The Impact of Odors on Bass

By Ronald F. Dodson, Ph.D.

When we think of fish and how they relate to their environment we should realize they use sensory capabilities that are common to most animals, including man. While the sense of feel is present, to survive in nature a creature is often too close to a predator before this is of any value. However fish do rely on vision, odor detection (smell) and hearing (detection of movement) for survival in their environment. If they are good at adapting these skills, they don't get eaten when they are small and get to be mature and larger fish.
   We enhance the visual appeal of lures by using a wide array of colors. There also has been the addition of sound chambers to increase the noise that baits give off as they come through the water.
   Of more recent vintage, the focus has been increasingly placed on developing additives that actually enhance the odor appeal of lures. The debate about the negative influence of odor on bass was first introduced into my fishing world when a couple of old timers allowed me to tag along on a crappie/bass trip. The explanation of why some folks could catch fish and others couldn't, in the same boat, was explained as a negative odor one guy was putting on the minnow when he handled them. I had realized early on that catfish were very sensitive to odors as a stimulus for feeding but bass or crappie? After all, a minnow was a minnow.
   Then came my formative years as I began to learn about lures and the use of artificial bait in general. A couple of articles appeared in some national outdoor magazines (on which I placed more emphasis than some English assignments in high school) which listed the whole range of things you could get on your hands and thus add a repellant factor to the lure as sensed by the bass. These included gasoline, oil, battery acid (never figured who tested this one with their hand), bug spray, and other associated petrochemical products.
   It was at this point that several things happened in my fishing career that saved me from spending long hours worrying about the impact of odors on lures. The first was that I predominately began to fish crankbaits and the style I used for presentation didn't permit much time for a bass to smell a bait while it passed through the strike zone. The second was learning of the test of odors on crankbait efficiency that occurred in Floyd Mabry's boat. Floyd was a person I enjoyed knowing. His design of crankbaits and the ability to use them are legendary and resulted in his entry into the Texas Fishing Hall of Fame. You need to further appreciate that while he was proving that cranks weren't just for trolling most other bass fishermen in the late 1960's were totally committed worm fishing enthusiasts.

...some chemicals emitted from ground up crayfish, shiners, shad etc. are repulsive to bass.

   The story goes that Floyd was in a school of summertime bass and his young fishing partner would spend time after each cast greasing up his crankbait with some secret recipe. Floyd was catching fish on practically every cast, but the young guy made a terrible mistake of giving the old pro a lecture about the importance of using an odor masker in keeping with what he had read in a recent hunting/fishing magazine. That did it, according to a buddy in an adjacent boat, Floyd quietly took off the lid on his gas tank, slipped the crankbait' into the gas and continued to catch bass.
   Well I wouldn't recommend this as an additive, but it sure must mask any human odor. It also sent a message that the human scent and even a strong odor such as gasoline was not as important on faster fished baits as we have begun to appreciate with slow moving ones.
   In fact the use of odor attractants, feeding stimulus or whatever you call them have been primarily focused as used on jigs, worms and other soft plastics that are fished slowly. The emphasis on additives to soft plastics was taken to a new height when companies began to develop spray on products or enhancers that are incorporated in the product.
   The Berkley folks went a step further than grinding up natural foods and making a solution out of their extracts. For several years Dr. Keith Jones, Director of Fish Research at Berkley has led a team whose focus has been on creating the basis of Power Baits through odor stimuli.
   In essence they have extracted the chemicals in major food sources and worked to determine which are the most effective for stimulating bass. Dr. Jones noted that there are some chemicals emitted from ground up crayfish, shiners, shad, etc. that are repulsive to bass. These are particularly concentrated in some specific organs. Obviously a bass doesn't have a choice when he eats the whole critter, but the logic of the research at Berkley and other companies is to give the bass more of the "good stuff" and eliminate bad odors or flavors.

The older a bass becomes, the larger its olfactory lobe and thus its odor detection capability becomes increased.

   The formulas are constantly being improved to the level that he indicated the present tournament grade strength that is offered has produced a 50% increase in angler success when compared to the effectiveness of the original Power Baits formula on the same lure.
   As a fishing biologist Dr. Jones emphasized the importance of the three senses that orientate a bass to its environment. The final attack by a bass, in most circumstances, is based on vision. Smell, or odor, is used to not only to detect potential food, but also the quality of the food. In other words, there are common features as far as smells from minnows, crawfish, and shad and unique scents emitted from each, which can be used for distinction of the species. Vibration is picked up by the bass and alerts it that something is in the neighborhood. The eyes, "ears" and "nose" on a bass act in concert to define if the thing in its environment is food or a predator.
   A benefit of artificial scents, according to Dr. Jones, is that you can reduce the negative factors and increase the positive stimulation by their presence on a lure.
   Since the greatest impact of odor stimuli to baits is on slow-moving baits I wanted to also get my friend Roy Greer's input. Roy, as you may recall from a Texas Pro article I wrote, is a fishery's biologist by training who left the fisheries management area and began the Weedless Lure Company which is now headquartered at Lake Fork. Roy markets a product called jig Juice as a spray-on additive for lures. His main products are jigs, spoons, and a tail spinner lure (Tail Kicker). He believes in spraying an additive on all three lures. Remember all three are usually fished as slow moving baits that are kept in the strike zone for extended periods of time thus allowing the fish greater time to "smell" the bait.
   Actually, Roy believes any additive serves both to mask human and other odors as well as give off a food appeal.
   The major advantage from his perspective is that fish hold a bait longer and thus this enhances the ability of fisherman to detect strikes. This is not a trivial issue since he is convinced that most folks get five times more strikes than they feel.
   His other argument for the importance of odor is offered in that the older a bass becomes, the larger its olfactory lobe and thus its odor detection capability becomes increased. Temper this further with the fact that older bass have a greater wealth of experiences in distinguishing good and bad odors you get the message that he strongly believes in odor enhancers.
   Bob Murray of Professional Sporting Goods in New Braunfels also discussed his new entry into the market called Bait React. This product, somewhat like the Berkley strategy, was according to Murray the result of work done on the chemical odor emitted from crayfish. Again the same theme was presented in that an attempt was made to emphasize the "appeal" sent out as the slick from the product spread from the lure.
   The message from all those who have developed these products is the same whether using odor enhancers or feeding stimuli, it is very important on slow moving baits.
   Having tried several of the products on the same lure with and without the products I can assure you that they are effective in increasing the number of strikes on slow moving baits.
   If it works for the pros then the additional time the bass holds on to a slow moving lure with these additives certainly can help individuals who may not have as keen a sense of feel to detect more fish.

Scents and Nonsense
Four Offensive Factors
Scents and Attractants: Do They Work?
Fish Attractants: Are They Really Worth It?