What Can Bass Smell- Fish Tales
Anglers are constantly bombarded with ads from the internet, sportsman shows, magazines and television from bait companies claiming to have the newest hot bait that will catch more bass. My goal is to help you filter out fact from opinion so you don’t end up with a garage full of baits that don't work and you won’t use. Let’s first define a fact and an opinion. Dictionary.com defines a fact as “something that actually exists; reality; truth; something known to exist or to have happened.” Dictionary.com defines opinion as “a belief or judgment that rests on grounds insufficient to produce complete certainty”. In order to determine fact vs. opinion in the bass fishing world, I decided to research some “fish tales” I have heard over the years. I wanted to know if there were any scientific findings that proved these “fish tales” to be true and if so, where did the research come from? Specifically, I wanted to know if fish attractants are effective and if so, how and why? If largemouth smell various scents (including human scent) transferred from our hands to our baits and if they can, does it deter them from biting the affected bait? Along with smell, I wanted to find out how taste and sight affects a bass’ feeding behavior. And lastly, hearing and vibrations; dose noise adversely affect a bass and what noises might stimulate a bass? These are topics I cover later in upcoming 'fish tales' articles.
In this article I will share with you published scientific research, or lack thereof, about attractants, how they attract bass and if non-prey scents (human, lotion, gas, etc.) act as a deterrent.
In order to discuss which scents attract or deter a bass, we need to understand the anatomy and function of a largemouth’s nostril. Largemouth bass have two sets of small nostrils on either side of their head where water flows in thru the front set and exits the rear set. Water moves across a folded membrane (olfactory rosette) that contains thousands of chemoreceptor cells that detect waterborne biological or chemical scent molecules. Once these receptor cells detect a scent, they send a signal to the brain where the brain interprets the signal. After the signal is interpreted, the bass then can determine the scent present and a course of action if necessary. A largemouth’s nostrils differ from humans in that their nasal passage is not connected to their throat, so scent and taste are two completely separate senses; also, their nostrils are not used for breathing. Bass use their sense of smell to detect prey, find a mate and detect pollutants. They can smell the presence of pheromones, sugar, salt, alcohol, amino acids, and bitter substances. Because bass can only detect biological or chemical scents that are water soluble and in molecular form, any attractant or stimulant that is oil based will not be perceived since oil is insoluble in water and the attractant molecules are too large. Also, the chemoreceptor can only detect scent molecules that are the same size or smaller than the receptor itself.
Now that we have reviewed the anatomy and function of a largemouth’s nostril, let’s talk about the scientific research regarding its sense of smell in relation to fish attractants. I began my search via the internet using basic search engines like Google and Yahoo. I found numerous articles about attractants on various web sites written by fisherman just like us. The issue I had with the information provided was that it contradicted other articles I had read on the same subject; and the information supplied as fact, did not contain any cited references for me to verify. Since my initial research did not reveal the information I was seeking, I looked to scientific search engines such as Microsoft Academic Search, Google Scholar and Scirus which include over 10 million academic published research papers. I looked for any research that related to largemouth bass, a largemouth’s sense of smell and fish attractants designed for largemouth bass. I browsed hundreds of topics and was unable to locate published research relating to this specific topic. Upon further research I found that most bait companies have their own independent research staff and keep their findings proprietary. I made note of this when I reviewed some of the bait company’s patent documents via the U.S. patent website and in reading the marketing material provided by bait manufactures. The fish attractant industry is a highly competitive multibillion-dollar trade so a bait company sharing any of their research with the public is highly unlikely. I did locate two doctors who specialize in the field of fish olfaction and taste; details of some interesting facts they discovered from their studies are below.
Dr. Jones is the director of fish research at Pure Fishing/Berkley Baits and the author of “Knowing Bass: The Scientific Approach to Catching More Fish.” His book covers the science of how bass use their senses to feed, how they relate to fishing lures and how they interact with anglers. Dr. Jones has also written numerous articles regarding general bass behavior that are posted on Berkleybaits.com. Some interesting facts that Dr. Jones noted are: 1. Presently, there is no evidence linking bass repulsion with human odor. 2. Detergents and soaps are offensive scents to bass. 3. The chemical DEET repels just about everything that swims, bass will reject a bait with the chemical on it and contamination of the hands can last up to 90 minutes after application. 4. That many food and lotion preservatives (specifically Benzene) have a scent that is offensive to bass. 5. That neither gas nor oil is repulsive to bass as bait dipped directly in both and presented was eaten with no apparent side effects. Another fact to note from Dr. Jones is that oil attractants are not water-soluble so bass can’t smell them nor are they good flavor carriers due to oil’s composition.
Dr. Caprio has a PhD in fish olfaction and taste, is on the Mystic Tackleworks scientific team, has helped develop the Bio-Pulse System, Attraxx Baits and Sci-X Feeding Stimulant. I communicated via email with Dr. Caprio and found that he did not have any published research regarding the sense of smell and/or attractants regarding to largemouth bass. Even though he did not have any specific studies regarding these topics, I was able to obtain some valuable information about how bass use their senses to hunt. Dr. Caprio stated that the smell of prey, or some appropriate lure that emits the correct biological scent, will make a bass become more alert but it won’t make it attack the source of the scent unless it is moving. The largemouth’s primary senses for hunting are its sight and lateral line which help in the detection of movement. Once a bass attacks a lure and it is ingested, the bass quickly determines both the lures feel and its taste. If both are not appropriate, the bass can spit out the lure before the angler even knows that the bass was on the end of his line.
I also spoke briefly with Phil at Pro-Cure Bait Scents. Pro-Cure has been making scents from fresh whole bait since 1991 and its products target salt water, river and fresh water species. Their products include bait gels, bait dyes, UV enhancers, egg cures and many more. Here is what I learned about Pro-Cure from Phil: their gel based products do leave a scent trail and its’ dispersement rate is controlled by water temperature and retrieve speed. Pro-Cure uses field studies from guides, tournament fisherman, charter captains and their employees to verify that their products help catch fish. Their Super Gel has a shelf life of approximately three years and if it gets on your boat, a little 409 should clean up the spill. Phil also said that Pro-Cure doesn’t make outrageous claims regarding their products but that in the hands of a competent angler, scent is a missing part of the fish catching puzzle.
In closing, I have come to the following conclusions regarding the uses and benefits of fish attractants. First, in order for a fish attractant to actually be labeled as an attractant it must be water soluble and emit molecules of scent that are small enough to be detected by the largemouth’s receptors. If the attractant fits these parameters it may help attract a bass, provide some flavor when ingested and possibly provide some additional holding time for an angler to get a good hook set. In order for a bait to hold a fish attractant and release it slowly, the bait must be porous or have a holding cavity of some sort in order for the attractant to be released at a slow rate. If the bait is not porous or have a holding cavity, the attractant applied must be formulated to stick to the lure and release slowly during the retrieve. Otherwise, once the bait hits the water the attractant will quickly dissolve before a bass even gets a chance to smell it. Secondly, since oil is not soluble in water, oil based fish attractants are not fish attractants at all but rather act as masking agents. One possible benefit of a masking agent is to cover any repulsive scent that the angler may have transferred onto the bait. These oil based products can also be used as a lubricant on swim baits. Many swim bait aficionados lubricate their swim baits so it slides easily in the largemouth’s mouth once ingested in hopes of obtaining a good hook set. Thirdly, due to the lack of any published independent research proving an attractant’s effectiveness, we have to rely on the bait manufactures proprietary research and claims and our own experience out on the water with these products.
I hope I have provided you with some insight regarding largemouth’s sense of smell and its function, the anatomy of its nostrils, and the difference between an attractant and a masking agent. I also hope I have given you useful information about the possible benefits and practical uses for these products in order to help you catch more fish. Until next time, stay focused, fish hard and I’ll see you out on the water.
References
1 Dr. Keith Jones. (2002). “Knowing Bass- The Scientific Approach to Catching More Fish.” Gilford, CT: The Lyons Press
2 Larry Larsen. (1989). “Bass Fishing Facts- An Angler’s Guide To Bass Lifestyles And Behavior.” Lakeland, FL: Larsen’s Outdoor Publishing
3 Unknown Author. (September 16, 1986). Porous Polymers. United States Patent. Retrieved 1/25/2011, from
4 Dr. Keith Jones. (July 1, 2009). Perfume to Some, Odors to Others. Berkley. Retrieved January 25, 2011, from http://www.berkley-fishing.com/my-berkley/angler-education/perfume-some-odor-others
5 Dr. Keith Jones. (October 1, 2009). Fish Attractants: Leave The Oil at Home. Berkley. Retrieved January 25, 2011, from http://www.berkley-fishing.com/my-berkley/angler-education/fish-attractants-leave-oil-home