Family Biotic Index Research Articles

Diversidad de insectos acuáticos como bioindicadores de la calidad del agua de la microcuenca del río jutiapa en las quebradas corralitos, limones y jutiapa del parque nacional La Tigra, Francisco Morazán, Honduras

El interés por conocer el estado actual de los cuerpos acuáticos y su evolución en el tiempo, ha estimulado una fuerte investigación durante las dos últimas décadas en la búsqueda de establecer estándares de juicio de “calidad de agua” que permitan satisfacer las demandas de uso del recurso. Una aproximación puede ser abordada a través del análisis de las características físico-químicas del agua y por otro lado, a través del uso de organismos indicadores de la calidad ambiental. En el período comprendido entre febrero y marzo (época seca) del 2009 se realizó una colecta de insectos acuáticos en la quebrada Limones, quebrada Corralitos y el río Jutiapa en el Parque Nacional La Tigra, Francisco Morazán, Honduras. El objetivo del estudio fue determinar la abundancia y la diversidad de insectos acuáticos bentónicos como bioindicadores de la calidad del agua y establecer las posibles relaciones con los parámetros físico-químicos de los sitios antes mencionados, mediante el análisis de parámetros comunitarios (Índice de Diversidad Shannon-Wienner, Índice de Berger-Parker, Índice de Similitud de Jaccard de la macrofauna bentónica y la aplicación del Índice Biótico de Familias BMWP-CR) para determinar la calidad del agua de las quebradas seleccionadas. En la quebrada Corralitos se colectaron 371 ejemplares, en la quebrada Limones 177 y en la quebrada Jutiapa 64, con un total de 612 especímenes, de 8 órdenes y 26 familias. El orden Díptera con 6 familias (siendo las principales Culícidae con 31% y las familias Simúlidae y Leptophlebiidae con 18.79%) representó el 51.96%. Los órdenes con menos especímenes fueron Lepidóptera (0.495%) y Plecóptera (0.16%). La quebrada más diversa fue la quebrada Limones y la menos diversa fue la quebrada Jutiapa. El mayor índice de dominancia fue para la quebrada Jutiapa, siendo la familia Leptophlebiidae más dominante. El índice de Similitud resultó ser mayor entre la quebrada Limones y la quebrada Jutiapa. El uso del Índice Biótico de familias permitió definir a las 3 quebradas de la microcuenca Jutiapa como de aguas de calidad regular, eutrofia y contaminación moderada con muy poca diferencia en los valores calculados, pero siempre dentro del mismo rango. De las 3 quebradas, la que presentó mayor contaminación orgánica fue la quebrada Corralitos, ubicada en la parte media, donde es impactada por diferentes cultivos, especialmente de café. Los resultados del índice de diversidad indican que la quebrada Limones podría ser considerada como un sitio de referencia por las buenas condiciones en su calidad biológica para futuras evaluaciones. Una comparación con los parámetros físicos y químicos del agua, permiten validar el uso del índice Biótico de Familias como una herramienta útil para la evaluación de la calidad de las aguas en ecosistemas de aguas continentales, por lo que se recomienda realizar estudios de la abundancia y de la diversidad de insectos acuáticos durante las diferentes épocas estacionales. DOI: http://dx.doi.org/10.5377/rct.v0i10.1061 Revista Ciencia y Tecnología, No. 10, junio 2012 pp 25-56

Effects of pollution on macroinvertebrates and water quality bio-assessment

Many large rivers in China have an inflow of contaminated water. Water pollution caused by urban sewage and agriculture, and occasionally pollution events from industries have become a significant stress on aquatic ecology. Pollution affects the biodiversity of the aquatic community and the species composition changes from natural species to tolerant species. The species composition of aquatic animals may reflect water pollution level. Extremely non-uniform distributions of functional feeding groups occurred as a result of high nutrient levels. A combination of chemical and biological methods constitutes the best approach for biological monitoring studies that measure water quality. Macroinvertebrates were used as bio-assessment indicator to determine the environmental quality of given water body. In this study, samples of water and macroinvertebrates were taken from several dozen sites in 14 rivers in China with different pollution levels, including the Yangtze, East, Weihe, Songhua, Yongding, and Panlong rivers. Macroinvertebrates were identified to genus or family level. Water samples were classified into different water quality grades according to the concentration of different substances. Five biological indices: taxa richness (S), density (D), total BMWQ score (t-BMWQ), average BMWQ score (a-BMWQ), and the family biotic index (FBI) were used for biological assessment of water quality. Analyzing macroinvertebrates’ occurrence in different water quality levels, taxa-specific indicators, which are defined as the taxa of macroinvertebrates that live in a certain water quality level but do not exist in other water quality levels were proposed for water quality bio-assessment. Leptophlebiidae, Siphlonuridae, Arctopsychidae, Perlidae, and Antocha sp. are the taxa-specific indicators for very good or good water quality; Chironomidae, Lymnaeidae, Tubifex sp., Limnodrilus sp., Limnoperna lacustris, Corbicula sp., Macrobrachium sp., Planorbidae, Glossiphoniidae, and Branchiura sp. are the taxa-specific indicators for very poor water quality; and Psychomyiidae and Hydroptilidae are the taxa-specific indicators for moderate water quality.

Ecohydrological analysis of Steelhead (Oncorhynchus mykiss) habitat in an effluent dependent stream in the Pacific Northwest, USA

ABSTRACTA conundrum exists in the US Pacific Northwest (PNW) whereby increasingly stringent federal environmental regulations governing the discharge of nutrients from wastewater treatment plants (WWTP) to low order streams may negatively impact salmonid species listed under the US Endangered Species Act (ESA). We examined baseflow, water chemistry, benthic algal biomass, macroinvertebrate diversity, and steelhead in the West Fork Little Bear Creek (WFLBC), Idaho, USA, above and below the city of Troy WWTP to explain why this creek is the most productive juvenile steelhead stream in the Potlatch River drainage. Discharge from the WWTP maintained 6 km of perennial flow during summer. Dissolved oxygen (DO) levels indicate that nitrification depressed DO below the Idaho state standard of 6 mg/L within the first 200 m downstream of the discharge. Because of rapid re‐aeration, DO concentrations recovered by 1.3 km. Despite high nitrate (0.12 – 4.3 mg/L) and total phosphorus (0.11 – 0.60 mg/L) concentrations 2.5 km downstream, benthic algal biomass remained below the US Environmental Protection Agency's ‘nuisance algae’ level (i.e., 150 mg/m2) throughout the stream. Family biotic index indicated good water quality conditions above and 2.5 km downstream of the discharge, although fairly poor condictions were found 200 m downstream from the effluent. The WFLBC ecosystem appears to have the capacity to accept and actually benefit from high nutrient loads from a WWTP. This work emphasizes the importance of developing a thorough understanding of the site‐specific biochemical functioning of an ecosystem before selecting and applying standard management practices. Copyright © 2013 John Wiley & Sons, Ltd.

Are Toronto’s streams sick? A look at the fish and benthic invertebrate communities in the Toronto region in relation to the urban stream syndrome

Impacts of urbanization on aquatic ecosystems are intensifying as urban sprawl spreads across the global land base. The urban stream syndrome (USS) identifies "symptoms" associated with urban development including changes in biotic communities, hydrology, water chemistry, and channel morphology. Direct relationships between road density (as surrogate of urbanization) and indicators of the USS were identified for streams in the Toronto region. Significant negative relationships were revealed between road density and biological (fish and benthic macroinvertebrate) richness, diversity, and fish Index of Biotic Integrity scores. Significant positive relationships were found between road density and tolerant fish/benthic macroinvertbrates, benthos Family Biotic Index scores, mean summer stream temperature, stream flashiness, and several water quality variables. Analysis of biological data showed that only four fish species and a reduced number of benthic macroinvertebrate families remained at the most urbanized sites. Road density was found to be a major determinant in both the fish and benthic macroinvertebrate community structure.

Ecological Assessment of Lake Hora, Ethiopia, Using Benthic and Weed-bed Fauna

Urbanization and human settlement in close proximity to the Ethiopian lakes are among the potential causes of changes in water quality and quantity. The drastic changes occurred into one of the Bishoftu crater lakes (Kilole) best exemplify this phenomenon. The purpose of this study was ecological assessment of Lake Hora using benthic and weed-bed fauna. Samples of benthic and weed-bed were collected monthly from September 2009 to March 2010 at 3 sampling stations (A, B, C), with a standard Ekman grab. Station A is in front of Ras Hotel, Station B is place of Irecha and station C was to the south crater of the lake. The benthic and weed-bed fauna of Lake Hora included a total of 6958 individuals within 27 taxa belonging principally to Copepod (2812) and Chironomidae (1460) and Ecdyonuridae (735). A high number of organisms were observed mainly at stations B and A (3198 and 2342respectively). The correlation result indicates that oxygen showed strong relation to benthic and weed bed fauna distribution and abundance. There were high number of individuals, taxa diversity, evenness and grate number of rare taxa of benthic and weed-bed fauna at stations A and B, but these stations were affected by the community around the lake area for different reasons (for example washing clothes, boat parking and others).However low density and abundance of macroinvertabrates at station C could be due to: low organic matter load at station C which was free of human interactions; steeply slope geographical setting of the profoundly and its catchment and low vegetation cover. The Family Biotic Index result for all the sampling stations was 7.55, according to Hilsenhoff Family Biotic Index this value is indicating likely severe organic pollution and very poor water quality in all sampling sites. As this research finding indicates Lake Hora needs protection management strategies to maintain its sustainable use. Keywords : Benthic Fauna, Ethiopia, Lake Hora, Specimens, Weed-bed

Evaluation of Deposited Sediment and Macroinvertebrate Metrics Used to Quantify Biological Response to Excessive Sedimentation in Agricultural Streams

The objective of this study was to evaluate which macroinvertebrate and deposited sediment metrics are best for determining effects of excessive sedimentation on stream integrity. Fifteen instream sediment metrics, with the strongest relationship to land cover, were compared to riffle macroinvertebrate metrics in streams ranging across a gradient of land disturbance. Six deposited sediment metrics were strongly related to the relative abundance of Ephemeroptera, Plecoptera and Trichoptera and six were strongly related to the modified family biotic index (MFBI). Few functional feeding groups and habit groups were significantly related to deposited sediment, and this may be related to the focus on riffle, rather than reach-wide macroinvertebrates, as reach-wide sediment metrics were more closely related to human land use. Our results suggest that the coarse-level deposited sediment metric, visual estimate of fines, and the coarse-level biological index, MFBI, may be useful in biomonitoring efforts aimed at determining the impact of anthropogenic sedimentation on stream biotic integrity.

Physical and Ecological Thresholds for Deposited Sediments in Streams in Agricultural Landscapes

Excessive sedimentation in streams and rivers remains a pervasive problem for the protection of aquatic habitat and the sustainability of aquatic communities. Whereas water quality criteria have been determined for suspended sediments in many jurisdictions across North America, comparably little has been done for deposited (also known as bedded) sediments. Through Canada's National Agri-Environmental Standards Initiative, assessment techniques and analytical tools were developed for estimating environmental thresholds for deposited sediments in agricultural watersheds in New Brunswick (NB) and Prince Edward Island (PEI) in the Atlantic Maritimes of Canada. Physical thresholds were developed through assessment of geomorphic metrics, which were then analyzed using y-intercept and 25th percentile approaches. For NB, there was strong agreement in physical thresholds for both analytical approaches (e.g., percent fines <2 mm were 7.5 for y-intercept and 6.9 for 25th percentile approaches). In contrast, physical thresholds for PEI differed considerably between approaches (e.g., percent fines <2 mm were 6.1 for y-intercept and 19.6 for 25th percentile approaches), likely due to a narrower range in agricultural land cover. Cross-calibration of our provisional physical thresholds for NB with ecological (i.e., benthic macroinvertebrate) assessments show that ecological thresholds, calculated as change-points in relationships between Ephemeroptera-Plecoptera-Trichoptera relative abundance or Modified Family Biotic Index and geomorphic criteria, were more liberal than physical thresholds. These results suggest that provisional thresholds developed using geomorphic criteria should demarcate change from the least disturbed condition and reduce the risk of sedimentation degrading benthic ecosystems.

A comparative analysis of biotic indices that use macroinvertebrates to assess water quality in a coastal river of Paraná state, southern Brazil

Biotic indices to monitor water quality are helpful tools for evaluating the health of rivers and lakes. In Brazil water samples are mainly analyzed using physical and chemical attributes, because most biotic indices were developed in other countries and their effective application to Brazilian ecosystems requires significant research. This study compared four biotic indices commonly used to evaluate water quality via benthic macroinvertebrates in order to determine which index best reflects ecosystem health in a coastal river in Brazil's Paraná state. We also analyzed functional feeding groups. The indices studied were: 1) EPT (percent of Ephemeroptera, Plecoptera and Trichoptera); 2) BMWP' (Biological Monitoring Work Party System); 3) BMWP'-ASPT (Average Score per Taxon); and 4) HFBI (Hilsenhoff Family Biotic Index). All indices were calculated from five samples collected from April 2005 to April 2006 at two stations on the coastal do Pinto River. The river's headwaters are inside a protected area but impacts increase downriver (e.g., towns, cattle grazing, tourism). The HFBI index did the poorest job of reflecting water quality. No one index performed better than the others, and all indices yielded water quality scores that did not accurately reflect macroinvertebrate community structure because all of them had differences between ordination scores and the structure of assemblage. The functional feeding groups protocol classified the lower stretch of the river as disturbed due to human impacts, suggesting that this method is a good one to evaluate health in environments.

Calidad y Disponibilidad de los Recursos Hídricos en tres Microcuencuas Costeras del Municipio de Tola, Nicaragua

Las actividades económicas, el crecimiento de la población en general; así como los cambios climáticos globales, han aumentado la presión sobre los recursos hídricos en el país. Esto se refleja tanto en una disminución en la disponibilidad, así como en la pérdida de calidad de estos recursos. En consecuencia, los gobiernos municipales han formado alianzas estratégicas con organismos internacionales e instituciones académicas para producir información base necesaria para la creación y ejecución de planes de ordenamiento territorial, a fin de planificar futuras demandas de agua. El desarrollo turístico en la franja costera del Municipio de Tola ha generado cambios en el uso del suelo, desprotección de las zonas de recarga de los acuíferos, posible riesgo de intrusión marina por el bombeo excesivo en la zona costera, y ha creado problemas con la disposición de residuos sólidos. Los resultados indican que hay disponibilidad de agua, tanto superficial como subterránea en las tres microcuencas costeras estudiadas; sin embargo su calidad se ha afectado por la presencia de heces fecales en las aguas de los pozos y por residuos de carbamatos en los ríos. El Índice Biótico de Familias de Hilsenhoff arrojó que el agua es relativamente mala en la parte alta y media de las 3 microcuencas. Fue identificada una especie nueva para el Pacífico Sur de Nicaragua (Theodoxus sp.) y una reportada por primera vez en 1972 en San Juan del Sur (Trinectes fonsecensis). Aunque el agua está disponible en cantidad, su calidad restringe su uso para consumo humano; por lo que es necesario concientizar a la población del municipio en cuanto a la protección, limpieza y uso adecuado de los recursos hídricos.DOI: http://dx.doi.org/10.5377/uyc.v5i8.314Universidad y Ciencia No 8 Año 5 2010 13-21

Determination of indicators and standards for tourism impacts in protected Karaj River, Iran

This study was conducted with the main objective of determining the indicators and standards for the impact of tourism on the protected Karaj River in Tehran Province, Iran. The survey was carried out during the visitors’ peak season at several recreational areas along the protected Karaj River. Discriminative analysis was used to differentiate between the sites in terms of visitor satisfaction. The indicators were as follows: trash in the water, trash along the river banks, water quality, number of visitors, visitors’ distance to river, and visitors’ awareness of indicators. The following standards are suggested to improve the management of the site, including less than 12 percent of trash (both on the water surface and river banks), a family biotic index of less than five, less than 625 individuals per hectare, settlement points of more than 9 m from the river and a score of more than 32 on the scale of visitors’ awareness of potential impacts.

The use of a Stream Visual Assessment Protocol to determine ecosystem integrity in an urban watershed in Puerto Rico

The growing need to protect stream ecosystems in Puerto Rico requires the development of monitoring procedures that help determine management priorities. Physical habitat assessments have been used to make quick evaluations that are cost efficient and easy conduct, yet they need to be studied further to understand their accuracy at predicting stream health. This study evaluated the efficiency of the Hawaii Stream Visual Assessment Protocol (HSVAP) at determining integrity of streams within the highly urbanized Rio Piedras watershed in Puerto Rico. To validate the protocol we compared results from HSVAP assessments conducted at 16 reaches with water quality and macroinvertebrate data collected at the same sites. Results from linear regressions between the water quality measures and HSVAP scores showed that there was no significant relationships ( R 2 = 0.48; p = 0.08). This implies that the protocol is not supported by the water quality data. However, results from regressions between macroinvertebrate diversity and the number of families per site showed a significant positive relation with HSVAP scores ( R 2 = 0.30; p = 0.02; R 2 = 0.24; p = 0.05). In addition, a significant negative relation was observed between HSVAP scores and the Family Biotic Index (FBI) ( R 2 = 0.32; p = 0.02). Comparisons between ratings obtained from the FBI and HSVAP scores suggest that the HSVAP classified sites as having higher quality than the biological metric. Based on these results, it can be concluded that the HSVAP is a good tool for a general assessment of the physical characteristics of a stream, but it needs modifications to accurately assess ecological quality of streams in Puerto Rico.

Are the streams of the Sinos River basin of good water quality? Aquatic macroinvertebrates may answer the question

Macroinvertebrate communities are one of the most used groups in assessments of water quality, since they respond directly to the level of contamination of aquatic ecosystems. The main objective of this study was the assessment of the water quality of the Sinos River basin (Rio Grande do Sul state, Brazil) through biotic indices based on the macroinvertebrate community ("Family Biotic Index - FBI", and "Biological Monitoring Working Party Score System - BMWP"). Three lower order streams (2nd order) were selected in each one of three main regions of the basin. In each stream, the samplings were performed in three reaches (upper, middle, and lower), totalling 27 reaches. Two samplings were carried in each reach over one year (winter and summer). A total of 6,847 macroinvertebrates distributed among 54 families were sampled. The streams from the upper region were of better water quality than the lower region. The water quality did not change between the upper, middle and lower reaches of the streams. However, the upper reaches of the streams were of better water quality in all the regions of the basin. The water quality of the streams did not vary between the summer and the winter. This result demonstrated that water quality may be analysed in both studied seasons (summer and winter) using biotic indices. The analysis of the results allows us to conclude that the biotic indices used reflected the changes related to the water quality along the longitudinal gradient of the basin. Thus, aquatic macroinvertebrates were important bioindicators of the water and environmental quality of the streams of the Sinos River basin.

A Comparison of Urbanization Effects on Stream Benthic Macroinvertebrates and Water Chemistry in an Urban and an Urbanizing Basin in Southern Ontario, Canada

Abstract Benthic invertebrate communities were compared in several watersheds within an urban basin and an urbanizing basin in southern Ontario, Canada. The urban watersheds of the Lake Ontario basin and the urbanizing watersheds within the Lake Simcoe basin share similar geologies, soils, and climates, but differ in the stage of urban development within these two basins. Correspondence analysis showed that invertebrate populations formed distinct groups split between these two basins owing to intense urban development in the Lake Ontario watersheds versus the agricultural nature of the Lake Simcoe basin. Canonical correspondence analysis ordinations indicated that the major environmental gradients were related to urban land cover (imperviousness), chloride, nitrates and stream order factors. Urban land cover and chloride were most strongly associated with the first axis. The typical logarithmic relationship between urban land cover and benthos found in other studies was not evident in this study. Rather, 9 of the 12 metrics tested had significant linear relationships with urban land cover. The Hilsenhoff Family Biotic Index and percent Oligochaeta metrics showed the strongest positive linear relationships with urban land cover. Pollution sensitive groups (Ephemeroptera, Plecoptera, and Trichoptera) along with richness and diversity measures decreased with increasing urbanization.

Influence of Open Space on Water Quality in an Urban Stream

Much attention has been given to the impairment of streams in urban areas and to the value of green space in preventing degradation. However, few studies have examined whether green space can remediate water quality downstream of contaminant sources. To assess the degree to which an ecological preserve was able to ameliorate upstream water quality impairments, we examined changes in conductivity, total inorganic nitrogen (TIN), and a family biotic index (FBI) for benthic macroinvertebrates in a partially urbanized stream in eastern New York state, USA. We expected conductivity, which results mainly from road de-icing salt, to decrease in the green space due to dilution from low-conductivity surface runoff. We also expected TIN and FBI to indicate stream improvements in response to increased vegetative cover in the green space. Contrary to expectations, conductivity did not improve in the ecological preserve, although TIN and FBI values did improve. Differences in scales of response explain this contrast in recovery/conductivity responded to basin-wide percentage impervious surface cover (ISC), while TIN and FBI responded to riparian-scale ISC, which declined sharply in the ecological preserve. Conserving riparian green space can aid natural recovery of TIN and FBI. In contrast, controlling conductivity requires watershed-wide management.

Do Karst Rivers "deserve" their own biotic index? A ten years study on macrozoobenthos in Croatia

In this study we present the results of a ten year survey of the aquatic macroinvertebrate fauna along four karst rivers: Jadro, Žrnovnica, Grab and Ruda, all of them situated in the Middle Dalmatia region of Croatia, in an attempt to construct the Iliric Biotic Index, which will be more applicable for the water quality analysis than the most frequently applied biotic index in Croatia, the Italian Modification of Extended Biotic Index. The rivers geologically belong to the Dinaric karst, unique geological phenomena in Europe. Benthic macroinvertebrates were collected along each river at 15 sites by standard methods of sampling along with several physicochemical parameters, including: temperature, dissolved oxygen, carbon dioxide, alkalinity, hardness and pH. Univariate and multivariate techniques revealed differences in the macroinvertebrate community structure as well as in physicochemical parameters between the Karst rivers and continental rivers. Based on those differences, the Iliric Biotic Index was proposed as the standard of karst river water quality in Croatia in accordance with the EU Water Framework Directive. Differences between the Iliric Biotic Index and the most commonly used biotic indices in the European Community and the USA (The Biological Monitoring Working Party (B.M.W.P.) scores, i.e. Extended Biotic Index, Indice Biotique, Family Biotic Index) suggest that karst rivers need a new biotic index.

Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed1

Orzetti, Leslie L., R. Christian Jones, and Robert F. Murphy, 2010. Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed. Journal of the American Water Resources Association (JAWRA) 46(3):473‐485. DOI: 10.1111/j.1752‐1688.2009.00414.xAbstract: This study tested the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining habitat, selected water quality variables, and benthic macroinvertebrate community metrics in 30 streams with buffers ranging from zero to greater than 50 years of age. To assess water quality we measured in situ parameters (temperature, dissolved oxygen, and conductivity) and laboratory‐analyzed grab samples (soluble reactive phosphorus, total phosphorus, nitrate, ammonium, and total suspended solids). Habitat conditions were scored using the Environmental Protection Agency Rapid Bioassessment Protocols for high gradient streams. Benthic macroinvertebrates were quantified using pooled riffle/run kick samples. Results showed that habitat, water quality, and benthic macroinvertebrate metrics generally improved with age of restored buffer. Habitat scores appeared to stabilize between 10 and 15 years of age and were driven mostly by epifaunal substrate availability, sinuosity, embeddedness, and velocity depth regime. Benthic invertebrate taxa richness, percent Ephemeroptera, Plecoptera, Trichoptera minus hydropsychids (%EPT minus H), % Ephemeroptera, and the Family Biotic Index were among the metrics which improved with age of buffer zone. Results are consistent with the hypothesis that forest riparian buffers enhance instream habitat, water quality, and resulting benthic macroinvertebrate communities with noticeable improvements occurring within 5‐10 years postrestoration, leading to conditions approaching those of long established buffers within 10‐15 years of restoration.

Evaluación de la calidad de las aguas del estero Limache (Chile central), mediante bioindicadores y bioensayos

The water quality in the Limache stream was evaluated at five sampling stations during the pe- riod of low water flow. At each station, aquatic macroinvertebrates were collected and the following parame- ters were measured in situ: pH, conductivity, dissolved oxygen, and total dissolved solids. The biological oxy- gen demand, total phosphorus, and total nitrogen were determined in the laboratory. Water toxicity was deter- mined through toxicity bioassays with the microalga Pseudokirchrneriella subcapitata. Thirty-three macroin- vertebrate families were found and the dominant taxa were Dugessidae, Oligochaeta and Chironomidae. A significant correlation was found among the Family Biotic Index ChFBI, conductivity, and total dissolved solids (r = 0.92; p < 0.05). Species diversity was lowest, as was the growth rate of P. subcapitata, at the sta- tions with the greatest anthropogenic activity and in the discharge zone of a domestic wastewater treatment plant.

Evaluación de la calidad de las aguas del estero Limache (Chile central), mediante bioindicadores y bioensayos

Se evaluo la calidad de las aguas del estero Limache en cinco estaciones de muestreo en el periodo de bajo caudal. En cada estacion se colectaron macroinvertebrados acuaticos, se midio in situ pH, conductividad, oxigeno disuelto, y solidos disueltos totales. En el laboratorio se determino la demanda biologica de oxigeno (DBO), fosforo total y nitrogeno total. Tambien se determino la toxicidad del agua mediante bioensayos con la microalga Pseudokirchrneriella subcapitata . Se determinaron 33 familias de macroinvertebrados, los taxa dominantes fueron Dugessidae, Oligochaeta y Chironomidae. Se encontro correlacion significativa entre el indice biotico de familias (ChIBF), la conductividad electrica y los solidos disueltos totales (r = 0,92; p < 0,05). La menor diversidad de especies y tasa de crecimiento de P. subcapitata fue en las estaciones con mayor actividad antropica y en la zona de descarga del efluente de una planta de tratamiento de aguas domesticas.

Community structure of macrozoobentos and bioassessment of water quality in Hujiaxi Stream of Qingjiang River Basin, Hubei Province

2006年4月至2007年3月,对清江流域上游一二级支流—胡家溪的大型底栖动物群落结构进行了调查研究,并利用生物指数对河水水质进行了系统评价.结果表明,共采集到大型底栖动物87种,其中环节动物3种,软甲动物3种,水生昆虫76种,软体动物5种.群落表现出明显的时空特点,6月份的物种最多,12月份的物种最少,S5的物种最多,S1的物种最少;各微生境中共有种占据优势,物种相似性均大于75%;功能摄食群则以收集者占优,共计达51种.群落密度在4月份达到最大,为3293ind./m²;而生物量则在12月份达到最大,为163g/m².采用Shannon多样性指数、生物指数和科级水平生物指数对胡家溪水质评价的结果是河水水质比较清洁.;Community structure of macrozoobenthos and the bioassessment on water quality in a second order river—Hujiaxi Stream of Qingjiang River basin were investigated from April 2006 to March 2007. The results showed that, among collected altogether 87 species of macroinvertebrates, there were 3 species of Annelida, 3 species of Mollusca, 76 species of aquatic insects, and 5 species of Malacostraca. The community structure exhibited obvious spatial and temporal variations. The species number reached its peak in June, and descended to the lowest in December. There was the largest species number in Site 5, and more species macroinvertebrates were presented in June than those in other months. Over 75% of the collected species could inhabit in all six types of microhabitats. The density of the community reached its peak in April at 3293 each/m², while biomass attained its peak in December at 163 g/m². The water quality was bio-assessed with Shannon-Weaner diversity, Biotic Index (BI) and Family Biotic Index (FBI), and results showed that the river water was fairly clean during the sampling period. Considering the coincidence with physical-chemical parameters, BI and FBI bio-assessment methods were much fit to apply in rivers of China.

Louisiana waterthrushes (Seiurus motacilla) and habitat assessments as cost‐effective indicators of instream biotic integrity

Summary1. Benthic stream animals, in particular macroinvertebrates, are good indicators of water quality, but sampling can be laborious to obtain accurate indices of biotic integrity. Thus, tools for bioassessment that include measurements other than macroinvertebrates would be valuable additions to volunteer monitoring protocols.2. We evaluated the usefulness of a stream‐dependent songbird, the Louisiana waterthrush (waterthrush, Seiurus motacilla) and the Environmental Protection Agency Visual Habitat Assessment (EPA VHA) as indicators of the macrobenthos community in headwater streams of the Georgia Piedmont, U.S.A. We sampled macrobenthos, surveyed waterthrushes and measured habitat characteristics along 39 headwater reaches across 17 catchments ranging from forested to heavily urbanised or grazed by cattle.3. Of the indicators considered, waterthrush occupancy was best for predicting relative abundances of macrobenthic taxa, while the EPA VHA was best for predicting Ephemeroptera–Plecoptera–Trichoptera (EPT) richness. Individual components of EPA VHA scores were much less useful as indicators of EPT richness and % EPT when compared with the total score. Waterthrushes were found along streams with higher % EPT, a lower Family Biotic Index (FBI) values and greater macrobenthos biomass.4. While macroinvertebrates remain one of the most direct indicators of stream water quality, stream bird surveys and reach‐scale habitat assessments can serve as cost‐effective indicators of benthic macroinvertebrate communities. Using stream‐dependent birds as an early warning signal for degradation of stream biotic integrity could improve the efficacy of catchment monitoring programmes in detecting and identifying perturbations within the catchment.