Saturday, February 16, 2013

Rockethub Fundraiser For Flint River Research

Yesterday I started a crowd funding effort, to raise $2000 for research equipment for further ecological research in the Flint River of north Alabama. The link is: Basically I'm looking to buy a good oxygen meter for Biological Oxygen Demand (BOD) work, a combination pH/Total Dissolved Solids meter, and a new good quality seine net. If you can help, I appreciate it, of course!

Sunday, October 21, 2012

Creek Chubs At The Flint River, Oct. 20

We went out to the Flint River at Oscar Patterson Road yesterday to look for scarlet and silver shiners. The river was fairly high and fast, to the point that our usual sampling methods in the river weren't really working. But then we examined a side channel that was flooded yesterday, and is usually just a series of stagnant pools. At lot of the shiners and chubs had taken refuge in this sheltered channel. We found about a dozen scarlets, one silver, and 5 or 6 creek chubs. Mike Sandel has proposed on the NANFA Forum to start a project to monitor creek chub growth and reproductive status at a range of sites throughout their wide range. We think that's a good idea, so now we have our first creeks for the project. The first photo shows this flowing pool just before it rejoins the river. The second photo focuses on the island separating the channel from the river to the right, with a view of the small cut that allows the channel to rejoin the river. The river was moving at least a half meter per second at this point; great for darters, not so great for typical shiners and chubs.

Tuesday, October 02, 2012

PVAS Talk This Weekend, Oct. 6

I've been strangely distracted for almost two months since the last post. But, this weekend, Saturday Oct. 6, I'll be doing an invited talk at the Potomac Valley Aquarium Society in Fairfax, Virginia. The topic is broadly Stream Ecology, but in particular I'll look at what factors can shape the diversity of fish species in two very different stream systems - Sipsey Fork in north Alabama, and the lower Congo River in Africa. It's a big topic for a 45 minute talk but I think I have it all boiled down. Also, Kelly and Stefanie are presenting a poster on our silver shiner research at the Southeastern Fisheries Council meeting in New Orleans on Nov. 8 and 9. We have over a year's worth of data now, and the big news is that the Flint River population of silver shiners spawns in February/March, while the other at all well-studied population in Ontario spawns in May/June. Water temperature seems to be a major cue, not surprisingly, and of course spring comes later in Ontario than Alabama. It should be good. Just for fun, here's a photo of a male scarlet shiner from Limestone Creek about 8 years ago, I don't think I ever posted it here.

Monday, August 13, 2012

The Flint On August 11

We went to the Flint River at Oscar Patterson Road this past Saturday, Aug. 11, in search of silver shiners and scarlet shiners. We haven't caught a fully adult silver shiner since June, but we're getting good at finding sub-adults in the 45-70 mm SL range. This is interesting for us because we're trying to understand the population structure of the species, which no one else has really looked at. Saturday's trip followed over an inch of rain on Friday, so the river was up some and was more turbid than recently. Four of us were there, including Stefanie, Josh and Becca. This time we didn't find fish easily upstream from the bridge, with higher, faster water there, but we found fish under and downstream from the bridge which we haven't since June. Not surprisingly fish move around as the river changes. The first picture is the "parking lot" at this area, which on Saturday was a lot wetter and muddier than it has been for a while. I usually try to park close to the bridge because that's where we enter the river, but I declined the mudding.
Here's the fish we collected, euthanized in formaldehyde. The most obvious fish in this shot are sub-adult silver shiners, but we also collected some large scarlet shiners. We'll have to go out again before the end of the month, assuming Josh doesn't collect enough fish on his own.

Monday, August 06, 2012

Multiple Size Classes Of Silver Shiners In The Flint

I think we're making progress solving one question from the last year. We've caught mostly large, adult silver shiners in our work. This begs the question of the population structure of the species, i.e. what size are given year classes and how many of them are there relative to adults. In the last several weeks we've made several collection of smaller silver shiners. Last Sunday Stefanie and I caught a bunch of fish I thought were all scarlet shiners. Upon closer examination in the lab, we realize that almost half of them are silver shiners, in the size range 50-68 mm SL. And Josh netted a bunch of silver shiners downstream in the Flint that are in the size range 70-85 mm SL, almost the size of ones we've typically caught. As we've learned more about silver shiners in terms of their preferred microhabitats in the river we're finally catching a more diverse population. It doesn't sound like much, but I'm happy!

Tuesday, July 10, 2012

Blue Spring, in Jackson County, Alabama

I took the Ichthyology class on a field trip this afternoon for the lab component. We went to Blue Spring in the Paint Rock Valley of Jackson County, Alabama. This is a surprisingly round, deep spring that is honest-to-God blue sitting at the base of a broken limestone/sandstone/chert steep slope of an ancient mountain. Water enters the spring basin from under the road through several fissures at a fairly steady rate. The pool was lower today than I've ever seen it, but it was still a good 2 meters deep in the middle, and 13 deg. C, the temperature of local groundwater. There's also a spring run that joins Guess Creek about 200 meters downstream. We seined some very big striped shiners from the spring, and finally netted some blacknose dace. But that was it; in the past we've caught johnny darters, blueside darters, and sculpins in the pool. The first photo is a view from the west end of the basin; note the Fontinella moss in the water in the foreground. Water temperature at the surface was 66 deg. F (the only thermometer I had...) and total dissolved solids was 138 ppm, about right for local groundwater.
The next photo is a view of the spring run. We netted mostly striped shiners and BIG blacknose dace out of this, along with tennessee snubnose darters, a single big male stripetail darter, and one cute sculpin. When we started netting in Guess Creek downstream of the confluence we caught a bigeye chub, Hybopsis amblops, whose presence indicates the creek is basically clean, clear and cool which is certainly what it looked like.
The next photo catches Ethan clambering up from the spring to the road which is heavily engineered at this point. You can see the mountain slope behind him, with some hint of the broken nature of the slope.
And finally, a hazy view of Brittany walking on the road to the cars. The mouth of the spring entering the basin is directly below her, in the pile of visible rocks on the edge of the spring. We were there for several hours, being rained on, and everyone worked well with no complaining. As we left thunder was closer and the rain was picking up, so we left before it got bad. Seeing as how it's only rained about 6 cm locally in the last month we need the heavy showers that started.

Sunday, July 01, 2012

The Warm, Low, Flint River

Here are two pictures from the past week. The Flint River has been running about 78-80 deg. F, even in flowing, deeper, shaded spots where we've made the measurements. That has to REALLY push the thermal tolerance of species like the silver shiner. Below is a picture of one of the two adults we captured this past week, a relatively small one, ~70 mm SL.
The Flint looks nice and bucolic in the following picture, but it's extremely low water. Today we're in to our fifth or sixth day in a row of temperatures >100 deg. F. I hope to soon have a photo or two of the apparent juvenile silvers we captured this past week at this site.