The objective of this study was to obtain a bioassessment using benthic macroinvertebrates to meet TMDL (Total Maximum Daily Load) criteria for an oligotrophic (Lake Seminary) and an eutrophic (Lake Jesup) freshwater system in Seminole County, Florida. Monthly sampling of the benthic macroinverterbrate communities provided important biological data necessary to construct TMDL protocol and trophic state. Since macroinvertebrates are near the base of the food chain, they not only provide a critical role in the natural flow of energy and cycling of nutrients through the food web, but also provide a good indication of water quality by their presence and abundance. This study suggests that TMDL protocol and reversal trends in eutrophication can be successfully monitored using benthic macroinvertebrate data. Comparative methodology between the LCI and conventional methods indicate that the LCI is a valid, cost-effective and rapid bioassessment method when compared to the conventional method and that the conventional method is an effective tool when more in depth benthic studies are needed as it shows distinct seasonal patterns and accounts for more of the sensitive, intolerant taxa. Furthermore, this type of biological monitoring and trend analysis aids in the implementation of anthropogenic controls that targets waters for TMDLs in suspect systems. When integrated within a watershed management plan, multi-metric indexing functions as an effective overall indicator of the biological condition within a waterbody responding to its watershed.

Black Creek is a small watershed located in Wise County, Virginia, west of the town of Norton. At the time of this survey, the watershed encompassed approximately 929 hectares of mine and forest lands with a small recreational area. Black Creek proper is a third-order stream approximately 6.7 km in length from its headwaters to its confluence with the Powell River in Kent Junction. Black Creek and several of the tributaries within the watershed were previously identified as areas impacted by acid mine drainage. The watershed was used in a study to identify sources of acid mine drainage and the best methods for its evaluation. The acid mine drainage sources were first identified using visual inspection and field chemistry. Additional stream segments were then included in the assessment process using metal (aluminum, copper, iron, magnesium, manganese, and zinc) analyses of both overlying water column and sediments. Using an upstream reach of Black Creek as a reference, short-term toxicity testing was employed, as well as a long-term purge study. The pH at sampling locations ranged from 2.75 to 7.87 SU, and conductivity ranged from 196 μmhos/cm to 2040 μmhos/cm. All metals were elevated when compared to the reference. Water column samples collected from locations with low pH were acutely toxic to Daphnia magna and Pimephales promelas. Mortality was high in the elutriant test at locations where pH was low, conductivity was elevated, metals were high, or a combination of these. In the initial sediment tests, all sampling locations were significantly different than the reference for survival of Chironomus tentans and reproduction of D. magna. One location was significantly different than the reference for survival of D. magna. In the sediment tests completed after two months, survival of C. tentans was only different from the control in three locations but was significantly different for growth at all locations. Reproduction by D. magna was again significantly less than the reference at all locations. At eight months, only two locations were significant for survival of C. tentans and after 15 months, no significant differences occurred between any stations. The study indicates that stream segments that are severely impaired by acid mine drainage are easy to identify using visual inspection and field water chemistry. Those that are moderately impaired require more investigation and may not be responsive to short-term toxicity tests. Benthic macroinvertebrates, leaf packs, and periphyton were evaluated in the field. Benthic macroinvertebrate communities and leaf-pack breakdown were evaluated at nine locations, while periphyton was evaluated at the mouth of Black Creek, as well as five sites in the Powell River receiving system. While leaf-pack information and benthic macroinvertebrate samples yielded similar information, benthic sampling was much simpler and less time consuming. Additionally, benthic macroinvertebrate sampling, particularly over several sampling events, was more sensitive at the most severely impacted AMD stations. The stations were broken down into five different categories in order to better determine which evaluation techniques were most sensitive and cost-effective. The five categories were Non-Impaired, Slightly Impaired, Moderately Impaired, Severely Impaired, and Severely pH impaired. Once the locations were categorized, each method used to evaluate toxicity was examined to determine which methods best identified acid mine drainage impairment in the Black Creek watershed. The methods utilized include the following: basic water chemistry; metals analysis of sediments and water column; acute toxicity testing using both D. magna and P. promelas; short-term elutriant and sediment tests; chronic sediment test using C. tentans and D. magna; a purge study; benthic macroinvertebrate sampling; leaf-pack and algal-tile studies. After evaluating these methods, it was determined that using basic water chemistry and benthic macroinvertebrate sampling were the best methods for evaluating acid mine drainage impairment in this watershed. The reference station was identified as Non-Impaired. Two stations located in the lower portions of Black Creek (L11 and L1) were also Non-Impaired or only Slightly Impaired with the benthic macroinvertebrate results indicating little impairment. Stations U2, U6, U7, and BBM were also found to be Slightly Impaired. The station on the margin of the wetland, U5, was Moderately Impaired. Two previously identified areas of impairment, U9 and U10, (Cherry et al. 1995) were identified as Severely pH Impaired and Severely Impaired, respectively. / Master of Science

Agriculture, urbanization, and human activities, if not managed carefully, can expose a water body to environmental degradation, decreased water quality, and ultimately impaired benthic macroinvertebrate assemblage conditions. In streams where the benthic macroinvertebrates are impaired, the stream itself will not be meeting the water quality standards set forth in the Clean Water Act. As a result, the goal of this study was to establish relationships between benthic macroinvertebrates and their stressors so that stressor levels that would not adversely impact the benthic macroinvertebrates could be determined. Stressors such as sediment, habitat, water quality, landuse, watershed characteristics, and livestock numbers impact the benthic macroinvertebrate assemblage conditions. Since sediment is recognized as the Nation's leading pollutant and since the benthic macroinvertebrates live in the sediment on a stream bottom, this study placed emphasis upon the investigation of sediment as a primary stressor to the benthic macroinvertebrates. The specific objectives of this study were to develop relationships between the benthic macroinvertebrates and sediment and other stressors for Virginia streams, to evaluate the accuracy of the stressor/benthos relationships, and to discuss the implications of the study results for development of benthic TMDLs. A procedure to determine the relationships between stressors and benthic macroinvertebrate assemblage conditions was developed. Existing data on sediment, habitat, water quality, landuse, watershed characteristics, livestock numbers, and benthic macroinvertebrate assemblage conditions were compiled for 34 stations with 105 samples collected from the fall of 1996 to the fall of 1998. The 34 stations were located within 13 counties in Virginia (Rockbridge, Rockingham, Augusta, Frederick, Shenandoah, Page, Loudoun, Fairfax, Prince William, Fauquier, Culpeper, Rappahannock, and Madison) and in watersheds dominated by agricultural, urban, and forested landuses. Virginia currently uses the Rapid Bioassessment Protocol (RBP) method in its Biological Assessment Program. The RBP compares habitat and biological measures of the benthic macroinvertebrates to reference conditions using individual metrics. VADEQ's Biomonitoring Database, together with Ambient Water Quality Monitoring reports, GIS data layers, and VADCR's Hydrologic Unit Animal Census Database provided all of the necessary information for the stressor variables and benthic macroinvertebrate conditions. Accordingly, the stressor/benthos relationships were evaluated using statistical analyses procedures such as forward, backward, and stepwise multiple regression techniques; correlation analysis; principal component analysis; and r-square analysis. The statistical results indicated that sediment alone cannot be used to assess the benthic macroinvertebrate assemblage conditions. Other stressors such as dissolved oxygen, flow, % urban land, total suspended solids, temperature, stream velocity, substrate, hardness and alkalinity greatly impact the benthic macroinvertebrate assemblage conditions. The study results also indicate that the individual metrics within the RBP procedure are just as critical as the final RBP values in describing the benthic macroinvertebrate assemblage conditions. Upon completing the steps needed to develop stressor/benthos relationships, the validity of the relationships were verified for their application to other streams in Virginia. Validation was completed using 10 stations with 29 samples from the fall of 1996 to the fall of 1998. The 10 stations were located within 8 counties in Virginia (Bedford, Montgomery, Pulaski, Giles, Botetourt, Albemarle, Orange, and Culpeper) and in watersheds dominated by agricultural, urban, and forested landuses to correspond with the stations used to develop the stressor/benthos relationships. The implications of the relationships with regard to TMDLs were also studied using total suspended solids (TSS) loadings, turbidity levels, and embeddedness levels as the stressors of concern. The results for all benthic stations within Virginia showed that moderately impaired streams generally need to reduce the amount of embeddedness by 11, reduce turbidity levels by 5 FTU (57%), and reduce TSS values by 7 mg/L (68%) to meet a threshold value that would no longer adversely impact the benthic macroinvertebrates. Similarly, for the severely impaired stations throughout Virginia to meet threshold values, embeddedness amounts need to be reduced by 22, turbidity reduced by 57 FTU (93%), and TSS reduced by 74 mg/L (96%). This study was important since the proposed stressor/benthos relationships can provide policymakers with a useful tool to determine stressor thresholds that will not adversely impact the benthic macroinvertebrate assemblage conditions for use in developing benthic TMDLs in Virginia. The stressor/benthos relationships could also be used to determine the impact of certain activities or stressors on the benthic macroinvertebrates assemblage conditions in a given stream. / Master of Science

As atividades agrícolas, principalmente as monoculturas, exigem grande utilização de insumos. A aplicação constante de defensivos agrícolas, como herbicidas, pesticidas e fungicidas, tem promovido crescentes impactos sobre os recursos hídricos e biota neles presentes, principalmente em organismos não alvo dessas substâncias. O presente estudo teve como principal objetivo avaliar os efeitos do fungicida Pyrimethanil na comunidade de macroinvertebrados bentônicos, por meio do monitoramento ambiental em unidades experimentais de campo (mesocosmos) e ensaios ecotoxicológicos laboratoriais com indivíduos da espécie Chironomus sancticaroli. Os mesocosmos foram construídos utilizando-se seis caixas de água com volume equivalente a 1500 litros. A contaminação dos mesocosmos com Pyrimethanil foi realizada por meio de pulverização direta na superfície da água aplicando-se uma concentração equivalente a 0,1 mg/L de Pyrimethanil nos mesocosmos contaminados. Dessa maneira, os mesocosmos foram divididos em três réplicas contaminadas e três réplicas controles. O monitoramento e coleta de amostras de água e macroinvertebrados bentônicos foram realizados com frequência mensal, durante o período de um ano. O fungicida Pyrimethanil não ocasionou alterações significativas nas variáveis monitoradas. Da mesma forma, a estrutura comunitária de macroinvertebrados bentônicos apresentou características semelhantes entre os mesocosmos contaminados e controles. Entretanto, durante o monitoramento, os mesocosmos controles apresentaram valores significativamente mais elevados na abundância de indivíduos e quantidade total de táxons quando comparados aos valores observados nos mesocosmos contaminados com Pyrimethanil. / Agricultural activities, mainly monocultures, require large use of inputs. The constant application of agrochemicals, as herbicides, pesticides and fungicides, has promoted impacts on water resources and biota at the center, especially on non-target organisms such substances. This study aimed to evaluate the effects of fungicide Pyrimethanil in benthic macroinvertebrate community through environmental monitoring experimental units of field (mesocosms) and laboratory ecotoxicological tests with individuals of Chironomus sancticaroli. The mesocosms were made using six tanks with maximum volume equivalent to 1500 liters. The contamination of the tanks with Pyrimethanil was performed by spraying of water on the surface by applying a fungicide concentration equivalent to 0,1 mg/L. Thus, the mesocosms were divided into three contaminated replicas and three controls replicas. The monitoring and sampling of water and benthic macroinvertebrates were performed on a monthly basis during the period of one year. The fungicide Pyrimethanil does not cause significant changes in monitored variables. Similarly, the community structure of benthic macroinvertebrates were similar characteristics between the contaminated and control mesocosms. However, during the monitoring, the mesocosms controls had significantly higher values in the abundance of individuals and total number of taxa compared to the values observed in the mesocosms contaminated with Pyrimethanil.

As atividades agrícolas, principalmente as monoculturas, exigem grande utilização de insumos. A aplicação constante de defensivos agrícolas, como herbicidas, pesticidas e fungicidas, tem promovido crescentes impactos sobre os recursos hídricos e biota neles presentes, principalmente em organismos não alvo dessas substâncias. O presente estudo teve como principal objetivo avaliar os efeitos do fungicida Pyrimethanil na comunidade de macroinvertebrados bentônicos, por meio do monitoramento ambiental em unidades experimentais de campo (mesocosmos) e ensaios ecotoxicológicos laboratoriais com indivíduos da espécie Chironomus sancticaroli. Os mesocosmos foram construídos utilizando-se seis caixas de água com volume equivalente a 1500 litros. A contaminação dos mesocosmos com Pyrimethanil foi realizada por meio de pulverização direta na superfície da água aplicando-se uma concentração equivalente a 0,1 mg/L de Pyrimethanil nos mesocosmos contaminados. Dessa maneira, os mesocosmos foram divididos em três réplicas contaminadas e três réplicas controles. O monitoramento e coleta de amostras de água e macroinvertebrados bentônicos foram realizados com frequência mensal, durante o período de um ano. O fungicida Pyrimethanil não ocasionou alterações significativas nas variáveis monitoradas. Da mesma forma, a estrutura comunitária de macroinvertebrados bentônicos apresentou características semelhantes entre os mesocosmos contaminados e controles. Entretanto, durante o monitoramento, os mesocosmos controles apresentaram valores significativamente mais elevados na abundância de indivíduos e quantidade total de táxons quando comparados aos valores observados nos mesocosmos contaminados com Pyrimethanil. / Agricultural activities, mainly monocultures, require large use of inputs. The constant application of agrochemicals, as herbicides, pesticides and fungicides, has promoted impacts on water resources and biota at the center, especially on non-target organisms such substances. This study aimed to evaluate the effects of fungicide Pyrimethanil in benthic macroinvertebrate community through environmental monitoring experimental units of field (mesocosms) and laboratory ecotoxicological tests with individuals of Chironomus sancticaroli. The mesocosms were made using six tanks with maximum volume equivalent to 1500 liters. The contamination of the tanks with Pyrimethanil was performed by spraying of water on the surface by applying a fungicide concentration equivalent to 0,1 mg/L. Thus, the mesocosms were divided into three contaminated replicas and three controls replicas. The monitoring and sampling of water and benthic macroinvertebrates were performed on a monthly basis during the period of one year. The fungicide Pyrimethanil does not cause significant changes in monitored variables. Similarly, the community structure of benthic macroinvertebrates were similar characteristics between the contaminated and control mesocosms. However, during the monitoring, the mesocosms controls had significantly higher values in the abundance of individuals and total number of taxa compared to the values observed in the mesocosms contaminated with Pyrimethanil.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-02-29T13:12:51Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Maria José Pinheiro Anacléto.pdf: 6289419 bytes, checksum: a5bad1c5254340842bfb8f794c251188 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-03-10T16:58:14Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Maria José Pinheiro Anacléto.pdf: 6289419 bytes, checksum: a5bad1c5254340842bfb8f794c251188 (MD5) / Made available in DSpace on 2016-03-10T16:58:14Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Maria José Pinheiro Anacléto.pdf: 6289419 bytes, checksum: a5bad1c5254340842bfb8f794c251188 (MD5) Previous issue date: 2015-08-31 / This study evaluated the temporal distribution of macroinvertebrate community relating one year of normal rainfall (2010) and one year of atypical rainfall (2014), in order to investigate the changes in the composition and structure of benthic macroinvertebrate communities in a hydropower project reservoir in a rain atypical scenario. The study was conducted in the same sampling area and sampling sites in the years 2010 and 2014, at the reservoir of Nova Ponte Hydroelectric Plant, located in the Triangulo Mineiro region, in Nova Ponte, River Basin Araguari, by using benthic macroinvertebrates as bioindicators in the environmental assessment. The results showed a low abundance and diversity of related organisms in 2014 year of atypical rain. The areas around the reservoir showed changes according to the use and occupation of land. However, human activities have tightly changing the water resources, interfering with the communities that live there. / O presente trabalho avaliou a distribuição temporal da comunidade de macroinvertebrados relacionando um ano de pluviosidade normal (2010) e um ano de pluviosidade atípica (2014), com o intuito de investigar as alterações na composição e estrutura de comunidades de macroinvertebrados bentônicos em um reservatório de empreendimento hidrelétrico em um cenário de chuva atípica. O estudo foi realizado na mesma área amostral e nos mesmos sítios amostrais nos anos 2010 e 2014, do reservatório da Usina Hidrelétrica de Nova Ponte, localizada na região do Triângulo Mineiro, no município de Nova Ponte, Bacia do Rio Araguari. Usando os macroinvertebrados bentônicos como bioindicadores na avaliação ambiental. Os resultados apresentaram uma baixa abundância e diversidade de organismos relacionado em um ano de chuva atípica. As áreas do entorno do reservatório apresentaram alterações de acordo com o uso e ocupação do solo. No entanto, as atividades humanas vem alterando fortemente os recursos hídricos, interferindo as comunidades que lá habitam.

Permafrost thaw slumping along lakeshores in lakes of the Mackenzie Delta Uplands, NT is known to alter water chemistry significantly. Its impact on benthic communities and persistent organic pollutant (POP) behaviour in lakes is not known. Benthic invertebrate communities responded to slumps through changes to community composition and size spectra. Larger taxa tended to dominate in lakes with slumps. Variability in biomass size spectra was related to total dissolved nitrogen concentration and slump size. Concentrations of POPs in Gammarus were negatively correlated with total phosphorus and positively correlated with the percentage of the catchment slumped. Lakes with slumps generally had higher mean concentrations of POPs in Gammarus (ex. ΣPCBsDisturbed = 27.54 ng/g lipid, ΣPCBsUndisturbed = 16.97 ng/g lipid; ΣDDT Disturbed =18.47 ng/g lipid and ΣDDTUndisturbed =10.86 ng/g lipid). Benthic invertebrate biomass was also negatively correlated with concentrations of contaminants in Gammarus, supporting the biomass dilution hypothesis. Thaw slumps have large enough impacts on the physico-chemical characteristics of lakes that they alter benthic invertebrate community composition and size-structure, and contaminant concentrations in Gammarus.

The Trinity River is an urbanized, effluent-dominated river, and is heavily relied upon for drinking water. The benthic macroinvertebrate community has been monitored for over 20 years, with the focus of this dissertation on three studies (1987-88, 2005, and 2011). Water quality improvement following dechlorination resulted in increased benthic metrics. Overall habitat quality, in-stream cover, surface water total organic carbon, sediment total organic carbon, near-field urban land-use, near-field forested land-use, surface water surfactant toxic units, and depositional sediment biofilm fatty acids all have statistically significant relationships with benthic macroinvertebrate metrics. These relationships are better defined with increased taxonomic resolution at the genus/species level for all benthic taxa, including Chironomidae and Oligochaeta. It is recommend that benthic identifications for state and city water quality assessments be done at the genus/species level. A novel method for quantifying depositional sediment biofilm fatty acids has been produced and tested in this dissertation. Benthic metrics are directly related to fatty acid profiles, with several essential fatty acids found only at upstream sites.

This post-fire study was conducted to characterize and observe fire induced changes in physical habitat parameters, water-quality conditions and macroinvertebrate assemblages in the Little Creek watershed, a tributary to Scotts Creek located in Cal Poly’s Swanton Pacific Ranch in Davenport, California. Pre-fire data was collected by a Cal Poly student, John Hardy, for his 2017 thesis. Post-burn bioassessment surveys for this study were repeated at four of the same study sites used by Hardy to provide comparisons to the California Stream Condition Index via a modified version of the State of California’s Surface Water Ambient Monitoring Program protocol. Macroinvertebrates were taxonomically identified to the family level. Commonly used bioassessment indices were utilized in conjunction with Stepwise regression and Analysis of Variance on both pre- and post-fire datasets to illustrate how physical habitat and water quality parameters changed after the fire and to determine the significance of collected environmental variables (stream shading, cross sectional area, and median particle size) as predictors of macroinvertebrate community structure. Despite most of Little Creek having moderate and high burn severities, it was found that physical habitat, water quality and benthic macroinvertebrate populations were not greatly disturbed by the 2020 CZU lighting complex fire. Proportions of highly disturbance/pollution sensitive taxa and increased following the wildfire and there was a dramatic shift from collector-gatherer to predator organisms. Comparison of pre- and post-fire data in this study showed fire having a minimal effect on the studied watershed. Difference in study goals and associated protocols used in the pre- and post-fire studies and the low water year following the wildfire, complicates statistical comparisons and poses threat to the validity of results. However, there is opportunity for further investigation about the ability of an ecosystem to successfully recover from natural disasters and disturbances, specifically when there is little human impact (or influence) on the ecosystem.

The objective of this research was to determine if physical and microbial sediment characterizations could be used to explain benthic macroinvertebrate distribution in two branches of Lake Ray Roberts, Texas.