Learning about bites too late is a grand old American pastime. Should have been there last week. Is it possible to forecast when lakes were about to turn red hot?
Fisheries rise and decline for a variety of interrelated reasons. But the fisheries on the launchpad, ready for a meteoric rise in catch-rates and average size, tend to fall into one or more of these categories:
* Conditions during the walleye spawn were perfect several years in a row a few years back;
* Quality regulations have been successful, allowing average size and catch-rates to rise;
* A high-fat, high protein prey species like smelt or alewives has been introduced or is rebounding from a decline;
* Climatic or other conditions are changing in a way favorable to walleyes;
* For some reason, people are simply ignoring walleyes in a great fishery.
Northern Changes
In-Fisherman Field Editor and former Ontario resource manager, Gord Pyzer, insists global warming is more readily noticeable the farther north you go, and he wonders: Will it benefit or cripple fish populations? “It’s one of those things where a little knowledge is a dangerous thing, because the issue is so complex,” Pyzer says. “But whether you believe in global warming or not, the past 15 years have been the warmest on record. We’re seeing climate change and Bay of Quinte, Ontario, one of the world’s top trophy walleye fisheries, is an example.”
Logic insists it would become a better walleye fishery because of warming, but walleyes share that water with smallmouths. Earlier ice-outs in spring and the abundance of good spawning habitat make things optimal for smallmouths. In Lake Oahe, South Dakota, walleyes could well be the winners, but in Quinte, they could eventually lose out because habitat may favor bass.
“The belt for the best crappie or smallmouth fishing is shifting north,” Pyzer says. “Marginal to mediocre fisheries—such as lakes too shallow to guarantee over-winter survival in the North—could shift and improve. The big losers could be the walleyes in the southern end of their range, where waters could become too warm. Walleyes require a reasonable amount of time in water under 50°F during winter for the spawn to be successful. Eggs don’t develop properly in a walleye with a body temperature that rises too high for any length of time in winter.
“Conversely, waters that have been too cold on the northern end of their range become increasingly favorable for over-winter survival and spawning. Impacts are greater in the North. We’ve seen a 4°C to 5°C change in average annual temperatures. Smallmouths spawn earlier and find optimal conditions for growth more often than in the past. Rising populations of bass can spread into niches classically held by walleyes. Recruitment is just unbelievable right now for warmwater species. Black crappies are appearing in places where we’ve never had them before.”
Dr. Peter Colby, former head of the walleye research program for the Ontario Ministry of Natural Resources, has ideas about which lakes may become even better walleye lakes in the near future, due to warming, according to Pyzer. Rainy Lake, already on fire, has slot-limits and a lower limit of 3 fish, but numbers and size seem to be on the upswing due to a combination of environmental factors, as well. Meanwhile, Colby thinks Lake Nipigon, always a phenomenal lake-trout water but a nominal walleye fishery, might turn the corner to become optimal for walleyes. It’s a very large lake, and, like Lake of the Woods and Lac Seul, two world-class waters, big lakes will be the real winners for walleyes in a global-warming scenario.
