For the people that say that tournaments are more damaging to the fisheries than a few people keeping fish every now and then are 110% correct!! Last year I had to do a research paper on tournament mortalities and what you will find is disgusting. The biggest reason is tournament fishermen don’t know how to treat there fish. I can count on one hand the number of people that do most of the things that the biologist say to do. Some of the easiest thing to do is to keep your live well pump running at all times, use ice to keep the water cool because cold water can hold more oxygen than warm water can, and add keep alive powder. In the research that I did it said to put salt in the live wells, I’m not sure but I think that the powder has salt in it.
A study was done in Florida a couple of years ago that had two groups.
Group #1 added ice and salt and used recalculating aeration. Fresh water was added two or three times during the day to flush out toxic ammonia.
Group #2 pumped fresh water through their live wells all day but did not use ice or salt, all anglers ran live-well aerators continuously.
Mortality of fish from Group #1 using ice, salt & recirculation averaged only 14%. Group #2 using constant fresh-water flow-through averaged a mortality of 18%.
Summer time is the worst time for tournament mortalities. This is some of the results that I found on line I can’t find the bibliography to give you the exact website but this is hard evidence that doing tournaments in warm water is worse than in cold water.

January 27-30 2004 -1462 Largemouth Bass were officially weighed-in. Initial mortality was recorded and 19 were brought to the weigh-in dead. Delayed mortality was very low only one fish died in the pens. Also there was 20 fish that had expanded swim bladders threw out the tournament that had died during the second and third day of the tournament. Water temperature was 56 degrees.
February 21-22, 2004 - largemouth bass were officially weighed-in. There was four fish that was initially brought to the weigh-in dead. And again delayed mortality was very low no fish died in the pens. In this tournament they did aside experiment in witch they “fizzed� the fish. Fizzing is a thing when they puncture the swim bladder witch allows them to deflate there swim bladders so they can swim upright again. The swim bladders are needed to puncture because they were caught in depths greater man 30 feet. What happens when fish are caught that deep is they are brought up threw the water column so fast they are unable to deflate there swim bladder on the way up. Water temperature was 58 degrees.
March 26-28, 2004 - 904 largemouth bass were officially weighed-in. No fish were brought to the weigh-in dead40 fish were caught and kept in the pens and 38 fish were in the pens that was electro shocked. . In the fish that was held in the pens only one fished died. This tournament they used electro shocking and only one of fish died in the pens. Water temperature was 66 degrees.
July 10 -11, 2004. - 163 largemouth bass were officially weighed-in. Initial mortality rate was much higher I this tournament in this one there was 17 that were brought to the weigh-in dead. In the pens 94% of the tournament caught fished died. (Two lived) and all 20 electro shocked fished died Water temperature was 87 degrees.