Krafty (Raif Killips) from the Fly fishing and Beyond blog has a post about the invasive species problem in the United Kingdom. The usual suspects are involved, mitten crabs, zebra mussels, and even mink. Check out the thought provoking postings on his blog.
So what are we to do about all this? Well, I guess exercise caution and conduct ourselves responsibly and thoughtfully. While pollution may be a minor vector for species invasions it's not hard careful waste disposal and recycling we can reduce pollution. Between trips we can also follow basic biological control by decontaminating our clothes and equipment.