an unusual slant on exotic release

If my memory serves me that was the release of a few hundred in 1999 and a couple thousand in 2006. It has not been established that they where actually extirpated though before the introductions, which is why I did not mention it. One was caught in 1999 that was 70lbs during intensive sampling for the fish. No question however that the fish is on the brink and has been for some time.

Yeah, that's been an issue- they didn't really survey for gar or snapper before re-introduction; they took the absence of evidence as evidence of absence. I know they didn't mark the released turtles prior to 2006, and I doubt they marked the released fish. Oh well.

Edited by Newt, 25 November 2008 - 12:21 AM.

Ah... So for non T&E species, the Pigeon River in NC is probably the flagship. Here's some links:

http://web.utk.edu/~mjwilson/index.php
http://www.ncwildlif...g00_dec04_4.htm

You might search a bit about that. We had some of the nice folks involved with it present at the NC Convention in 2007. There was also a nice article in the last SFC publication about recovery of introductions using the polymer shots. I wonder if the good Dr. Neely has access to a pdf of that?

And there's stuff going on in your state I'm working to model Etheostoma in OH, PA, WV, KY, and IN to find geological patterns and limits of their known historic range. Perhaps this will also suggest where they may have been overlooked (camurum is alive and well in the Licking River, for example, but was overlooked this summer due to gear bias by OEPA).

Prior to my interest in this, Brian Zimmerman (Zimmermans & ODNR) and Marc Kibbey (OSUM) have both expressed interest in investigating reintroduction for Ohio Nothonotus, and IN & PA are interested in the data, as will be USFW if they uplist maculatum. However, Ohio seems is the only place where fish need moved around, and with that, probably only maculatum. Columbus with its lowheads and pollution was put in a very inconvenient place!

With the models, perhaps we can explain a little more of the variation. Patterns emerge when you use maps to visualize what you're trying to quantify. We might also show problem before throwing a bunch of money and fish at a river. For example, the Olentangy, in its current fragmented state, may contain too little connectivity or total area of good habitat to overcome local disturbance, thus resulting in a reextirpation (which is what we don't want).

For example, here's one layer I'm analyzing for spotted darter:

 OH_HI_OH.jpg   150.56KB   1 downloads

This map, I think, suggests that having enough drift available is one of the criteria for a viable population of maculatum. Look how much of the Darby and Walnut Creeks intersect with that deep drift, vs. populations that were either extirpated (Mahoning) or remain in low abundance (Waldhonding), but fortunately didn't have to survive the onslaught of Columbus (which if they did, they may have been extirpated as well, if this drift layer is a true relationship).

So in thinking about the Olentangy again, examine the length intersecting deep till, and see how much smaller it is than the Darby, for example. You pair that little amount of good historic habitat (which may have just been a "sink" population?) with contemporary fragmentation and decreased bedload conveyance, a drought hits and you've got nuthin. However, we might offset that with a minimum flow agreement from Delaware Lake.

That paired with other layers and microhabitat data may put forth a more informed guess as to what historically happened, and what we currently need to address, to ensure a successful reintroduction.

I'd be very glad to hear other thoughts about this, and why I'm posting some exploratory work before it's even been, well, proposed lol. I was so excited when this map came together, I had to share Don't worry, the ace in my sleeve is a layer no one will probably consider. It's also nice to be working in an area that has such a need that I can just collaborate openly (molecular people have it bad). So don't anyone burn me on my enthusiasm

As for variatum in IN, they only historically occurred in the Whitewater River, where they are present on pretty much every riffle, just in historic abundances, which looks really scary. The river seems to be a top-down regulated system, where predators are running the game. That is, you'll have no trouble finding smallmouth bass (predator guild) or macroinvertebrates (grazer guild), but you'll find minnows and darters (insectivore guild) crammed into tiny corners of habitat in extremely low abundances (Remember Newt's Little River experience this summer?). So there's not much to do there, and it's a good source for variatum in the Great Miami.

That said, I'm interested in investigating the Great Miami proper, regardless of the cess pool that it appears to be. It's priority one for low water sampling. Substrate embeddedness is a HUGE problem from Piqua to West Milton, but once beyond all those dykes, it gets loose again. The lower Stillwater is in decent shape as well. Who knows what's out there. Arthur Morgan's less permanent flood control designs may have allowed for things to persist, if the dykes didn't compact all the substrate in the lower Mad and Stillwater.

The Little Miami is already one of my replicate streams. We'll see what we find. I was going to do prelim sampling there this fall for the microhabitat scale, but just ran out of time and energy.

Hope y'all find this fun and informative. I know it wasn't directly asked for, but I thought it was relevant, especially when considering reintroduction or explaining exotic invasions, etc. KNOW YOUR SYSTEM!

Todd

Edited by farmertodd, 25 November 2008 - 12:04 PM.