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.
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.
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.
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.
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.
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