Targeting Spawning Bass

[river rat316]

I wanted everyone to see this before walleye opener is upon us it shows how important it is to leave nesting bass alone in our northern waters please read! (I dont know how to link so this will be very long but is well worth the read!)

Conservation Concern or Needless Restriction?

It’s spring and you spot a big bass circling in the shallows. The fish is 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 personal angling ethics.

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

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

Who is right and who is wrong? Indeed, does fishing for spawning bass have an impact?

The Illusion of Abundance

Interestingly, the answer depends on where you live. And geography may very well play a key biological role. In the southern half of the United States and Mexico, for example, where anglers routinely enjoy year-round fishing seasons, bass grow quickly and mature early. Take, for example, a four-pound smallmouth bass in Alabama, Tennessee or Kentucky. A fish that size is likely to be five or six years old and to have spawned several times.

The very same smallmouth, though, living in northern Minnesota, northern Michigan or Ontario is likely to measure twelve inches in length, weigh 15 ounces and never have spawned. Let’s look at it another way. If you were to catch 15 or 20 of these foot-long sausages in a day, you wouldn’t consider it much of a feat. Yet, from a fish-age perspective, it is comparable to catching 15 or 20 four pound plus smallmouth bass in more southern waters. Most would consider that a feat of heroic proportions.

Some other things to consider. Generally speaking, most southern lakes, rivers, pits, ponds and reservoirs are bass friendly in terms of living conditions. The water is warm year-round and there is plenty of food. Sometimes, so much, that species like striped bass are planted to control the forage base. Southern lakes, rivers and reservoirs are also usually less complex in terms of species mix and diversity.

By comparison, northern bass waters are like the Amazon rainforest. They give the illusion of abundance. But it’s a false impression. A typical northern bass lake, like Minnesota and Ontario’s famed Rainy Lake and Lake of the Woods, grows about three or four pounds of fish flesh per acre annually on a sustainable basis. But that meager productivity is then spread among 30, 40 or more different species of fish. Everything from walleye, perch, pike and muskies to suckers, ciscoes and whitefish. So the amount of annual production apportioned to the bass population is peanuts. In fact, it measured as ounces an acre a year.

And unlike in many southern lakes and reservoirs, bass in northern waters are usually neither the top predator nor the most abundant species. More often, they are relegated to occupying environmental niches within the lake, river or reservoir that you find them.

Protect Adults or Aid in Reproduction?

In consideration of some, or all, of these factors, fisheries agencies in several northern states and Canadian provinces close the bass season during the spring spawning period. Sometimes the strategy is designed to protect potentially vulnerable adults. Other times, it is tailored to ensure the survival of as many bass eggs and fry as possible. Usually it is intended to achieve both objectives.

Spring bass closures have taken on even greater importance in recent years following the efforts of Ontario MNR bass scientist Dr. Mark Ridgway. For the past 16 years, 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 70 years worth of data. Ridgway's findings have 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 is the fact that northern 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 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.

“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.

The young-of-the-year that the small bass produce are at a distinct disadvantage in terms of reaching the critical size necessary to survive 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 bass 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."

Of course, these conditions do not affect southern bass … or southern bass anglers … where cold water temperatures and frozen lake surfaces are almost unimaginable. In the more moderate, even semi-tropical, areas of North America, largemouth and smallmouth bass can feed year round. For all intents and purposes, they can avoid the crucial winter starvation period resulting in fitter bass and greater numbers of spawners. In fact, the annual production of steady, stable, secure and strong bass year classes increases the further south you travel.

What about Catch and Release in the Spring?

That appears to help answer another north - south dissimilarity question. The impact of angling … even on a catch and release basis … for nesting bass. In the south, the often long drawn-out spring spawning period is considered by many anglers to be the best time to go fishing. In the north, however, the practice can be harmful, and according to Ridgway, can seriously decrease reproductive success.

“There is a tendency for bass to abandon the nest because of physiological stress,” he says. “Other scientists have taken detailed physiological measurements and the bass were truly exhausted. Nest abandonment was high.”

The studies that Ridgway refers to, were cooperative ones recently undertaken by researchers working with the Center for Aquatic Ecology, 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 the spring, but the season for other species is open. They wanted to assess the impact of pre-season 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 the anglers were observed targeting nesting bass under the guise of fishing for another species … typically walleye, pike, perch or crappies. When the researchers went underwater and counted the number of bass with visible hook wounds, they found 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, it was possible that every single nesting male could have been killed.

But the season was closed so the researchers turned their attention to determining if the “illegal” catch-and-release angling they had observed had any affect on the reproductive success of the bass population? It did, they say, in a major way.

In the lakes and rivers that received the greatest amount of pre-season angling, the reproductive success was the lowest. Fewer than half the bass nests were successful. On the other hand, in the lakes and rivers where catch-and-release angling for nesting males was minimal, 84 percent of the guarding males successfully raised a brood.

There also appeared to be a relationship 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 ten minutes to return to its nest, the eggs and fry were predated upon more than 90 percent of the time and over 90 percent of the nests were abandoned. Even when the males returned to the nest in as short a period as two to five minutes, more than half the nests were eventually deserted.

Ontario Ministry of Natural Resources biologist Barry Corbett, who recently completed an extensive multi-year 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 obvious facial hook wounds … and the number of the rusticus strain of crayfish ringing the beds and harassing the bass.

“It was like a scene out of the movie Aliens,” Corbett says. “There were so many crayfish 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 the bass and then returned it to the nest.”

Aliens from above and aliens from below … it’s enough in many northern lakes and rivers to give the bass fits, say the Canadian and American researchers. "Illegal pre-season 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 rates.

“And we should never forget,” cautions Ridgway, referring to the paltry thirty percent of male smallmouth that are pre-selected to spawn each season, “that there are no more bass waiting out there to come in.”

(Side Bar)

Russian Roulette

According to Dr. Mark 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, spring spawn conditions can be wonderful. The ice can go out early, water temperatures can warm up quickly and large genetically fit fish can nest ahead of time. These conditions occurred across most of North America in the spring of 1983. But then something else occurred. Freeze up in the fall was delayed and warm summer conditions were extended. The spring of 1984 also arrived ahead of schedule, so the winter bass starvation period was short lived. As a result of all these conditions meshing together perfectly, the 1983 bass year class was the biggest most biologists had ever seen. In fact, so many bass were born in 1983 that they sustained many bass fisheries for years, well into the mid- and late 1990s.

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. Similar to what happened in the spring of 1995 over much of the northern bass range. Warm temperatures soared early and bass flooded the shallows and nested. Anglers and biologists alike reported seeing dense balls of fry everywhere. Many crossed their fingers and hoped the 1995 bass hatch was going to mirror 1983.

It didn’t. Record cold weather swept across much of the mid-Western United States and Canada in late October and early November. Winter dragged on for eternity. And a superb bass year class in the making was dealt a blow.

(Side Bar)

Be Careful What You Wish For

An ancient Chinese proverb warns to be careful what you wish for … it may come true. Without understanding the complex biological factors at play across the huge and diverse geographical range that we find largemouth and smallmouth bass … anglers often misinterpret the management subtleties. Often they lobby for the implementation of policies and practices they see in other jurisdictions. After all, they reason, if it works in Florida or Texas why not in Minnesota or Ontario? And sometimes they find biologists and politicians who are only too willing to give them what they want.

It’s not talked about openly in scientific circles, but there remain some fish managers … especially in northern areas … who do not support bass management policies or practices. Even though bass populations have been established for over a century in many areas, the result of stocking efforts in the late 1800s and early 1900s, some biologists still view bass as “exotic” and “non-native species” that compete with native fish like walleye and trout. At the extreme edge, a few biologists believe bass in these areas should be totally eradicated.

Hence, when bass anglers come knocking on their doors with the suggestion that more liberal practices should be implemented, such as fishing for bass on beds, they are often welcomed with open arms. That why you need to be careful what you wish for. You just might get it

[cheektowaga]

Interesting read RiverRat! I for one have never had a problem waiting the extra couple of weeks for the bass opener and have never targeted a spawning bass. I fish a lot in a small northern MN lake and news like this can get a guy a little worried.

I personally feel a lot of it has to do with the ladder part of the article and the timelines of ice-on and ice-out. Plus, it's another reason to pray for open water. The sooner the better!

P.S. River, we share a common area and occupation, you should shoot me an email sometime. cheektowaga at hotmail