By Dr. Hal Schramm

 

In Part I of this feature I provided scientific information that bass can become harder to catch. In the short term, that’s a result of learning. In the long term, it’s a result of genetic changes. Scientifically valid information also suggests that intense fishing pressure can result in bass that are harder to catch. But how does this apply to the “real world?”

Unlike the experimental studies, this analysis uses skilled bass anglers fishing the major lakes and rivers of America. The data are the catches in major tournaments sponsored by Bass Angler Sportsman Society (now B.A.S.S.) from 1972 to the present. Data were analyzed for 4 to 14 tournaments per year over the 41-year time period, a total of 310 events.

The catch rates, measured as the number of bass weighed-in per angler day, are shown below. The catch rates, as you would expect, varied widely within and among years, but a slight upward trend is evident. Statistical analysis (regression, for the scientists and statisticians in the crowd) revealed a statistically significant upward trend that equated to an increase in catch rate of 0.06 bass per angler day per year.
chart
Catch rate measured as weight also increased significantly over the 41-year time span. Weight of bass brought to the scales increased at a rate of 0.2 pounds per angler day per year. The average weight per fish has increased an average of 0.015 pounds per year.

The analysis is imperfect because the tournament formats have changed in several ways that affect estimates of catch rate. The tournaments from 1972 to 1992 had higher limits (7 to 10 bass per day), which might result in greater catch rates. Analyzing only the tournaments with five bass limits, catch rate increased 0.1 bass per angler day per year, a slightly greater rate of increase than when all tournaments were included in the analysis.

My analysis is based solely on catches in major tournaments. At the current level of competition and financial rewards for top finishes, many anglers are fishing for five big bites. This focus on large bass could suppress potential increases in catch rates, so the increase in catch rate may be even higher if all bass were included in the catch.

The obvious conclusion from this analysis of real-world fisheries is that catch rate is increasing, which does not support reduced catchability and the contention that bass are getting harder to catch.

I’ve heard statistics described as lying with numbers. Numbers don’t lie, but statistics have to be interpreted wisely. First, is an increase in catch rate of 0.06 bass per angler day per year meaningful? I leave that to your interpretation, but let me state the result a little differently: If the present rate of increase in catch rate continues, it will take 16 years before the average catch per angler day increases by one bass.

I think it is important to consider this change in the context of how bass fisheries and fishing have changed in 40 years. To do so, we have to look where there are no data, no statistical analyses. I offer four premises with which you can agree or disagree.
bass
Premise 1: Bass abundance and size structure probably have increased. Wisely chosen harvest restrictions, prevalence of catch and release, and evolution of fish-healthy tournament formats and boat livewell systems should result in lower fishing mortality. Greater survival means more and potentially larger bass. Reliable comparison of today’s bass populations with those 30 or 40 years ago isn’t possible because sampling methods have changed, but many of my gray-bearded colleagues would agree that bass populations are as strong or stronger today than 20 or 30 years ago. If bass abundance and size are greater, catch rate should be greater.

Premise 2: Better fishing equipment. Boats, motors, rods, reels, trolling motors are all improved. Sonar has broken the air-water barrier and connected anglers with the fish. Thirty years ago we interpreted orange blips on a flasher and dragged plastic worms and jigs to “see” what was on the bottom and if fish were present. Today, sonar/GPS units allow anglers to run from waypoint to waypoint and use several imaging systems to check out the watery world beneath them without ever making a cast. Now, many anglers don’t even pick up a rod until they see fish on the screen.

Premise 3: Not just new lures, but entirely different types of presentations—such as stickworms, drop shots, bladed jigs, swimbaits, super-deep crankbaits, giant flutter spoons, and umbrella rigs―enter the marketplace every year. If bass learn to avoid lures, as studies have shown, the ever-changing menu of lures presents a steep learning curve for a critter with the brain the size of an 8-ounce slip sinker.

Premise 4: Information. The advent of the professional bass angler and an unprecedented profusion of print and electronic media have put the wisdom of millions of hours of expert angler experience and knowledge at anglers’ fingertips.

My conclusions? Bass in most waters are at least as abundant as they were 50 years ago, and likely they’re bigger on average. Anglers have better equipment for getting to and finding the fish, and the arsenal of lures is massive and ever changing. Anglers are more knowledgeable than ever, with millions of hours of experience right at their fingertips. We should be catching the heck out of them.

But we aren’t, and even top-tier anglers stumble and don’t catch a thing sometimes. I must conclude that bass are, indeed, getting harder to catch.