Amount Of Fine Sediment Research Articles

Evaluation of Fine Sediment Intrusion into Whitlock-Vibert Boxes

Abstract We compared the amount of fine sediments intruding into gravels contained in buried Whitlock–Vibert (W–V) boxes to that of surrounding spawning gravels. Fine sediments ( 0.12) or between unwrapped W–V boxes and surrounding gravel (P > 0.33). Comparison of increase in percent fines smaller than 2.0 mm between unwrapped boxes and surrounding gravels revealed no statistical difference (P = 0.52), with high test power (0.9032). Our study indicates that W–V boxes will not trap or accumulate fine sediments in amounts significantly different from surrounding gravels; therefore, their use can provide representative results in incubation studies.

Differences in Macroinvertebrate Taxa Richness and Density between Samplers Located along the Shoreline and inside the Navigation Channel of the Kanawha River, West Virginia

Abstract Two types of basket samplers (gravel and large-cobble) were deployed near the shoreline and inside the navigation channel in the Kanawha River, West Virginia. In general, gravel basket samplers suspended in the water column collected more macro-invertebrates and more taxa than large-cobble basket samplers deployed on the river bottom. Gravel basket samplers collected significantly more individuals inside the navigation channel than near the shoreline, whereas large-cobble basket samplers collected significantly more individuals along the shoreline than inside the navigation channel. Taxa richness was not significantly different between the shoreline and the navigation channel. We attributed the observed differences to the relative amounts of fine sediments in the two areas of the river.

Description of Brown Trout Redds in a Mountain Stream

We sampled redds of brown trout Salmo trutta in a mountain stream to describe egg location and substrate composition after spawning and during egg incubation. A single-probe freeze-coring device was used to sample egg depth and substrate composition. We found eggs throughout redds but most often in the front half of the tailspill (the substrate mound that accumulates as the redd is excavated progressively upstream). Eggs were buried between 2 and 23 cm below the substrate surface but were most frequently 9–12 cm deep. Spawning fish cleaned substrate particles less than 6.3 mm in diameter from egg pockets, yet the percentage of particles smaller than 1.7 mm in egg pockets was correlated with that outside redds. Egg pockets contained particles larger than 50 mm more often than did any other location, indicating that particles of this size were used as egg pocket centrums. The percentage of 1.7-mm and smaller particles in egg pockets was higher in winter than in fall. We conclude that (1) spawning brown trout 20–40 cm in total length substantially alter the substrate in egg pockets; (2) the amount of fine sediment in egg pockets is positively correlated with that in the adjacent streambed; and (3) fines accumulate in egg pockets during the incubation period.

Effects of sedimentation on the behavior and distribution of riffle insects in a laboratory stream1

Abstract Studies were conducted to determine the effects of 3 levels of sedimentation on the behavior and distribution of selected mayflies, stoneflies and caddisflies in artificial laboratory streams. Most species responded negatively to increased levels of sedimentation; all preferred unsedimented over heavily sedimented substrate. Sensitivity to sedimentation differed among species with size, morphology, and behavior accounting for much of the variation. As sediment levels increased, more of the test substrate became uninhabited. Density per cobble increased only slightly with greater quantities of fine sediment. Nonburrowing species were unsuccessful in gaining access beneath cobbles when the undersurfaces and sides were sealed in fine sediments.

Ordination of some littoral benthic communities in Bear Lake, Utah-Idaho.

Bottom invertebrate communities were compared along the western shoreline of a large oligotrophic lake (Bear Lake, Utah-Idaho). A technique of community ordination was used for the comparisons. Ordination indicated that differences among stations were associated with local differences in bottom type. The bottom type was apparently influenced by isolation from lake currents, nutrient additions, and increased amounts of fine sediments and organic matter. The amount of silt+clay was the most important sediment factor affecting the invertebrate communities. Most communities were dominated by a small species of larval chironomid, Tanytarsus.