Most fish eat mosquito larva. I use the goldfish in my ponds for this since a) they are very hardy and b) they don't cause any trouble with the other critters.
There is a fish called the mosquito fish -
Apparently in CA they are given away for mosquito control. Here in FL they are not used as much mostly because they seem to interfere with native species.
Tadpoles, goldfish and even some meat-eating bugs (like dragonfly larva) all eat mosquito larva. I don't have a mosquito issue here at all. Dragonflies also eat the adult mosquitoes, as do frogs/toads, bats, spiders and birds. For that reason I stopped using my "Mosquito Magnet".
A Mosquito Magnet totally collapses the population of mosquitoes in 3/4 to 1 acre within 6 weeks - and it works!
So if you have a serious issue, like a potential disease issue, I'd get the Mosquito Magnet going (you can get them at Home Depot). After 6 weeks all your mosquitoes will be gone. Then just keep normal fish and wildlife in your pond and you should be fine.
In general, we need to consider NOT just killing off everything, since other critters that we like and need depend on these pests for food. And it seems all our chemicals are just creating super bugs that nothing can kill. Seems like that is a much more serious issue. Just MHO, but I'm sticking to it!