Application of the target fish community model to an urban river system

Several models have been developed to assess the biological integrity of aquatic systems using fish community data. One of these, the target fish community (TFC) model, has been used primarily to assess the biological integrity of larger, mainstem rivers in southern New England with basins characterized by dispersed human activities. We tested the efficacy of the TFC approach to specify the fish community in the highly urbanized Charles River watershed in eastern Massachusetts. To create a TFC for the Charles River we assembled a list of fish species that historically inhabited the Charles River watershed, identified geomorphically and zoogeographically similar reference rivers regarded as being in high quality condition, amassed fish survey data for the reference rivers, and extracted from the collections the information needed to define a TFC. We used a similarity measurement method to assess the extent to which the study river community complies with the TFC and an inference approach to summarize the manner in which the existing fish community differed from target conditions. The five most abundant species in the TFC were common shiners (34%), fallfish (17%) redbreast sunfish (11%), white suckers (8%), and American eel (7%). Three of the five species predicted to be most abundant in the TFC were scarce or absent in the existing river community. Further, the river was dominated by macrohabitat generalists (99%) while the TFC was predicted to contain 19% fluvial specialist species, 43% fluvial dependent species, and 38% macrohabitat generalist species. In addition, while the target community was dominated by fish intolerant (37%) and moderately tolerant (39%) of water quality degradation, the existing community was dominated by tolerant individuals (59%) and lacked intolerant species expected in the TFC. Similarity scores for species, habitat use specialization, and water quality degradation tolerance categories were 28%, 35% and 66%, respectively. The clear pattern of deviations from target conditions when observing fish habitat requirements strongly suggests that physical habitat change should be a priority for river enhancement in the Charles River. Comparison of our target and existing fish communities to those from a comprehensive study of Northeastern fish assemblage responses to urban intensity gradients revealed very similar results. Likewise, comparison of our TFC community and affinity scores to those of other TFCs from similar regions also yielded similar results and encouraging findings. Based on the positive results of these comparisons, the utility of the findings from the inference approach, and the widespread adoption of the TFC in the Northeast US, it appears that the TFC approach can be used effectively to identify the composition of a healthy fish community and guide river enhancements in both highly urbanized and non-urbanized streams and rivers in the Northeast US.     

Precipitation and river water chemistry of the Piracicaba River basin, southeast Brazil

Annual precipitation and river water volumes and chemistry were measured from 1995 to 1998 in a mesoscale agricultural area of southeast Brazil. Precipitation was mildly acidic and solute concentrations were higher in the west than in the east of the basin. Combustion products from biomass burning, automobile exhaust, and industry typically accumulate in the atmosphere from March until October and are responsible for seasonal differences observed in precipitation chemistry. In river waters, the volume-weighted mean (VWM) concentrations of major solutes at 10 sites across the basin were generally lower at upriver than at downriver sampling sites for most solutes. Mass balances for major solutes indicate that, as a regional entity, the Piracicaba River basin was a net sink of H+, PO4(3-), and NH4+, and a net source of other solutes. The main stem of the Piracicaba River had a general increase in solute concentrations from upriver to downriver sampling sites. In contrast, NO3- and NH4+ concentrations increased in the mid-reach sampling sites and decreased due to immobilization or utilization in the mid-reach reservoir, and there was denitrification immediately downriver of this reservoir. Compared with tributaries of the Chesapeake Bay estuary, the Piracicaba River is affected more by point-source inputs of raw sewage and industrial wastes than nonpoint agricultural runoff high in N and P. Inputs of N and C are responsible for a degradation of water quality at downriver sampling sites of the Piracicaba River drainage, and water quality could be considerably improved by augmenting sewage treatment.     

Biodiversity,ecohydrology, threat status and conservation priority of the freshwater fishes of river Gomti,a tributary of river Ganga (India)

Extensive surveys were conducted to explore the diversity of fishes, distribution patterns, abundance, threat, and habitat status in the upper, middle, and lower stretch of river Gomti, a tributary of river Ganga. Altogether 56 fish species belonging to 20 families and 42 genera were collected from various sampling sites. Of the 56 species, five belong to the ‘endangered’ (EN) category and 11 belong to the vulnerable (VU) category. Six major categories of habitat were identified and pattern of fish assemblage and dominant genera in each habitat studied. Considerable differences were observed in the fish species richness and relative abundance (RA) of the species in the different sampling sites of river Gomti. Shannon–Wiener biodiversity index has been calculated for the fishes indicating considerable variation (p < 0.05) across the river. Apart from Indian Major Carps (Labeo rohita, Catla catla, Cirrhinus mrigala), Chitala chitala, Notopterus notopterus, Ompok pabda, O. bimaculatus, Labeo bata, L. calbasu, Cirrhinus reba, Channa marulius, Bagarius bagarius, and Clupisoma garua were the important species. All the species have been reported for the first time in this river. Indiscriminate catch, poisoning, using of fine mesh sized nets, dumping of sewage, siltation, water abstraction, changing land use pattern, decreased water discharge, and exotic species threaten the fish diversity. Urgent need exists for taking up research on the priority fish species and their habitat. Restoration measures have been proposed based on ecosystem scale approach for fish biodiversity conservation.     

Application of best subset method for river water quality modeling: A study on Godavari River,India

The utilization of water quality analysis to inform optimal decision-making is imperative to achieve sustainable management of river water quality. A multitude of research works in the past has focused on river water quality modeling. Despite being a precise statistical regression technique that allows for fitting separate models for all potential combinations of predictors and selecting the optimal subset model, the application of best subset method in river water quality modeling is not widely adopted. The current research aims to validate the use of best subset method in evaluating the water quality parameters of the Godavari River, one of the largest rivers in India, by developing regression equations for different combinations of its physicochemical parameters. The study involves in formulating best subset regression equations to estimate the concentrations of river water quality parameters while also identifying and quantifying their variations. A total of 17 water quality parameters are analyzed at 13 monitoring sites using 13 years (1993–2005) of observed data for the monsoon (June–October) period and post-monsoon (November–February) period. The final subset model is selected among model combinations that are developed for each year's dataset through widely used statistical criteria such as R², F value, adjusted R²_a, AIC_c, and RSS. The final best subset model across all parameters exhibits R² values surpassing 0.8, indicating that the models possess the ability to account for over 80% of the variations in the concentrations of dependent parameters. Therefore, the findings demonstrated the appropriateness of this method in evaluating the water quality parameters in extensive rivers. This work is very useful for decision-making and in the management of river water quality for its sustainable use in the study area.     

Diffusion of Policy Discourse into Rural Spheres Through Co-Management of State Forestlands: Two Cases from West Java,Indonesia

In the context of state forestland management in tropical regions, the implementation of a co-management approach has been widely advocated in order to include the voices of local people and accommodate their interests in management decision-making. Most co-management literatures, however, underestimate the significance of statutory authority held by state to control forestlands and resources. By clarifying the implications of state ownership of forestland, this article aims to critically examine co-management processes with reference to Foucault's notion of power and subject. Case studies were conducted at two co-management pilot sites in Gunung Halimun-Salak National Park, West Java, Indonesia. Findings demonstrate that co-management processes actually materialize shared decision-making arrangements between state forest bureaucracy and rural people through the application of equity approaches, such as deliberation, negotiation, and experimentation. At the same time, these processes can also function to diffuse state policy discourse in rural spheres, which makes rural subjects who accept and practice the policy discourse. The research also reveals that the diffusion process is complex and does not necessarily make a durable subject unless they are pertinently organized. The results of this research indicate that co-management of state forestlands is a double-edged process for local people who risk becoming a proxy of state bureaucracy in the implementation of state policy. Proponents of co-management should, therefore, critically examine whether new institutional arrangements, which are developed through co-management, truly reflect values and needs of local people and assist them to develop a pertinent subject to deal with it.     

Community perspectives on managing health of peri-urban river system: evidence from the Hawkesbury-Nepean river catchment,Australia

In this study, we examine aspects of community values and perspectives on goods and services received from the river along with issues related to sustainable management of the river. The study reveals that the contemporary values placed on rivers by communities are mostly associated with recreational and leisure activities. The distance from the river and age of the participants appeared as the most influential social demographic factors affecting participants' perspectives on river health. The study indicates that people tend to develop a strong bond with the natural resources around them and the amount of time spent at a location is directly related to the strength of this relationship. To assess the general river condition and health, a number of visual indicators (e.g., floating debris) were suggested. If properly standardised and calibrated, such indicators have the potential to develop cost-effective monitoring tools for detecting seasonal and spatial changes in river health.     

Nitrous oxide dynamics in a braided river system, New Zealand

Recently the Intergovernmental Panel on Climate Change (IPCC) emission factor EF5-r was revised downward to a value of 0.0025 kg N?O-N per kg NO?-N leached. It was not reduced further due to the continued uncertainty surrounding the dynamics of N?O in river systems. There have been few studies where river system N?O yields and fluxes have been measured. In this study, we examined the relationship between NO?-N and N?O-N fluxes at 10 sites along a braided river system (84 km) over a 397-d period. Isotopic analysis of NO?-N river water samples and the potential agricultural nitrogen (N) sources demonstrated that the NO?-N came from agricultural or sewage sources. Percent saturation of N?O varied with site and date (average, 114%) and correlated with river N?O-N concentrations. Modeled N?O fluxes (16-30 μg m(-2) h(-1)) from five sites were strongly related to river NO?-N concentrations ( r2 = 0.86). The modeled N?O-N fluxes ranged from 39 to 81% of the IPCC-derived emissions based on the NO?-N load in the river over 397 d and do not support further lowering of the EF5-r. Further in situ river studies are required to verify the N?O-N fluxes and the calculated gas transfer velocity values for these braided river systems.     

A historical perspective of river basin management in the Pearl River Delta of China

Three innovations in water and soil conservancy technology in the Pearl River Delta of South China, i.e., dike building, land reclamation, and dike-pond systems, were examined from a historical perspective. They were found to best reflect local farmers' efforts to cope with the challenges of various water disasters and to build a harmonious relationship with the changed environment. These technologies were critical to the agricultural success and sustainability over the past 2000 years, and reflected local farmers' wisdom in balancing land use and environmental conservation. Imprudent use of a new agricultural technology could damage the environment, and could disturb the human-environment relationship, as evidenced by the more frequent flooding that followed inappropriate dike building and premature reclamation. It is suggested that as the urbanization and industrialization process in the delta region continues, the kind of thinking that made the water and soil conservancy sustainable needs to be incorporated into the design of similar technologies for water use and river basin management today.     

GM(1.1)模型在水磨河水体污染预测中的应用

以水磨河，搪瓷厂桥，七纺桥，联丰桥，米泉桥4个监测断面，以近6a来的BOD3、DO的环境监测值为依据，应用灰色理论建立GM（1．1）模型，对各断面冬季（10月-3月），夏季（4月-9月），全年的BOD5、DO浓度进行预测，并在此基础上进一步分析了水体污染变化的原因。     

Chemical pollution monitoring of the River Pinios (Thessalia--Greece)

The impact of human activities and environmental factors on the fluctuation of chemical and physicochemical parameters along the Pinios River and its tributaries was studied. Their seasonal variations throughout the years 1996-1998 are also presented. Most of the parameters (physical or chemical) measured in this survey exhibited high spatial and temporal variability. High temperatures during the warm period, attributed both to meteorological conditions and to the geographical relief of Thessalia plain, cause a restriction of the water flow, an accumulation of organic matter and the depletion of the dissolved oxygen in the water. Conductivity and hardness are high during the warm and wet period for different reasons. At the seaward part of the river high conductivity and hardness values indicate extended admixture of seawater. COD values fluctuated seasonally. Among the studied stations along the Pinios River the most polluted was the area where the river has passed the city of Larissa.     

Ecological Status of a Margaritifera margaritifera (Linnaeus, 1758) Population at the Southern Edge of its Distribution (River Paiva, Portugal)

An important population of the critically endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) was surveyed at the edge of its southern distribution (River Paiva, Portugal). Although an earlier study suggested that this population had a very low number of individuals (<500), a narrow distribution, and was mainly comprised by old specimens our data contradict these findings. Our assessment estimated a population with probably more than 5,000 individuals distributed across 80 km of the river length. From the 32 sites surveyed, 19 contained M. margaritifera with higher abundances verified in the middle and upper parts of the river (a maximum of 78 ind. per 100 m of river stretch was recorded). The pearl mussels showed a clear preference for areas near the banks, in shallow water, sandier and gravel sediments, and a high degree of riparian vegetation cover. The population structure was skewed with a very high percentage of large (and old) animals but 3.7 % of the individuals collected were juveniles (<60 mm in length); therefore, this population can be considered functional. Environmental characterization indicated that this river is still in excellent or good condition although some areas showed deterioration due to discharge of domestic effluents. The main conservation requirements of M. margaritifera in the River Paiva include maintaining the water quality (and if possible stopping the discharge of domestic effluents), increasing riparian vegetation cover, removing several weirs to increase connectivity, and increasing trout density.     

Proposed methodology to delineate bodies of groundwater according to the European water framework directive. Application in a pilot Mediterranean river basin (Málaga,Spain)

The term “body of groundwater” represents a new administrative tool established by the water framework directive (WFD) in order to manage European groundwaters. Its practical application raises some difficulties due to unclear definitions and the large heterogeneity of European aquifers. In this work, a methodology is proposed to carry out the delineation of bodies of groundwater according to the requirements of the WFD. This methodology faces up to some of the major difficulties that can arise during the delineation, such as the identification of bodies of groundwater in multilayered aquifers, boundaries between superposed groundwater bodies, and delimitation in low permeability materials or in dismembered aquifers. In order to show its practical application, the proposed methodology is applied in a pilot Mediterranean river basin located in southern Spain. Results show that previous knowledge of the hydrogeological conditions is necessary to enable a correct delineation of groundwater bodies. Finally, alternative procedures are proposed for low permeability and small aquifers in order to reduce the number of groundwater bodies identified and simplify their overall management.     

Vegetative Ecological Characteristics of Restored Reed (Phragmites australis) Wetlands in the Yellow River Delta, China

In this study, we compared ecological characteristics of wetland vegetation in a series of restoration projects that were carried out in the wetlands of Yellow River Delta. The investigated characteristics include plant composition structure, species diversity and community similarity in three kinds of Phragmites australis wetlands, i.e. restored P. australis wetlands (R1, R2, R3 and R4: restored in 2002, 2005, 2007 and 2009, respectively), natural P. australis wetland (N) and degraded P. australis wetland (D) to assess the process of wetlands restoration. The coverage of the R1 was 99%, which was similar to natural wetland. Among all studied wetlands, the highest and lowest stem density was observed in R1 and R2, respectively, Plant height and stem diameter show the same trend as N > R2 > R1 > R3 > D > R4. Species diversity of restored P. australis wetlands became closed to natural wetland. Both species richness and Shannon–Wiener index had similar tendency: increased first and then decreased with restored time. The highest species richness and species diversity were observed in R2, while the lowest values of those parameters were found in natural P. australis wetland. Similarity indexes between restored wetlands and natural wetland increased with the restoration time, but they were still less than 50%. The results indicate that the vegetation of P. australis wetlands has experienced a great improvement after several years’ restoration, and it is feasible to restored degraded P. australis wetlands by pouring fresh water into those wetlands in the Yellow River Delta. However, it is notable that costal degraded P. australis wetland in this region may take years to decades to reach the status of natural wetland.     

Reducing risks of maintenance dredging on freshwater mussels (Unionidae) in the Big Sunflower River, Mississippi

In response to proposed dredging in a 122-km reach of the Big Sunflower River, Mississippi, we studied freshwater mussels (family: Unionidae) using qualitative, semi-quantitative, and quantitative (0.25 m(2) total substratum removal) methods in 1987, 1993, 1994, 2001, 2002, and 2003. Our objectives were to identify important mussel resources, to devise methods for minimizing dredging risks, and to identify habitat improvement features. Approximately 60% of the fauna was located on two high-density shoals characterized by extreme dominance of the commercially valuable threeridge (Amblema plicata). Shallow nearshore and main channel areas comprised approximately 10 and 88% of the aquatic habitat in the project area; however, these areas were of less importance for mussels and supported densities of approximately 5 and 0.5 individuals/m(2), respectively. Throughout the project area the mussel fauna exhibited little or no evidence of recent recruitment, dominance of relatively few species (either A. plicata, or the bank climber Plectomerus dombeyanus), and low species diversity (H') and evenness. No federally listed endangered or threatened mussels were found, although the pyramid pigtoe (Pleurobema pyramidatum), a species listed as endangered in Mississippi, was collected in and upstream of the project area. Two other state-listed species, Plethobasus cyphyus (sheepnose) and Quadrula cylindrica (rabbitsfoot), were only found on gravelly shoals upriver of the project area. Maintenance plans were redesigned to minimize environmental damage; a hydraulic cutterhead dredge will be used in most of the mainstem to reduce risk to nearshore habitats. High-density assemblages on four shoals will not be dredged and 150 and 100 m buffer zones will be left immediately up and downriver. Enhancements for aquatic biota will be created with gravel substratum and wing dams.     

Water quality modelling of the river Yamuna (India) using QUAL2E-UNCAS

This paper describes the utility of QUAL2E as a modelling package in the evaluation of a water quality improvement programme. In this study, QUAL2E was applied to determine the pollution loads in the river Yamuna during its course through the national capital territory of Delhi, India. The study aimed at examining the influence of different scenarios on river water quality. Four different pollution scenarios were analysed besides the 'business as usual' situation. The study revealed that it was necessary to treat the discharge from drains to the river Yamuna and diversion of a substantial load to the Agra canal for further treatment was also essential. It was also established through this study that maintaining a flow rate of more than 10 m(3)/s in the river could also help preserve the river's water quality. To clearly display the model outcomes and demarcate polluted zones in the river stretch, model results were interfaced with a Geographical Information System (GIS) to produce cartographic outputs. In addition, uncertainty analysis in the form of first-order error analysis and Monte Carlo analysis was performed, to realise the effect of each model parameter on DO and BOD predictions. The uncertainty analysis gave satisfactory results on simulated data.     

Networks,Agency and (De)stabilization: The Issue of Navigation on the River Wye,UK

This paper assesses the way in which an actor network presiding over the management of the River Wye has stabilized through accepting a particular view on the issue of navigation. The paper provides an account of how the network was challenged by a dissonant actor who, through reviving an old company, developed a counter network. It is argued that network stabilization is a form of consensus-building and it is contended that the way in which an issue is defined is crucial in terms of the successful enrolment of actors. The paper illustrates some of the conflicts and complexities encountered in resource planning, suggesting that research of this nature should trace actors back through time as well as through space if dynamics between actors involved in rural planning and management are to be effectively understood.     

Direct and indirect benefits of improving river quality: quantifying benefits and a case study of the River Klang,Malaysia

This paper describes the potential benefits to be gained from improving the quality of urban rivers and evaluates the methods commonly used to quantify such benefits. The difficulties encountered in quantifying non-use benefits in developing countries are discussed with particular reference to the River Klang that drains the urban conurbation of Kuala Lumpur in Malaysia, where as in many other locations in developing countries the only potential benefits are the most difficult to justify, namely indirect and non-use benefits.     

Time Series Forecasting of Cyanobacteria Blooms in the Crestuma Reservoir (Douro River, Portugal) Using Artificial Neural Networks

In this work, time series neural networks were used to predict the occurrence of toxic cyanobacterial blooms in Crestuma Reservoir, which is an important potable water supply for the Porto region, located in the north of Portugal. These models can potentially be used to provide water treatment plant operators with an early warning for developing cyanobacteria blooms. Physical, chemical, and biological parameters were collected at Crestuma Reservoir from 1999 to 2002. The data set was then divided into three independent time series, each with a fortnightly periodicity. One training series was used to “teach” the neural networks to predict results. Another series was used to verify the results, and to avoid over-fitting of the data. An additional independently collected data series was then used to test the efficacy of the model for predicting the abundance of cyanobacteria. All of the models tested in this study incorporated a prediction time (look-ahead parameter) equal to the sampling interval (two weeks). Various lag periods, from 2 to 52 weeks, were also investigated. The best model produced in this study provided the following correlations between the target and forecast values in the training, verification, and validation series: 1.000 (P = 0.000), 0.802 (P = 0.000), and 0.773 (P = 0.001), respectively. By applying this model to the three-year data set, we were able to predict fluctuations in cyanobacteria abundance in the Crestuma Reservoir, with a high level of precision. By incorporating a lag-period of eight weeks, we were able to detect secondary fluctuations in cyanobacterial abundance over the annual cycle.     

Distribution and Significance of Epipsammic Algae in the Coastal Shore (Ibeno Beach) of Qua Iboe River Estuary, Nigeria

The distribution of epipsammic phytoplankton in the coastal shore (Ibeno beach) of Qua Iboe River estuary was studied in the early summer (between October and December) of 1998. The results revealed the presence of Actinoptychus undulatus, Aphanizomenon flos-aquae, Astasia fustis, Chromulina globosa, Cocconeis pediculus, Cymatopleura solea, Cymbella lanceolata, Euglena intermedia, Lyngbya majusculata, Microcystis sp., Nodularia spumigena, Navicular rhynocephala, Oscillatoria nigroviridis, Pinnularia viridis, Rhoicosphenia curvata, Trachelomonas volvocina and Urceolus cyclostomus in the sandy beach. The mean species density of the epipsammic algae encountered in the beach ranged from 16 to 7600 organisms per hectare. The density, however, decreased with increase in sampling distance from the low tide level. Actinoptychus undulatus was the most abundant and widely distributed phytoplankton while Aphanizomenon flos-aquae was the least encountered species. The occurrence of A. flos-aquae and other toxin producing cyanobacterial species of Lyngbya majusculata, Microcystis sp., N. spumigena and O. nigroviridis in the sandy beach are of serious health significance.