Epilithic diatoms of the St. Lawrence River and their relationships to water quality

1998 ◽  
Vol 76 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Euan D Reavie ◽  
John P Smol
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Fecal Coliforms ◽  
Weighted Averaging ◽  
Quebec City ◽  
Diatom Assemblages ◽  
Epilithic Diatoms ◽  
Epilithic Diatom ◽  
St Lawrence River

Epilithic diatoms were sampled at 48 sites along the St. Lawrence River, from Salaberry de Valleyfield to Québec City, in an attempt to determine how diatom assemblages were related to measured water quality variables. Canonical correspondence analysis was used to explore the relationships between environmental variables and patterns in the epilithic diatom assemblages. "Distance downstream from Cornwall" was determined to be the strongest variable influencing the structure of epilithic diatom assemblages, likely due to the effect of tides (favouring aerophilic species) closer to the river outlet. Variables related to pollution (suspended solids, fecal coliforms, chlorophyll a) also explained significant (P < 0.05) amounts of variance in the diatom assemblages. The optima of common diatom species to suspended solids were explored further. Reconstructive models using weighted-averaging calibration and regression illustrated that "distance from Cornwall" and concentrations of suspended solids, fecal coliforms, and chlorophyll a, the most influential variables, could be inferred from the diatom assemblages. When compared with the inference models developed for pollution variables using epiphytic diatom assemblages (attached to macrophytes or Cladophora), the epilithon model appears to perform better.Key words: diatoms, rocks, epilithic, St. Lawrence River, water quality, calibration.

Seagrass depth range and water quality in southern Moreton Bay, Queensland, Australia

1996 ◽  
Vol 47 (6) ◽  
pp. 763 ◽  
Author(s):  
EG Abal ◽  
WC Dennison
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Light Attenuation ◽  
River Mouth ◽  
Total Suspended Solids ◽  
Quality Parameters ◽  
Depth Range ◽  
Moreton Bay ◽  
A Site

Correlations between water quality parameters and seagrass depth penetration were developed for use as a biological indicator of integrated light availability and long-term trends in water quality. A year-long water quality monitoring programme in Moreton Bay was coupled with a series of seagrass depth transects. A strong gradient between the western (landward) and eastern (seaward) portions of Moreton Bay was observed in both water quality and seagrass depth range. Higher concentrations of chlorophyll a, total suspended solids, dissolved and total nutrients, and light attenuation coefficients in the water column and correspondingly shallower depth limits of the seagrass Zostera capricorni were observed in the western portions of the bay. Relatively high correlation coefficient values (r2 > 0.8) were observed between light attenuation coefficient, total suspended solids, chlorophyll a, total Kjeldahl nitrogen and Zostera capricorni depth range. Low correlation coefficient values (r2 < 0.8) between seagrass depth range and dissolved inorganic nutrients were observed. Seagrasses had disappeared over a five-year period near the mouth of the Logan River, a turbid river with increased land use in its watershed. At a site 9 km from the river mouth, a significant decrease in seagrass depth range corresponded to higher light attenuation, chlorophyll a, total suspended solids and total nitrogen content relative to a site 21 km from the river mouth. Seagrass depth penetration thus appears to be a sensitive bio-indicator of some water quality parameters, with application for water quality management.

scholarly journals The use of epilithic diatom assemblages in assessing land use in Silago, Southern Leyte, Philippines

2019 ◽  
Vol 12 (2) ◽  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Tolerance Index ◽  
Diatom Species ◽  
Diatom Assemblages ◽  
Pollution Tolerance ◽  
Land Use Types ◽  
Freshwater Bodies ◽  
Forested Areas ◽  
Epilithic Diatom

Silago is a municipality in Southern Leyte in which logging for high-quality timber and land clearing for agricultural purposes threaten stream ecosystems. The objective of this study was to assess the response of diatom assemblages in relation to land use. Diatoms and water quality sampling was done at 27 sites on two sampling occasions (June and July 2014). Multiple diatom metrics were calculated to measure the response of diatoms to changes in land use. In all, 135 diatom species distributed to 48 genera were recorded. The results showed that diatom species and their attributes gave similar responses to those obtained in environmental variables. Pollution tolerance index classified all sampling sites as oligo-b-mesosaprobic. Meanwhile, Cymbella richness, percent motile taxa, and percent Achnanthidium minutissimum indicated good water quality in forested areas, distinguishing them from other land use types. Contrary to other studies, species richness was found to increase with greater degrees of disturbance, thus giving unreliable evaluation of water quality. Overall, the study suggests that epilithic diatoms can be applied in biomonitoring of freshwater bodies in the country.

The Effect of Water Purification Ecological Engineering on the Cao Yang Round Creek

1991 ◽  
Vol 23 (1-3) ◽  
pp. 121-131 ◽  
Author(s):  
Wang Chongxiao ◽  
Cai Jie ◽  
Zhou Jiaxin ◽  
Xu Sailan ◽  
Yu Yiping ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Water Purification ◽  
Water Body ◽  
Vascular Plants ◽  
Water Surface ◽  
Suspended Solids ◽  
Ecological Engineering ◽  
Total Suspended Solids

It nas been proved that planting various aquatic vascular plants with proper arrangements of time and space in tne eutropnic water of tne Cao Yang Round Creek nas formed an effective and stable ecological system for purifying water. Within two years, the water quality of the Round Creek has been improved significantly. The density of algae (content of chlorophyll a) has dropped by 95%, the total suspended solids is decreased by more tnan 90%, and COD is also reduced by 50%. The transparency of the water has increased from 15cm Before treatment to 53cm after treatment. Some parts of tne Creek are clear enough to see the bottom, to count tne fish. At the same time, beautification and planting of plants on the water surface has been carried our, together with the purification of the water. In this way, tne sightseeing value of water body is also increased. The paper intends to probe an efficient way of harnessing the eutropnic water By practicing witn purification, Deautification and plant planting all at one time.

scholarly journals Exploring the Influence Mechanism of Meteorological Conditions on the Concentration of Suspended Solids and Chlorophyll-a in Large Estuaries Based on MODIS Imagery

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 375
Author(s):  
Cheng He ◽  
Youru Yao ◽  
Xiaoman Lu ◽  
Mingnan Chen ◽  
Weichun Ma ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Quality Parameters ◽  
Meteorological Conditions ◽  
Water Bodies ◽  
Water Quality Parameters ◽  
Yangtze River Estuary ◽  
Modis Imagery ◽  
Chla Concentration

In estuary areas, meteorological conditions have become unstable under the continuous effects of climate change, and the ecological backgrounds of such areas have strongly been influenced by anthropic activities. Consequently, the water quality of these areas is obviously affected. In this research, we identified periods of fluctuation of the general meteorological conditions in the Yangtze River Estuary using a wavelet analysis. Additionally, we performed a spatiotemporal evaluation of the water quality in the fluctuating period by using remote sensing modeling. Then, we explored how the fluctuating meteorological factors affect the distribution of total suspended solids (TSS) and chlorophyll-a (Chla) concentration. (1) The results show that from 2000 to 2015, temperature did not present significant fluctuations, while wind speed (WS) and precipitation (PR) presented the same fluctuation period from January 2012 to December 2012. (2) Based on the measured water sample data associated with Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, we developed a water quality algorithm and depicted the TSS and Chla concentrations within the WS and PR fluctuating period. (3) We found that the TSS concentration decreased with distance from the shore, while the Chla concentration showed an initially decreasing trend followed by an increasing trend; moreover, these two water quality parameters presented different inter-annual variations. Then, we discussed the correlation between the changes in the TSS and Chla concentrations and the WS and PR variables. The contribution of this research is reflected in two aspects: 1. variations in water quality parameters over a wide range of water bodies can be evaluated based on MODIS data; 2. data from different time periods showed that the fluctuations of meteorological elements had different impacts on water bodies based on the distance from the shore. The results provide new insights for the management of estuary water environments.

scholarly journals Sampler collection gadget for epilithic diatoms

2007 ◽  
Vol 67 (4) ◽  
pp. 681-683 ◽  
Author(s):  
SE. Salomoni ◽  
LC. Torgan ◽  
O. Rocha
Keyword(s):  
Water Quality ◽  
Water Quality Monitoring ◽  
Density Variation ◽  
Quality Monitoring ◽  
Diatom Community ◽  
Epilithic Diatoms ◽  
Epilithic Diatom

This work present a new gadget for sampling epilithic diatoms from both lentic and lotic enviroments. The sampler consists of a polystyrene cylinder, left to float on the surface of the water, to which stone substrates are attached. This epilithic diatom sampler (EDS) can be used to detect spatial and temporal richness and density variation in the study of the diatom community, as well as in water quality monitoring.

scholarly journals Environmental Indicators of Water Quality in the Cibin River (Transylvania, Romania)

2013 ◽  
Vol 15 (1) ◽  
pp. 91-116
Author(s):  
Ramona Iancu ◽  
Letiţia Oprean ◽  
Diana Stegăruş ◽  
Ovidiu Tiţa ◽  
Adrian Boicean ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Samples ◽  
Suspended Solids ◽  
Environmental Indicators ◽  
Point Of View ◽  
Fecal Coliforms ◽  
Human Consumption ◽  
Human Populations ◽  
Quality Indices ◽  
Physical Chemical

ABSTRACTWater pollution has become a worldwide problem and its influence over the health of human populations grows every day. This study was carried out to determinate the rate level of pollution of the Cibin River (Transylvania, Romania) via physical-chemical and microbiological tests. Water samples were measured at six different locations along the Cibin River for a period of 12 months. Analysis methods used to determine physical-chemical quality indices for water were as follows: O2- ISO 5814/99, pH - SR ISO 10523-97, PO4-KIT Merck, SO4-- PS/LE 17, conductivity - Sonda, NH4+- SR ISO 7150-1/2001, NO3-- SR ISO 7890/2000, NO2-- SR EN 26777 - ISO 6777/2002, chlorides - SR ISO 9297/2001, CCOCr - SR ISO 6060/96, CBO5- SR ISO 5815/95, suspended solids - STAS 6953/81, residues - STAS 9187/95. The water samples were analyzed also from a sanitary and public health point of view, for example: total number of mesophilic bacteria, total number of yeasts and moulds, total coliforms, total fecal coliforms, Enterococcus and Escherichia coli, according to current Romanian legislation and normatives (Order 1146/2002). The significant results place the river in the first (sampling stations 1, 2 and 3) and second (sampling stations 4, 5 and 6) water Quality Class. Due to the fact that the upper dam reservoir at Gura Râului is the main source of drinking water for Sibiu, it is certain that this water presents optimal characteristics for human consumption and is thus declared to be one of the healthiest water sources in Romania.

scholarly journals Transitions in diatom assemblages and pigments through dry and wet season conditions in the Red River, Hanoi (Vietnam)

2019 ◽  
Vol 152 (2) ◽  
pp. 163-177 ◽  
Author(s):  
Thi Thuy Duong ◽  
Hai Yen Nguyen ◽  
Thi Phuong Quynh Le ◽  
Trung Kien Nguyen ◽  
Thi Thu Huong Tran ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Light Availability ◽  
Red River ◽  
Artificial Substrates ◽  
Tropical Rivers ◽  
Wet Season ◽  
Hydrological Change

Background and aims – Biomonitoring is an important tool for assessing river water quality, but is not routinely applied in tropical rivers. Marked hydrological changes can occur between wet and dry season conditions in the tropics. Thus, a prerequisite for ecological assessment is that the influence of ‘natural’ hydrological change on biota can be distinguished from variability driven by water quality parameters of interest. Here we aimed to (a) assess seasonal changes in water quality, diatoms and algal assemblages from river phytoplankton and artificial substrates through the dry-wet season transition (February–July 2018) in the Red River close to Hanoi and (b) evaluate the potential for microscopic counts and high-performance liquid chromatography (HPLC) analysis of chlorophyll and carotenoid pigments for biomonitoring in large tropical rivers. Methods – River water (phytoplankton) and biofilms grown on artificial glass substrates were sampled monthly through the dry (February–April) to wet (May–August) season transition and analysed via microscopic and HPLC techniques. Key results – All phototrophic communities shifted markedly between the dry and wet seasons. Phytoplankton concentrations were low (c. thousands of cells/mL) and declined as the wet season progressed. The dominant phytoplankton taxa were centric diatoms (Aulacoseira granulata and Aulacoseira distans) and chlorophytes (Scenedesmus and Pediastrum spp.), with chlorophytes becoming more dominant in the wet season. Biofilm diatoms were dominated by Melosira varians, and areal densities declined in the wet season when fast-growing pioneer diatom taxa (e.g. Achnanthidium minutissimum, Planothidium lanceolatum) and non-degraded Chlorophyll a concentrations increased, suggesting active phytobenthos growth in response to scour damage. Otherwise, a-phorbins were very abundant in river seston and biofilms indicating in situ Chlorophyll a degradation which may be typical of tropical river environments. The very large range of total suspended solids (reaching > 120 mg/L) and turbidity appears to be a key driver of photoautotrophs through control of light availability. Conclusions – Hydrological change and associated turbidity conditions exceed nutrient influences on photoautotrophs at inter-seasonal scales in this part of the Red River. Inter-seasonal differences might be a useful measure for biomonitoring to help track how changes in suspended solids, a major water quality issue in tropical rivers, interact with other variables of interest.

scholarly journals Influence of extended drought on water quality in tropical reservoirs in a semiarid region

2015 ◽  
Vol 27 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Gustavo Girão Braga ◽  
Vanessa Becker ◽  
José Neuciano Pinheiro de Oliveira ◽  
Jurandir Rodrigues de Mendonça Junior ◽  
Anderson Felipe de Medeiros Bezerra ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Algal Growth ◽  
Freshwater Ecosystems ◽  
Semiarid Region ◽  
Drought Period ◽  
Tropical Reservoirs ◽  
Quality Degradation ◽  
Brazilian Semiarid

AimDrought periods often occur in Brazilian semiarid region and are supposed to induce water quality degradation by changes in physical, chemical and biological properties of freshwater ecosystems. Reservoirs in this region are used as drinking-water supplies and are exposed to wide volume fluctuations during drought periods due to lack of precipitation and high evaporation rates. This study aimed to identify patterns on water quality of two reservoirs during a long drought period. It was expected that more arid and shallower conditions would favor algal growth by enhancing nutrient availability, causing a decrease on water quality.MethodsThe study was based on monthly sampling over 20 months (May 2011 to December 2012) at two tropical reservoirs on Brazilian semiarid region. Precipitation and volume data were obtained from environmental agencies. Transparency was measured on field using a Secchi disk and conductivity, nutrients, suspended solids and chlorophyll-a were analyzed on laboratory. Temporal changes in all environmental variables were analyzed in each reservoir using two-way cluster analysis and also principal component analysis (PCA).ResultsThe volume of both reservoirs decreased considerably over the study because of low or shortage of precipitation. It was possible to detect two opposite patterns of chlorophyll-a in each reservoir throughout the drought season: in the first one phytoplankton growth was favored, while in the second one chlorophyll-a decreased by high inorganic turbidity. Both reservoirs tended to increase their turbidity and conductivity during the drought period due to shallow conditions, which probably contributed to sediment resuspension.ConclusionsWater level reduction during the extended drought period, contributed for water quality degradation due to high algal biomass and also high turbidity found during drought period. Local factors, as the nature of suspended solids, play an important role on predicting water quality.

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