Author: Joseph McMurry OwenPublisher:
ISBN:
Category : Aquatic invertebrates
Languages : en
Pages : 60
Book Description
Seasonal and Longitudinal Changes in Functional Feeding Group Composition of Benthic Macroinvertebrates in the San Marcos River, Texas
Author: Joseph McMurry OwenPublisher:
ISBN:
Category : Aquatic invertebrates
Languages : en
Pages : 60
Book Description
Seasonal and Longitudinal Investigation on the Impacts of Recreational Activities on the Aquatic Macroinvertebrate Community Within the San Marcos River
Author: Ovie Oluwanisola AgarePublisher:
ISBN:
Category : Benthos
Languages : en
Pages : 88
Book Description
In the San Marcos River, recreational activities are most pronounced between April and October. Given the continued urbanization and increasing population in San Marcos there is need for a quantitative study on the possible effect of elevated recreational activities on the aquatic macroinvertebrates within the river. Furthermore, currently, there has been no study which quantified patterns in macroinvertebrate drift and benthic community structure simultaneously in the San Marcos River. Information on drift patterns and benthic macroinvertebrate habitat relationships is necessary to understand mechanisms for species persistence within the San Marcos River. In this study, I examined the seasonal and longitudinal patterns of benthic macroinvertebrate community composition at three different sites within the San Marcos River. I also examined the seasonal and longitudinal response of the drifting aquatic macroinvertebrates to changes in their habitat as a result of recreational activities in the San Marcos River. Tubing and swimming accounted for most of the recreation activity (>90%). Across all seasons, the upstream most study site had the highest drift densities compared to two downstream study sites. Canonical Correspondence Analysis (CCA) results explained 15.3% of the variability in the San Marcos River benthic macroinvertebrate community among vegetated habitats and 23.9% among open substrate habitats. Study results indicated that drift is related to benthic abundance. Macroinvertebrate drift densities followed the typical circadian pattern observed in other river systems and results indicated no increase in macroinvertebrate drift density during the peak recreation period. Conclusively, study results indicated that macroinvertebrates at the two upstream sites were not impacted by recreation and turbidity. However, the lower most study site, based on the CCA results indicate that substrate and turbidity are factors influencing the macroinvertebrate community.
Longitudinal and Seasonal Variation in Macroinvertebrate Taxonomic and Functional Feeding Group Composition of a Central Texas Stream
Author: Darrel C. SolanikPublisher:
ISBN:
Category : Benthos
Languages : en
Pages : 96
Book Description
Longitudinal Changes in Stream Benthic Macroinvertebrate Community Trophic Structure Along Two Central Texas Headwater River Continua
Author: Brian Richard CreutzburgPublisher:
ISBN:
Category : Benthos
Languages : en
Pages : 68
Book Description
Taxonomic Diversity, Assemblage Structure, and Biotic Integrety of Benthic Macroinvertebrates in the Guadalupe-San Marcos River System
Author: C. Lexi SmithPublisher:
ISBN:
Category : Freshwater biodiversity
Languages : en
Pages : 0
Book Description
Freshwater ecosystems are historically known to support a wide range of biodiversity at various trophic levels. However, the loss of freshwater biodiversity is related to trends in deteriorating water quality caused by anthropogenic disturbances that negatively impact bioindicator communities (e.g., benthic macroinvertebrates; BMI). I incorporated parameters of the Texas Commission of Environmental Quality (TCEQ) Rapid Bioassessment Protocols (RBP) to assess taxonomic diversity, assemblage structure, and biotic integrity of BMI in the Guadalupe – San Marcos River System (GSMR) in Texas. I sampled 25,512 BMI from 44 sites of the GSMR within various sampling methods, regions, habitats, and substrates. Taxonomic diversity and assemblage structure of BMI appeared to be homogenous across the river system regardless of sampling method, habitat, and substrate. However, regions suggested the San Marcos River of having the highest alpha diversity, lowest beta diversity, and greatest biotic integrity compared to the observed anthropogenic disturbance of the Guadalupe River overall. My study emphasizes the need for improved efforts towards large river management and conservation efforts of biotic communities by identifying the structural relationship of BMI assemblages in the GSMR. My results will help improve bioassessments and continuing research for BMI assemblages found within a large river system.
Benthic Macroinvertebrate Community Structure in Relation to Water Quality and Habitat in the Upper Pecos River, Texas
Author: Greg L. LarsonPublisher:
ISBN:
Category : Aquatic animals
Languages : en
Pages : 44
Book Description
Macroinvertebrate Functional Organization, Diversity, and Life History Variation Along a Sierra Nevada River Continuum, California
Author: Richard Lee BottorffPublisher:
ISBN:
Category : Freshwater ecology
Languages : en
Pages : 384
Book Description
Macroinvertebrate Community Structure and Function in Seasonal, Low-land, Tropical Streams Across a Pristine-rural-Urban Land-use Gradient
Author: Julie Elizabeth HelsonBenthic Macroinvertebrate Community Composition and Distribution Related to Seasonal and Geochemical Changes in a Chronically Acidified Stream
Author: Darlene Marie MadarishPublisher:
ISBN:
Category : Acid pollution of rivers, lakes, etc
Languages : en
Pages : 470
Book Description
Spatial Variation in Macroinvertebrates in Groundwater-dominated Rivers
Author: Kirby Lynn McCready WrightPublisher:
ISBN:
Category : Benthic animals
Languages : en
Pages : 0
Book Description
Benthic macroinvertebrate communities in riverine ecosystems are shaped by both local and large-scale influences. Most models of riverine community structure are grouped into either discrete or continuum conceptual models. However, there is much uncertainty in how these two classes of conceptual models apply to macroinvertebrate communities in the physicochemically consistent headwaters of spring-influenced rivers. This thesis examined benthic macroinvertebrate community composition and biomass among local discrete geomorphic mesohabitats (riffles, runs, and pools) and along an upstream to downstream gradient in two spring-fed rivers in central Texas (San Marcos River and Comal River, Hays County). The goal of my thesis was to examine the relative importance of downstream distance from springhead versus smaller-scale habitat conditions (i.e., mesohabitat units) in explaining the variation in macroinvertebrate community structure in these two spring-based subtropical riverine systems. I hypothesized that, because I sample in the upper physicochemically consistent reaches of both rivers that local mesohabitat conditions would explain more variation in community composition than downstream distance from springhead. I expected this change in community composition would be driven by replacement of taxa rather than differences in taxonomic richness. I also predicted that non-native benthic species would be more evenly distributed throughout the study reaches due to the consistency of physicochemical conditions. Finally, I predicted that the distribution of taxa specific biomass contributions will follow patterns seen in community composition change and will reflect taxonomic density estimates. To test these hypotheses, I sampled macroinvertebrates and local habitat parameters from mesohabitat types along three reaches in the first ~4 km of each river. I also determined biomass of each taxon and community-wide patterns of biomass distribution of benthic macroinvertebrates. I found that variation in taxonomic composition in both rivers was driven to a greater or equal amount by upstream to downstream distance from spring-influence, and by mesohabitat type. Taxonomic diversity did not vary with distance from springhead but was consistently lower in pool mesohabitats when compared to runs and riffles in both rivers. Compositional changes and patterns in b-diversity within mesohabitat types among study reaches indicated that replacement (as opposed to richness differences) was the main mechanism leading to patterns of b-diversity. I found that a non-native snail (Tarebia granifera) and an endemic spring snail (Elimia comalensis) appear to be spatially partitioning habitat in an upstream- to downstream manner. Finally, I found that Tarebia granifera constituted the largest proportion of benthic macroinvertebrate biomass in several study reaches downstream from springheads.