This sounds very familiar. In New Zealand we have a lot of trouble with "didymo"[1], an invasive algae which thrives in cold freshwater environments, clogging up rivers with lots of green slime. It is very easily spread by humans doing recreational activities such as fishing and boating, inadvertently carrying it from one place to the next.
As such we've had intensive public education campaigns here, instructing people to carefully clean down things like boots and boat hulls with either hot water or bleach solution[2]. Its spread continues, though perhaps less quickly than without such a campaign.
As such we've had intensive public education campaigns here, instructing people to carefully clean down things like boots and boat hulls with either hot water or bleach solution[2]. Its spread continues, though perhaps less quickly than without such a campaign.
[1] https://en.wikipedia.org/wiki/Didymosphenia_geminata [2] https://en.wikipedia.org/wiki/Didymosphenia_geminata#/media/...