The Kenora Bass International, one of the country's premier bass fishing tournaments was held this past weekend on Lake of the Woods and to say that at least some of the fish were mixed up and acting weirdly is an understatement.  

Like most of the continent, Northwestern Ontario has been shaking and baking this summer under scorchingly hotter than normal conditions.  Indeed, the water temperature in many of the massive million acre lake's shoreline shallows and backwater bays has exceeded 80 F or 27 C for much of the summer.   So why in the world were anglers finding and catching smallmouth bass this weekend on beds?    

That is right.  Nesting summer smallmouth.  

As a general rule, smallmouth bass spawn in the spring as soon as water temperatures approach 60 F / 16 C in temperature.  And, according to Ontario Ministry of Natural Resources scientist Dr. Mark Ridgway, the biggest fish spawn first.   

For the past two decades, Ridgway has headed up a team of biologists working out of the Harkness Laboratory of Fisheries Research in Algonquin Provincial Park.  His work on the smallmouth bass of Lake Opeongo has contributed to the longest continuous census of any animal population on earth.  It’s approaching 80 years worth of data.  Ridgway's findings have also shed new light on the factors that determine the reproductive success and year class production of smallmouth bass in northern lakes and rivers.  

One of Ridgway’s most significant discoveries, for example, is the fact that northern range smallmouth don't spawn for the first time until they are between five and nine years of age and between 10 inches and 16 inches in length.  More importantly, precisely when a smallmouth lays its eggs or guards a nest is based on the size of the fish.  As a general rule, large males and females spawn earlier in the spring than their smaller brothers and sisters.  This difference is hugely important for reasons we’ll see in a minute.  

Perhaps Ridgway’s most astonishing finding, though, is the revelation that only about one-third of all the smallmouth bass big enough to spawn in a northern lake actually reproduce in any given year.  Even more amazing, the factors that determine which bass will comprise the one-third spawning group are established during the previous summer.      


(Northern range smallmouth bass use the summer to feed voraciously and gain weight to survive the winter starvation period.  So why in the world are they nesting in August?)

“What this means,” says Ridgway, “is that if you pull a bass off a nest there is no rush of new fish waiting to move in.  Once the spawning decision is made, it is absolutely final.  Pull a male off his nest and no one else will replace him.”    

Furthermore, says Ridgway, if the population of larger smallmouth is angled down, smaller bass must be rushed to the front … ahead of their time … to assume the spawning chores in subsequent years.  But smaller bass spawn later than larger fish.  This fact holds true even when they are the only nesters left in the lake.   

That means that when fall arrives, the young-of-the-year that the small bass produce are at a distinct disadvantage in terms of surviving the winter starvation period.  In the north, for all intents and purposes, bass don’t eat once a lake freezes.  As a result, young-of-the-year smallmouth must eat and grow fast enough in the first year of their life … typically to the size of your little finger … to survive to the following spring. So every day they’re delayed in the egg-laying stage is another potential nail in their coffin.  Still, it can get worse.  

"Once you force small bass to start spawning ahead of their time,” Ridgway explains, “because you’ve ratcheted down the big bass population, their reproductive life span becomes only one or two years.  Like the young-of-the-year, they starve to death during the winter.  These smaller nesting bass, typically 12 inches or so, have a very high mortality rate.  It is the cost of reproduction.  Very few of these fish survive to reproduce twice.  But, as nesters increase in size, up to seven, eight, nine plus years of age, you get a much higher return rate.  These older fish do not pay a survival price in terms of reproduction like the smaller fish do."  

According to Ridgway the odds of north country bass surviving the first year of their lives are about the same as playing Russian Roulette.  It’s a game, by the way, southern bass don’t have to play.  

According to Ridgway, the best possible scenario occurs when the ice leaves northern lakes early in the spring, water temperatures warm up quickly and large genetically fit fish nest ahead of schedule.  If "freeze up" in the fall is then delayed and warm summer conditions are extended it is even better still.  And if the following spring arrives early once again, it is the best of all possible worlds for the fish.  

Indeed, that is precisely what happened way back in 1983 and 1984 when conditions meshed together perfectly to produce the biggest bass year class most biologists have ever seen.  

But having all the stars line up perfectly is rare.  More often, says Ridgway, you can have a wonderful spawn, and then see all the gains you thought you made in the summer, wiped out over the winter.   

Which brings us back to the conditions on the weekend.  Given that the water temperature in Lake of the Woods long ago reached and then super exceeded the 60 F temperature that normally sparks smallmouth to spawn, why were large males nesting in August? 

Surely any young of the year that might hatch at this late stage will be too small to survive the winter starvation period.  And the "cost of reproduction" to the adults must be fatal as well.  

Yet, at least one of the anglers, OFAH's Mike Miller, says he and his partner have caught smallmouth spawning in the same area during KBI in previous years as well.  

 Talk about a suicidal life-style strategy.