[presidio9]

Here, let's try this again:

There were worms here 15m years ago. Most of them got wiped out by the ice age. Conclusion: The natural state of our forests is to have worms. 10m years is not long enough for the salamander to evolve. I can promise you that there have been worms in the forests of NY where I live for at least 30 years and the fauna has not been negatively effected. Raccoons eat em. Skunks eat em. Foxes eat um. Snakes eat 'em. Moles eat 'em. Shrews eat 'em. I suspect bats and owls eat 'em, but who knows.

I agree that zebra mussels are a problem. I do not share your concern when it comes to earthworms.

[cogitator]

As I said, I don't see the earthworms as nearly the problem as other invasives, but there is interesting information that indicates they are an invasive species that can cause some ecosystem alteration under the right circumstances. Certainly this appears minor compared to what some of the other invasives can do (nutria is a great example).

In Maryland, last year we had a semi-major incident when snakehead fish from China were found in a pond. It's likely that the person that released them didn't know that they could potentially become a big problem. Releasing snakeheads is probably considerably worse than releasing earthworms (as the article notes, many of the people who did it probably thought it was good for the environment). But because they are introduced and not part of the indigenous natural ecosystem, if they survive they have the potential to alter that ecosystem. The pattern with invasive species has been that the natural ecosystem in which the invasive species are introduced does not have the 'controls' in place that determine the population of the invasive species in its own natural environment, and the invasive species thus out-competes the natural residents. Ecosystem change happens naturally, but the increased ability of organisms to move via human-aided processes accelerates ecosystem change.