NOAA Teacher at Sea
Lynn M. Kurth
Aboard NOAA Ship Oregon II
July 25 – August 9, 2014
Mission: Shark/Red Snapper Longline Survey
Geographical area of cruise: Gulf of Mexico and Atlantic
Date: August 8, 2014
Lat: 32 12.678 N
Long: 079 38.599 W
Weather Data from the Bridge:
Wind: 10.6 knots
Barometric Pressure: 1014.56 mb
Temperature: 29.1 Degrees Celsius
Science and Technology Log:
I imagine that the names of the crew, the feeling of the boat rocking, the sounds of the water and constant hum of the boat’s engine will fade from my memory. However, there’s one moment at sea I will not quickly forget. It was late in the evening when the crew brought aboard a small hammer-head shark. In the middle of nine people quickly hauling in countless sharpnose sharks, calling out data and moving around fishing gear the female hammer-head rotated one her eyes to look directly at me. At that moment I could feel/sense how people, the ocean and its inhabitants are all inextricably connected.
When a shark uses just one eye the accuracy of its depth perception is limited but the clarity of the image is increased. So, when the hammerhead looked over at me she probably had a pretty clear image of me but would not have been extremely accurate in judging how far away I was. Sharks’ eyes are similar to human eyes with a few “bonus” features to help them survive in the depths of a marine environment. One of these features is called a tapetum. A tapetum is a reflective layer of tissue which lines the back of the eyeball and magnifies the amount of light that enters the eye. Because of this, animals with tapetums (cats, cows, dogs, sharks, etc…) can see extremely well with just a little amount of light. When the hammerhead looked over at me and blinked a few times I was not seeing her eyelid move but rather something called a nictitating membrane. A nictitating membrane is a covering that some sharks use to protect their eyes when they are hunting or in danger of being damaged.
Did you Know?
- Some sharks such as the Great White Shark will roll their eyes back in their head to protect them when they are attacking their prey or fighting
- It is uncertain how much color sharks can see but cells called cones which allow color to be seen have been found in sharks’ eyes.
- A shark’s field of vision is almost 360 degrees with the exception of a blind spot directly in front of the shark’s nose and a second blind spot directly behind its head
Teaching issues/topics that I have personally encountered enables me to teach with passion and expertise. Reflecting on my most rewarding teaching experiences I realize that many involve sharing personal experiences that I’ve encountered. Although many of my Wisconsin students have never seen the ocean it is my goal to help them understand that oceans and humans are inextricably connected. It hasn’t been difficult to make connections between what my students need to know as 21st-century learners and the science that I have been part of during my experience at sea. I am confident the students who I have the privilege of teaching will come to know and understand what we have already learned about the ocean and its inhabitants, what remains unknown, and how they are an important part of what happens to our oceans and its inhabitants in the future.