We Cross Now To Captain Obvious:
In news that shouldn't surprise anyone anymore, it turns out that legally requiring ships to decontaminate their ballast water before entering closed lake ecosystems, reduces the harm caused to that lake ecosystem from invading species in the ballast water.
That this should have been done from the first sighting of an invasive native-species-destroying life-form goes without saying, that it didn't happen is/was down to the pure profit-driven nature of the early shipping companies.
To Infi.. - *To Mars And Beyond!*
Now we want to go to Mars and colonise. Besides then becoming an invasive species ourselves, imagine our surprise when we set up habitats there and discover that some overlooked little microbe on one of the rover robots got there before us and found Mars to be the dream home...
"WTF? How come there are clumps of goo growing everywhere?"
Because we never figured bacteria on the outside of spacecraft would survive a trip in space but surprise - we actually know now that it does.
Best of luck with the accidental terraforming when we finally get there.