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

A 24 hour analog clock, hung on a wall. the NOAA logo is at the center of it. it is about 14:05 (2:05 pm).
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.

6 Replies to “Martin McClure: Let’s Talk Sharks, August 4, 2023”

  1. I’m so envious! The dolphins, the super moon – really all your pics – AMAZING! (I tried to watch the rocket launch, but it was too hazy here. 🫤) THANKS for allowing us to live vicariously through you!! 💕

  2. I am lucky to be here supported by so many people and happy to share this incredible experience with you and everyone else.

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