The effort to save the Lake Mille Lacs tourism industry in the face of an abrupt halt of the cherished walleye fishing season Monday will be ecologically, economically and legally complicated.
That's what legislators and others on a new working group heard repeatedly Tuesday at their first meeting.
Legislators remained incredulous that a special legislative session is actually needed or that the Department of Natural Resources (DNR) is not able simply to extend the walleye season through Labor Day despite the population collapse.
Donald Pereira, a DNR biologist, laid out a complex problem he said was caused by various factors, including too many fish dying when they were released, invasive species, prolific predator fish and climate change.
Spiny waterfleas, native to Europe and Asia, eat zooplankton, which is supposed to be food for native fish.
The Clean Water Act has improved lake clarity, but that has sent younger walleye into deeper parts of the lake, where they are often prey for predators, including older walleye.
Warmer water temperatures increase hook mortality, or the rate at which fish die after being caught and released.
If some prevailing climate change models are correct, resulting warmer temperatures would be fatal in the long-term for tullibee (or cisco), which is important walleye prey, Pereira said.
