Spring. The water has warmed to 62 degrees in shallow coves and pockets. Time for bass to start bedding. And time for the annually recurring debate about bed fishing.
What biologists know
The male bass fans out an area to expose clean, hard bottom. He owns that piece of bottom, and vigorously defends it against intruders. He lures ready-to-spawn females to his sacred nest, and then stimulates them to deposit eggs. The eggs are quickly fertilized, and the buck spends the next three to four days fanning the eggs to keep them free of silt and well supplied with oxygen while guarding them from a long list of nest-marauding insects, crayfish and fish.
It is, indeed, an interesting time of the year when the bass’s prey becomes its predator.
The recently hatched fry stay in the nest for the next eight days, and the guarding male continues his vigilant patrol.
When a bass is caught and removed from the nest, the eggs or fry usually perish. Untended eggs are quick to suffocate or are eaten by predators. Unattended fry, too, are an easy meal for a variety of fish, even fish that normally feed only on small invertebrates.
Nest-guarding bass caught and immediately released return to their nests and resume their guardian duties. But “immediate release” means different things to different anglers.
The longer a bass is exposed to air, the slower the bass is to return to the nest. Also, a bass played for a longer time is slower to return to the nest. The longer a nest is untended, the more eggs are lost to nest predators.
The guarding male’s instinctive obsession to tend the nest dwindles as the egg mass is reduced. At some point, egg predators remove enough eggs that the bass may abandon the nest, even though some eggs still remain. Somehow the bass is able to determine that the number of eggs has been reduced, and several studies have found that egg depredation was the most significant factor determining nest abandonment.
Bass caught and displaced from the nest will return to the nest, but bass released farther from the nest take longer to return. In a study on bass nesting behavior we did years ago in Florida, a radio-tagged, nesting male was caught in a tournament and weighed in. Within 48 hours, the bass was back on its bed. The nest was 3 miles from the weigh-in site.
Unfortunately, returning to the nest hours later may not be important if nest predators have already eaten most of the eggs.
The grand prize
All the research presented above is about the effect of catch and release on the nest guardian — the male bass. The prize from bed fishing is not the buck bass, but the big female. Research specifically on female bass is limited.
A colleague in Florida surgically implanted radio transmitters in female bass, and then tracked them to spawning sites. The bass spawned several weeks after the operation.
On the other hand, pre-spawn bass caught and subjected to conditions that simulated live-release tournaments spawned but produced smaller offspring that hatched later than undisturbed fish.
Results from several studies show that capture and handling cause stress responses in fish, but similar responses also occur with intense swimming activity, such as might occur when bass are crashing a school of shad. More studies are needed to determine if angling stress affects reproductive output.
You be the judge
Summing up, catching a bedding bass, immediately unhooking it, preferably without taking the fish out of the water, and immediately releasing usually has little or no effect on nest success.
But the longer a nest-guarding bass is kept off a nest, the less likely it is that the nest will produce bass fry. It is clear that bed fishing may reduce the number of successful bass nests and the number of fry produced each spring.
But is this bad? More successful nests means more bass produced, but it also means more competition among the young bass, slower growth and higher mortality.
I know of no large, public waters in Mississippi, or throughout the southeast, where bass reproduction limits recruitment. A single bass nest may contain 20,000 or more eggs. It takes only a few successful bass nests per 5 or 10 acres of water to produce a good year class unless adverse environmental conditions intervene.
On the other hand, intense bed fishing with harvest or poor fish handling may have drastically different effects.
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