Re: NANFA-L-- A Deluge of Snakeheads

Todd D. Crail (tcrail at UTNet.UToledo.Edu)
Wed, 12 Oct 2005 07:28:19 -0400

----- Original Message -----
From: "Bob Bock" <bockhouse at>
> It wouldn't surprise me if the snakeheads took down the bass population.
Considering that they've only been in the Potomac system for two years, they
appear to have reproduced at a phenomenal rate. This looks like it's really
going to be a disaster. Like Boiga irregularis and Guam.

Not necessarily. You have two completely different scenarios there for the
invasion, with Guam (or Hawaii, or the Galapagos, or Carribean islands, etc)
being FAR more sensitive to a new predator in the network explicitly because
of the island biogeography. What would happen in Guam if a colony of
predators floated in on some drift from a typhoon? The same thing may
happen, just not in the scale of our lifetimes. The insane bird
biodiversity may ONLY be because no predator has appeared on the island,
prior to our noticing there were a lot of different birds there, no?

Conversely, these things are arriving on far faster scale than geologic time
(within our lifetimes). So, I'm not saying this is a good thing for
humanity's sake, since we're only really a burp in that geologic time as

My guess is... The snakeheads are filling an empty or vaccant niche, which
recruitment from each brood is exceptionally high, and why it appears
they're populating at an incredible rate. The invasion front is going to
look like the things are crawling out of every crack and crevice in systems
that have this empty or vaccant niche, we _may_ observe a bottleneck in
native predators, but probably when it's all done and said, there's not
going to be much of a difference except that other predators will have less
food than before the introduction, and the possibility that a couple species
will experience loss due to heavy predation because they happen to cross
food networks with the snakehead or try and nest in the same area which gets

Yes, this falls apart when considering nile perch. But that's nile perch...

Be FAR more concerned about those wiley asiatic carps that are loose in the
Mississippi. They may have a less charasmatic demeanor to their villainry.
But they interrupt the food networks where everyone above needs to feed, and
that... That's a problem.

The Muddy Maumee Madness, Toledo, OH
It's never too late to have a happy childhood.
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