Catch-and-Release Bass Mortality

[SKollmann]

Results of conservation research study that appeared in the lastest edition of In-Fisherman.

 

Many studies have examined mortality associated with catch-and-release bass fishing, but not all have been well controlled . . . and results have been variable. A recent study in Texas adds data to the discussion.

 

Researchers housed bass caught by electofishing in holding tanks at water temperatures between 45 degrees and 81 degrees. After the acclimation period, fish were netted and a 2/0 hook imbedded by hand in the jaw, gills, or esophagus. Bass were then played on a medium-action rod until they could easily be grasped by their lower jaw. After unhooking, they were returned to holding tanks and observed for three (3) days to check survival.

 

In this experiment, hooking location affected survival while handling time, playing time, and water temperature did not. Combining the results of this and a previous study into a model of survival, the researches predicted that at temperatures between 45 degrees and 81 degrees, 98% of jaw-hooked bass survive, while survival drops to 55% for fish hooked in the esophagus. When fish died after release, it was typically within three (3) hours. Only among fish hooked in the esophagus did significant mortality occur later.

 

The authors report that an average of 72% of tournament-caught bass survive based on a collection of studies. Survival in these events is inversely related to water temperature. The study shows, however, that a broad range of water temperatures had no effect on survival of immediately released bass. The relationship between survival and water temperatures in tournaments is likely attributable to other stressors, such as prolonged confinement in livewells, oxygen deficiencies, and handling during the weigh-in.

[Mike Clifford]

Results of conservation research study that appeared in the lastest edition of In-Fisherman.

 

Many studies have examined mortality associated with catch-and-release bass fishing, but not all have been well controlled . . . and results have been variable. A recent study in Texas adds data to the discussion.

 

Researchers housed bass caught by electofishing in holding tanks at water temperatures between 45 degrees and 81 degrees. After the acclimation period, fish were netted and a 2/0 hook imbedded by hand in the jaw, gills, or esophagus. Bass were then played on a medium-action rod until they could easily be grasped by their lower jaw. After unhooking, they were returned to holding tanks and observed for three (3) days to check survival.

 

In this experiment, hooking location affected survival while handling time, playing time, and water temperature did not. Combining the results of this and a previous study into a model of survival, the researches predicted that at temperatures between 45 degrees and 81 degrees, 98% of jaw-hooked bass survive, while survival drops to 55% for fish hooked in the esophagus. When fish died after release, it was typically within three (3) hours. Only among fish hooked in the esophagus did significant mortality occur later.

 

The authors report that an average of 72% of tournament-caught bass survive based on a collection of studies. Survival in these events is inversely related to water temperature. The study shows, however, that a broad range of water temperatures had no effect on survival of immediately released bass. The relationship between survival and water temperatures in tournaments is likely attributable to other stressors, such as prolonged confinement in livewells, oxygen deficiencies, and handling during the weigh-in.

 

That's why I have a major problem with tournaments in IL river systems, especially if they are held in the spring.

They get exemptions from the C&R mandate in IL, while nobody else is allowed to keep and kill.

So essentially, they can pull smallies off their beds, tote them around in the boat, handle them a few times and drop them far from their original spawning location.

...and 28% are going to die in addition to this?

 

The IL, Miss., Wabash and Ohio can sustain that kind of pressure and are not included in the spring release mandate.

Already imperiled flows like the Kankakee cannot sustain more damage, period.

 

We held a conservation event on the Kankakee not long ago, and I was happy to persuade a guy to release a smallmouth as it was still in the C&R season.

Then I learn from a CPO (who was none too happy about what he was telling me) that a group had acquired an exemption for a tournie.

The guy with one smallie in his bucket was such an insignificant event after putting the rest of it into perspective.

Thanks for the article, Steve.