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NFC: Exotic crayfish

Okay, folks, I'm one of those who generally reads tales of environmental 
disaster with a very jaundiced eye.  I've found that many reports are 
exagerrations, nonsense, just plain false, or some combination thereof.

I especially have mixed feelings about 'exotic' introductions, I'm a little 
afraid to admit here.  As a hunter and fisherman, I've been the beneficiary 
of such introductions as rainbow, brook and brown trout, largemouth bass, 
pumpkinseeds, ringnecked pheasant, hungarian (gray) partridge, chukar 
partridge, valley quail and a few others.  All of these have filled habitat 
niches that were, in whole or in part, not utilized by native species, at 
least in my 'home' state of Montana and in Washington, where I lived for a 
few years.  I can't really say that I'm sorry that any of these 
introductions took place.

Before I get flamed forty ways to Sunday, let me say that I certainly 
recognize the negative effect that zebra mussels, carp and a number of other 
introductions have had on local environments!

I've gotta admit, my experience of this past weekend re-iterated that  
reports of environmental damage from introduced species should *never* be 
dismissed lightly.

Somewhere (possibly on this list) I read a little while ago about the 
devastating effect crayfish are having on certain Arizona mountain streams.  
Crayfish? I thought...I'll believe that when I see it.

Well, I have seen it.  On a camping trip with my two sons last weekend, we 
stopped for a few minutes along the East Verde River to let the boys fish 
for stocked trout.  It's a very pretty location, just below the Mogollon Rim 
of Zane Grey/Louis L'Amour fame.

The *only* life we saw in the stream - a creek, really - was crayfish.  
Though I searched diligently for over an hour, I found NO aquatic insects of 
any description, nor was any aquatic plant life in evidence.

I have never in my life seen such a population of crayfish - sorry I have no 
idea which species!  Every rock - I'm not kidding - that I turned over had a 
crayfish under it!  Probably over 90 percent of them were between 1 and 2 
inches long, mostly on the smaller side.  I saw only three juvenile 
crayfish, which I looked for specifically, and only two over 2 inches, 
although there was one pincer lying on the bottom that was clearly from a 
larger individual than any that we saw.

In trying to speculate what the future holds for the stream, I suppose it's 
cannibalism time for the crayfish - I don't know what else there is for them 
to eat!  Hopefully there are otters, raccoons, herons and other animals in 
the area that can utilize the crayfish as a food source and moderate the 
population in the future...

Just further grist for that old NFC slogan - never release any animal - or 
plant - into the wild!  The effect is unknown, the potential for damage is, 
for want of a better word, extreme!

I'm sure I'll be a little more open-minded when reading reports of habitat 
degradation by introduced species in the future.  This old dog learned 
something new?  Will wonders never cease!

Scott

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