Here’s a very, very important illustration, which shows how we spook the heck out of fish with our boats.
This is a representation of a fish’s lateral line. As you can see in the blow-up box, each of the tiny dots you see on a fish’s flanks, which make up its lateral line, has a delicate sensory cell. And all of those cells are connected, via the lateral line canal. This explains how fish can detect tiny changes in water pressure, as they’re struck by pressure waves. Another fish swimming by, a rock falling into the water, and a boat are all examples of things that can cause such pressure waves.
Of course, you already knew it was possible to spook fish, either with your boat or otherwise. You’ve probably seen a bass become startled when a lure plopped down too close to it, or a redfish dart away when you slammed a hatch on your boat. What many of us fail to realize is just how sensitive that lateral line is, and just how easy it is for us to spook those fish.
Let’s say, for example, you drop a one-ounce lead weight in the bottom of your boat. Can a near-by fish really hear a noise like that? Without a doubt. And while it may not flee in terror, it might raise its guard and decide not to strike your lure, too.
The bottom line? Fish can “hear” (sense) a lot more than we think they can. And everything from that falling weight to a running engine to a pinging fishfinder can add to their discomfort level, turning a feeding fish into one with lock-jaw. So the next time you approach a hot-spot, remember to keep the sounds levels low and evade the effects of that lateral line.