28 de outubro de 2021

Nolichucky River - Jackson Islands (Cherokee NF)

Written quite a while ago back at the beginning of the semester, I thought I would share this here. Due to COVID-19 restraints, campus vans were not available for Vertebrate Zoology field trips. However, I managed to convince Dr. Laughlin to share some tips about the location where we usually do a lab to find freshwater fish biodiversity. I decided to go do some exploring there on my own. The place? The Cherokee National Forest's Jackson Islands southeast of Jonesborough, Tennessee (the state's oldest town).

There is always a lot of biodiversity on a brief stop to Jackson Islands. The Nolichucky River seems to be more amazing and full of life every time I visit. While much of the river has been purged of life by thick, alluvial mica-sand released by human development upstream (i.e. riverside subdivisions and agricultural runoff from rows of tomatoes and corn), the Jackson Islands enable several sets of shallow riffles and shoals to prevail in the otherwise sluggish water of the Tennessee Dog Days. In these shoals, gigantic schools of fish (of all shapes, sizes, and ecological niches) dart amongst rocks and aquatic plants. "It's like a jungle," Dr. Laughlin told me, entangled by a mesh of rivercane and boxelders embraced by native, twining vines.

  1. Warpaint Shiners (Luxilus coccogenis) - Even outside of the breeding season, hundreds of Warpaint Shiners still boasted vibrant face-masks and fins. Swimming against the current, their upturned mouths consistently point skyward to hunt along the top of the frigid, mountain water being re-oxygenated over the slippery rocks. I usually find these much higher in elevation, filtering into small tributaries away from the main river systems. More aggressive and widespread Western Blacknose Dace (Rhinicthys obtusus) also schooled with the shiners, feeding downward in the currents.
  2. Sharphead Darter (Etheostoma acuticeps) - One of the best finds of the day was a federally-threatened Percidae; the Sharphead Darter. At first, I thought it was a typical Redline Darter (more common "back home" in the limestone lower reaches of the undammed Holston River watershed). Nope! This species is endemic to the Nolichucky River basin, sometimes occurring in the lower reaches of the Holston, but is much less common than most other rare Appalachian darters. It was found in the fastest, roughest, and clearest water in the shoals; darting under one of the last boulders not filled in by silt. It was incredible how dark and secretive the animal was, much more aware and robust than the more common species observable through the water's surface.
  3. Banded Darter (Etheostoma zonale): A widespread species, this unique fish was behaving "tropically," at least as far as pigment production goes. Even though it was long-past the breeding season, all individuals captured still retained crimson-red bands on their dorsal fins and vivid, emerald-green bands checkered across their sides. These were somewhat reclusive fish, crawling over pebbles on long, suction-cup-like pectoral fins.
  4. Tangerine Darter (Percina aurantiaca): These were massive darters; very perch-like in behavior. Instead of sitting on the bottom for extended periods of time, they were actively swimming against the current and hunting for several minutes at a time. Most of their breeding coloration was entirely gone, and some of the larger individuals rivaled 6" in length, cutting through the water much too quickly for capture.
  5. An eastern range extension (on iNaturalist, at least) for the Yellow Bullhead (Ameiurus natalis) in the Southern Appalachians. Several small juveniles were stuffed deep within the hair-like, red-tinted boxelder roots extending into the sluggish water just ahead of the shoals. Likely, sedimentation and a changing climate has brought them upstream into this more montane water. The pictured juvenile also had rather sharp pectoral barbs, and my fingers learned just how sharp from firsthand experience. A few larger ones were spotted, but not captured, as bullheads are surprisingly quick.
  6. Lots of juvenile River Chub (Nocomis micropogon) were frantically "rooting" like wild hogs on the sandy bottom of the water. Adults were abundant, too. These fish are kind of the keystone nest-builder, forming pebble mounds all of their heterospecifics also need for spawning. It's kind of funny to see them at this young, wild-eyed stage where they are much more vulnerable to predators and starvation, but not yet tasked with constructing a multi-species microhabitat.
  7. Wavy-rayed Lampmussel (Lampsilis fasciola), with a lure mimicking the tangerine darter. This lure attracts smallmouth bass, which try to eat the "fish," and in turn get doused with a cloud of parasitic larvae (glochidia). These baby freshwater mussels parasitize the bass, until they are old enough to become water-cleaning filter feeders. It appears to be a form of symbiosis, in some strange, exaggerated way.
  8. Native sunflowers growing abundantly in the fencerows of wide, sprawling pastures as the Unicoi Mountains give way to the Great Valley. One is very tall, with narrow leaves and large flowers; the Maximillian Sunflower (Helianthus maximiliani). Hundreds of their four-foot-tall stalks rose up anywhere tractors cannot reach.
  9. There are always copperheads (Agkistrodon contortrix) to help across the road on the way back to campus across Buffalo Mountain. On a warm evening, just after a drizzling rain, they emerge to hunt salamanders, cicadas, and of course, endothermic mice and birds, also actively searching for rain-enticed prey. Unfortunately, humans and copperheads have a lot of conflicts, and most drivers seldom hesitate to flatten any snake intentionally; if they even notice it in the first place. Usually, I'm able to pull off to the side of the road and use a stick or snake tongs to scoot the cinnamon-roll-shaped ball of scared pit viper across the road, but sometimes they have sustained pretty substantial injuries. (Please watch out for snakes while driving. They belong here, too).

Unlinked Species of Fish (without observations) Found around the Jackson Islands, 2021

  • Whitetail Shiner (Cyprinella galactura)
  • Telescope Shiner (Notropis telescopus)
  • Tennessee Shiner (Notropis leuciodus)
  • Northern Hogsucker (Hypentelium nigricans)
  • Redbreast Sunfish (Lepomis auritus)
  • Green Sunfish (Lepomis cyanellus)
  • Bluegill (Lepomis macrochirus)
  • Smallmouth Bass (Micropterus dolomieu)
Posted on 28 de outubro de 2021, 05:24 PM by cadecampbell cadecampbell | 10 observações | 3 comentários | Deixar um comentário

12 de julho de 2021

New River Expedition - 2021

Notes from the Blue Ridge Discovery Center New River Expedition I helped guide this year

  • Margined Madtoms (Noturus insignis), on average about 4-6" in length, emerge from deep, narrow crevices under smooth, rounded stones in tributaries that tie into the New River. Especially in quiet pools near waterfalls, they can be captured by hand or with a dipnet while hunting. They have beautiful black margins on their dorsal and caudal fins, too.
  • Pickerel Frog (Lithobates palustris) toxins are powerful in this area. I received a nice dose from the observed individual in some cuts I had in my finger from invasive canary-grass reeds, which burned profusely for a few minutes. Another guide ended up getting the toxins in his eyes, with similar effects.
  • Salamander activity surprisingly scarce; even after rain.
  • A great deal of unusual, small fish live in the New River tributaries. Best viewed/captured at night with lights above 500 lumens.
  • Mountain Mint (Pycnanthemum sp.) and Wild Beebalm (Monarda fistulosa) make a pretty amazing Oswego Tea at camp. Boil in a bush pot, strain through a bandana into a cup, and it tastes like a rich, strong cool mint; herbal edition. Camp kids enjoyed it.
  • Wild Garlic (Allium vineale) garlic bread is pretty great. Once again, enjoyed by the kids on the trip.
  • Lots of Southern birds mixed with northern species on the river in the willow trees. Great Egrets glide to the song of Warbling Vireos, Orchard Orioles, Yellow-throated Vireos, and Acadian Flycatchers. Wood Thrushes and Eastern Wood-Pewees abundant.
  • Apparently, an abnormally large number of deer and beaver chews were located on the river.
Posted on 12 de julho de 2021, 09:15 PM by cadecampbell cadecampbell | 4 observações | 2 comentários | Deixar um comentário