Friday, June 17, 2011

{Press} Marine Matters: Seeing in the Dark

The Free Press | Melissa Waterman | June 8, 2011

"My eyesight is not what it once was. Actually, to be honest, I have never had good eyesight. In elementary school, my constant squinting ultimately led a teacher to suggest to my mother that I take a vision test. Lo and behold, I was pronounced decidedly nearsighted. My mother duly marched me off to a store in Fall River to purchase my very first pair of remarkably ugly glasses. When I came out of the building sporting my new glasses I quickly realized that trees were not undifferentiated masses of green: they bore individual leaves!

As an adolescent I anguished about my scholarly look. As a young adult I worried about an apocalyptic New World in which my glasses were broken and no replacement lenses existed. As an occasional sailor and kayaker, I fretted about losing the damn things overboard. Still, I could see pretty well most of the time.

Now my eyes are on another tack. Text in the morning newspaper has taken to wavering. The writing on packages in the grocery store has softened into a fog. Names and numbers in the telephone directory are hopeless. In order to read, I must consign myself to yet another pair of glasses, this time reading glasses.

North Atlantic right whales, however, have no such option. These migratory mammals cannot afford the luxury of bad eyesight. In order to seek and find prey, the right whale must use its sense of sight in the dark waters of the deep ocean. Fortunately, it has eyeballs the size of grapefruits to do so. According to Dr. Scott Kraus, vice president of research at the New England Aquarium in Boston and co-author of Disappearing Giants: The North Atlantic Right Whale, right whales rely on their eyesight for close-range navigation. A right whale's vision is well adapted to the lower levels of light found in the ocean, yet retains fairly high resolution.

Right whales, however, continue to get tangled up in fishing gear. The Consortium for Wildlife Bycatch Reduction estimates that 78% of known North Atlantic right whales (those identified by photographs) have been entangled in line at least once. Most of the time the whales can free themselves; other times they cannot, and die, either by drowning or from infections brought on by the wounds the tightening lines caused.




This is bad because there aren't very many North Atlantic right whales left in the world; the entire population of 400 or so migrate into the Gulf of Maine each summer. It's also bad because right whales are protected under the Endangered Species Act and the Marine Mammal Protection Act. If the mortality rate of the North Atlantic right whale reaches an "unsustainable" level, major federal constraints are sure to follow.

Thus, the experiments conducted by Kraus and fellow whale researchers this summer in Cape Cod Bay under the auspices of the Bycatch Reduction consortium are important. The researchers want to learn if right whales have the visual ability to see the ropes and fishing gear they get entangled in and also to figure out how to make the rope more visible to those whales. The logic is that no right whale really wants to get all twisted up in ropes. If given a clear signal that the rope is there, they will avoid it.

But what does a right whale actually perceive down in the briny deep? Do they see colors as you and I might? Using PVC pipe instead of rope in order to avoid any chance entanglements, the scientists are situating white, red, green, black and glow-in-the-dark rope structures in the water near whales that are feeding in Cape Cod Bay and monitoring the animals' reactions.

The project just began in May, and no results are available. But it certainly has sparked my imagination. Pretend you are a right whale, as big as a school bus, migrating through cold Cape Cod Bay, gulping masses of sand lance and other small fish into your gullet on Stellwagen or other undersea banks. You rise and fall through the water column, sunning on the surface when tired, rubbing your body on the gravelly bottom when feeling a touch itchy. And then you see them, popsicle-colored tubes lined vertically before you. Do you swerve around the white, red, green and black PVC pipes only to find yourself inexplicably drawn to the glow-in-the-dark version? What colors of the Crayola box will keep a right whale from harm?"

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