Duluth, MN (NNCNOW.com)
Alexis Burke teaches kids about fish on the main level of the Great Lakes Aquarium.
One floor below, near the aquarium's quarantine tank for new fish, she likes to talk about phenology.
"Phenology is tracking signs in nature that tell us about the changing seasons." said Burke.
In the quarantine room, there's a tank of Coho salmon waiting to go on exhibit.
"This is a great time of year for us to get juvenile Cohoes because these animals are fall spawning animals." said Jay Walker, aquarium director of operations.
The phonological change of seasons from summer to autumn means the fall spawning salmon of Lake Superior are about to gather off the mouths of the big lake's rivers.
"You can actually see them coming into the rivers. Fall water is a little cleaner." said Walker.
Anglers with the proper fishing license will soon have ample opportunity to catch a few salmon as they begin the spawning run.
Jay Walker of the Aquarium urges people to fish fairly early in the run.
It is true that salmon die after spawning and their bodies degrade rapidly even before the eggs are laid.
Those bodies then decay to keep the rivers full of nutrients for other creatures.
It's all part of the natural change of summer to fall.
"Alexis Burke of the aquarium tells us that seasonal changes, of course, affect animals any seasonal change; not just summer into autumn." said Burke.
"Spring phenology is one of my favorites because it tells us winter is ending."
After last winter, many of us will be happy if the change from fall to winter comes a little bit later this year.
In Duluth for Nature Matters, Dave Anderson, KBJR 6 and Range 11.
Lake Superior salmon are actually non–native species.
Both Cohos and chinooks were stocked here beginning in the late1960's.
Pink salmon are thought to have escaped from a fish farm in the 1950's.