Aquatic Monitoring Research Articles

Estimating time series phytoplankton carbon biomass: Inter-lab comparison of species identification and comparison of volume-to-carbon scaling ratios

An inter-calibration exercise was conducted to assess the performance of six phytoplankton taxonomists working within the Danish National Aquatic Monitoring and Assessment Program (DNAMAP). For species abundance and cell volume, a 2-fold difference was found among different estimates for subsamples from the same sample, which in turn cascaded into large differences in the species-specific carbon biomass contribution. The mean total carbon biomass estimated showed high variability (CV 43%) among the six taxonomists, but large variations were present within results produced by individual taxonomists (CV 8–50%), and one of the taxonomists produced significantly lower estimates than the others. Using data from phytoplankton time series samples, we also assessed the effect using a table of species-specific cell volumes versus cell volume measurements from a sample on carbon biomass values. For an example, the older cell-volume-to-carbon conversion method with fixed carbon-conversion constants was compared to the more recent approach of scaling biovolume to carbon biomass based on established regressions. We found that the regression between community biomass estimated by the old method versus the more recent equation yielded a slope close to 1, thus indicating general similar community biomass estimated between the methods. Type II regression suggested a high degree of variability in the estimates (17%). The highest degree of uncertainty was found by type II linear regression, when we compared the community biomass of diatoms estimated by cell sizes measured by sample to diatom community biomass estimated from cell sizes from a table of fixed cell sizes. In this analysis variation among methods for carbon estimation of individual samples was as high as 114%. Therefore, we recommend that, particularly for diatoms, cell volumes should be determined from the sample, or that table values be based on monthly estimates for at least the dominant diatom species for each study area.

GC-MS Fingerprinting of Fatty Acids of Freshwater Mollusc Lamellidens Marginalis using Different Columns, TR-Waxms and TR-FAME

GC-MS is an important instrument in lipid profiling and lipid biomarker identification. The choice of columns and detectors is important in analysis and identification of the biomolecules. In the present study, GC-MS fingerprinting of fatty acids (FAs) in different tissues of freshwater mollusc Lamellidens marginalis was carried out in GC-MS with two different columns, TR-FAME and TR-WaxMS, to examine if choice of columns and detectors influence the identifications of the lipids. These sentinel organisms are used in aquatic pollution monitoring studies as they accumulate toxic environmental contaminants to levels well above those present in the surrounding environment thus providing information on the spatio-temporal pollution trends. FAs identified in different tissues include the saturated FAs palmitic acid (C16:0), margaric acid (C17:0), stearic acid (C18:0), monounsaturated FAs (MUFAs) oleic acid (C18:1), eicosenoic acid (C20:1) and polyunsaturated fatty acid (PUFAs) linoleic acid (C18:2). More numbers of FAs were detected in TR-FAME column than TR-WaxMS column. Several non-fatty acid compounds like butylated hydroxyl toluene (BHT) and dibutyl phthalate were also identified in the FAME (fatty acid methyl ester) preparation using NIST (MS) library. It was interesting to note that the FA peaks (6/14) were outnumbered by the non-fatty acid peaks (8/14). Such compounds could be taken as unidentified FAs unless powerful detectors like MS are available and can lead to erroneous inferences. The study showed that the choice of columns and detectors influenced the identification of the compounds. The information generated on fatty acid profiles of this bivalve could serve as baseline data for this species in searching for lipid biomarkers for aquatic pollution monitoring studies.

Effect of Copper Sulphate on the Regulation of Nitrogen Metabolism in the Rita rita Fish

Effect of copper sulphate (CuSO4.5H2O) to Rita rita (catfish) species was investigated using toxicity index of 96 hours LC50 and the quantal response determined by the statistical probit analysis method. In response to the lethality of the copper toxicant, behavioral anomalies (locomotor response) of the exposed fish species were studied as indication of toxic effects of the heavy metal. Fish species shows different mortality responses to the varying concentrations of copper sulphate studied (10-50 ppm) due to toxicity. Copper was significantly (no overlap in 95% C.L of 96 hrs LC50 values) more toxic to Rita rita fish. 96 hrs LC50 values were revealed to be 34 mg/l. On termination of the experimental period (7 days, 15 days and 30 days) the biochemical analysis: tissue protein; total free amino acids; ammonia and urea. There is need to control the use of copper because of its observed toxicity and fish avoidance test shows to be an important predictive and sensitive biomarker in aquatic monitoring and pollution management.

Estrogenicity and Genotoxicity Detection in Different Contaminated Waters

ABSTRACTOwing that Oreochromis niloticus is resistant to different aquatic environments, four contaminated sites were selected: decentralized engineered ecosystem (DEE) and conventional wastewater treatment plants (WWTP); urban lagoon; and gasoline-contaminated marshland. Endocrine disruption was assessed by alkali-labile phosphate (ALP) quantification, genotoxicity by micronuclei frequency, and morphological changes by hepatosomatic and gonadosomatic indexes. The ALP baseline of non-exposed O. niloticus males was low, compared with other fish species in the literature. Endocrine disruption was observed in fish exposed to raw wastewater of WWTP and DEE, discharge point of channeled river in the urban lagoon, and water from gasoline-contaminated marshland. After treatment in the DEE, the endocrine disruption effect was removed. The micronuclei frequency corroborated with the ALP results in most cases and proved to be a useful tool to assess genotoxicity in fish. The exposure time of 15 days was not enough to provoke morphological effects in most samples. However, in all gasoline-contaminated samples, the fishes showed an increase in the hepatosomatic index followed by a decrease in the gonadosomatic index. The tested biomarkers showed feasibility, sensibility, reproducibility, and were complementary in the assessment of chronic ecotoxicity; therefore, we recommend them to compose a suitable protocol for aquatic monitoring programs.

Heavy metals induce oxidative stress and trigger oxidative stress-mediated heat shock protein (hsp) modulation in the intertidal copepod Tigriopus japonicus

Heat shock proteins (hsps) are induced by a wide range of environmental stressors including heavy metals in aquatic organisms. However, the effect of heavy metals on zooplankton at the molecular level remains still unclear. In this study, we measured the intracellular reactive oxygen species (ROS) level and the antioxidant enzyme activities for 96h after exposure to five heavy metals: arsenic (As), cadmium (Cd), copper (Cu), silver (Ag), and zinc (Zn) in the intertidal copepod Tigriopus japonicus. Activities of the antioxidant enzymes were highly elevated in metal-exposed copepods, indicating that heavy metals can induce oxidative stress by generating ROS, and stimulate the involvement of antioxidant enzymes as cellular defense mechanisms. Subsequently, transcriptional changes in hsp gene families were further investigated in the metal-exposed groups for 96h. The ROS level and glutathione (GSH) content were significantly increased in Ag-, As-, and Cu-exposed copepods, while they were only slightly elevated in Cd- and Zn-exposed groups. Based on the numbers of significantly modulated hsp genes and their expression levels for 96h, we measured the effect of heavy metals to stress genes of T. japonicus in the following order: Cu>Zn>Ag>As>Cd, implying that Cu acts as a stronger oxidative stress inducer than other heavy metals. Of them, the expression of hsp20 and hsp70 genes was substantially modulated by exposure to heavy metals, indicating that these genes would provide a sensitive molecular biomarker for aquatic monitoring of heavy metal pollution.

Genotoxic effects of water from São Francisco River, Brazil, in Astyanax paranae.

Aquatic monitoring is an important tool for identifying potential compounds in rivers that may damage the environment. Here, we evaluate the potential genotoxic effects of water samples from São Francisco River (Brazil) using the micronuclei (MN) assay in resident species, Astyanax paranae. Four seasonal collections occurred between the years 2009 and 2010, at three locations between two nearby cities in the region. It was clearly observed an increase of MN frequency in fish caught in the river. This result is most likely due to the sewage contamination from the treatment plant, the waste pesticides from crops and the lack of riparian vegetation along the river, especially during the winter when there was a significant increase in the frequencies of MN. These results indicate that compounds in waters from São Francisco River may have genotoxic effects and consequently, cause damage to the environment as well as to human health.

Sensitivity of structural and functional indicators depends on type and resolution of anthropogenic activities

Few researchers have assessed the important management questions regarding the sensitivity of indicators of aquatic ecosystem condition and the specificity with which anthropogenic development activities are described. Furthermore, there is limited knowledge as to the potential of structural and functional indicators to generate complementary knowledge about ecological condition that can be used to inform watershed management. We assessed 20 metrics of ecological structure and function at 19 riverine sites across the Red River watershed in the summer of 2010 using a gradient approach to test predictions that: (1) indicator sensitivity would vary with the specificity at which landscape development is described (i.e., coarse – land use [e.g., agriculture], medium – specific human activities [e.g., crop cultivation] and fine – management practices [e.g., crop rotation]); and (2) structural and functional indicators respond to different types and specificity of anthropogenic development. Evaluation of indicators revealed that indicator sensitivity was frequently greater for assessment of specific human activities (i.e., wastewater treatment, crop cultivation or livestock production), than for broad land-use categories (i.e., agriculture or urban). Structural and functional indicators were often associated with different types of anthropogenic development suggesting additive rather than redundant assessment information. Structural indicators were almost exclusively associated with crop cultivation and agricultural land cover. In contrast, functional indicators were generally associated with gradients of wastewater treatment and urban land cover. Our results demonstrate that aquatic ecosystem assessment programs would benefit from considering the specific anthropogenic development activity to be assessed and managed in order to evaluate and select the most sensitive indicators of stream condition. Furthermore, combined use of structural and functional indicators in aquatic monitoring program appears to improve detection of anthropogenic impacts in a multiple stressor environment.

Phytoplankton functional and morphological groups as indicators of environmental variability in a lateral channel of the Upper Paraná River floodplain

AIM: Models of phytoplankton functional classification based on functional (FGs) and morphological (MBFGs) traits can be an important tool in aquatic monitoring. In this long-term study on phytoplankton, the goal was to use these two approaches to explain the changes in this community in an active channel of the Upper Paraná River floodplain, depending on the environmental conditions imposed by the hydrosedimentological regime. METHODS: Samples were taken between 2000 and 2013. RESULTS: 196 taxa were identified. Bacillariophyceae and Cyanobacteria showed higher contribution to biovolume. Were recorded 11 FGs (A, C, E, H1, J, Lo, M, MP, N, P and X1). The FGs C, Lo, M, MP, P and X1 were common to both periods. Already the FGs A, E, H1 and J occurred only in limnophase, while the FG N occurred only in potamophase. Were recorded seven MBFGs (I, II, III, IV, V, VI e VII). All seven MBFGs occurred in both hydrological periods, however the MBFGs III, VI and VII contributed with high biovolume values mainly in the limnophase. The FG P and MBFG VI were indicator of eutrophic status, while the FG M and MBFG VII were indicators of mesotrophic status. Only FGs reflected the environmental variability. CONCLUSION: The classification of phytoplankton in FGs and MBFGs represented an important tool for understanding of the behavior and dynamics of the species in relation to environmental conditions. However, the FGs appear to be more related to environmental variation this lotic channel than MBFGs. Probably this is related to the refinement of this classification, which reflected the changes in the community, in long-term scale, influenced by local and regional characteristics imposed by the hydrosedimentological regime of the Paraná River.

Sampling trace organic compounds in water: A comparison of a continuous active sampler to continuous passive and discrete sampling methods

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23h for CLAM and 29days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

Passive sampling of perfluorinated chemicals in water: In-situ calibration

Perfluorinated chemicals (PFCs) have been recognised as environmental pollutants that require monitoring. A modified polar organic chemical integrative sampler (POCIS) is able to quantify aqueous PFCs. However, with varying external water velocity, PFC sampling rates (Rs) may change, affecting accuracy of derived water concentrations. To facilitate field deployment of this sampler, two methods of in-situ calibration were investigated: performance reference compounds (PRCs) and passive flow monitors (PFMs). Increased Rs's (by factors of 1.2–1.9) with PFM loss rate (g d−1) were observed for some PFCs. Results indicate PFMs can be used to correct PFC specific Rs's for more reliable estimates of environmental concentrations with a precision of about 0.01 L d−1. Empirical models presented provide an improved means for aquatic monitoring of PFCs. The PRC approach was unsuccessful, confirming concern as to its applicability with such samplers.

On the diet of two endemic and rare species of Trichomycterus (Ostariophysi: Trichomycteridae) in the Jordão River, Iguaçu River basin, southern Brazil

The diet and the eect of body size on the feeding habits of Trichomycterus crassicaudatus and Trichomycterus stawiarski, collected in the Jordão River, an import tributary of the Iguaçu River basin, were investigated. Samples were collected in august 2003 during the Jordão River Energetic Complex Aquatic Fauna Rescue and Monitoring program. Stomach contents were evaluated through the frequency of occurrence, permutational multivariate analysis of variance (PERMANOVA), si-milarity percentage analysis (SIMPER) and non-metric multidimensional scaling analysis (MDS) methods. A total of 86 stomach contents of T. stawiarski and 36 of T. crassicaudatus were assessed. The species presented an insectivorous feeding habit, with differences in the diet composition of the “smallest” and the “largest” individuals. Ephemeroptera nymphs, lar-vae and pupae of Diptera, organic detritus and plant fragments were the most important food items. Both species feeding habits were based mainly in benthic aquatic immature insects.

Design of Aquatic Product Traceability System Based on Anti-Collision RFID Techniques

The traceability management system of aquatic product is based on RFID techniques which could obtain the function of aquatic products statistics and water quality monitoring automatically. The system frame, hardware and software design of micro-controller and anti-collision algorithm are issued in this paper. The identifying of aquatic product and water quality monitoring information are delivered to the management system and the speed of reading operation is increased greatly.

Anti-Collision Algorithm Based on RFID Aquatic Shelf Life Monitoring System

Tag collision is one of the key issues of the RFID system,it increases the energy consumption and slot overheads of passive tags.After giving a brief analysis of the existing anti-collision algorithms,a novel anti-collision algorithm based on the characteristics of a continuous distribution serial number of RFID aquatic shelf life monitoring system was proposed,The algorithm firstly uses the collision information to generate two initial serial number,then identifies all tags via minus 1 and add 1 of the initial tag serial number.Simulation results show that the proposed algorithm has a faster identification speed and less tag transmission bits.

A Process-Based Hierarchical Framework for Monitoring Glaciated Alpine Headwaters

Recent studies have demonstrated the geomorphic complexity and wide range of hydrologic regimes found in alpine headwater channels that provide complex habitats for aquatic taxa. These geohydrologic elements are fundamental to better understand patterns in species assemblages and indicator taxa and are necessary to aquatic monitoring protocols that aim to track changes in physical conditions. Complex physical variables shape many biological and ecological traits, including life history strategies, but these mechanisms can only be understood if critical physical variables are adequately represented within the sampling framework. To better align sampling design protocols with current geohydrologic knowledge, we present a conceptual framework that incorporates regional-scale conditions, basin-scale longitudinal profiles, valley-scale glacial macroform structure, valley segment-scale (i.e., colluvial, alluvial, and bedrock), and reach-scale channel types. At the valley segment- and reach-scales, these hierarchical levels are associated with differences in streamflow and sediment regime, water source contribution and water temperature. Examples of linked physical-ecological hypotheses placed in a landscape context and a case study using the proposed framework are presented to demonstrate the usefulness of this approach for monitoring complex temporal and spatial patterns and processes in glaciated basins. This approach is meant to aid in comparisons between mountain regions on a global scale and to improve management of potentially endangered alpine species affected by climate change and other stressors.

Optimising the sampling effort in riparian surveys

Riparian condition is commonly measured as part of stream health monitoring programs as riparian vegetation provides an intricate linkage between the terrestrial and aquatic ecosystems. Field surveys of a riparian zone provide comprehensive riparian attribute data but can be considerably intensive and onerous on resources and workers. Our objective was to assess the impact of reducing the sampling effort on the variation in key riparian health indicators. Subsequently, we developed a non-parametric approach to calculate an information retained (IR) statistic for comparing several constrained systematic sampling schemes to the original survey. The IR statistic is used to select a scheme that reduces the time taken to undertake riparian surveys (and thus potentially the costs) whilst maximising the IR from the original survey. Approximate bootstrap confidence intervals were calculated to improve the inferential capability of the IR statistic. The approach is demonstrated using riparian vegetation indicators collected as part of an aquatic ecosystem health monitoring program in Queensland, Australia. Of the nine alternative sampling designs considered, the sampling design that reduced the sampling intensity per site by sixfold without significantly comprising the quality of the IR, results in halving the time taken to complete a riparian survey at a site. This approach could also be applied to reducing sampling effort involved in monitoring other ecosystem health indicators, where an intensive systematic sampling scheme was initially employed.

Quantifying spatial and temporal variability of macroinvertebrate metrics

Since the introductions of the Habitat Directive and the European Water Framework Directive, water authorities are now obliged to monitor changes in conservation value/ecological quality on larger spatial scales (opposed to site scale), as well as to indicate the level of confidence and precision of the results provided by the monitoring programs in their river basin management plans (European Commission, 2000). To meet these requirements, analyses of the statistical power of the monitoring programs should be implemented. Currently, the statistical properties associated with aquatic monitoring programs are often unknown. We collected macroinvertebrate samples from 25 meso-eutrophic drainage ditches in the Netherlands and selected 7 taxonomic richness metrics for the evaluation of spatial and temporal variability. Simulations were performed to investigate the effects of changes in (1) the total number of species included in a taxonomic richness metric and (2) the relative number of rare species included in a taxonomic richness metric. Of the 7 metrics evaluated, the number of common species required the smallest number of monitoring sites, followed by the number of Gastropoda species, and the number of species. Also, results showed that metric variability will decrease when the proportion of rare species included in a taxonomic richness metric is reduced or the total number of species included is increased. Irrespective of the metric applied a large effort will be required to detect change within drainage ditches in the Wieden, due to high spatial variability. Therefore, we need to explore the possibilities of applying alternative more cost-effective methods for sampling and sample processing in biomonitoring programs.

Early Trends in Landcover Change and Forest Fragmentation Due to Shale-Gas Development in Pennsylvania: A Potential Outcome for the Northcentral Appalachians

Worldwide shale-gas development has the potential to cause substantial landscape disturbance. The northeastern U.S., specifically the Allegheny Plateau in Pennsylvania, West Virginia, Ohio, and Kentucky, is experiencing rapid exploration. Using Pennsylvania as a proxy for regional development across the Plateau, we examine land cover change due to shale-gas exploration, with emphasis on forest fragmentation. Pennsylvania's shale-gas development is greatest on private land, and is dominated by pads with 1-2 wells; less than 10 % of pads have five wells or more. Approximately 45-62 % of pads occur on agricultural land and 38-54 % in forest land (many in core forest on private land). Development of permits granted as of June 3, 2011, would convert at least 644-1072ha of agricultural land and 536-894ha of forest land. Agricultural land conversion suggests that drilling is somewhat competing with food production. Accounting for existing pads and development of all permits would result in at least 649km of new road, which, along with pipelines, would fragment forest cover. The Susquehanna River basin (feeding the Chesapeake Bay), is most developed, with 885 pads (26 % in core forest); permit data suggests the basin will experience continued heavy development. The intensity of core forest disturbance, where many headwater streams occur, suggests that such streams should become a focus of aquatic monitoring. Given the intense development on private lands, we believe a regional strategy is needed to help guide infrastructure development, so that habitat loss, farmland conversion, and the risk to waterways are better managed.

The utility of body size indices derived from optical plankton counter data for the characterization of marine zooplankton assemblages

To evaluate the utility of size-based indices derived from an Optical Plankton Counter (OPC) through detection of spatial and temporal trends in zooplankton biomass, zooplankton size data were collected with an OPC across the Scotian Shelf region of the northwest Atlantic Ocean in April and October of 1997, 1998, and 1999. Eight size-based indices were computed – three simple size metrics (arithmetic mean, geometric mean, coefficient of variation) and metrics derived from the Normalized Biomass Size Spectrum (NBSS; X- and Y-coordinates and curvature of a fitted quadratic function) and the Pareto distribution (Y-intercept and slope). Results indicate that the simple size indices and those derived from the Pareto distribution consistently accounted for the greatest portion of annual variation in zooplankton biomass whereas indices derived from the NBSS accounted only for some secondary patterns. Simple indices also accounted for the greatest portion of spatial variance in zooplankton biomass whereas the NBSS and Pareto accounted for secondary patterns. Patterns in zooplankton communities based on these indices reflected broad taxonomic trends and were related to independent observations on atmospheric and hydrographic conditions in the study area. Size-based zooplankton data from continuous survey instruments can provide powerful adjuncts to both freshwater and marine aquatic monitoring.

Design and Implementation of Real-Time Monitoring and Intelligent Management System for Intensive Aquaculture

Extensive aquaculture has been used in Chinese aquaculture farms for a long time. Inefficient and high consumption are main shortcomings for this aquaculture type. This paper designed and implemented an aquatic parameters real-time monitoring and management system based on water quality sensors, wireless sensor network and information management technologies. The system can monitor water quality parameters in real-time and automatically (or manual) control aquaculture equipment according timing, threshold or mobile short message service. Also, according to different aquaculture objects, the system provides one-stop information services as aquaculture disease warning and diagnosis, bait feeding etc. The applications in eight different regions in China have proved the system can effectively improve the intensive aquaculture informatization level and realized the whole process of aquaculture information management.

Contaminants of Concern in the Marine Environment: The Need for New Monitoring and Assessment Strategies

Contaminants of Concern in the Marine Environment: The Need for New Monitoring and Assessment Strategies More than 156 million people, over half of the U.S. population, live in the coastal zone. These areas contribute $7.9 trillion to the U.S. economy. Economic development within the coastal zone may result in the discharge of chemical contaminants into coastal ecosystems from sewage treatment plants, industrial point sources and urban and agricultural nonpoint source runoff. Aquatic monitoring programs have long measured legacy contaminants such as DDT and PCBs, but are increasingly being asked to focus on modern commercial chemicals that as a group are referred to as Contaminants of Emerging Concern (CECs). CECs present many challenges, often because measurement methods don’t yet exist nor have toxicological studies yet been conducted to place monitoring results in proper context. This challenge is exacerbated because many CECs interact with hormone systems in wildlife to affect reproduction and development in ways that are not assessed through traditional toxicological evaluations.