Keeping Bass Alive

Why bass die — Initial and 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.

Occasionally, however, fish die during the course of a tournament day. These fish, dead at weigh-in, are referred to as "initial mortalities."

Initial mortality is highly variable. It ranged from zero percent to over 30 percent in 130 live-release tournaments studied since the 1980s. The initial mortality of bass caught in tournaments run by B.A.S.S. has been very good — less than 5 percent. However, B.A.S.S. only operates about 20 events a year. While these large events are nationally publicized, they represent only a small fraction of the tens of thousands of bass tournaments conducted annually across the country.

Universities and state fisheries agencies have conducted studies to determine the survival of bass caught, transported, weighed and released alive after bass tournaments. A Texas Tech University study summarized published reports from 20 separate investigations of 130 individual bass tournaments. That analysis showed that water temperature is the most significant factor related to initial mortality. But other factors — hooking and handling injury, exposure to sustained low dissolved oxygen, temperature shock, toxic chemicals, or chemical shock — can, and do, contribute to initial mortality.

But, initial mortality is only part of the total mortality that bass suffer in tournaments. Some fish, even though they appear active and healthy after weigh-in, die after release. This mortality is called post-release, or delayed, mortality. Delayed mortality was also highly variable among the studied tournaments, ranging from zero to 52 percent.

However, this variability in survival is actually the bright spot! If mortality is low in some events, then it can be improved in all of them. That's exactly what this book is trying to help you achieve.


By following the procedures described in these articles, we believe survival of all bass caught and released in tournaments can consistently be over 90 percent — even under the toughest conditions.



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