The last thing you want to do is bring home spoils of battle that are, well, spoiled. But that's precisely what far too many anglers do. Anglers have certain habits in handling their just-caught fish that are really bad. That's particularly true in where anglers pursue trout. Trout are legendarily delicious, but they're also exceptionally prone to spoilage.
We all love to eat trout, and catching them is fun, but there are a few things that really work against you. When you catch trout, they're aggressive. You've got to catch them when they're there, and then they're gone. So the tendency is to unhook them, and quickly get the bait back in the water. The tendency is not to take care of them. Unfortunately, trout is one of the most delicate fish that swims.
The other problem with trout is that the meat is so tender; it's very susceptible to naturally occurring enzymes that deteriorate it. Enzymatic action is tough. The fish's own body enzymes actually work to break down the fish. If you've ever purchased a quarter of beef, and had it hung for two weeks, that's enzymatic action that's causing that beef to self-tenderize when it's hanging in a cooler. The same thing is happening to fish in an ice chest, but it's a lot faster. Fish has close to no connective tissue, its short grain, easy to dissolve, easy to digest. Those enzymes immediately go to work, and the biggest source of them is the guts, the intestines. People don't realize how quickly the enzymes penetrate the body wall and get into the meat.
Recreational anglers can't necessarily follow suit. In the case of fee based trout ponds, the caught trout may not legally be sliced, gutted or filleted while on site. Anglers have to keep the fish whole, but they can greatly hinder the enzymatic breakdown by keeping the fish exceptionally cold. Most will purchase a bag of ice, drop it in the chest and assume it's keeping everything inside cold. The first few fish you drop on top of the bag will have one fillet that may be nice and cold. Everything above that will be cool but far from cold, and its downhill from there!
PUT YOUR FISH ON ICE IMMEDIATELY AND CLEAN THEM AS SOON AS POSSIBLE TO AVOID SPOILAGE, ESPECIALLY IN HOT WEATHER!