Giant Northern Crappies

The "good old days" for many crappie anglers are right now, especially for those living in the northern portion of the crappies' range, in states like New York, Michigan, Wisconsin, Minnesota, and the Canadian provinces of Ontario and Manitoba.

Black crappies in this region have never been more plentiful, have never grown bigger and have never enjoyed such a bright future. This is curious, because crappies are supposed to be "good ole boys," relishing warm southern impoundments and flourishing in places like Arkansas and Mississippi.

Indeed, if you were to draw a line of latitude, from east to west through Kentucky, you're more likely to associate crappies with flooded tree-filled reservoirs, spider rigs, dusty coveralls, and grits, than natural northern lakes with cabbage weeds, slipbobbers, fleece-lined pants, and Red River cereal.

So what in the world is going on? Is there no respect for tradition?

Northern Expansion

"Black crappies are one of the best indicators of climate change," says Dr. John Casselman, Adjunct Professor of Biology at Ontario's prestigious Queen's University. For almost 40 years, prior to his retirement in 2008, Casselman was the Senior Research Scientist in the OMNR's Lake Ontario Research Unit. The same year he retired, the American Fisheries Society honored him with its Award of Merit for his lifetime of scientific achievements. It was only the 40th time the Society has deemed a member worthy of such lofty recognition.

"Black crappie populations are expanding exponentially," he says. "We're seeing it in our electrofishing surveys. The fish are seemingly coming from nowhere and they are big, beautiful, and abundant."

Scott Smithers echoes Casselman's observations. Smithers is the OMNR's biologist in the Kemptville District, situated in southeastern Ontario along the north shore of Lake Ontario and the St. Lawrence River. Black crappies are native to this part of the country, but Smithers says new populations have been popping up everywhere over the last two decades.

"Until about 1990," says Smithers, "if you mentioned black crappies to most anglers around here, they'd look at you like you had two heads. But now, crappies are expanding their range, exploiting new ecological niches and anglers are enjoying unbelievable fishing."

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Some of the crappie range expansion is natural, with the fish migrating into adjoining lakes and rivers via interconnected creeks and canals. But much of the movement is also surreptitious, not to mention illegal, courtesy of the "bait bucket brigade."

"Anglers have access to the Internet," says Smithers. "When they read about a desirable fish, they start transporting it to new lakes. That's not wise. We're seeing crappie populations springing up, even in lake trout lakes far removed from any natural crappie waters. There is only one way the fish could have found their way in."

Regardless of how black crappies reach new waters, the fish are finding the new northern digs to their liking. They're flourishing, despite a perception that crappies only prosper in warm, lush, southern habitats. So what is occurring?

"What happens," explains Casselman, "is that the first few fish to find their way into a new system grow extremely large and do so quickly. After three or four years, they mature and start contributing additional year-classes. Recruitment explodes and young-of-the-year fish move into connected waterways. And warm El Niño years give them a boost.

"Whenever that first crappie year-class explodes in a new lake, it is gigantic. There are also more nutrients and prey available in the system during these climate events. So, the first fish grow large, reproduce successfully and explode in numbers."

Even more to the point, Casselman notes that having "space" between the strong El Niño year-classes, as opposed to the fish pulling off successively strong hatches, benefits emerging crappie populations. More space means less competition for food and healthier, more robust fish.

Overlooked Populations

Smithers notes that anglers, through their fishing habits, and resource agencies, by their management strategies, have unwittingly aided blossoming crappie populations. "Outside of a few weeks in spring, when the fish are spawning, most northern anglers haven't traditionally fished for crappies. Nearly all of our lakes are natural, heavily structured, contain large areas of cabbage and coontail, and have complex fish communities with walleye, lake trout, muskie, northern pike, yellow perch, and largemouth and smallmouth bass. Unlike in the central and southern U.S., anglers haven't yet discovered how to catch crappies consistently in the summer.

"What is also interesting about crappies," Smithers adds, "is that they're not a species you're likely to catch by accident. You don't luck into many great crappie catches. They're a fish you need to specifically target. So they're basically untouched all summer.

"In fall, steelhead runs are underway, bass fishing is hitting high gear and hunting season is opening, so another peak crappie bite is often overlooked and the fish continue expanding since harvest is light."

If you're a crappie angler, all of this good news is enough to make your head spin, but it gets even better. In places like southern Ontario's Kawartha Lakes, the famous string of walleye, bass, and muskie waters east of Toronto, fishing pressure during the open-water season has historically been high enough that winter ice-fishing season has been closed, until new panfish regulations were implemented last year. Combine these factors with a steadily warming climate and it's little wonder that black crappie populations are exploding across the North Country.

Still, it begs the question: If crappie anglers are routinely catching 13-, 14-, 15-, even 16-inch-slabs, and crappie populations are flourishing in parts of the continent where lakes and rivers freeze for much of the winter, have we been wrong all these years, thinking black crappies are "warmwater" fish? The answer is "yes."

Growth To Maximum Size

"When it comes to fish reaching maximum size," says Casselman, "slow and steady wins the race. In conditions that are warm, fertile, and almost too perfect, they grow quickly, almost burn out in a sense and achieve a smaller ultimate size. On the other hand, if the water is too cold and there aren't enough nutrients, they grow too slowly to reach their maximum size. We see this in lake trout populations in the extreme Far North. Fish with a moderate growth rate and moderate food supply tend to reach maximum size. This is true for muskies and it may be true for crappies living in the northern half of their range."

The dynamics of fish growth is a subject Casselman has spent much of his life exploring, studying data gathered by observing under a microscope the cleithrum bones of muskies from across North America. The pioneering research he carried out with his friend, the late Dr. Ed Crossman, is for many in the science community, the definitive word on the subject of fish age, growth, and ultimate size.

In a nutshell, fish are cold-blooded, growing best within a narrow range of optimal water temperatures. When those temperatures remain warm and constant throughout the year, fish like crappies grow quickly, continuously, and mature early. But all of that growth comes at a cost. The fish die of old age — burn out — early.

When cooler optimal temperatures prevail, fish like crappies grow more slowly and mature later in life. Cooler water and slower growth allow the fish to live far longer. But despite a long lifespan, crappies still don't achieve maximum size. Somewhere between these two extremes lies the quintessential moderate growth that Casselman says allows the fish to live to their maximum life expectancy, and thus achieve maximum size.

It's important to note that the two divergent growth strategies don't necessarily involve north-to-south geographical differences. Two lakes can literally lie across the road from one another, if one is a shallow, warm, eutrophic environment, and the other a deep, cold, oligotrophic ecosystem.

The potential for a body of water to produce numbers of fat, platter-size crappies appears to be dependent on water temperatures and fertility that allow them to flourish and grow at a moderate rate.

"It could be," says Casselman, "what we're seeing in New York, Wisconsin, Minnesota, and Ontario is that with climate change, water temperature has increased just enough that crappie growth rates have been stimulated enough that the fish are now reaching, or almost reaching, their maximum age and ultimate size."

What's The Downside?

While crappie anglers living in the northern half of the crappies' range can be excused for pinching themselves to make sure this isn't a dream, they might also reasonably ask, what's the downside? And will phenomenal fishing continue?

"Of all the fish that make up the warmwater community in the Great Lakes basin," says Casselman, "crappies are the most prolific. When conditions are ideal, they can produce huge year-classes. But like any invader, the first year-class tends to explode because there's no competition. Eventually, the fish seem to outdo themselves, subsequent year-classes compete with one another for food and space, and the population eventually stabilizes. That steady-state population is usually considerably lower than when the fish first arrived."

While it's true that anglers can expect to see a leveling off of crappie populations in the future, Casselman is quick to point out that climate change isn't going away soon. Indeed, he refers to the massive bank of data he and his colleagues have collected over the years that shows even a 1°C increase in water temperature can have a dramatic impact on black crappie recruitment and year-class strength. Given the black crappie's status as a recent invader, it's likely we've only scratched the surface in the northern half of the range, in terms of witnessing the fish's eventual full impact.

Smithers can hardly believe his eyes every time he lifts a sampling net. "Crappie populations are exploding in southern Ontario," he says. "The number of fish in places like Rice, Sturgeon, and Cameron lakes, and the Scugog River is amazing. And it seems every time we turn around we discover another new fishery."

The same thing is happening across the northern half of the black crappie's range. Existing populations are spreading and colonizing interconnected waters. Traditional fisheries are producing more consistent year-classes, and once-marginal crappie fisheries are now yielding trophies. "These are the days," says Smithers, "we'll be telling our grandkids about."

The Crappie Happening

The interconnected waterbodies making up the Kawartha Lakes in southern Ontario form a major part of the Trent Canal system linking boaters and anglers with Lake Ontario and Lake Huron. The city of Peterborough, about one hour east of Toronto, lies at the center of the chain. Long famous for their walleye, bass, and muskie fisheries, the Kawarthas now have exploding crappie fisheries. Anglers are enjoying spectacular fishing throughout the year, but for the first time ever in 2010, lakes like Rice, Sturgeon, and Cameron were opened to ice fishing. Don't wait to get in on this once-in-a-lifetime action.

Interspecific Competition

Everything in nature comes at a price. In the case of exploding black crappie populations and the colonization of new waters, there is a corresponding drop in the number of some other species. Walleyes are the fish most often negatively affected by crappies. When conditions favor crappies, they can out-compete juvenile and young-of-the-year walleyes for food and space. Crappies also have been shown in some waters to be "heavy consumers" — predators of larval walleye.

While the expansion of a native crappie population into an adjoining water is natural, anglers planting crappies where they do not exist is unwise. If crappies, or any other species for that matter, were meant to be in a natural body of water, they would already be there. Leave stocking decisions to the professionals.