Saturday, March 27, 2010

Watch for "blue walleye" this summer

blue tint to walleye tail
It goes unnoticed by most anglers but an increasing number of walleye (and perch) caught in Red Lake and all other lakes in Manitoba, Ontario and Quebec, are turning blue!

In this photo from July of last summer, Bow Narrows Camp angler Macy Lagarde holds a walleye whose tail fin and back has a blue tint.

Two researchers from the University of Wisconsin - Washington County have discovered the blue color seems to be something new. It is caused by a protein that they have called Sandercyanin.

Sander is the genus name for walleye and cyanin is Greek for blue.

The protein is created by the walleye themselves in their slime and the amount of it increases with each month of summer.

The blue tint is seen best in the dorsal and tail fins but can be anywhere on the top half of the body.

It should be noted that the blue-colored walleye are not the blue pike that became extinct from the Great Lakes. They are regular walleye whose color has changed from yellow to blue.

UWWC researchers Steve Schaefer and Wayne Schaefer say Sandercyanin acts as a sunscreen for the fish and it is possible that the blueing of the walleye is being caused by more solar radiation striking the earth from a thinning of the ozone layer due to man-made chemicals in the atmosphere.

They have also documented that the phenomenon is moving southward, into Minnesota and Michigan.

The researchers ask anglers to report catches of blue walleye to them and to send them samples of the blue slime.

Report catches by clicking on their blog Blue Walleye which also contains the latest information on the subject.

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