CALGARY -- An invasive species of fish is taking over Frank Lake and the province says options to remove Prussian carp are limited so it is encouraging anglers to catch and dispose of them when caught. No one knows when the invasive species was introduced into the body of water but Greg Wagner first saw them in the spring of 2019 and now there are thousands upon thousands. He's the volunteer caretaker at Frank Lake. "Prussian carp are a nuisance," said Wagner. "They're an invasive species and shouldn't be here and we'll see what the long-term ecological effects are as time goes by, unfortunately."