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At least 19 recordsLinked to original sources
PubMed2025

Microbial genomic database of the Yangtze River, the third-longest river on Earth.

Microbes play an important role in mediating the nutrient cycling in the river ecosystem as a hotspot for biogeochemical processes. Due to scattered sampling efforts, however, there is a lack of a systematic study of the diversity of prokaryotic genomes in the Yangtze River, the third longest river on Earth. Here, we collected 602 metagenomic datasets of water, sediment and riparian soil samples spanning the Upper, Middle, and Lower basins of the Yangtze River over a 6,300 km continuum. We reconstructed 8,110 qualified genomes represented by 927 species-level genomes at the 95% ANI threshold, spanning 31 bacterial and five archaeal phyla. We further showed that more than half of these species (61.3% ~ 82.4%) were novel according to the genomic comparison against the curated databases, greatly expanding the known diversity of river prokaryotes. This dataset depicts an overview of microbial genomic diversity in the Yangtze River and provides a resource for in-depth investigation of metabolic potential, ecology, and evolution of riverine microbiomes.

Rivers↗
PubMed1979

PCB removal from the Duwamish River estuary: implications to the management alternative for the Hudson River PCB cleanup.

The results of the Duwamish River PCB cleanup and recovery project are discussed as a basis for comparison in selecting potential management alternatives for removing PCB residues in the Hudson River. Application of the Pneuma dredge system at the Duwamish River spill site removed approximately 92% of the PCBs spilled. No significant changes in the PCB load of suspended matter and water column were observed. These results suggest that a carefully planned dredge/disposal operation can be effective in minimizing environmental impacts in the Hudson River. On the basis of observations of the Duwamish case, the existing baseline data on the distribution of PCBs in the Hudson River, and the removal alternatives and associated environmental tradeoffs, hot spot dredging is recommended as the best practical alternative.

Accidents↗
PubMed2025

Genomic-based revelation of genetic structure and adaptive characterization of Schizopygopsis malacanthus in the Jinsha River and Yalong River.

BACKGROUND: As a highly specialized class of schizothoracine fishes, Schizopygopsis malacanthus has attracted much attention due to its widespread distribution. To investigate the impact of the Qinghai‒Tibet movement on S. malacanthus, we analyzed the genetic evolutionary history of this species. RESULTS: These results showed that there was a high level of genetic differentiation between Jinsha River (JSR) populations and Yalong River (YLR) populations. The genetic diversity of intra-YLR populations was higher than that of the intra-JSR populations. There was gene exchange of the Suwalong population to the Huoqu and Ganzi populations. Furthermore, both of the JSR and YLR populations exhibited a gradual increase in the genetic differentiation index from low to high altitudes, and the effective population of high-elevation populations has gradually expanded. In high-altitude populations, the selected genes were enriched in DNA repair, light transduction, and energy metabolism, reflecting the genetic basis for their migration to higher altitudes. CONCLUSIONS: S. malacanthus populations had the higher genetic differentiation and genetic diversity in the JSR and its main tributary YLR. Therefore, we should preserve high-elevation natural river sections as much as possible and reserve habitats for their migration and diffusion.

Animals↗
PubMedDate not supplied

[Viral flora (coliphages and human enteroviruses) found in river water after an urban district (Saint-Etienne). I. Comparative study of four simple and inexpensive methods for concentration and isolation of river-water viruses (author's transl)].

Four methods for the concentration of human enteroviruses in the waters of the river Furan were surveyed: the original method described by WALLIS, of adsorption of viruses on PE-60 polyelectrolyte; a modified version of the Wallis method; a method using a different polyelectrolyte available in France, the POE; the two-phase system described by SHUVAL. The best results were obtained when using the method of adsorption on polyelectrolytes, and the second method was finally chosen for field surveys.

Adsorption↗
PubMed1976

Distribution of Bdellovibrio bacteriovorus in sewage works, river water, and sediments.

Bdellovibrio was found in all liquid phases of the sewage works examined. The predator was also found in all the river sediments and sewage-polluted river waters examined but could not be found in some unpolluted river waters. Bdellovibrio was able to multiply on the high numbers of bacteria present in the aerobic percolating filter film but could not survive in anaerobic sludge. Similarly, the predator was present in the aerobic surface layers of river sediments but not in the anaerobic bottom layers. The major source of Bdellovibrio in the polluted rivers examined were sewage works effluents, and numbers in both river water and sediment were correlated with river water quality. It was unlikely that Bdellovibrio was important in reducing numbers of other bacteria in either sewage or river sediment.

Cell Count↗
PubMed1976

Monograph on "Lithoglyphopsis" aperta, the snail host of Mekong River schistosomiasis.

We discuss the morphology, histology, ecology, distribution, systematics, and evolutionary relationships of "Lithoglyphopsis" aperta Temcharoen, the snail host of Mekong River Schistosoma sp., and part of a vast, complex, endemic hydrobid fauna consisting of 11 genera and over 80 species. "L" aperta is a member of the Hydrobiidae (as broadly outlined by Fretter & Graham, 1962), subfamily Triculinae (as defined by Davis, 1968b). "L" aperta cannot be assigned to Ltihoglyphopsis because its shell and radula differ from those of the type-species, L. modesta (Gredler) from China, and because L. modesta is apparently more closely allied to other Mekong River genera in these traits. The female reproductive system of "L." aperta is similar to that of Tricula burchi Davis, a species from NW Thailand outside the Mekong River drainage. It is not possible to assign aperta to a named genus until the morphologies of numerous other hydrobiid taxa in the Mekong River are unknown. "L." aperta is typically hydrobiid in grade of morphological organization, in the nervous digestive, ctenidial and male reproductive systems. Differences from other hydrobiid taxa are in the female reproductive system and micromorphological features of the digestive tract. "L." aperta and species of Tricula from Thailand have a female reproduction system where sperm enter at the posterior end of the mantle cavity and travel to the bursa copulatrix via a spermathecal duct. These and related traits are the basis for the subfamily Triculinae. Hydrobiid taxa from Europe (Hydrobiinae s.s.) belong in a different phyletic line, where sperm enter the female reproductive system at the anterior end of the mantle cavity and travel via a ciliated groove in the palial oviduct to the bursa copulatrix. "L." aperta, as well as taxa of the Pomatiopsinae (e.g. Oncomelania, Pomatiopsis), differ from most known mesogastropods in lacking a hypobranchial gland. "L." aperta, other triculines, pomatiopsines and hydrobiines, as well as taxa studied in the Bithyniidae, Truncatellidae and Assimineidae differ from other mesogastropods, e.g. Viviparidae, Pleuroceridae, Littorinidae, etc., in that the salivary glands are dorsal to the nerve ring i.e. do not pass through the nerve ring. "L." aperta lives on solid substrata, particularly wood, shells and leaves in the Mekong River from Khemarat, Thailand, to the Cambodian border, 200 river miles downstream. The range probably extends another 100 river miles downstream to Kratie, Cambodia. It is an "r"-selected species by having a high density-independent mortality and using much of its resources for reproduction. The species is a colonizer in a river with severe annual floods. Females live less than 12 months; they apparently lay eggs in late January or February and die. In early March neither adults nor young can be collected. By mid or late March young suddenly flourish. The new generation does not mature until late May or June, after the beginning of the rainy season...

Animals↗
PubMedDate not supplied

Biochemical genetic variation in populations of golden trout, Salmo aguabonita: evidence of the threatened Little Kern River golden trout, S.a. whitei.

Eight wild populations of the High Sierra golden trout, Salmo aguabonita, and one domestic stock of rainbow trout, Salmo gairdneri, were examined for biochemical-genetic variation in eight protein systems. Variation within the eight systems was determined by at least 10 loci in both golden and rainbow trout and all the alleles identified in rainbow trout were observed as electro-phoretically identical phenotypes in golden trout. Variation was observed at an average of 51 percent of the loci in the golden trout samples and for five of the 10 loci in the rainbow trout. Average heterozygosity ranged from 12.6 to 13.9 percent for seven of the golden trout populations with one showing a low value of 5.4 percent. A comparable estimate of 12.1 percent was found for the rainbow stock. On the basis of genetic variation and allele frequencies at three loci, the eight golden trout populations were divided into two distinct groups. Three populations sampled from the Little Kern River basin tended to be genetically distinct from two additional Little Kern River basin populations and from three geographically distinct populations sampled from the eastern Kern River area. The former three populations were hypothesized to be of a recent rainbow-golden hybrid origin. Trout in the other two Little Kern River basin populations, sampled in head-waters of a stream tributary to the Little Kern River, were considered to be the threatened Little Kern golden trout, S. a. whitei Evermann, due to their high degree of genetic similarity to the geographically distinct subspecies S. a. aguabonita sampled from the eastern Kern River area. The finding of substantial genetic variation in the wild golden trout populations indicates that this threatened species is not at present genetically impoverished and thus does not appear to be in immediate danger of extinction through lack of adaptive capability.

Alcohol Oxidoreductases↗
PubMed2026

Elevation-structured viral ecological strategies along glacier-fed rivers on the Qinghai-Tibet Plateau.

The Qinghai-Tibet Plateau, a climate-vulnerable source of Asia's major rivers, harbors underexplored viral communities critical to ecosystem functions. By integrating 597 metagenomes from the Yangtze, Yellow, Lancang, and Yarlung Tsangpo rivers with 85 public available glacial metagenomes (Tibetan Glacier Genome and Gene catalog), we built the Glacier-to-River Virome Catalogue, encompassing 36,358 vOTUs and 897,250 viral protein clusters, to decode viral adaptation and ecological influence across elevation gradients. Our results reveal that high-altitude conditions favor viruses with elevated Guanine-Cytosine content, larger genomes and more cold-adaptation genes. A central finding is a systematic viral lifestyle shift from temperate in glaciated regions to lytic viruses downstream, accompanied with decline of pathogens carrying antibiotic resistance genes along the glacier-to-river gradients. Further, viral auxiliary metabolic genes transition from glacier nutrient scavenging (e.g., nitrogen and sulfur transporters) to downstream mineralization processes (e.g., denitrification) in plains highlights their role in biogeochemical cycling. These findings position viruses as pivotal regulators of microbial community structural and functional dynamics to glacier-to-river gradient change and biogeochemistry in the Qinghai-Tibet Plateau, providing critical insights into climate response in vulnerable Asian water towers.

Ice Cover↗
PubMed1976

Calcium content of river water, trace element concentrations in toenails, and blood pressure in village populations in New Guinea.

Several studies carried out on industrialized population groups have revealed the presence of an inverse relationship between hardness of drinking water and certain cardiovascular parameters, e.g., death rates, blood pressure, blood cholesterol, etc. In the present paper an attempt was made to see whether such an association also exists in primitive population groups who drink untreated water collected directly from rivers. Blood pressure was measured in persons living in villages along the banks of the Wogupmeri river in New Guinea. The water was analyzed for calcium content. Trace element concentrations were also determined in toenails from the same subjects to see whether a correlation existed. Calcium content of river water decreases as the river flows downstream, while blood pressure of the villagers living along this river increases. The trace element analysis of toenails revealed strong correlations between aluminium and vanadium. The concentrations of these two elements decrease with age. This association is present in both sexes, in adults and in children. A similarly strong correlation also exists between these two elements in staple food. The results of the present investigation tend to confirm the findings of other studies indicating an apparently beneficial effect of relatively hard water on cardiovascular parameters. The concentration of aluminium and vanadium in toenails show interesting trends, the biological meaning of which, if any, is still unknown.

Adolescent↗
PubMed1975

A comparison of food habits of white perch (Morone americana) in the heated effluent canal of a steam electric station and in an adjacent river system.

Analysis of the stomach contents of 97 white perch, Morone americana, taken from the effluent canal of a steam electric station (S.E.S.) and 106 white perch from adjacent Patuxent River waters indicated similar food habits from September 1970 through August 1971. However, 35% of all white perch taken from the heated effluent canal contained small pieces of coal and cinders, whereas only 3% of the river specimens contained such items in their stomachs. Fly ash and coal dust are present on the bottom of the S.E.S. canal, whereas little such material, if any, can be found on the river bottom in the study area. This suggests the canal fish were actively feeding in the heated effluent and not simply moving into the canal after feeding in the river. No significant difference (Pgreater than0.05) was found between the average wet weight stomach contents of the river and canal fish within the same mouth.

Animals↗
PubMed1976

Optimal control of artificial aeration in river networks.

Under suitable conditions, artificial in situ aeration is an appropriate and economical method of alleviating water pollution. Regional planning for the control of water pollution can properly consider the use of artificial aeration on a river network in conjunction with other pollution abatement techniques. Application of optimization methods can yield significant savings in the aeration energy consumption required to produce a given level of impact on a polluted river network. The confluence of two rivers, each receiving effluent discharges and subject to artificial aeration control, is first investigated. It is shown that the optimal feedback aeration strategy in one branch of the river system not only depends on measurements of the water quality in that branch, but also on the water quality measurements in the second branch. With these results as the foundation, the optimal aeration control strategy is then determined for a generalized river network modeled as a graphical tree. Various properties of the optimal aeration policy are illustrated by computational examples.

Air↗
PubMedDate not supplied

[Studies on the quality of water of the right side tributaries of the Po River; Trebbia and Nure, in 1971-1973].

In the period 1971-73 samplings were taken out monthly at the mouths of the two right side tributaries of the river Po, Trebbia and Nure. The aim of the research was to value the water quality, the polluted load conveyed to the river Po and to compare the real load with the one estimated on the basis of inhabitants and the basin area. Both the water courses are torrent-like rivers with highflow values in the winter and low flow values in the summer (July and August). There are no important industries in the basins studied and the high polluted effluents, mainly domestic and agricultural discharges, are placed in the plain tracts of the rivers at few kilometers from the mouths. As far as the water quality of both rivers is concerned, most of the chemical parameters maintain suitable levels for fish life and drinking purposes; on the contrary the microniological indexes exceed the limits for bathing fixed by the Italian Ministry of Health by 100 E.coli 100/ml. and by 1000 total coliforms 100/ml. in about 90 and 70-80% of samplings. The comparison between real and calculated loads has shown a good agreement for BOD and chloride in Trebbia and for BOD and phosphates in Nure.

Italy↗
PubMed1975

Analysis of river water and drinking water from seven European countries.

During the months of June to August and September to December 1972 and again from January to April 1973, the river and drinking water at a number of points in seven European countries was examined for fluorescent content. The purpose of the river water studies was to identify any traces of fluorescent whitening agents (FWAs) and relate them as far as possible to knolementary role and also helped to interpret the scatter of the control level of the river water studies. Identification and separation were carried out by means of a combination of spectrofluorimetry and thin layer chromatography. Detection limits and reproducibility of the methods of determination are explained in the chapters V/3-7 (methods of analysis for FWAs. The second river water survey showed that at only one sampling point (Borås in Sweden) there was detectable concentrations (up to 8 ppb) of a lipophilic unsulfonated FWA [2, 5-BIS (BENZOXAZOL-2-YL)THIOPHENE], And these were still about 1 ppb in the third survey. JENSEN and co-worker had previously detected this substance at the same location. No traces of FWAs were detected in any of the other tests. The detection limit in river water was 0.01 ppb (1 part per American billion = 10(-3) gram per metric ton). For identification purposes, a test mixture of six FWAs each with a different chemical constitution and different fields of application was used, and this was first exposed to light in an aqueous solution for some minutes.

Chromatography, Thin Layer↗
PubMed1976

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a 10-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminium bydroxide concentration method. The isolation of A and B Coxackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contaminated water (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Enterovirus↗
PubMed1976

Presence of certain enteroviruses (Coxsackie) in sewage effluents and in river waters of Roumania.

The paper presents the results of research studies conducted during a lo-year period (1962-1971) with the view to detect certain enteroviruses (Coxsackie) from sewage, river and drinking water samples, and from the filter sand of drinking water-works supplied with river water. The method consisted first in preconcentrating the samples collected on immersed gauze pads, secondly in the concentration of the virus samples by the following methods-used either separately or in parallel: the Amberlite method, the yeast cell and the aluminum hydroxide concentration method. The isolation of A and B Coxasackie viruses averaged 29.12% in the sewage samples and 14.66% in the river water samples. Lower values were found both in aqueduct water and in the filter sand (2 positive samples out of 65 and 3 positive samples out of 39, respectively). A seasonal distribution of the viral incidence was evidenced in the sewage samples with lower value in the river water, while the frequency decreased with the distance from the pollution source. For the lightly contamined waters (river and aqueduct waters) the yeast cell concentration method gave the best results, this method being also the single reliable method for Coxsackie virus isolation from the filter sand samples.

Animals↗
PubMed2026

Nitrogen sources and concentrations shape algal odor compounds: Key drivers of β-cyclocitral and β-ionone in water bodies of the lower Yangtze River.

Taste and odor (T&O) compounds derived from cyanobacterial blooms pose escalating threats to freshwater security worldwide, yet the drivers of specific T&O metabolites remain poorly constrained. Here, we investigated the dual effects of nitrogen (N) sources and concentrations on the production of β-cyclocitral and β-ionone, two algal-derived T&O compounds, through integrated field surveys (54 sites across lakes and rivers) in the eutrophic lower Yangtze River, China, and laboratory cultivation of typical cyanobacteria (Microcystis aeruginosa and Pseudanabaena cinerea). Our field data revealed that the concentrations of β-cyclocitral and β-ionone in lakes and rivers were not significantly different, but increased with the trophic level index. Redundancy analysis and Mantel analysis showed that Microcystis and Pseudanabaena were potentially dominant contributors to β-cyclocitral and β-ionone in the water column. Structural equation modeling and variation partitioning analysis showed that enhanced nitrate (NO3--N) significantly promoted the production of these compounds. Laboratory experiments demonstrated that inorganic N (NaNO₃) maximized total T&O yields by promoting algal biomass, whereas organic N (urea and glutamic acid) elevated the T&O production per unit biomass by 1.5- to 9.5-fold. Notably, Pseudanabaena exhibited a 2.3-fold higher β-ionone yield than Microcystis, with greater sensitivity to N concentrations. Our study highlights the critical role of nitrogen pollution, both source and concentration, in the production of T&O compounds by phytoplankton and provides reference data for managing T&O issues in rivers and shallow lakes.

Norisoprenoids↗
PubMed1978

Polybrominated biphenyl (PBB) contamination of the Pine River, Gratiot, and Midland Counties, Michigan.

Michigan Chemical Corporation, St. Louis, Michigan manufactured PBB from 1970 until November 20, 1974. Studies in 1974 showed significant quantities of PBB in effluent discharged from the facility and in water, fish, ducks, and sediments from the Pine River. Fish uptake rates and bioconcentration factors were estimated. Followup surveys over the three year period since the termination of PBB production indicate a decline in PBB loadings to the river but no significant corresponding decline of PBB levels in sediments, fish and duck tissue. A Michigan Department of Public Health warning against consumption of Pine River fish from St. Louis downstream to its confluence with Chippewa River remains in effect.

Animals↗