Manipulating/managing the environment is always a very tricky job. Factors not even considered in the original plan can easily come up, causing even further problems. I'm sure we can all think of examples of "good ideas" that we now know may have not been the best choice in the long run. Off the top of my head I would mention, predation control, introduction of non-natives, or fire suppression. I know these are all controversial and have their pros and cons, but they make the point that when managing the environments, we never fully understand the long term effects.
As such, I was pleased to read an article yesterday about controlling carp in Utah Lake. The issue is this - Carp need to be controlled in Utah Lake. There is a virus that has been present in British lakes, and now in Arizona that kills only carp. One might think this was a great solution to the problem. But is it?
Again, we don't fully know the answer to this question, but I was impressed with the forethought of the Utah June Sucker Recovery Implementation Program (who works on Utah Lake). Reed Harris, director of the program states that "There were three different diseases that we know kill carp. We're just reluctant to bring in a disease when we can't control it and we don't know (everything) about it."
He also goes on to say that "Well, the disease down at Mohave affected a lot of other fish besides carp."
That's because of what Harris called "collateral damage" to fish the virus doesn't target. When carp die by the thousands, it fouls the water. That makes it unpleasant for humans and unhealthy for other fish. It's one of the hard-to-predict consequences if people begin tinkering with viruses to kill carp.
"We think that catching them and using them in some sort of productive way is probably a better way," Harris said. "It's a little more controlled, and we feel like that way we can watch and see what happens."
So, Harris and his team will opt to use nets and round up at least 75% of the carp (which they say will be enough to improve water quality), and they'll use the carp for things like fertilizers, pet food, etc.
One other aspect of this story is that the virus would kill the fish for free, where the netting will cost over 9 million dollars. Even though it may seem costly upfront, we don't know how much it might cost down the road if the virus got out of control.
Is their course of action the best choice? I'm not sure any of us can make that call. BUT, I for one would like to say Kudos to the managers of this project for their forethought and inclusiveness.