Inside the Gray Matter of an Arctic Grayling

On the south bank of the Klutina River, near Copper Center --- I'm sitting on a muddy rock, trying to think like an arctic grayling. Nothing's coming to mind.

A couple of guys expended a bit more energy trying to understand grayling in the late 1960s. They emerged with some interesting insights into the behavior of one of Alaska's most popular game fish.

Gian Vascotto, then with the University of Manitoba, and James Morrow, then a researcher with the University of Alaska Fairbanks, spent much of the summer of 1968 on their bellies, peering into McManus Creek in Interior Alaska. Using "a brushy barrier for concealment," they studied six pools of the river in great detail, lying motionless to watch grayling for up to 14 hours at a time.

In what must have been a buggy but rewarding summer, the researchers found that the biggest grayling seemed to call the shots. Large grayling always lurked closest to the bottom of the deepest pools, while smaller fish hung at medium depths. The real shrimps were found near shore.

Vascotto and Morrow were able to recognize individual grayling, and they found that grayling usually had a favorite spot they occupied all summer. If a fish was caught, "the subordinate ranks moved up and occupied new territories."

If a pool was disturbed, the grayling all congregated in the deepest part of the pool. When the coast seemed clear, the smallest fish were the first to venture back, boldly occupying the deepest parts of the pool. Then the researchers noted an odd ritual as the larger grayling returned. A larger grayling would move alongside the smaller grayling as if it were preparing to parallel park. The larger fish drifted sideways toward the smaller one until they were practically touching. One of the fish, usually the large one, would then swim about 15 centimeters ahead and arch its body into a bow, with the concave side toward the smaller fish. Holding this half-moon position, the larger grayling drifted backwards and sank below the smaller grayling. The larger grayling then rose from below the smaller one, which then drifted backward. The smaller one would then drift out of the picture or pull up parallel and take the lead role in the same strange ritual. The researchers watched the rapid display five different times.

They also watched the grayling feed and checked the stomach contents of the fish to come up with the following conclusions, which may interest a few anglers:

• Grayling fed very little, if at all, on rainy days.
• Large grayling at the head of a pool rarely traveled far to check out drifting food items. Instead, they turned to face the oncoming object and waited for it to reach them.
• When large grayling went up for food on the surface, they ascended slowly, mouthed the food slowly, and sank only slightly faster than they rose.
• Smaller grayling subject to more competition, would often leap out of the water to chase flying insects. In one case, "a 10-cm fish chased a crane fly for 2 1/2 meters, jumping out of the water four times and capturing the insect in the air on the last leap."

I'll need the same determination as that grayling to cross the roaring Klutina River tomorrow. Or maybe I'll just use the bridge.