Freshwater Courses Research Articles

<strong>Trichoptera in Flanders (Belgium): An ecological and phylogenetic characterization of the order</strong>

Flanders is a very densely populated region in the economic heart of Europe. To monitor the anthropological impact on the biological integrity of the freshwater courses, the Flemish Environment Agency (VMM) uses the Multimetric Macroinvertebrate Index for Flanders (Gabriels et al. 2006) which was recently developed under the influence of the European Water Framework Directive (WFD, EU 2000). This multimetric tool replaces the Belgian Biotic Index (BBI: range 0=dramatically poor quality to 10=very good quality), a monitoring system based on the sensitivities to pollution of the different macroinvertebrate taxa (De Pauw & Vanhooren 1983, De Pauw et al. 1986). Although recently replaced, the BBI has been used for the past 20 years and this extensive monitoring campaign produced a considerable amount of information on the distribution of macroinvertebrate taxa in Flemish freshwater courses. The Trichoptera (caddisflies) constitute one of these taxa. Unfortunately, determinations of caddisflies as part of the BBI monitoring, are accomplished only at the family level. Specific information on the occurrence and ecological preferences at the species level is scarce and outdated. The only comprehensive report documenting the occurrence of Trichoptera in Belgium dates back to 1984 (Stroot 1984) and since then only minor revisions and additions to the original report have been published (Stroot 1985, 1987; Stroot & Neven 1989). Therefore, the objectives of our research are to update the old species records and to elaborate and improve the ecological and phylogenetic knowledge of the Flemish Trichoptera by (a) identifying the caddisfly species that occur in Flanders; (b) determining their present distribution; (c) detecting which environmental variables influence this distribution; (d) studying whether the relationship among these variables and the species assemblages can be used to distinguish among the ecoregions in Flanders, which are based on similarities in climate, geology, geomorphology, (geo)hydrology and soil characteristics (Sevenant et al. 2002) and (e) investigating the phylogenetic relationships among the Flemish Trichoptera and evaluating their accordance with the current taxonomic classification.

SALT-FREE DYEING - A NEW METHOD OF DYEING ON LYOCELL/COTTON BLENDED FABRICS WITH REACTIVE DYES

Abstract Cellulosic/regenerated blended fabrics dyed with reactive dyes require a large amount of salt, which pollutes fresh watercourses. Due to the hydrolysis of the dye, the dyeing effluent consists of a large amount of hydrolysed dye, and it requires a high volume of water to remove the hydrolysed dye in a wash-off process. Lyocell/cotton fabrics were dyed with reactive dyes using conventional methods and pretreating the fabric with polyvinylamine chloride (at five different concentrations). Pretreated samples were dyed without using salt as an electrolyte. The influence of pretreatment on K/S value, wash fastness, rubbing fastness, tensile strength, flexural rigidity and crease recovery were determined. It was found that pretreatment of Lyocell/cotton fabrics with polyvinylamine chloride increases dye uptake and shows good wash fastness and rubbing fastness. There was a slight increase in crease recovery angle and flexural rigidity in the pretreated sample. It was determined that polyvinylamine chloride was found to be effective for pretreatment in salt-free dyeing of Lyocell/cotton fabrics.

Impact of Reuse Water on Golf Course Soil and Turfgrass Parameters Monitored Over a 4.5-Year Period

Population growth and water limitations in the southwestern United States have led to golf courses in many communities to be encouraged or mandated to transition to reuse water for irrigation purposes. A monitoring program was conducted on nine golf courses in the Las Vegas valley, NV, for 4.5 years to assess the impact of reuse water on soil–turfgrass systems {bermudagrass [Cynodon dactylon (L.) Pers.], perennial ryegrass (Lolium perenne L.), bentgrass (Agrostis palustris Huds.)}. The nine courses selected included three long-term reuse courses, three fresh water courses, and three courses expected to transition to reuse water during the monitoring period. Near-surface soil salinity varied from 1.5 to 40.0 dS·m−1 during the study period with the highest peaks occurring during summer months and on long-term reuse irrigated fairways. Although soil salinity at several depths on fairways and greens increased after transition to reuse water, this did not lead to a systematic decline in leaf xylem water potential (ΨL) or color. When the data were grouped as fresh, transition, or reuse irrigated, soil salinity on reuse courses were statistically higher (P < 0.05) than fresh and transitional courses, yet plant response on reuse courses was not statistically different (P > 0.05) than that observed on fresh courses. The fact that summertime plant parameter values often declined under lower salinity levels and the electrical conductivity of the irrigation water was rejected as a significant variable in all backward regression analysis to describe plant response indicated that management differed significantly from course to course. We conclude that proper irrigation management, based on a multitiered feedback system (soil–plant–atmospheric monitoring), should be able to maintain favorable salt balances and plant response as long as irrigation volumes are not restricted to where deficit irrigation occurs.

Thinlip grey mullet Liza ramada (Mugilidae) caught in a

Two individuals of thinlip grey mullet Liza ramada were collected in a southern Norwegian brook (58° 22’ N, 8° 37’ E) on 12th September 2007. The fish were 8.7 and 9.0 cm in total length, 6 and 7 g in total mass, and most probably in their first year of life. The nearest known spawning area of the species is south of the English Channel, meaning that they had probably moved at least 900 km across the North Sea during their first growth season. To our knowledge, this is the first published observation of the catadromous thinlip grey mullet from a Scandinavian freshwater course.

Water quality assessment using remote sensing techniques: Medrano Creek, Argentina

Two spectral bands of the visible spectrum [0.45–0.52 μm (Blue), 0.52–0.60 μm (Green)] of satellite images obtained by LANDSAT 7 ETM+ have been used in this study to follow the contaminated waters of Medrano Creek when it flows into Río de la Plata River. The former is one of the five fresh watercourses going through the Metropolitan Area of Buenos Aires, Argentina, where 13 million people live. Previous studies have shown that the water quality of Rio de la Plata at the outlet of Medrano Creek has decreased more than 50% as a source of water for human consumption. The non-treated effluents of the textile industry probably affect the water quality. We have developed a model that predicts the water quality index (WQI) of surface waters in the study area and uses linear regression analysis. The model has been validated using a data set of 12 physicochemical parameters obtained during the last 3 years. The potentiality of using satellite images was confirmed by the results: (a) to trace the organic contamination (associated with dyes) in freshwater systems and (b) as tools for decision making in the management of water resources.

Water Quality Changes in Golf Course Irrigation Ponds Transitioning to Reuse Water

Irrigation ponds on nine golf courses in southern Nevada were monitored for water quality over a 1600-day period. Three of the golf courses were fresh water courses, three were courses scheduled to transition to reuse water during the study period and three were long term users of reuse water. Salinity [electrical conductivity (EC)], NO –3-N, PO4-P, pH, algal chlorophyll concentration, clarity, temperature, oxygen, and all major cations and anions were analyzed on a monthly basis. A selected fairway on each course was equipped with water meters to assess irrigation volumes on a bimonthly basis. Estimates of salt and NO –3-N loading on fairways were made by weighting irrigation volumes with concentrations of salt (assuming 700 mg·L–1 per dS·m–1) and NO –3-N measured in the irrigation ponds. Pond spectral reflectance measurements were obtained on a single monitoring day and correlated with water quality parameters. EC, temperature, NO –3-N, PO4-P, algal chlorophyll concentration and clarity all demonstrated significant changes in all irrigation ponds that transitioned to reuse water (p < 0.05). Multiple regression analysis revealed that as much as 75% of the variability in pH in some irrigation ponds could be accounted for based on water quality parameters measured, with higher R2 values associated with elevated HCO–3 concentrations. Spectral reflectance (individual wave bands and spectral indices) was shown to be correlated with pH, clarity and algal chlorophyll concentration (R2 = 0.66** to 0.82***) with a well defined threshold relationship between clarity and the spectral index R705/R670. Average yearly NO –3-N loads on fairways averaged 8.5 kg·ha–1·yr–1 on fresh water courses, 86.5 kg·ha–1·yr–1 on transition courses and 209.8 kg·ha–1·yr–1 on long term reuse courses (all significantly different at p = 0.05). Average yearly salt loads on fairways averaged 11,959 kg·ha–1·yr–1 on fresh water courses, 14,675 kg·ha–1·yr–1 on transition courses and 27,445 kg·ha–1·yr–1 on long term reuse courses (long term significantly different at p = 0.05). Such results indicate that significant attention must be given to irrigation strategies used on reuse irrigated golf courses to properly manage for higher nitrogen and salt loads.

Influence of nutrient levels on uptake and effects of mercury, cadmium, and lead in water spinach.

In Southeast Asia the aquatic macrophyte water spinach (Ipomoea aquatica Forsk.) is a popular vegetable that is cultivated in freshwater courses. These often serve as recipients for domestic and other sorts of wastewater that often contain a variety of pollutants, such as heavy metals. In addition, fertilizers are frequently used where water spinach is cultivated commercially for the food market. To estimate the importance of ambient nutrient concentrations for accumulation of mercury (Hg), cadmium (Cd), and lead (Pb) in water spinach, plants were exposed to nutrient solutions of different strength and with varying metal concentrations. Metal-induced toxic effects, which might possibly affect the yield of the plants, were also studied. The lower the nutrient strength in the medium was, the higher the metal concentrations that accumulated in the different plant parts and the lower the metal concentration in the medium at which metal-induced toxic effects occurred. Accordingly, internal metal concentrations in the plants were correlated to toxic effects. Plants exposed to metals retained a major proportion of the metals in the roots, which had a higher tolerance than shoots for high internal metal concentrations.

Répartition des parasites branchiaux du poisson d’eau douce Barbus martorelli Roman, 1971 (Teleostei : Cyprinidae) et tendance à une évolution d’intensité contraire des myxosporidies et des monogènes en fonction de l’âge de l’hôte

L’étude de la parasitofaune branchiale de 558 Barbus martorelli a été menée dans un cours d’eau douce aux alentours de Yaoundé (Cameroun) en milieu tropical, afin d’obtenir des informations sur la répartition des agents pathogènes dans une population d’hôtes sauvages ; ces données sont indispensables dans la recherche de moyens pour éviter les pertes énormes souvent observées en pisciculture intensive. Cette analyse a révélé la présence de deux espèces de myxosporidies (Myxobolus barbi et M. njinei) et de huit espèces de monogènes (Dactylogyrus bopeleti, D. insolitus, D. simplex, D. maillardi, Dogielius martorellii, Dogielius sp., une espèce de Gyrodactylidae et une larve de Polystomatidae). Quatre poissons n’ont pas présenté de parasites, 24 ont présenté une infection monospécifique et 530 une infection plurispécifique. Chaque individu infesté a hébergé en moyenne quatre espèces de parasites. Alors que la prévalence et l’intensité moyenne parasitaire diminuaient avec la taille de l’hôte pour les protozoaires, le phénomène inverse a été observé pour les helminthes. L’effet sexe a été noté dans l’infestation de B. martorelli par la myxosporidie M. njinei et par la plupart des espèces de monogènes. Les femelles ont ainsi été plus infestées que les mâles en raison de leur biologie en période de frai. Enfin, la richesse des espèces parasitaires a semblé affecter négativement le poids des hôtes.

Effects of discharge reductions on salt wedge dynamics of the Ebro River

AbstractThe Ebro River is the largest freshwater course of Spain with a discharge (in the lower course) that has been reduced in the last few decades due to the construction of several dams and the corresponding increase of water demand and river regulation. The lowest stretch of this river (about 42 km) behaves most of the time as a highly stratified estuary with a salt wedge. The dynamics of this salt wedge are important from the ecologic and economic points of view and depend mainly on the river discharge, although other factors (like bathymetry and climatology) play a non‐negligible secondary role. The wedge dynamics would also be affected by the planned river diversion scheme towards other areas of Spain. This diversion plan would mean a reduction of about 15% of the annual discharge (in the Ebro lower course) and the corresponding impact should be carefully assessed.With that aim a two‐layer hydrodynamic numerical model has been employed to evaluate the role of flow regulation in the Ebro salt wedge dynamics, with particular emphasis on the potential discharge reduction due to the planned water diversion. The model has been calibrated with data acquired during four field campaigns (one per season) carried out during 1999 and 2000. Different scenarios of discharge reduction have been studied. Model results suggest a significant increase of salt wedge extent and permanence associated with the planned diversion scheme. This would entail an increase of saltwater intrusion problems both for aquifers and crops. Copyright © 2003 John Wiley & Sons, Ltd.

Treatment of cellulose with cationic, nucleophilic polymers to enable reactive dyeing at neutral pH without electrolyte addition

AbstractReactive dyeing of cotton requires very high concentrations of salt, which pollutes freshwater courses. The dyeing effluent is highly colored as a result of high levels of hydrolysis of the dye, and high volumes of water are used in the wash‐off process to remove the hydrolyzed dye in order to achieve the excellent wash‐fastness levels expected. A substantive cationic, nucleophilic polymer was applied to cotton as a pretreatment agent prior to dyeing. This enabled salt and alkali to be completely eliminated from the dyeing process, significantly reducing the duration of the dyeing process and requiring less than 50% of the volume of water compared with those of the standard reactive dyeing processes. Dyeings secured using the pretreatment method required one simple washing stage to give wash‐fastness values equal to those observed for the standard reactive dyeings that required several wash‐off stages. The color strength of the pretreated dyeing was also slightly higher than that of the standard dyeings, and this was attributable to a reduction in dye hydrolysis and hence a higher fixation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1026–1031, 2003

Geoelectrical investigation beneath Behbiet ElHigara and ElKom ElAkhder archaeological sites, Samannud area, Nile Delta, Egypt

AbstractGeoelectrical resistivity and resistance geoscanning techniques were conducted on Behbiet ElHigara and ElKom ElAkhder archeological sites for two purposes. The first was aimed to study the palaeohydrography and the subsurface geological picture of these sites; for this purpose, 19 vertical electric soundings were conducted along two E–W profiles across the sites. The results indicate that both archaeological sites represent buried high sand gizeras occupied by the ancient Egyptians as they were safe from the high floods and near to the freshwater courses that passed by the sites. The second purpose was to delineate any buried archaeological remains under the soil. For this purpose, resistance geoscanning survey was conducted on the two sites, together with three detailed and shallow geoelectric resistivity profiles along ElKom ElAkhder for more confirmation. The results indicate that the low‐resistivity clayey deposits predominate on the two sites. Behbiet ElHigara is characterized by shallow, circular and small‐extent anomalies that could be referred to small granitic blocks at shallow depths, whereas at ElKom ElAkhder, a high resistivity anomaly embedded within a low resistivity clayey facies was noticed: this could represent the buried sand gezira (islet) of ElKom ElAkhder. Copyright © 2002 John Wiley & Sons, Ltd.

Infraspecific variation in two species of aquatic hyphomycetes assessed by RAPD analysis

During a survey of aquatic hyphomycetes isolated from foam patches in a stream of the Central Region of Spain, random amplified polymorphic DNA (RAPD) profiles were used to analyse the infraspecific variability within the populations of the two dominant species, Heliscus lugdunensis and Articulospora tetracladia . Thirteen foam samples were collected along ∼ 1 km of the stream course and strains of these two species were cultured from single conidia. More than 100 isolates of each species were subjected to PCR under low-stringency conditions, using two primers derived from consensus sequences of the 5·8S rRNA gene. The Heliscus and Articulospora strains could be divided into seven or five different RAPD types, respectively, each group containing at least four isolates. Up to 10 of these different genotypes could be detected in the same foam sample. The distribution of these RAPD types among the foam samples seems to be random. These results suggest the presence of a relatively stable pool of fungal genotypes colonizing the plant substrates along the stream. However, the mechanisms of fungal dispersion occurring in freshwater courses could also account for the high percentage of RAPD groups shared among relatively distant foam patches.

Mercury in freshwater fish and clams from the Cerro Prieto geothermal field of Baja California, México.

Several reports have expressed concern about the potential toxicity hazards and environmental contamination of mercury emissions from geothermal fields in Hawaii, New Zealand, Iceland, California and Mexico. Inorganic mercury discharged from the sources may accumulate in the sediments of rivers or lakes and, after microbiological methylation may become concentrated in the edible tissue of fish. This study involves assessment of geothermal mercury pollution arising from Cerro Prieto. For this purpose the fish Tilapia mossambica and the clam Corbicula fluminea were collected from the freshwater courses of the Mexicali Valley. Reports indicated that in 1982, 13 t of T. mossambica were destinated for human consumption. A further aim was to provide base line data and information relevant to the level of mercury contamination for the Mexicali Valley.