Smallmouth are vulnerable in fall

The more we learn about smallmouth bass, the less we know about them.
They are oddballs. Bronze-finned enigmas wrapped up in riddles. And no one knows that better than Dr. Mark Ridgway.
As a fisheries scientist with the Aquatic Ecosystems Science Section of the Ontario Ministry of Natural Resources, Ridgway has spent a good portion of his life tracking smallmouth bass through every stage of their life development and all four seasons.
Donning scuba gear and following the fish with sophisticated radio tracking devices, he is on a first-name basis with many of his subjects. Indeed, his research out of the Harkness Science Laboratory on Lake Opeongo in Algonquin Provincial Park has contributed to the longest continuous census of any animal population on Earth.
Yet he admits that every time he answers a question about the ecology of smallmouth bass, he finds two new ones staring him in the face.
One of the toughest questions Ridgway finds on his plate these days is why smallmouth bass in our part of the world behave the way they do in the fall.
And he is concerned that if anglers and fisheries managers don’t become more aware of what happens between September and freeze-up, many smallmouth populations may be jeopardized.
In northern smallmouth waters like those found in Sunset Country, Ridgway says crayfish molt in mid- to late-August. The trigger for the crawdads to shed their armour-like skeletons, he believes, is changing photoperiods.
With crayfish forage scarce and their stomachs starting to growl, shrinking light levels appear to trigger the bass to move to their fall and eventual winter locations.
It’s the critical period of the year when survival hinges in the balance.
“The young-of-the-year stuff is well understood,” Ridgway says. “But I think the story is played over again for the adults. They literally starve over the winter.
“That is why the fall period is so critical. It’s desperately important for them to binge feed prior to the winter starvation period,” he stresses.
While many anglers believe they can time this shift from summer to fall locations based on water temperature, Ridgway says temperature is not the key.
“One year you’ll get a warm fall and they’ll be moving at 15 C (60F). Another year, you’ll find them moving when the water temperature is 10 C (50F).
“So the temperature is variable.”
What isn’t a variable, Ridgway discovered, is the timing. His data show that smallmouth move each year to their autumnal areas a week after the fall equinox.
Preservation of the stocks at these sites is a major concern for Ridgway. Like summer home ranges, the bass faithfully flock to fall sites and reuse them, year after year.
But there is an unfortunate twist. Fall locations are significantly fewer in number and much smaller in size. As a result, you often find the entire adult smallmouth population of a lake—or major portion of a lake—crammed into very few locations.
How many smallmouth will pack themselves into a fall location?
“Thousands,” says Ridgway. “That is what makes them so vulnerable. And they’re always adult fish considerably above average size and weight for the lake.
“You can go back to these spots day after day, season after season, and pull out large fish,” he adds. “It can be a huge problem because you’re taking out the reproductive population.
“There is legitimate concern about angling for smallmouth during the nesting season,” Ridgway continues, “But frankly, I think killing and even moving fish when they’re bunched up on fall sites is something anglers and managers ought to be thinking about, as well.
“You get far greater portions of the populations concentrated in these areas. You’d have to cover miles and miles of shoreline in the summer time to find the same number of fish.”
What does it all mean? For certain, adult bass packed like sardines into a few main lake areas are more vulnerable in the fall than at any other time of the year.
Not only are the fish concentrated, but in order to survive the winter starvation period, they’re on an all-out, dawn to dusk, high-protein eating binge.
What could be a better dream for an angler? The largest fish in the lake, bunched up on a few spots, in a feeding frenzy.
Not surprisingly, the unsuspecting angler who stumbles across one of these spots thinks he has died and gone to heaven. The lake appears to be “crawling” with fish. A veritable “bass factory.”
Ironically, that assessment could be the furthest thing from the truth. Instead, removing smallmouth from these sites, at this time of the year, may be akin to shooting ducks in a barrel. Or killing the geese that lay the golden eggs.
Equally perplexing for Ridgway is when anglers catch bass from strategic fall-feeding locations and release them miles away. Can the smallmouth find their way home before freeze-up? Will they winter with other bass?
Or, will they cease feeding, struggle to find familiar territory, run out of time, and starve to death as a result of missing out on the fall feeding frenzy?
As Ridgway will tell you—answer one question and it raises another.