Now they are going to tell us what we can and can’t collect for “personal fun”. Screw em.
Goldfish are a species of carp, and as such, have similar predatory behavior in the presence on non-carp species. They aggressively compete for the available food, and their presence drives out other native species.
Invasive species are a problem everywhere, not just in Colorado, and it takes a while to establish a new equilibrium in the ecosystem that has been disturbed. Just look at the various invasive species that have escaped into the wild in the Florida Everglades, even the presence of alligators cannot keep them under control. Ball Pythons will even attack and consume young alligators. No match, though, for an adult bull alligator.