biological contamination

I agree with you DlBerlin. The only point I was trying to make was that Emprr_angl is concerned with marine aquarium enthusiast dumping a small amount of water into drains weekly when in reality the amounts of water brought in by ship ballasts is who knows how much greater and more dangerous to the Great Lakes. When you look at the comparison between the two and which has made a greater impact on the Great Lakes it really makes no sense why he would go after marine aquarium enthusiasts. Notice this quote “James Carlton concluded that on any given day at least 7,000 species of "aquatic hitchhikers" are probably present in the ballast water en route between continents. Every 12-14 weeks on average, yet another alien species manages to establish itself in U.S. coastal waters.” If he feels the need to write letters to anyone it should be to the ship owners, or maybe to the nations allowing these ships to import non-indigenous species into Canada and the US. He should also consider who he addresses if someone tries to put there hippo tang who out grew there 10 gallon saltwater tank into some inland lake the tang has zero chance of living. Now if some college student thought it would be cool to dump his two piranhas into the same lake one night which has a chance of doing more damage. I guess he wasn't really talking about fish but it still can relate in a way.

sorry

Sorry guys I wasn't trying to be negative at all I'm just fascinated in this type of stuff. For example did you know that there are 139 invasive species (59 plant, 24 algae, 25 fish and 14 mollusk) that have been introduced into the great lakes since the 1800's? And of at least 13 have made a large negative impact. In my opinion one of the worst is the water milfoil, which has the power to spread rapidly and suck the oxygen out of healthy lake ecosystems. Others not mentioned by others include the purple loosestrife and the water flea (sea flea to the salmon fisherman).
Emprr_angl if your interested in invasive species you should look into the history of lake Victoria, which is located in Africa. In the 1960's European biologists felt that they could introduce a species commonly named the nile perch for locals and Europeans for fishing recreations. There was little effect for a short period then it was noticed that the perch was feeding on local fish called cichlids which was eaten by natives. After a short period of time all of the cichlids had been eaten so now the perch were without food as well and there population declined rapidly. I thought this is a great example of the extreme effects invasive species can have on a stable ecosystem.
Again I'm sorry to anyone that I offended