/pdf/mountain-rivers-revisited-5gdsdlaw8w.pdf

Mountain Rivers Revisited

http://www.des.ucdavis.edu/research/sihlab/pdfs/Phenotype%20Management.pdf

Phenotype management: a new approach to habitat restoration

We assessed the efficacy of passive gravel addition at forming catostomid spawning habitat under various flow regimes in the Cheoah River, a high-gradient tailwater river in North Carolina. The purpose was to provide a case study that included recommendations for future applications. A total of 76.3 m3 (162 tons) of washed gravel (10–50 mm) was passively dumped down the streambank and into the channel in four locations. Gravel sites differed in terms of average reach slope, bank slope, and the initial volume of gravel added, which could have influenced gravel entrainment. Maps of gravel movement under various flows suggested that large-magnitude discharges (≥113 m3/s) caused extensive migration; however, less obvious, smaller discharges (∼28 m3/s) still caused substantial shifting, which may influence the stability of catostomid spawning substrates. Following gravel addition, the proportion of gravel in the streambed was significantly higher at all gravel sites. However, comparisons of sites to r...

http://www.srs.fs.usda.gov/pubs/ja/2010/ja_2010_mcmanamay_001.pdf

Gravel Addition as a Habitat Restoration Technique for Tailwaters

Ecosystem Flow Recommendations for the Susquehanna River Basin

Aquatic biodiversity continues to decline as humans modify the landscape, mainly because of stream habitat alterations and loss caused by urban development. Bluehead chubs may mitigate some effects of instream habitat degradation by providing clean gravel substrate via their spawning nests. We used path analysis, an extension of multiple linear regression, to explore the relationships among instream habitat degradation, adult chub abundance, chub nesting activity, and chub reproductive performance. Age-0 chub abundance was best explained by small adult abundance and nest abundance. Habitat disturbance indirectly and negatively influenced age-0 chub abundance through adult chubs and nest abundance. Percentages of pool and run habitat also had indirect negative effects on age-0 chub abundance. Several metrics of chub nesting activity (nest density [proportion of substrate occupied by nests], average nest size, and number of nests) were explained by both adult chub abundance and nesting site conditions. Variability among stream systems described significant variation in adult chub abundance and nesting characteristics and, if unaccounted for, would have resulted in large unexplained variability. Chub nesting activity served as a link between habitat degradation, adult chub abundance, and their reproductive performance. Our study provides preliminary evidence that bluehead chubs’ nesting activity may be a mechanism of their persistence in degraded stream reaches. We recommend confirmatory studies through in-stream manipulative experiments.

Bluehead chub nesting activity: a potential mechanism of population persistence in degraded stream habitats

Spawning behaviors were filmed and observed in the nest-building minnows, the bluehead chub, Nocomis leptocephalus, and river chub, N. micropogon. Analysis of videotapes exposed previously unreported behaviors (e.g., female retroflexure) and a precise sequence of male-female interactions that coordinated a successful spawn. Reproductive behaviors were classified into six sequential categories (interim, approach, alignment, run, clasp, dissociation) to facilitate interspecific comparisons. The most conspicuous differences between species involved the intensity of the female's retroflexure and the male's spawning clasp (strong in N. leptocephalus vs. weak in N. micropogon) and reproductive behaviors of subordinate males. In N. leptocephalus, subordinate males spawned concurrently and independently of the resident male over a communal nest, whereas in N. micropogon a subordinate acted like a satellite male and stole spawns from the nest-building male. In addition, heterogeneric spawning clasps invol...

Spawning Behaviors in the Bluehead Chub, Nocomis leptocephalus, River Chub, N. micropogon and Central Stoneroller, Campostoma anomalum

/pdf/nocturnal-reproductive-behavior-in-semotilus-atromaculatus-43nnu43w53.pdf

Nocturnal Reproductive Behavior in Semotilus atromaculatus (Pisces, Cyprinidae)

/pdf/pebble-nests-of-four-semotilus-species-uzsnmoikb8.pdf

Eugene G. Maurakis

Papers

Spawning Behaviors in the Bluehead Chub, Nocomis leptocephalus, River Chub, N. micropogon and Central Stoneroller, Campostoma anomalum

Nocturnal Reproductive Behavior in Semotilus atromaculatus (Pisces, Cyprinidae)

Pebble-Nests of Four Semotilus Species