Similar scenes unfold daily along the Emerald Coast every time a surf angler casts out a pompano rig for the first time. Confidence is low that an inch-long piece of what looks like “dried bubble gum” will catch one of the most prized game fish on the beach. But they stick to the program as recommended, and after a short wait, get a bite and land their intended quarry. Shaking their head no longer in disbelief, but in wonder how that fish found his tiny artificial offering. Can fish smell bait, underwater?
Can Fish Smell Underwater?
The question begs not so much a matter of “IF” fish can smell underwater, but rather “HOW”.
Olfaction, as scientists refer to the sense of smell, includes the ability of fish to detect odorants dissolved in the water around them. In many fish, water enters and exits through openings called “nares,” which look much like nostrils and direct water across specialized olfactory tissue. Sensory cells then send information about those dissolved chemicals to the brain.
Water is the medium exposed to sensory nerve packs where scent stimuli are collected by these organs and transported via nerve cells to the nearby brain to be interpreted.
For fish, this may even be a matter of life or death. Odors may not only determine where prey items are, but they are being consumed by members of their own species and even when members of their own (or similar) species are being preyed upon by larger predators.
Some fish can also detect chemical alarm cues released when another fish is injured. These cues have traditionally been called “Schreckstoff,” a German term meaning “fright substance.” When detected by nearby fish, these chemicals can trigger behaviors such as darting, hiding, schooling or freezing. Research continues to reveal just how complex these alarm cues can be, with multiple chemical compounds potentially working together to produce the response.
The configuration of olfactory sensors in the head of each fish species is a key to how they feed and protect themselves. Some fish species have even evolved with extra sensory organs called “barbels,” from the Latin ‘barbula‘ meaning “little beard”. These slender whisker-like appendages are most often near the mouth, thus thought to aid the fish in finding food in low visibility conditions like poor light or high turbidity.
They are most often associated with various fresh and saltwater catfish species which have eight barbels. Members of the king croaker species in the family Sciaenidae may exhibit only one barbel, while black drum in the same family may have 12 or 13. Still, barbels are more than simple feelers. They contain numerous sensory receptors, including taste buds, that help fish locate and evaluate food in low visibility. Combined with the fish’s sense of smell and other sensory systems, they provide another way to detect what is happening in the surrounding water.
Fish’s senses are so keen they may detect not only food, but through pheromones find potential mates, or sense hazards nearby in the day or night. Fish use a combination of senses to detect changes in their environment. Their olfactory system is particularly sensitive to dissolved chemical cues, while other sensory systems help them respond to factors such as temperature, water movement and changing environmental conditions.
The migration of salmon to the sea and back to spawn in the very same stream where they were hatched is well documented. Similarly, many saltwater species return yearly to spawn in the same waters, perhaps over the same reefs where they themselves were born.
Effect Of Temperature
Environmental variables may well affect the ability of fish to smell. Being cold-blooded vertebrates, fish are well aware of changes in the water temperature (as well as dissolved oxygen and many other less obvious trace elements) surrounding them.
Each species has a limited range of tolerance to the environment and their metabolism must adjust constantly to any of these changes in order to survive and propagate. If these changes occur faster than their metabolism can adjust, the fish goes into shock or may even die.
Fish also have a preferred range of temperature where most feeding and reproduction takes place. While there may be variations in the rate of chemical distribution through water due to temperature, there are certainly more profound changes in the metabolism of fish to sensory process the water itself simply because there is less need to. While temperature can affect how chemicals disperse through water, changing water temperatures also have a major effect on a fish’s metabolism and feeding activity. When metabolism slows, fish may feed less aggressively, regardless of how well they can detect food.
Fishbites = Gamechanger
After decades of research into fish feeding behavior, renowned marine biologist Dr. William “Bill” Carr developed the science that eventually led to Fishbites. Carr’s research helped show why so-called “stink baits” do not necessarily attract fish simply because they smell strong to humans. After several decades of research into fish feeding behavior, Dr. Carr’s study led to the invention of Fishbites.
These concentrated, artificially replicated natural odorants literally attract and stimulate fish to feed. Since then over 160 of these flavored scent baits and rigs have been developed and used successfully worldwide.
Here in our quiet little corner of the globe, these products have revolutionized the ease and reach of surf fishermen by providing a durable product that consistently produces fish.
Matthew Isbell, former coastal surf guide and successful videographer, better known as the “Bama Beach Bum” spoke a bit about Fishbites’ impact on the sport stating “I just don’t see how surf fishermen can be successful, or were as successful without it. What did everyone do before it was invented?”
Indeed, anglers had to (and still do) use strips and pieces of cut bait (like fish, shrimp, or squid) that were subject to spoilage and “washing out”. Hardly the durable and long-lasting non-refrigerated offerings we know and love now.
The Fishbites lineup now extends well beyond the scented strips and chunks commonly used for surf fishing. The company offers baits for surf, inshore, offshore and freshwater fishing, along with Fight Club soft plastics for species such as speckled trout, redfish and flounder.
Often anglers have observed fish “shoppin”’ their lures, where there is a distinct curiosity in the action, but a lack of commitment to try and eat it. Perhaps smell is the final key that initiates this desired effect. How many times have you been in a situation of seeing multiple fish that act interested, yet reluctant to bite your offering?
That is until the feeding activity of a single individual begins a frenzy. What happened in the water after that first fish stirred to action? Scent is often that unseen trigger that gets other fish to bite.
