The Eye of the Shark and SharkEye

As a student at Cornell in the early 1950’s, I experienced an instructor whose principal interest was the eye of the shark. I spent much of my time at Cornell in two buildings adjacent to or on the College of Arts and Sciences quadrangle: Baker Labs and Stimson Hall. I had various courses in all the buildings positioned around the quad, Morrill, McGraw, Goldwyn Smith and others. These sites were where I took courses in English, French, history, political science, philosophy, architecture, but those other two buildings were dominant. I had four years of physics or chemistry in Baker.  Professor Guy Everett Grantham, my professor of physics, provided the most amazing demonstrations of the principals of physics to illuminate his lectures; his demonstrations were referred to as Grantham’s Circus. The freshman chemistry course was taught by Professor Michael Sienko, a superb teacher and scholar. Thirty years later, I saw his wife in consultation at the University of Rochester Medical Center. She had a serious hematological disease. I found enormous gratification in trying to help this dedicated and accomplished former professor of mine by helping his wife. Stimson Hall is where I spent four years since it housed the spaces in which my major, zoology, now referred to as biology was taught. There I was taught comparative anatomy by Perry Webster Gilbert (1912–2000), professor, shark scientist, and the former Director of Mote Marine Laboratory. He pioneered the capture and study of live sharks and was considered one of the world's foremost experts on shark anatomy and behavior. His particular area of expertise was the shark’s eye. I read, recently, that he kept an index card on each student and that he had 5000 of them. I would very much like to see if I was among them and what he said about my performance, if that was part of the data he kept. I was invited to be a teaching assistant in comparative anatomy, which I did with much gratification. I learned that I liked teaching.

The shark’s eye is structured and functions much like a human’s eye. It has a cornea, an iris and pupil, and a retina made of cones (color vision) and rods. In addition, unlike the human eye, it has a layer behind the retina called the tapetum lucidum, which is composed of mirrored crystals that reflect light back to the retina. In bright light the crystals are shaded, as if they had sunglasses, to allow perception when light was adequate or bright. In the very cloudy water, often present in certain areas of shallower water and characteristic of the ocean depths, the tapetum lucidum reflects dim light not perceived by the rods back to the retinal rods providing sight not available to other sea creatures. The white shark, the predator at the top of the chain in the oceans, as a result of the tapetum lucidum can see the silhouette of a seal near the surface from murky depths and hone in and using its strong tail fin muscles accelerate to the surface and with a dramatically forceful thrust snag the seal in its teeth. Remarkably, its eye is capable of rolling back so that the cornea and lens are completely protected and instead the rear of the eyeball, a strong layer of connective tissue, is exposed, protecting against the violent response of the seals claws. A variety of animals have a tapetum lucidum, the shark’s eye reflects a green color, like the cat. It, however, is a prime adaptation for this predator. 

SharkEye AI identifies a Great White Shark

Great white sharks are found with increased frequency along the shores of Southern California beaches. Rare sightings have become more common though, the result of warming coastal waters, shifting their habitat north from off of the Baja peninsula of Mexico. In order to develop protective responses for swimmers and surfers, the application of artificial intelligence in a device dubbed “SharkEye”, to identify sharks migrating or feeding near southern California beaches, is being studied. It is being tested in the waters off Santa Barbara County. A drone flying at 120 feet, high enough to not disturb sea life, sweeps over a large swath of the coastal ocean waters. The “pilot” monitors a video and sends text messages about sightings to subscribers who have registered to get alerts, principally lifeguards, beach homeowners, and surfing instructors. Using these data for computer modeling, the scientists, also, are studying shark migration patterns to try to predict where and when sharks may most likely be present in the waters being used by people. Shark sightings have increased significantly in coastal California according to owners of surf stores and summer surf camps. Whereas in the past sightings were very rare, many beachside dwellers never having seen a shark fin, it now has become a common phenomenon to lookouts: persons on paddleboards prowling specifically for that purpose.  

Written January 2021