A fisheries biologist’s perspective
Four decades ago, I used to catch a lot of fish on a little offshore hump in a northern lake. The spot, about 50 feet in diameter, rose to 25 feet from much deeper water. It wasn’t on the paper map for the lake. Despite my efforts to triangulate the location from shore features, I often spent a lot of time searching, eyes glued to my flasher depth finder. When I finally located the hump, I’d toss a fishing marker off one side of it.
Now, each morning when I start my boat, three powerful computers (in addition to the one in the outboard motor) spring to life. The unit in the console monitors depth and provides a map showing one-foot depth contours, boat position, and waypoints marking desirable fishing spots. This unit will be used later in the day in side-scan and high-resolution down-scan modes to search for underwater cover and maybe fish. When I drop the trolling motor, one unit on the bow displays a map showing depth contours and objects above the bottom below the trolling motor; the other bow unit displays depth and objects on and above the bottom in a narrow field 80 feet directly in front of the trolling motor. I’m guessing some readers will think, “sounds like my boat.” Many anglers insist this is too much, reduces the challenge of catching fish, or is unsportsmanlike. Other anglers tout the benefits of adding more electronics. Diversity is good. Debate is healthy.
Fishing electronics
While Garmin Panoptix LiveScope and other forward-looking, real-time sonars appear to be drawing the fire right now, this and other sonar technologies are only the tip of the iceberg of anglers’ use, investment, and — maybe — addiction to a long list of electronic options.
We now take GPS and high-resolution bathymetric lake maps for granted. They certainly help keep me away from shallow-water hazards and identify potential fish-holding structure. When linked to my side-scan and forward-looking sonars, I can mark waypoints on fish or interesting habitat features without passing over them. And a SteadyCast sensor plus my GPS allows me to know the bearing and distance to that waypoint relative to the bow of my boat and make a pinpoint cast.
But there is a downside to the GPS and hi-res mapping: anybody that rides by can easily figure out what you are fishing. Even put a waypoint on it. That tiny hump in the northern lake that I often spent so much time locating? It’s on the GPS map if you zoom in, and I’ve marked it with several waypoints. Unfortunately, the spot hasn’t produced fish the last four or five times I fished it. Maybe that’s because a lot of anglers also have waypoints on my “secret” hump.
But the electronics revolution is more than LiveScope, sidescan, and GPS. Underwater cameras like AquaVu are hardly new technology; but they still get a lot of use, particularly in clear-water northern fisheries. Wait until they attach them to underwater drones.
Don’t overlook the obvious. Computers and smartphones, although now common, can be used in many ways — from weather forecasts to fishing reports to how-to videos — to improve your fishing efficiency and increase your catch.
Biological effects
Recreational fishing is size selective mortality. In harvest fisheries, like crappies, successful anglers often cull to harvest the greatest weight of legal-length fish. Some bass anglers select lures or fishing locations to increase the size caught. Most bass anglers release most or all of the fish they catch, but a low rate of mortality accompanies catch-and-release fishing whether the fish are released immediately or retained for weigh in in a tournament. Catfish anglers are somewhere between crappie and bass anglers.
Electronic devices can greatly increase the size selectivity. With heavy fishing effort, this size selectivity could reduce the numbers of large fish in a fishery. The extent to which that occurs depends on what the angler does with fish after capture, and that is completely independent of electronic technology.
Hyperstability is a fisheries term that refers to a situation of continued high catches due to greater fishing efficiency that masks a decline in fish stocks. This term originated in marine commercial fisheries where the health of a fish stock is often judged by the commercial landings: good catches imply a healthy fishery, declining catches indicate a stock in trouble.
But hyperstability equally applies to recreational fishing. And more specifically, sustaining high catch — whether measured by fish size or fish per hour — by increasing fishing efficiency specifically zooms in on fishing electronics. The potential adverse effects are even greater when the technology increases the catch of larger fish that have a greater spawning potential.
Advanced fishing sonar and other fishing electronics are no more likely to be banned than the use of cell phones. However, avoiding the potential adverse effects of increased catch and size selectivity that can result from these technologies will require greater vigilance by fisheries management agencies to ensure the abundance and favorable size structures of our fisheries remain intact.
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