I don't know if you guys have the same problems as we do here, but there's a lot of aquarists that have released a TON of pleco's everywhere here. I aim to kill them where I know they shouldn't be in the first place. Even as a little kid 20 years ago I was seeing them and hand catching them in the springs (releasing of course). This is fine because while they can travel down stream, they generally don't with the food source changes, and temperature changes. I know 2 lakes specifically where I'm paid to remove them by property owners. Because we all know pleco's like caves. Since florida is sand, the pleco's make caves in shallow water. Eating away at the property lines. And for one, he's lost a lot of cows because the pleco's make swiss cheese out of the ground and the cows sink and die, tainting the watering hole for drinking and of course losing a lot of money over cattle. And lets face it as anyone know's that breeds fish, you can't have pleco's. They eat the eggs. So they destroy your fishery.
While I don't like to kill a fish, I know that I've speared 5 common pleco's in 1 sitting that were all over 18 inches long. I even went swimming and hand caught one (that one was a TON of fun lol) when the water temps were lower. There are soo many large plecos in this lake that his section of dock that was on land just for sunbathing and looking out on the lake without being over the water now has about 3 feet of ground that has collapsed and needed to be filled in because it was a foot deep hole right as you stepped onto the start of the dock. From the start of that dock to the actual shore line is about 5 ft. The econlockhatchee river I've seen the shorelines expand about 8 feet in the past 5 or so years. Luckily in that section it's a concrete overflow going in, and a dam going out so hopefully they don't leave there naturally.
Killing gar and bowfishing? Well, tilapia are free game because florida fish and wildlife thought they would be a great idea. Except that they are mouth brooders and they destroy other fish beds and eat the eggs. There are no limits that I've seen on the lakes that I fish in for bass. Gar, well, I've killed one on purpose. Because typically when I'm using shiners I do get a few gar, I do my best to get the hook out and let it go on its way. This prick of a fish broke my line with 2 hooks in it already (NOT swallowed) attacked and broke a bobber and it bit again. Damn fish had to go. Florida gar about 20-22 inches.
Only upside is the amount of crawfish here in almost every lake, even a dead fish that goes to the bottom technically never goes to waste.