Don't Know How Many Of You Guys Listen To Npr But..

[fozzie.]

Invasive Fish

I think you can listen to it there.

Pretty interesting stuff, talking abou thow rainbow trout have been stocked outside their original range to the detriment of native species. Also talked about asian carp, and the effects they may have on the Great Lakes. Apparently the two folks interviewed feel the asian carp issue may not be as doom-and-gloom a scenario for the Great Lakes as predicted, due to the lower water temperatures there compared to the streams they've invaded in the Mississippi Valley.

[Al Agnew]

Yeah, what I got by listening somewhat between the lines on the Asian carp deal is that most biologists are not too concerned about them, not only because they are a warm water fish and the Great Lakes are mostly too cold, but also that they are algae and plankton feeders and the Great Lakes are too clear and don't have enough fertility to feed them. In other words, the whole issue is probably more political at this point than biological. They noted that there have been only two carp found within the shipping canal, and I'd guess it's quite possible that the cool water from Lake Michigan coming into the canal is probably mostly keeping them from coming into the canal.

I'm usually pretty impressed with Diane Rheem's knowledge of the subjects her guests discuss, but I think she had a lot of misconceptions about invasive fish species, use of rotenone, and angling in general. I got the sense that she was philosophically opposed to angling. And she kept coming back to some old quote in the book being discussed about the "manliness" of angling, as if fisherman are fishing because it's a macho thing. I wasn't in a place where I could call in, but I wanted to call in and say that in a lifetime of angling, until today the thought never crossed my mind that I was doing it because it was "manly". And especially since they were mostly discussing rainbow trout--since we all know that most trout fishermen are fly fishermen, and fly fishermen are thought to be more like effete snobs, not macho men. (Just joking!)

[fozzie.]

I agree, she was a lot less informed on this subject than others I've listened to her tackle. In a sense, it helped me put into perspective just how little the public at large may know about our nation's fisheries (and natural resources in general), their history, and management.

I guess I partially bought the guys' argument that the Great Lakes may be poor habitat for asian carp, but their cavalier attitude made me a little nervous. Underestimating the potential consequences of species introductions is what set the stage for the asian carp introduction in the first place.

[Thom]

Two thoughts on Asian carp not going into the great lakes because it is too cold.

In college I worked in a lab that did experminents on mutations and we purposedly exposed cells to environments that were not conducive to their growth and survival. In many cases they adapted and not only survived but sometimes thrived with the adaptations or mutations.

We seldom saw armadillos in this part of the country but they are common now though not plentiful but in a few years maybe. How about the Bees coming up from South America and adapting from the tropical weather to the colder winter desert climates?

The asian carp have devastated the tailwaters at Carlyle Lake in Illinois and the dead ones litter the banks and stream competing for food in the rock banks. I remember catching lots of large 12 and 13 inch crappie in those same rocks and that habitat but not any more to the extent as they were. Asian carp have become the Kudzu of the waterways and are not being controlled to my knowledge.

[Al Agnew]

Good points. However, I'm not sure that you can equate mutations in single cell organisms to the more complex mutations necessary to make a species like the carp able to adapt to a new habitat. Not saying it isn't possible, because that's what evolution is all about. Just that it isn't as likely to happen. Armadillos seem to be extending their range northward because of the exceptionally warm winters we've had since the mid-1980s (but I wonder how our more normal winters the last couple of years are affecting them). As for the bees, from what I understand they hybridized with the bees they encountered, and that was what made them gradually able to adapt to the cooler climate. I don't think there's anything the carp can hybridize with in the Great Lakes.

However, I agree that it may not be worth the gamble, and the Asian carp are an ecological disaster in waters warm enough to support them. The ship canal should never have been built in the first place, since connecting formerly unconnected watersheds is never a good idea. Whether the carp end up being a problem in the Great Lakes or not, sooner or later there are going to be more adverse consequences to such connections.

[Norm M]

It's not just Lake Michigan the COE is worried about. I was at the recent Illinois River Coordinating Council meeting and one of the COE members of that panel said the Asian Carp were in the Ohio River and there are canals connecting that river to the Great Lakes.

The COE also said they had found the Asian Carp as far north as LaCrosse on the Mississippi River. I'd have to look at a map to see if there was any possible connection to Lake Michigan or Superior.

[Midwest troutbum]

Asian carp and invasive non-native species are a prime example of why imported goods and our ports need to have more thorough inspections & regulations. Laws and regulations preventing non-native species introduction should be strengthened and criminal punishment to the extent of biological terrorism should be considered. Non-native species imports should be selectively outlawed on a case by case basis. When will we learn as a society to prevent further degradation of our natural resources & wildlife?