Hundreds of bass tournaments are held each year on Mississippi lakes, reservoirs and rivers, and some anglers attribute declines in bass populations to tournaments. The "tournament issue" is neither new nor restricted to Mississippi.

The effects of tournaments on bass populations have been hotly debated by anglers and biologists for more than 40 years. Live-release tournament formats alleviated some, but definitely not all, of the concern about tournament impacts. Several population modeling studies of live-release tournaments had minimal effects on the number of bass unless tournament angler catch approximated the number of bass in the population, a level of tournament fishing far greater than occurs even on the most popular tournament waters.

However, anglers, whether fishing tournaments or not, can affect the size structure of bass populations by reducing the number and proportions of larger fish.

Although catches in bass tournaments on Mississippi waters do not reach the level that modeling studies predict will affect the number of bass, tournament effort is still substantial, particularly on smaller and heavily fished waters, such as the navigation pools on the Tenn-Tom Waterway.

The results of a recent study at Sam Rayburn Reservoir, Texas, may be applicable to some of Mississippi's intensively fished waters. This landmark effort by Texas Parks and Wildlife Department biologists began with an armada of electrofishing boats collecting and tagging more than 6,000 adult largemouth bass during a three-night shocking blitz in October. They then conducted on-water creel surveys throughout the year to record the number of tagged bass caught and estimate exploitation, the proportion of the bass population removed.

Anglers interviewed during the creel surveys were partitioned into one of three groups: harvest-oriented anglers, tournament anglers who retained fish to be weighed in live-release tournaments and catch-and-release (C&R) anglers - anglers fishing exclusively for bass who released their fish immediately

At the end of the year, C&R anglers caught an estimated 117,254 bass, or 27 percent of the bass population, tournament anglers caught 31,050 bass, or 5 percent of the bass population, and harvest-oriented anglers caught 38,238 bass, or 6 percent of the population.

To properly interpret these results, it is important to realize that catches for all angler groups were estimates because the creel surveys, by design, collect data from only a portion of the anglers. To address this, the biologists appropriately included the potential for error in mortality estimates in subsequent calculations. Mortality of bass for harvest-oriented anglers is 100 percent, but mortality from catch and immediate release and mortality of tournament-caught bass can vary.

The researchers considered that mortality of fish caught and immediately released could range from 5-15 percent, and mortality of tournament-caught fish could range from 10-50 percent. As a result, mortality estimates are best presented as a range of minimum to maximum values.

The total fish removed in one year by harvest-oriented anglers plus the fish that died after release by C&R and tournament anglers was 7 to 24% of the catchable population. Harvest-oriented anglers accounted for 56-83 percent of the total fishing mortality, C&R anglers were responsible for 10-31 percent and tournament anglers contributed 6-28 percent.

The first thing that jumps out is that C&R and tournament anglers accounted for less mortality than harvest-oriented anglers. Tournament and C&R anglers can celebrate these results, but they can also use them as an incentive to make bass fishing even better.

While tournament and C&R anglers together accounted for less than half the mortality, they would have accounted for only 16 percent of the annual bass mortality if C&R survival increased to 95 percent and survival of tournament-caught bass increased to 90 percent.

While there is a lesson to be learned from the Rayburn study, it is also important to recognize that Sam Rayburn is 114,000 acres and has a strong bass population. Rayburn attracts approximately 300 tournaments per year that generate an estimated 150,000 angler hours of effort. The tournament fishing effort, though seemingly high, is only 1.3 angler-hours per acre per year on the giant reservoir.

The proportion of mortality attributed to tournaments will be higher where tournament pressure is higher per acre, which may be the case on some of Mississippi's smaller waters. When tournament fishing effort is high, it is even more important that anglers and tournament organizers do a better job of taking care of the fish during the tournament, at weigh in and during release. Extensive research on bass tournaments in Mississippi waters indicates there is room for improvement.

As demonstrated by the Rayburn study, mortality of bass caught in tournaments was only a small part of the mortality of bass. All anglers benefit from abundant bass populations with high proportions of large fish. Mississippi waters can support such bass populations, and anglers can do their part to sustain good bass fishing by practicing C&R and handling their catch to ensure high survival of the fish after release.