Author: Diane Katharine BarnesPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
Use of Benthic Macroinvertebrates to Assess Impacts of Agricultural Land Use in Nontidal Coastal Plain Streams
Author: Diane Katharine BarnesPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
Assessing Impacts of Animal Agriculture on Macroinvertebrates in Intermittent Coastal Plain Streams in the Southeastern USA
Author: Stephanie Nicole DavisPublisher:
ISBN:
Category :
Languages : en
Pages : 148
Book Description
Impacts of Land Use Disturbance on Fish and Aquatic Macroinvertebrate Assemblages in the Nolichucky River Watershed
Author: Hayley Sonia GotwaldPublisher:
ISBN:
Category : Agricultural ecology
Languages : en
Pages : 171
Book Description
Southern Appalachian watersheds of the United States are negatively affected by pesticides and fertilizers used in row crop agriculture. The objective was to determine if the amount of row crops is connected to changes in aquatic biotic assemblages draining the Nolichucky River watershed in east Tennessee. The hypothesis was the amount of row crops will negatively correlate with indices of biotic integrity (IBI) metrics for fish and benthic macroinvertebrates indicating healthy aquatic communities. For 18 sample sites in 2014 and 2015, IBI metrics were calculated. Water quality and elevation measurements were made before conducting IBIs. To assess changes in and amounts of land use/land cover (LULC), maps from 1999 to 2014 were produced with Landsat satellite imagery. Pollutant estimates (sediment, phosphorus, and nitrogen) were calculated using the Soil & Water Assessment Tool (SWAT) model. The area of row crops increased since 1999 (39 km2 in 1999 to 71 km2 in 2014). A principal component analysis was performed on LULC measurements from different scales (local, reach and catchment), water quality data, and elevation to produce a reduced set of explanatory variables that were uncorrelated but could be associated with IBI metrics. A canonical correspondence analysis associated fish metrics with LULC types: Impervious surfaces, non-row crop fields, and forest (p = 0.04 for axis 1 eigenvalue, p = 0.05 for species-environment correlations). For the benthic macroinvertebrate metrics, nonmetric multidimensional scaling found metrics indicative of poor stream health (percentage of oligochaetes and chironomids, percentage of nutrient tolerant organisms) were strongly positively associated with increasing use of row crops, impervious surfaces (p ≤ 0.01), and pollutant estimates (p ≤ 0.004). A redundancy analysis found increasing pollutant estimates were associated with fish metrics indicative of poor stream health (percentages of hybrids, piscivores, diseased fish, and number of sunfish species) (p = 0.03). When watersheds of tributary streams are converted to impervious and non-row crop field LULC, they function biologically like the larger main stem river. Although fish and benthic macroinvertebrate metrics indicated the tributary and main stem Nolichucky sites were in relatively good condition, increases in land conversion can further degrade stream biotic integrity.
Evaluating Benthic Macroinvertebrates as Bio-indicators of Freshwater Habitat Quality in an Eastern Oregon Agro-ecosystem
Author: Melissa A. ScherrPublisher:
ISBN:
Category : Agricultural pollution
Languages : en
Pages : 250
Book Description
The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that has been degraded by disturbance. In rivers, non-point source pollution affects the physical characteristics of the habitat and the endemic biotic assemblages. Aquatic macroinvertebrates are numerous and exhibit graded responses to various types of disturbance in the river, and may be used as indicators of habitat conditions. In this dissertation, macroinvertebrates were examined as bioindicators in the Umatilla River in eastern Oregon. The first study is a bioassessment of the impacts of agriculture on the benthic macroinvertebrate community in adjacent streams. The results of this study show that there are physical differences in habitat associated with adjacent land use, and the macroinvertebrate communities responded to these differences with changes in taxa richness and evenness. Indicator species analysis identified thirteen taxa which were indicative of habitat conditions associated with ideal habitat used as a reference condition, degraded habitat associated with agricultural land use, and transitional habitat associated with conservation/restoration management. The second study is a laboratory study in which the effects of temperature of a common mayfly nymph, Epeorus albertae (McDunnough) (Ephemeroptera: Heptageniidae) were evaluated. The study showed that not only the developmental rate of the nymphs was affected by temperature treatment (within a range of 18°C and 28°C), but the location of accumulated body tissues over time varied by temperature, with significant difference in the type of growth observed for insects held at the highest temperature. The third study examined the response of six indicator taxa to environmental variables as predictors of abundance in a non-parametric multiplicative regression. This study found that for all taxa examined, the two best predictors of abundance in the Umatilla River were turbidity and conductivity. Increased turbidity and conductivity are common effects of intensive agriculture in streams located in agro-ecosystems, but may potentially be mitigated by vegetative buffer strips and sustainable land use practices. Long term agricultural disturbance in the landscape has been shown to have lasting effects in the ecosystem which may be further exacerbated as global climate change increases dependence on freshwater resources. Understanding anthropogenic impacts on organismal communities and natural resources is vital to establishment of effective conservation, restoration, and maintenance of a healthy ecosystem.
Assessment Framework for Mid-Atlantic Coastal Plain Streams Using Benthic Macroinvertebrates
Author: J. R. MaxtedHabitat Quality, Land Use, & Acidification
Author: Determining the Association Between the Structure of Stream Benthic Macroinvertebrate Communities and Agricultural Best Management Practices
Author: Roger Holmes (M.Sc.)Publisher:
ISBN:
Category :
Languages : en
Pages : 174
Book Description
Farmers have been encouraged to adopt more sustainable farming practices (BMPs) that mitigate adverse agricultural effects on the natural environment. However, the ability of BMPs to protect or restore riverine systems continues to be questioned due to limited evidence directly linking BMP use with improved ecological conditions. The exclusion of hydrological pathways in previous field studies may explain why a direct link has not yet been established. The goal of this study was to assess the association between benthic macroinvertebrate community structure and the number and location of agricultural BMPs. Macroinvertebrates and water chemistry were sampled in 30 headwater catchments in the Grand River Watershed. Catchments exhibited gradients of BMP use and location as measured by the degree of hydrologic connectedness. Stepwise ordination regressions and variance partitioning were used to determine which environmental variables (i.e., BMP metrics, water chemistry parameters, habitat characteristics, and land use variables) were associated with benthic macroinvertebrate community structure. Water chemistry parameters were negatively associated with BMP metrics suggesting BMPs were mitigating losses of nutrients and sediments. However, BMP abundance and location explained minimal variation in benthic macroinvertebrate structure within the 30 sampled catchments. The absence of a strong association between BMPs and benthic macroinvertebrates may indicate a need for greater numbers and targeted siting of BMPS to improve water quality beyond a threshold point that would allow recolonization of intolerant invertebrate taxa. Focusing of conservation goals on ecological conditions and the promotion of BMPs that enhance in-stream habitat may also be required.
Effects of Watershed Land Use on the Benthic Macroinvertebrate Assemblages in Ridge and Valley Streams in Chattanooga, Tennessee
Author: Paul Leiper FreemanPublisher:
ISBN:
Category : Stream ecology
Languages : en
Pages : 156
Book Description
Effects of Land-use Change on Benthic Macroinvertebrates in the Upper Reaches of the Apies-Pienaar Catchment
Author: Joseph Alexander MuldersPublisher:
ISBN:
Category : Aquatic invertebrates
Languages : en
Pages : 122
Book Description
Urbanisation of catchment areas is a major cause of freshwater ecosystem degradation worldwide. As catchments become more developed and river ecosystems become increasingly engulfed in various land use activities, there is a growing need to understand these impacts on freshwater ecosystems. Benthic macroinvertebrates are extensively used as indicators of ecosystem health and have been an instrumental tool in ecosystem monitoring and management. The effects of changing land use on macroinvertebrates at a fine scale however, have not been extensively investigated. Therefore an investigation was conducted to compare chemical, physical and biological surface water quality parameters and aquatic macroinvertebrate community composition along the first 8 km of the Hartbeesspruit, which contains multiple land use types, in the upper Apies-Pienaar catchment in Gauteng, South Africa. Five sampling sites corresponding to changes in land use were sampled four times at six-week intervals from September 2013 to February 2014. Influential variables that were recorded included in-stream habitat, riparian cover, flow regime and surface water quality parameters. Physical surface water parameters that were tested in situ included pH, salinity, total dissolved solutes, temperature, clarity and conductivity. Ex situ surface water parameters that were tested included physical parameters (alkalinity and turbidity), chemical parameters (major ions, metal ions and nutrients), and biological parameters (bacteria, coliforms and Escherichia coli). Macroinvertebrates were sampled using Hester-Dendy artificial samplers, which, following a 6 week exposure period, were sampled three times from November 2013 to February 2014. Macroinvertebrates were identified to family level and counted. Macroinvertebrate community composition across sites was assessed through macroinvertebrate abundance, family richness, SASS score, ASPT, Shannon-Wiener index, Pielou s evenness, non-metric multidimensional scaling and Indval analyses. Nineteen families were collected, of which only three made up 80% of macroinvertebrates sampled. These families were Hirudinea, Chironomidae and Oligochaeta. Indices of macroinvertebrate community composition indicated a general increase in value from upstream to downstream which showed similar comparative variation between sites to physical water quality parameters (except temperature and clarity), major ions (except arsenic), the metal ion magnesium and nutrient sulphate. Surface water parameters showed patterns indicative of effects due to evaporation, dilution and connectivity of water flow along the stream due to the presence of dams and wetlands. Temperature was an important influence on macroinvertebrate abundance and family richness at a temporal scale. On a spatial scale the most influential parameters on macroinvertebrate composition were seen to be depth, turbidity and conductivity, and temperature to a lesser extent. The land use types that showed the greatest association with various assemblages were the urban, recreational and least transformed wetland land uses. Although major influential factors, this pattern was not seen to be strictly due to the input of contaminants arising from associated activities, nor the variation in physical characteristics, but rather the discontinuity in flow regime. It was concluded that at a fine scale, the strongest factors that influenced macroinvertebrate community composition along the Hartbeesspruit, was not land use type but rather the hydrological pathways of connectivity and stream flow that exist within the system. The hydrological pathways influenced values and concentrations of chemical and physical surface water parameters which in turn further influenced macroinvertebrate assemblages present.
Ecological Quality Assessment of Stream Ecosystems Using Benthic Macroinvertebrates
Author: Mi-Young SongPublisher:
ISBN:
Category :
Languages : en
Pages : 99
Book Description
In this study, we applied the SOM for ecological assessment using benthic macroinvertebrates in aquatic ecosystem. First, Chapter I, SOM was utilized to extract information from complex data of environmental variables and benthic macroinvertebrate communities residing in different micro-habitats. Although the sampling was carried out in a limited area, the patterns of environmental variables revealed spatial heterogeneity. The clustering of benthic macroinvertebrate communities in the trained SOM was efficient in showing temporal variation and evaluating water quality according to the conditions of different micro-habitats. Consequently, local spatial heterogeneity is important in revealing dynamics of community abundance and biotic indices, especially regarding restoration processes in polluted streams. Chapter II, the samples were grouped into three main clusters corresponding to distinc EPTC assemblages in the tributary streams of the Garonne River catchment, southern France. Lower richness and diversity of macroinvertebrates were observed in the areas affected by agricultural land use, being associated with high Total Dissolved Solids (TDS), Nitrate (NO3) and Chemical Oxygen Demand (COD). Tolerant EPTC species were identified as controlling parameters for the changes in the assemblages collected at the agricultural-impacted sites...