Late last winter, I stuffed two tip-ups into a bucket along with a couple dozen frozen tulibees, strapped the power auger to my quad 4 x 4, and headed off to an old familiar spot where I knew big pike gathered at late-ice.

The fish didn’t disappoint. The first one weighed about 18 pounds. The second pike felt twice as large, but I’ll never know for sure. Racing to the tip-up, I could hear the large metal spool whirling underwater. When I lifted it out of the hole, it sprayed water and looked menacing. Wrapping a finger around the braid would have removed a digit. And I couldn’t grab the line tightly enough to set the hook without burning my fingers. I’ve never felt anything so powerful, and I’ve landed several pike between 25 and 30 pounds over the years. I lost the fish eventually, but then it happened again, an hour later. Both events felt as though my line were attached to the bumper of a truck.

Back home that evening, I stripped off the line from my tip-ups and re-spooled them with 35-pound Berkley Gorilla braid. I also added fresh quick-strike rigs and honed the hooks. I could hardly sleep that night, and by daybreak I was back soaking freshly baited rigs.

The first fish, about a dozen pounds. The second fish, though, was a 431⁄2-inch horse, bulging with eggs, that weighed in the low 20s. I began to wonder: Was it a pair of fish like this one that had freight-trained me the day before? The next flag that flew answered my question. The tip-up shook and rocked violently in the hole, like a stick twirling in a blender. I couldn’t snug the line with a solid sweep, but somehow caught enough flesh in the fish’s mouth to slow it down and gain a semblance of control.

Ms. Pike and I sashayed back and forth for several minutes. Then she was right below the hole. So I looked, and saw the head of the biggest northern pike I’ve ever seen—and I’ve seen plenty of big pike, from the Canadian tundra to the Gulf of Sweden. She was humongous. All these years, I had believed such a beast existed but never guessed I had a chance to dance with her. As I strained to get the fish pointed up the hole, in classic big pike fashion, she turned on the afterburners and popped the superline like dental floss.

The scene was fitting: Late-ice, when the biggest and oldest members of many fish species congregate in large numbers in easy-to-reach and highly predictable locations. And therein lies the dilemma.

Many times, for many species of fish, winter ice-action is the best of the year. It can be so good, in fact, that it raises issues about seasonal vulnerability, overall harvest, and quality fish sustainability.

Three or four skilled catch-and-kill ice anglers fishing this same specific pike spot for a week or two could dramatically and negatively impact in a single season the lake’s longterm trophy-pike potential. Indeed, they could legally harvest numerous trophy-sized pike whose combined age would exceed several hundred years.

It’s happened in the past, in waters as large as Wisconsin’s Lake Winnebago. In the late 80s and early 90s, when Winnebago had an abundance of gizzard shad as a result of warm-weather conditions, trophy pike population flourished. When food is abundant during the spring, summer, and fall, pike (and walleye) enter the winter well-fed and, not surprisingly, ice anglers experience only mediocre success when fish have plenty to eat.  

In 1992, the shad base collapsed on Winnebago due to an unusually cool summer. That winter, the pike were hungry and anglers enjoyed outstanding success. Unfortunately, many large, mature, egg-laden females were harvested, and trap nets set the following spring revealed that pike numbers had plummeted as much as 81 percent from previous surveys. More than a decade later, Winnebago is still recovering from that single winter overharvest.

Especially during late winter and early spring, the largest, oldest, and most important members of a fish population (from a recruitment perspective) cram themselves into a small number of highly accessible, shallow, prespawn locations, where they can be extremely vulnerable to angling.

It can be especially problematic for spring spawning species like northern pike, walleye, perch, and crappies, when prime spawning areas are at a premium and major segments of the entire breeding population gather in only one or two spots. The same fish that might have been spread out along miles of shoreline and weedlines during the open-water season are now concentrated in one or two locales measuring just a few hundred square yards.

Ice fishing can also impact large lakes where access and travel are often impeded during the open-water season. Lake Superior is a good example. Even when you can get on the world’s largest water body during the open-water period, anglers tend to stay close to shore and keep a watchful eye on the weather. Superior is no place to be when the wind blows—even gently.

In the winter, though, when significant portions of the lake freeze, ice anglers can travel fairly easily via snowmobile or vehicle to locations as remote as the Apostle Islands. When safe ice exists, winter anglers can catch up to one-quarter of Wisconsin’s lake trout.

A similar scenario plays out on gigantic Green Bay. As many as two million perch are hauled up holes in the ice in the winter, compared to 1.5 million perch caught by anglers fishing during the much longer open-water season. No other season has the potential to host such easy angling access to vulnerable fish.

Slow-growing, cold-water-loving, longlived 20-, 30-, even 40-year-old lake trout are the most vulnerable. Reacting to the fact that lake trout feed heartily in cold water—and to observations of conservation officers who’ve witnessed on a single day’s patrol an entire year’s sustainable production of lake trout lying on the ice of a small lake—Ontario-based researchers have undertaken a decades-long study to document the impact of ice fishing.

On one carefully managed fishery in Northwestern Ontario, the scientists open the lake trout season on an experimental basis for a limited number of anglers for only 9 days each March. More than 15,000 lake trout have been harvested since the study began in 1985. Not surprisingly, the average length and age of the trout has shrunk steadily throughout the study period—just as one would expect. What no one imagined, though, is that the ice-fishing catch-per-unit effort (the amount of time spent and number of fish caught) has varied little throughout the experimental period.

In fact, in recent years it has peaked. In other words, even as the researchers are documenting the collapse of the trout population, ice anglers continue to catch as many or more lake trout than ever. How is this possible? The last remaining trout in the lake, as well as the vast majority of trout anglers, are now congregating around and concentrating on the key structural elements in the lake. This is ominously reminiscent of what preceded the collapse of many of the ocean’s greatest commercial fisheries.

Many biologists tell you that in a perfect world they’d manage every body of water on a lake-specific basis, delicately balancing predator and prey numbers, fishing pressure, and lake productivity. But in our imperfect world, fishery biologists are left to manage species on a broad region-wide or ecological-zone basis.

Anglers want the best possible fisheries. Some think “good fishing” means catching as many fish as possible, regardless of size. Others want at least a reasonable chance to catch a trophy-sized fish, even if they have to release it.

When fishing is good and large numbers of big fish are easy to catch, anglers flock to the lakes. At this point, ethics and law may conflict. Who can resist good fishing action? Daily catch and possession limits allow them to harvest fish, too; it’s legal, so why not? Many anglers argue that if biologists were concerned about anglers taking their limit, surely they’d change the rules.

But “legal” can sometimes be detrimental. Anglers tend to feel that if it’s legal, it’s ethical. Fishery managers routinely monitor fishing pressure on lakes and observe harvest rates skyrocketing.

Legal versus ethical is the single most significant dilemma facing anglers and fish managers today. Sadly, when the bite’s on, anglers tend to opt for what’s technically legal and not what may be more ethical. As for changing the regulations governing seasons and catch-limits, the process is typically laborious and requires years of data, public consultation, and legislative requirements. By the time the rules change, the problem—and the fish—will have disappeared.

*In-Fisherman Field Editor Gord Pyzer, Kenora, Ontario, is a former senior manager with the Ontario Ministry of Natural Resources.