Keeping Bass Alive – Initial & Delayed Mortality

One of the things that make black bass such great fish for tournament angling is the fact that they can be "recycled." That is, they are hardy fish that can be caught, weighed in, released and caught again at a later date.

One of the things that make black bass such great fish for tournament angling is the fact that they can be “recycled.” That is, they are hardy fish that can be caught, held in a livewell, weighed in, released and caught again a later day.

We know that some bass do die as a result of being caught in tournaments. You will see all kinds of numbers thrown out from study after study, some estimating that as many as half the bass caught in tournaments may die. But just what do those numbers really mean – and do they really matter?

Biologists refer to bass that are brought dead to weigh-in as “initial mortalities.” Initial mortality can be highly variable. In studies going back to the 1970s, summarized by researchers at Texas Tech University, it ranged from zero percent to over 30 percent of the day’s catch. That analysis showed that water temperature in the body of water where the fish were caught was the most significant factor related to initial mortality. Other factors such as hooking and handling injury, exposure to sustained low dissolved oxygen, temperature shock, etc., also contributed. Initial mortality in the more than 40 tournaments operated by B.A.S.S. each year is typically less than 5 percent.

We also know that initial mortality is only part of the equation. Some fish, even though they appear healthy at weigh-in, may die some time after release. This is called “delayed mortality.” Delayed mortality is seldom seen by the tournament angler since it occurs hours or days after the tournament. It can also be highly variable but again, water temperature has been shown to be the most critical factor. If fish are not cared for properly in the livewell and at weigh-in, delayed mortality can be even greater than initial mortality. 

But does tournament mortality really have an impact on bass populations? On the quality of bass fishing? We know that some fish may die as a result of tournaments, but overall those fish make up a very, very small portion of any bass population. For the 50+ years that bass tournaments have been around, there is no evidence that these losses are having a significant impact on our fisheries. In fact, recent studies have found that tournament-related mortality from traditional weigh-in formats comprised less than six percent of overall bass population losses in a given year. Far more bass die of natural causes each year than because of mortality resulting from all types of fishing — tournaments, catch-and-release or people harvesting fish to eat.

Boat livewells, aeration equipment, weigh-in procedures and especially angler awareness and knowledge have improved and evolved in the last decade to a point where the impacts of bass tournaments are not a significant concern to state fishery managers. Agency administrators rank impacts from bass tournaments very low even though the number of tournaments being held each year has increased substantially. The low level of agency concern reflects research that consistently demonstrates negligible population-level impacts of black bass tournaments.

If anglers and tournament organizers will follow the scientifically tested and proven fish-care procedures described in the publication Keeping Bass Alive, long-term survival of bass caught and released in any tournament can be consistently high, even under the toughest conditions…ensuring that we will be able to enjoy the sport for years to come.