Source: Hungry Minnow Run Amok?
Their suspicions were raised when they examined the stomachs of 36 mosquito fish netted from a stream near Los Angeles and found that 65% contained tadpoles, while just 56% had mosquito larvae. They then tested the fish’s prey preference in the wild and in the laboratory by setting up in-stream tanks and tabletop tubs stocked with minnows, Pacific treefrog tadpoles, and mosquito larvae. Even when the tanks were swarming with larvae, the minnows went for the tadpoles.
The authors of the above article were Lee Kats and Jeff Goodsell of Pepperdine University in Malibu, California.
Dr. Katz …
hopes the results will convince California officials to reconsider their policy of handing out the fish to anyone who asks. “Twenty years from now,” he says, “we are going to look at this practice and say: ‘What were we thinking?’ “
I have developed in over 20 years, an ecologically devised system that destroys the mosquito larvae eggs and doesn’t hurt native dragonflies, damselflies or frogs.
Mosquito fish destroy dragonfly and damselfly larvae also. Yet in my experience vector control officials are absolutely sure that they are right and that they know without question that introducing mosquito fish is the only way to control mosquitoes.
West LA vector control employees will even go around and put mosquito fish in ponds that have posted notices not to put mosquito fish in.
So you have to be vigilant but natural systems provide habitats for all sorts of creatures that we care about. Especially the Pacific chorus frog.
Best
Bob