Bits & Pieces: Can Bass See Line?

From the Field: Can Bass See Line?

Some years ago a classic experiment proved once and for all that largemouth bass could see line. The fish were conditioned by training them to eat food attached to one color (clear, yellow, or fluorescent blue) 8-pound-test monofilament, while shocked into avoiding identical food on lines of the other colors. Although avoidance of the clear line was less easily/rapidly learned by the young adult bass tested, all bass learned to avoid negative lines and select food from the positive-conditioning line. The tests were made before flourocarbon line became common. More on that in a moment.

Does this mean that bass won’t bite if they see line? No, it means they can learn to avoid lines if they have a chance. Fish killed and creeled the first time they bite have no chance. Those that are caught and released have a chance to associate the line with the being-caught experience, presumably negative. Thus, bass in lakes with intense catch-and-release practices by volunteers or under slot limits that force release are more likely to become line wary.

Does every released bass learn to avoid lines? No. For conditioning to take place, the bass must directly associate the line with the negative experience. The association must be instantaneous, and the many different stimuli associated with being hooked, then pulled, reeled in, and landed (perhaps netted then lipped), hook removal (perhaps photos were taken) and rough release create a series of negative events, many of which are far removed from the initial “bite on a possibly edible item with line attached” perceptions. It likely is hard for individual bass to learn what particular thing to fear.

But, bass do become harder to catch after exposure to angling. Several studies have shown 70 percent of the naive bass in small, never-fished waters can easily be caught in about 14 days of fishing by one or two anglers. Naive bass can be caught using rope! But, modern lakes contain many bass that have been caught and released several times. Whatever specifics they may have learned to avoid, some bass appear to have acquired a general sense of caution, inspiring them to strike less immediately and to more closely examine lures. These bass are more likely to react to lines, non-natural colors, boat noises, lure splashes, or any other unnatural sensory perception associated with anglers. 

And then, as mentioned earlier, there’s the topic of fluorocarbon, which is billed as being nearly invisible to fish because of its high refractive index. We have one unpublished study from Berkley Fishing scientists (Dr. Keith Jones) in which equal numbers of nylon monofilament and fluorocarbon lines were hung vertically in a raceway tank, with each of the lines attached to an electronic sensor. Randomly roaming bass were much more likely to run into the fluorocarbon than the monofilament, proving that fluorocarbon was indeed more difficult for bass to see.

In the extreme, trout in some heavily fished catch-and-release-only rivers have apparently learned to relax and stop fighting in anticipation that the angler will release them. And they are usually caught using very light tippets—2-pound test or less. Still, some bite, so the line/leader connection isn’t their most critical perception factor.

Personally, I use as light a line as possible, line with color matching water color, and fluorocarbon leaders. I’ve been beaten in my boat by better anglers using heavier line. It’s just one of many factors influencing catch rate.

-Ralph Manns

In the Mail: Fishing Lure Stamps

In March of this year, the U.S. Postal Service (USPS) dedicated Freshwater Fishing Lures stamps at Johnny Morris’ Wonders of Wildlife National Museum and Aquarium in Springfield, Missouri. The stamps showcase five popular lure designs (crankbait, spoon, in-line spinner, and wakebait and popper topwaters) through striking close-up photographs. According to the USPS, each has a unique history and has played a significant role in fishing. From the earliest handmade wooden lures to swimbaits made of modern materials, there are countless freshwater lures available, each designed to meet the specific needs of the angler.

“With these stamps, the Postal Service celebrates the beauty and ingenuity behind some of America’s most successful lures,” says John DiPeri, USPS Western Region vice president. “As our design team would tell you, fitting subjects in such a tiny frame is no small feat. However, with their miniature size and design flourishes, fishing lures make ideal stamp subjects. Fish find each of these designs irresistible, and we think you will too.” Greg Breeding, an art director for USPS, designed the stamps using original photographs by Sarah Cramer Shields.

Funding for Fish: Sport Fish Restoration—75 Years

The Sport Fish Restoration Program celebrates its 75th anniversary this year. The program was created in 1950 with the passing of the Federal Aid in Sport Fish Restoration Act (also known as the Dingell-Johnson Act). Modeled after the Wildlife Restoration Act of 1937, the Sport Fish Restoration Act dedicated permanent funding for fishery conservation. The original Dingell-Johnson Act was funded through a 10 percent manufacturer excise tax on fishing tackle, rods, and reels. In 1984, the Wallop-Breaux Amendment expanded revenue by extending taxes on fishing equipment such as fish finders, trolling motors, and recuperating a portion of taxes levied on motorboat fuels.

The Sport Fish Restoration Program provides funding to U.S. states, the District of Columbia, and U.S. territories for fishery projects, boating access, and aquatic education. According to the U.S. Fish and Wildlife Service (USFWS), which oversees the program, fund apportionments are formulated on 40 percent of a state’s size in square miles and 60 percent on the number of fishing licenses sold. No state or territory receives more than 5 percent, nor less that one to one-half of one percent of the total funds available nationally.

Since the Act was passed, it has generated over $11 billion for the conservation and restoration of sportfish and their habitats, boating access, and aquatic resources education, the USFWS reports. To see a full list of 2025 apportionments by state and territory visit fws.gov/program/sport-fish-restoration.

-In-Fisherman

From the Archives: Crappie Size and Catchability

Anglers are best at catching middle-size crappies, according to a tagging study in three states by researchers at Mississippi State University.* Dr. Steve Miranda and Brian Dorr tagged about 3,000 black crappies and a similar number of whites, ranging from 8 to 16 inches, in five bodies of water.

Tag returns from anglers showed the lowest catch rate for small fish of both species, gradually increasing from 8 to 12 inches, with catchability declining for the biggest crappies. Crappies from 10 to 13 inches were most likely to be caught. Small white crappies were particularly elusive and the largest black crappies also evaded anglers. Fishing tackle and method, and differences in behavior and habitat among different sizes apparently affected catch rates.

For fishery managers, the results provide information for setting length limits. To cut harvest substantially, a protected slot-length limit of 10 to 13 inches should be effective, while a length limit of 10 inches may be ineffective, at least in the region studied.

-Steve Quinn

*Miranda, L. E., and B. S. Dorr. 2000. Size selectivity of ­crappie angling. N. Am. J. Fish. Mgmt. 20:706-710.

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