>>214756824
Many fish who feed on mosquito larvae would starve, the fish who feed on those fish would starve, the populations of freshwater fish would be heavily impacted. The mosquitos competitors would thrive, creating natural highways for new invasive species of which there are too many to even guess which ones would take over where. And the mosquitos natural predators, like the dragonfly, may not fight these new invaders to their liking.
Nature is in a balance, but its a fragile one. Everything is constantly hungry for each other and trying to gain an advantage. Whenever we disrupt something the effects are always more than we imagine.