Where's The Crawfish?

[exiledguide]

Actualy last Friday afternoon on the James below Shelvin Rock I noticed many more crawfish in shallow slack water than I 've since I started fishing the river in 2008. Before friday I hadn't noticed many crawfish in the river maybe it's because the river is so low. I have noiced every Goggle Eye I've cleaned this year has been full of crawfish. But I've also noticed a lot less crawfish sticking out of the throats of the SM LM and KY bass that I've released.

[exiledguide]

20 years ago was 1991. I was married that year. DOH!

So, what you're saying is, our distant past was the 1990s? (the 1990s! Really?) The 1980's (30 years ago).

Good grief. Who cares about crawfish. What happened to my life.

Hey quit youre crying. My distant past was the 40s. I remember fishing with a stainless steel rod and an Ocean City reel and black braided line.

[ozark trout fisher]

go to NFoW, there is a stupid amount of crawfish in that river.

Or anywhere in the Gasconade drainage. It's crazy how many crawfish you see in the Big Piney, Little Piney, etc.

I have only been fishing Ozark streams for just a little over a decade, so not long enough to really comment on a long term increase or decline though...

[Tim Smith]

I remember when I was a kid (30 plus years ago) that a local river was just full of huge mussels. I mean like about the 10 or 12 inches wide, but no more. I have seen over the years a steady decline to were there aren't any there anymore. my theory is that chemicals in the water has decimated them on that stretch of river for there is more agriculture in my neck of the woods.

Mussels have a hard time getting out of the way of bad water quality the way fish can. They're sensitive bioidicators of water quality and you never saw a more pissed off sewage treatment plant operator then when they found out we would be monitoring those to test effects on their operation.

[Tim Smith]

Nothing scientific of course but I've just noticed a big decline in crawfish sightings in the last 20 years. What shapes your opinion there is no general decline?

Skepticism is the default position until there is solid data.

You've got a hypothesis that has some supporting observations. I believe your observation that numbers are down where you are looking. But how many places did you look and what species did you check and did you check at the same times of year? It takes a lot of work to be sure about a broad general statement like that.

[Tim Smith]

How on earth do they raise all of those crawfish in Louisana? They do not have subustrate, all I see is silt and mud? Just wondering.

Those crayfish are Procambrus acutus and Procambarus clarkii and the same refuge principle applies. Those crayfish can reach high densities because there aren't any fish predators, and as Muddy says, they can also burrow where they do find predators. Those species dominate in silty low oxygen systems...rice fields and such. The same thing happens with Orconectes immunis in some silty Midwest headwater streams. O. immunis dominates the crayfish assemblage where the streams are slow and shallow with low water quality that fish can't survive. Bigger crayfish species with bigger claws like Orconectes virilis become the dominant crayfish species when predator fish are present because they outcompete the smaller crayfish species for refuge. It's a trade off that plays off between being adapted for systems with and without fish.

[joeD]

Thanks Tim. Have a beer. Relax.

[Mitch f]

Skepticism is the default position until there is solid data.

You've got a hypothesis that has some supporting observations. I believe your observation that numbers are down where you are looking. But how many places did you look and what species did you check and did you check at the same times of year? It takes a lot of work to be sure about a broad general statement like that.

It based on the three or four rivers I mainly fish, I admit. As I said before, nothing scientific.

Tim, What part of the state do live? Let's go fishing sometime

[Tim Smith]

Thanks Tim. Have a beer. Relax.

No content here.

[Tim Smith]

It based on the three or four rivers I mainly fish, I admit. As I said before, nothing scientific.

Tim, What part of the state do live? Let's go fishing sometime

I'd like that, Mitch. I'm back and forth across the Ozarks from Colorado to Illinois to Louisiana traveling for work and family. I'm be back in late October.