Monday, July 30, 2012

River Secrets-The Shocking Truth

A recent Friday found me helping out with a DNR electroshocking survey of a local river.  The crew was made up of some college students, some Park Service personnel, the local DNR guys, and me.  Because you see my son is the area Fisheries Biologist, and if there isn't a Take your Geezer Dad to Work Day there darn well ought to be.

It is a fascinating process.  You have a pair of "barges" each with a generator and a holding tank.
The power goes to three "wands" that zip current into the water.  You advance upstream in formation, netting the befuddled fish as they float past.

It is a little like "Ghost Busters" technology, but perhaps with less dire consequences if you "cross the beams"

Here is yours truly in full Ghost Buster mode:

It is actually a little more complicated than I would have thought.  One boat runs an Alternating Current system, the other is Direct Current.  AC stuns the fish if they are close enough, but seems to annoy them into flight at more distant ranges.  DC on the other hand exerts a strange Siren Song to fish, they float along in lazy fashion following the electrical current.  You can reach the electrode under brush piles and actually draw the groggy fish out from underneath.  So when there were islands and such to deal with we used the AC boat to drive fish towards DC. 
It works, but I am always brainstorming ways to improve technology.  I think the whole AC/DC trick might work better if we added a sound system:

This could work.  The AC/DC lads seem like decent sorts, I could see them consenting to a remix of some of their Greatest Hits for a good cause.  But one of the DNR techs is a bit of a heavy metal fan, and I suppose he might have a difficult time-when "Waterway to Hell" came on-not turning the amps up to 11.  And after all, we are just trying to stun the fish.

You find a lot of interesting critters in a pristine river.

A Brook Lamprey.

A Central Mud Minnow, fairly close cousin of pike and muskies!

The oddly named Horny Head Chub.  Lord knows what kind of Google Search traffic that is going to bring to the blog.....

Two species of Sculpins.  I actually felt a little bad laying the electro hurt on these small, innocuous life forms.  But I can happily report that the survival rate at release time was 100%.

Really, the star attraction on this river is Brown Trout.

After being measured and recorded this one was in a big hurry to be released!

I am describing the electro shocking process in greater detail because I recognize that it is not something most people will ever have a chance to experience.  Wading upstream on a delightful summer day I observed that "This is so much fun it should be illegal."

Of course, if you are not working for the DNR it totally is!

1 comment:

Honeybee said...

My dad had us counting back yard earth worms in much the same way, though the resultant surfacing population was more destined for a fishing hook than back to underground. The simple apparatus he concocted was TOTALLY dangerous, I'm sure. But, I'm here to tell the story so it either wasn't that powerful (not true) or us kids dodged the Big One (many times over). :>)