PROVO, Utah (AP) -- A Brigham Young University study has concluded what many have believed for some time: fish brought into Utah to combat mosquitos is killing a native fish.
For decades, thousands of imported mosquitofish have been used to protect Utah County residents from mosquitoes.
But the BYU study says the fish are killing one of Utah's most threatened native fishes, the least chub.
The once-abundant chub has all but disappeared over the last 50 years.
BYU ecology professor Russ Rader says there's only about three to six healthy populations left in small springs in the West Desert.
For the past several years, evidence has been mounting that the fish harm not only least chub but also the threatened spotted frog. That's why wildlife officials now only allow the fish to be used to combat mosquitos in ornamental ponds.
(Copyright 2004 by The Associated Press. All Rights Reserved.)