Asian carp were intentionally brought to the US for aquaculture in the 1970s. Some of those fish then escaped into other bodies of water. The cost of ocean shipping had nothing to do with it.
Thank you for the response. In all seriousness, you are giving me an education on shipping that I did not have.
However, to my point, is it possible that invasive species would be less infested in freshwater areas had we as a species done much less sea based transport because it was cost prohibitive?
https://nyis.info/invasive_species/asian-carp/