Every good freshwater fisherman knows that the better he or she understand his quarry and its environment the better the chances of fooling the fish to strike at what appears to be food.
For Largemouth Bass in particular, their sense of smell is highly developed. In fact the commercialization of million dollar Bass fishing tournaments has led to leading scientific breakthroughs in the understanding of how well Largemouth Bass can smell and sense chemicals in the water and how they react to these smells.
Recently, Dr. John Caprio of Louisiana State University measured the nervous response of bass to a variety of amino acids; the amino acids L-arginine and L-Lysine were especially potent. Funnily enough theses two amino acids are potently present in baitfish; furthermore Dr. Caprio also showed that bass can sense a dilution of four ounces of L-arginine mixed with 6,000 gallons of water.
Dr. Caprio’s research has found that when bass encounter the smell of something they believe to be food, they go through four stages.
- Arousal: bass detects the smell of something that they perceive to be food.
- Search, the bass attempts to find the object.
- Analyze: the Bass analyzes the object with its eyes,
- Taste: and the final the taste test.
Among many of Dr. Caprio’s findings are what smells and chemicals Bass find repulsive which may prevent you from making your catch.
One of the top chemicals which repel Bass is a chemical called L-Serine which is a amino acid secreted by human skin, other serious offenders are DEET which is most prevalent in insect repellents.
Dr. Caprio has found that Bass can detect levels of DEET and L-Serine as low as 1 part per million in the water. Other bass-offending substances commonly used by anglers include many food and lotion preservatives, especially derived from benzene which forms the active ingredient of many sunscreens.
So it goes without saying, be careful what you put on your hands before you handle your freshwater fishing lures or set live baits, because many fish species can literally smell you coming!