolphins surface. I wrote in a previous post about the teacher’s charge to help students feel emotionally secure so that they can learn. Finding ways to let them experience amazement at our world is another dimension to this. In first grade students learn about the phases of the moon and I always encourage my students to look for the moon throughout the night and day. It is notoriously hard to get a good picture of the moon with a cell phone, but I took this video before putting my phone away and just looking.

View of the moon from NOAA Ship Oregon II

Ship Rules

When I return to my classroom in August, I will spend a lot of time teaching my students about the rules of the school and the classroom. Of course, this is not always popular, but I do my best to explain the purpose of each rule and invite students to think about what could happen if we don’t follow it. (Admittedly, we sometimes get silly with these scenarios.) Children often feel bombarded by rules and that they are uniquely burdened by them. So I think it’s important to share examples of rules adults have to follow, as well. I’m going to have lots of great examples of rules Ms. Vanderdonckt had to follow while at sea. When you’re on land and close to the nearest hospital, your health and safety might be your own business. But on a ship far from shore, your health and safety affects everyone. If somebody were to be careless and get injured, it could jeopardize the entire mission that has been so carefully planned.

There are rules that are written and taught explicitly and then, of course, there are unspoken rules of etiquette and society that we just have to pick up on. This is something many neurodivergent students can struggle with. Special educators use tools like social stories to help them understand various social scenarios and explicitly teach expectations. Being in a completely different type of social environment is forcing me to simply ask people about etiquette and expectations. This is another dimension of my learning experience that I wasn’t even expecting. I knew I had a lot to learn about science and fishing, but I’m learning just as much by asking somebody, “Hey, if you’re working in your office with your door open does that mean it’s okay to ask a question?” Fortunately, people are very kind about teaching me the ropes.

Cheyanne, wearing a blue hard hat and an orange life vest, grins for a photo, hands in pockets. she is on the deck of NOAA Ship Oregon II. Behind her we see two other crewmembers with the CTD (conductivity, temperature, and depth probe). the sky is light blue and mostly cloudy. — Hardhats and PFDs (Personal Flotation Devices) are mandatory during operations. (Photo credit: Kleys Murillo)

Accessibility Corner

As a special educator, I’d like to share some insights and tips with teachers and caregivers that I am thinking about on my journey. As parents do shopping for the new school year, a big item on the list is new shoes. Many young students and/or students with fine motor challenges have difficulty tying shoes on their own. Velcro can be a great help but what if the pair your child is begging for have laces? My packing list suggested slip-on shoes because on a ship you need to get in and out of your shoes frequently and quickly. I don’t find most slip-ons comfortable so I’m using these elastic laces for my favorite sneakers. The bumps help me adjust them to my perfect comfort level. These could be great for students (or adults) who have trouble tying independently or who have sensory issues requiring fine tuning of laces. There are many brands, sizes and colors available.

close up view of two shoes with interesting, bumpy elastic laces. the shoes are on feet, which are propped up on something in the corner of the deck; we can see the railing and a bit of the water beyond. — My favorite pair of sneakers are easier to get on and off quickly with elastic shoelaces

Did You Know?

Sargassum is a type of floating brown algae. It can provide shelter and food to many types of marine life. It plays an important role in supporting life in the Atlantic Ocean but it can also cause issues when a lot of it washes up on shores at once. To learn more about sargassum, visit https://oceanservice.noaa.gov/news/sargassum/

clumps of sargassum floating in bright blue water, topped by bright blue sky with only a few hints of clouds — Sargassum floats on the surface of the water in the Atlantic Ocean

September 6, 2023September 6, 2023

Martin McClure: Reflections, August 29, 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 29, 2023

Latitude: 39° 9′ 0.6084” N

Longitude: 123° 12′ 28.0332” W

Air Temperature: 29.4° Celsius

Science and Technology Log

Sharks use many senses to hunt their prey. For long range hunting, they use smell and detecting pressure changes, similar to hearing. They are famous for having a keen sense of smell. Some studies conclude that they can, in theory, detect blood at 1 per 20 million parts in water. So, they clearly use smell to hunt. They also have a keen sense of “hearing.” They can detect some low frequency sounds, the kind made by injured fish, from a kilometer away.

a very close-up photo of the eye of a sandbar shark. around the eye, we can see tiny pores in the shark's skin - these are the ampullae of Lorenzini — The eye and amupullae of Lorenzini of a sandbar shark

As sharks get closer to their prey, they use their eyesight. While they see in black and white, they can see well unless it is nighttime or if the water is cloudy.

They also have a sense that humans do not. They have a lateral line along the side. This is a series of canals that helps them detect vibrations in the water.

As the shark closes in on the prey, sharks engage their ability to detect slight electrical impulses, electrosense. For this they use their ampullae of Lorenzini. These are pores on the skin that lead to canals filled with a conductive gel containing keratan sulphate. They can detect the electrical impulses that are given off by other fish. Some sharks use this sense to find fish that are hidden under sand on the ocean floor.

close-up view of a cross section of shark skin with pores (ampullae of Lorenzini) visible, revealing the keratan sulphate that fills them — Shark skin cross-section showing keratan sulphate and ampullae of Lorenzini

Sharks may use their sense of touch by bumping into a potential prey target. Finally, they might use their sense of taste to decide if their target is indeed food.

Personal Log

As I return to my own teaching position in a classroom, I continue to reflect back on how everyone on board NOAA Ship Oregon II took all of the volunteers under their wing to “show them the ropes,” and teach them more than they could have learned in any classroom. It was clear that the whole crew was proud and eager to share their own specialty with us. For me, I was poking my nose into every nook and cranny, looking for stories to include in my blog. I was always welcomed with a smile and regaled with great stories. Far too many to include in my blog. I was impressed with the detailed and patient answers to my basic questions. This included not only the professional NOAA scientists and crew but also the other volunteers on board as I was the only one on the science crew who was a novice in marine biology. So, thank you Josh, Cait, Hannah, Macie and John.

But I was not the only one to be tutored in the details of life on the ship. Trey Driggers spent many hours discussing shark science with the other volunteers. The NOAA Corps members joined in the hauls and shared their experiences with the other volunteers. Their friendliness, openness and supportive presence added a lot to the team. They shared their own career journeys and at least one of the volunteers is seriously considering joining the NOAA Corps. John Brule, a volunteer, was working on his dissertation on parasites. (I am a convert. Parasites are fascinating and well deserving of detailed scientific study.) He engaged with the other volunteers on wide ranging subjects and guided them on dissections.

John, at right, looks on as a volunteer leans over a dead shark on a table mid-dissection; the volunteer is grasping tools in each hand to lift up and extract the shark's gills for additional study — Doctoral candidate John Brule guides undergraduate volunteer in removal of shark gills

The fishing/deck crew readily discussed not only their jobs and experiences but also shared their knowledge of fish behavior and how weather conditions affect the likely catch.

dark storm clouds gather above the ocean at sunset — Storm clouds gathering over the ocean

In the end, of all the amazing things I experienced, my most enduring memories are of people sharing their love of their chosen field, reaching out to guide and teach the novices. It is really people, connecting to others, that makes an education impactful.

September 23, 2019

Kathy Schroeder: Sharks, Sharks, and More Sharks! September 23, 2019

NOAA Teacher at Sea

Kathy Schroeder

Aboard NOAA Ship Oregon II

September 15-October 2, 2019

Mission: Shark/Red Snapper Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: 9/23/19

Weather Data from the Bridge (at beginning of log)

Latitude: 28.07
Longitude: 93.27.45
Temperature: 84°F
Wind Speeds: ESE 13 mph
large swells

Science and Technology Log

9/21/19-We left Galveston, TX late in the afternoon once the backup parts arrived. After a few changes because of boat traffic near us, were able to get to station 1 around 21:00 (9:00 pm). We baited the 100 hooks with Atlantic Mackerel. Minutes later the computers were up and running logging information as the high flyer and the 100 hooks on 1 mile of 4mm 1000# test monofilament line were placed in the Gulf of Mexico for 60 minutes. My job on this station was to enter the information from each hook into the computer when it was released and also when it was brought onboard. When the hook is brought onboard they would let me know the status: fish on hook, whole bait, damaged bait, or no bait. Our first night was a huge success. We had a total of 28 catches on our one deployed longline.

Kathy and red snapper — *NOAA TAS Kathy Schroeder with a red snapper caught on the* Oregon II

We caught 1 bull shark (Carcharhinus leucas), 2 tiger sharks (Galeocerdo cuvier), 14 sharp nose sharks (Rhizoprionodon terraenovae), 2 black tip sharks (Carcharhinus limbatus), 7 black nose sharks (Carcharhinus acronotus), and 2 red snappers (Lutjanus campechanus). There were also 3 shark suckers (remoras) that came along for the ride.

sandbar shark — *Sandbar shark – no tag.* Oregon II

I was lucky to be asked by the Chief Scientist Kristin to tag the large tiger shark that was in the cradle. It took me about 3 tries but it eventually went in right at the bottom of his dorsal fin. He was on hook #79 and was 2300mm total length. What a great way to start our first day of fishing. After a nice warm, but “rolling” shower I made it to bed around 1:00 am. The boat was really rocking and I could hear things rolling around in cabinets. I think I finally fell asleep around 3:00.

9/22- The night shift works from midnight to noon doing exactly what we do during the day. They were able to complete two stations last night. They caught some tilefish (Lopholatilus chamaeleonticeps) and a couple sandbar sharks (Carcharhinus plumbeus). My shift consists of Kristin, Christian, Taniya, and Ryan: we begin our daily shifts at noon and end around midnight. The ship arrived at our next location right at noon so the night shift had already prepared our baits for us. We didn’t have a lot on this station but we did get a Gulf smooth hound shark (Mustelus sinusmexicanus), 2 king snake eels (Ophichthus rex), and a red snapper that weighed 7.2 kg (15.87 lbs). We completed a second station around 4:00 pm where our best catch was a sandbar shark. Due to the swells, we couldn’t use the crane for the shark basket so Kristin tried to tag her from the starboard side of the ship.

We were able to complete a third station tonight at 8:45 pm. My job this time was in charge of data recording. When a “fish is on,” the following is written down: hook number, mortality status, genus and species, precaudal measurement, fork measurement, and total length measurement, weight, sex, stage, samples taken, and tag number/comments. We had total of 13 Mustelus sinusmexicanus; common name Gulf smooth-hound shark. The females are ovoviviparous, meaning the embryos feed solely on the yolk but still develop inside the mother, before being born. The sharks caught tonight ranged in length from 765mm to 1291mm. There were 10 females and 3 male, and all of the males were of mature status. We took a small tissue sample from all but two of the sharks, which are used for genetic testing. Three of the larger sharks were tagged with rototags. (Those are the orange tags you see in the picture of the dorsal fin below).

measuring a shark — *Taking the three measurements*

king snake eel — *King snake eel caught on a longline.*

Personal Log

I spend most of my downtime between stations in the science dry lab. I have my laptop to work on my blog and there are 5 computers and a TV with Direct TV. We were watching Top Gun as we were waiting for our first station. I tried to watch the finale of Big Brother Sunday night but it was on just as we had to leave to pull in our longline. So I still don’t know who won. 🙂 I slept good last night until something started beeping in my room around 4:00 am. It finally stopped around 6:30. They went and checked out my desk/safe where the sound was coming from and there was nothing. Guess I’m hearing things 🙂

Shout out! – Today’s shout out goes to the Sturgeon Family – Ben and Dillon I hope you are enjoying all the pictures – love Aunt Kathy

September 24, 2018

Kristin Hennessy-McDonald: Flotsam and Jetsam, September 23, 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 23, 2018

Weather Data from the Bridge

Latitude: 3006.07N

Longitude: 08741.32W

Sea Wave Height: 1m

Wind Speed: 8.64 knots

Wind Direction: 199.7

Visibility: 7 nautical miles

Air Temperature: 27.6

Sky: 95% cloud cover

Science and Technology Log

Over the past few days, we’ve fished a mix of station depths, so I’ve gotten to see a number of new species as we’ve moved out into deeper waters.

At a C station, which is a station at depths between 183 and 366 meters, we caught a Mako Shark (Isurus oxyrinchus). This catch was so unexpected that a number of crew members ventured out to the well deck to snap a picture. She was a beautiful juvenile between 1-2 years old.

Kristin and Mako Shark — Our current NOAA Teacher at Sea, Kristin Hennessy-McDonald is all smiles when grabbing this quick picture before releasing the female Mako shark. [Photo Credit: Ensign Chelsea Parrish, NOAA]

juvenile female mako shark — Juvenile Female Mako Shark

I also saw my first kingsnake eel, a long eel with a set of very sharp teeth. On a later station, we caught a juvenile that we were able to bring on deck and examine. We also caught a Warsaw grouper (Hyporthodus nigritus), which had parasites on its gills and in its fins. Gregg Lawrence, a member of the night shift on loan from Texas Parks and Wildlife Coastal Fisheries unit, and I removed the otoliths and took samples of the parasites.

Measuring the Warsaw Grouper [Photo Credit: Gregg Lawrence]

We had one catch that brought in 20 Red Snappers. Red Snappers are brought on deck, and a number of samples are taken from each one of them for ongoing assessment of the Red Snapper population. In addition to the otoliths, which allow the scientists to determine the age of the fish, we also take samples of the gonads, the muscle, the fins, and the stomach. These allow the scientists to perform reproductive and genetic tests and determine what the snappers ate. While 4 members of the science team onboard collected samples, Caroline Collatos, the volunteer on the day shift, and I insured that the samples were properly packaged and tagged. Everyone working together allowed the process to run smoothly.

On the latest B station, which was about 110 meters deep, we caught a number of species, some of which I had not gotten to see yet. In addition to Gulf smoothound sharks (Mustelus sinusmexicanus), we caught a Scalloped hammerhead shark (Sphyrna lewini) and a Sandbar shark (Carcharhinus plumbeus) that we had to cradle due to their size. The Sandbar shark was a bit feisty, but I got the chance to tag her before we released her.

Gulf smoothound shark (Mustelus sinusmexicanus)

Scalloped hammerhead shark (Sphyrna lewini)

We work in the rain. Thankfully, they had some extra rain gear for me to put on, so that I would not get drenched while we were setting the line. For the most part, the rainstorms have been sprinkles, but we did have one downpour while we were going toward a station.

Personal Log

Between setting lines, I have been busy checking up on my studenats’ work back in Memphis. One of the great things about having a one-to-one school is that the students are able to do their work on Microsoft Teams and turn it in for me to grade it thousands of miles away. I have loved seeing their how they are doing, and answering questions while they are working, because I know that they are learning about the cell cycle while I am out at sea learning about sharks.

One of the things that has really surprised me over the past week is how much my hands hurt. It was unexpected, but it makes sense, given how much of the work requires good grip strength. From insuring that the sharks are handled properly to clipping numbers on the gangions to removing circle hooks from fish on the lines, much of the work on the science team requires much more thumb strength than I had thought about. I know my students have commented that their hands hurt after taking notes in my class, so I thought they would get a kick out of the fact that the work on the ship has made my hands hurt.

Did You Know?

Sharks are able to sense electrical fields generated by their prey through a network of sensory organs known as ampullae of Lorenzini. These special pores are filled with a conductive jelly composed primarily of proteins, which send the signals to nerve fibers at the base of the pore.

Quote of the Day

Remove the predators, and the whole ecosystem begins to crash like a house of cards. As the sharks disappear, the predator prey balance dramatically shifts, and the health of our oceans declines.

~Brian Skerry

Question of the Day

How many bones do sharks have in their bodies?

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.