RISKS/IMPACTS: Ecologically, the zebra
mussels cause many problems. One such
problem is that they need to attach to a hard
surface to survive, and these hard surfaces could
be anything from many manmade objects to
other animals. Zebra mussels will attach to
crayfish, turtle shells as well as other mussels.
When a native mussel has zebra mussels
attached, the native mussel loses its ability to
move, feed, breath, and breed. Eventually this
will lead to the death of the native mussel.

So if a crane picks up a crayfish or small turtle or mussel and flies over to another body of water and deposits it there you have contamination.
I'm not saying just give up, but it's not all on the boaters and shouldn't be.
Get ready for new laws, like we need more!