You spot a big bass circling in the shallows, obviously protecting its nest. Your heart skips a beat. But do you pick up a rod and cast to the bedding bass? It all depends on where you live, what your local state or provincial regulations allow, and even your own conservation philosophy.

In many jurisdictions, bass fishing is a year-round sport. Big cast-for-cash competitions often are timed to coincide with the major waves of bass moving shallow to spawn. Indeed, last January at the Florida BASSMASTER Top 150 event on Lake Tohopekaliga, Dean Rojas shattered the all-time BASSMASTER weight record. Rojas sight-fished his way into the record book by targeting bedding bass. His four-day catch of 20 bass weighed 108 pounds, 12 ounces, anchored by his first day five-fish limit of 45 pounds, 2 ounces.

In many parts of North America, Rojas’ feat would have been forbidden. The bass season is closed and intentionally fishing for them is illegal. Additionally, key bass spawning areas are sometimes declared out-of-bounds sanctuaries, where it’s against the law even to angle for other species for which the season is open.

Who is right? Who is wrong? Does fishing for spawning bass have an effect?

The Illusion Of Abundance

Interestingly, the answer depends on where you live. And geography may play a key biological role. In the southern half of the United States and Mexico, for example, areas with year-round fishing seasons, bass grow quickly and mature early. Take, for example, a three-pound smallmouth bass in Alabama or Tennessee. A fish that size may be five or six years old and has spawned several times.

The same age smallmouth in northern Minnesota, Michigan, or Ontario likely measures 12 inches in length, weighs 15 ounces, and has never spawned. Let’s look at it another way. If you caught 15 or 20 of these foot-long sausages in a day, you wouldn’t consider it much of a feat. Yet that would be comparable to catching 15 or 20 three-pound-plus smallmouth bass in southern waters—a great feat.

Other points to consider: Generally speaking, most southern lakes, rivers, pits, ponds, and reservoirs offer bass-friendly living conditions. The water’s warm year-round with plenty of food. Sometimes, so much so that species like striped bass are stocked to control the forage base.

By comparison, northern bass waters are like the Amazon rain forest. They give the illusion of abundance, but it’s a false impression. Typical northern bass lakes, like Minnesota and Ontario’s famed Rainy Lake and Lake of the Woods, grow about three or four pounds of fish flesh per acre annually on a sustainable basis. And that meager productivity is spread among 30 or more species of fish. The amount of annual production apportioned to the bass population is measured as ounces per acre per year.

And unlike many southern rivers and reservoirs, bass in northern waters are not the top predator. More often, they’re relegated to occupying environmental niches within a lake, river, or reservoir.

Protect Adults Or Increase Reproduction?

In consideration of some or all of these factors, fishery management agencies in several northern states and Canadian provinces close the bass season during the spring spawn. Sometimes the strategy is designed to protect potentially vulnerable adults. Other times, it’s to ensure the survival of as many bass eggs and fry as possible. But usually it’s intended to achieve both objectives.

Spring bass closures have gained even greater significance in recent years following the efforts of bass researcher Dr. Mark Ridgway of the Ontario Ministry of Natural Resources. For the past 16 years, Ridgway has headed 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, nearly 70 years worth of data. Ridgway’s findings have shed light on factors that determine the reproductive success and year class production of smallmouth bass in Ontario waters.

One of Ridgway’s most significant discoveries was that smallmouth of this region don’t spawn for the first time until they’re between five and nine years old and between 10 and 16 inches long. Also, the timing of an individual’s spawning is based on its size. As a rule, large males and females spawn earlier in spring than smaller fish. 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 adult smallmouths actually attempt to spawn in a given year. Moreover, the factors that determine which bass comprise the limited spawning cadre are established during the previous summer.

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

“Furthermore,” Ridgway says, “if the population of larger smallmouth is fished down, smaller bass must be rushed into the spawning stock—ahead of their time—to assume the spawning chores in subsequent years. But smaller bass spawn later than larger fish, even when small bass are the only nesters left in a lake.”

The offspring that small bass produce are at a distinct disadvantage in reaching the critical size necessary to survive the winter starvation period. For all intents and purposes, bass don’t eat once a lake freezes. As a result, young-of-the-year bass must eat and grow fast enough in the first year of life—typically to the size of your little finger—to survive to the following spring. Thus every day’s delay in the egg-laying stage is another potential threat to survival. But the scenario gets worse still.

“Once the big bass population has been ratcheted down through harvest, small bass are forced to start spawning ahead of their time, thereby reducing their reproductive life span to just one or two years,” Ridgway explains. “Like the young-of-the-year, they starve to death during winter. Smaller nesting bass, 12 inches or so, suffer a high mortality rate—the cost of reproduction.

“Few of these fish survive to spawn twice. But, as the size of nesters increases, up to seven, eight, nine or more years of age, the return rate is much higher. Older bass don’t seem to pay a survival price in terms of reproduction as smaller fish do.”

These severe conditions scarcely affect southern bass or southern bass anglers, as frozen lakes are rare south of Kansas. In warmer regions, largemouth and smallmouth bass can feed year-round. They essentially avoid the crucial winter starvation period, yielding fitter bass and greater numbers of spawners. The annual production of strong year classes of bass increases the farther south you travel.

Catch and Release

What about catch and release of spawning bass? Several northeastern states recently have imposed such a regulation, banning harvest yet allowing anglers to target bass. In the south, the often long spring spawning period is considered by most anglers to be the best time to fish. In the north, however, the practice can be harmful, and according to Dr. Ridgway, can seriously decrease reproductive success.

“Bass tend to abandon their nests due to the physiological stress of being caught,” he says. “Other scientists have taken detailed physiological measurements and found the bass truly exhausted. Nest abandonment was high.”

Those studies were cooperative ventures by researchers working with the Illinois Natural History Survey, the Ontario Ministry of Natural Resources, and the Queen’s University Biological Station. The biologists selected a series of lakes and rivers in southeastern Ontario, near the Ontario-New York border where the bass season is closed in spring, but the season for other species is open. They wanted to assess the effects of preseason catch-and-release angling on the reproductive success of largemouth and smallmouth bass.

In one of the lakes (Lake Opinicon) as many as 63 percent of anglers were observed targeting nesting bass under the guise of fishing for another species—typically crappies, walleye, pike, or perch. When the researchers went underwater and counted the number of bass with visible hook wounds, they found that in the most heavily targeted lake, almost 100 percent of the nesting males had been caught and released. If the bass season had been opened, every single nesting male possibly could have been harvested.

But the season was closed so the researchers turned their attention to determining if the illegal catch-and-release fishing they’d observed affected the spawning success of the bass population? It did, they say, in a major way.

In the lakes and rivers that received the most preseason angling, spawning success was the lowest. Fewer than half the bass nests were successful. But in the lakes and rivers where catch-and-release angling for nesting bass was minimal, 84 percent of the guarding males successfully raised a brood.

A relationship also appeared between the time it took a male bass to return to its nest after being caught and released and the rate of nest abandonment. When a groggy bass took more than 10 minutes to return to its nest, the eggs and fry were preyed upon more than 90 percent of the time and over 90 percent of the nests were abandoned. Even when males returned to the nest in two to five minutes, more than half the nests eventually were deserted.

Ontario Ministry of Natural Resources biologist Barry Corbett, who recently completed an extensive multiyear smallmouth bass tracking study on Lake of the Woods, reported seeing the same thing. In order to surgically implant radio transmitters inside a number of bass, Corbett waited until the males were guarding nests. When he dove below to net a fish, he says he was shocked to see two things: The number of males with hook wounds and the number of the exotic rusty crayfish harassing the bass.

“It was like a scene out of the movie Aliens,” Corbett says. “So many crayfish were surrounding the nests, waiting for a chance to gobble up the eggs, that we had to leave a technician underwater to protect the site, while we placed the transmitter inside a bass and then returned it to the nest.”

“Aliens from above and aliens from below,” say the Canadian and American researchers. “Illegal preseason angling of nesting bass,” they concluded, “even on a catch-and-release basis, appears to be detrimental to overall fry production and survival because of an increase in brood predation and male nest abandonment.

“And we should never forget,” cautions Ridgway, referring to the paltry 30 percent of male smallmouth that are preselected to spawn each season, “that no more bass are waiting to move onto the nests.”

*Gord Pyzer, Kenora, Ontario, is a field editor for In-Fisherman magazine. Formerly a senior manager with the Ontario Ministry of Natural Resources, he now operates a fishing and deer hunting guide service on Lake of the Woods. Contact Gord at 807/468-4898 or .