A study on distribution of natural radionuclide polonium-210 in a pond ecosystem

This paper presents the results of an investigation on the distribution of²¹⁰Po in Mutharasanallur pond ecosystem. It has been demonstrated that²¹⁰Po is non-uniformly distributed within the ecosystem. The results of the study show a dissolved²¹⁰Po concentration in pond water of 1 4mBq 1₋₁. The sediment samplso recorded a²¹⁰Po activity of 59 9 Bq kg₋₁. The aquatic organisms showed differential accumulation of the radionuclide with enhanced bioaccumulation in soft tissues and muscle. The²¹⁰Po activity in the biota fell within the range of 1·2–53 3 Bq kg₋₁ (wet wt). The bivalve mussel,Lamellidens marginalis was identified to accumulate higher concentration of²¹⁰Poin soft tissues, suggesting that these organisms could serve as a bio-monitor of²¹⁰Po radionuclide in a freshwater system. The concentration factors of²¹⁰Po for the biotic components ranged from ∼10²–∼10⁴. Analyses of the results indicate that prawn and fish represent an important source of supply of²¹⁰Po to humans via dietary intake. Results of²¹⁰Po activity in the abiotic and biotic components of the pond ecosystem were higher when compared with those of Cauvery river system, the primary water source of the pond.     

Validation of a Chiral Liquid Chromatographic Method for the Degradation Behavior of Flumequine Enantiomers in Mariculture Pond Water

In this work, flumequine (FLU) enantiomers were separated using a Chiralpak OD‐H column, with n‐hexane‐ethanol (20:80, v/v) as the mobile phase at a flow rate of 0.6 mL/min. Solid phase extraction (SPE) was used for cleanup and enrichment. The limit of detection, limit of quantitation, linearity, precision, and intra/interday variation of the chiral high‐performance liquid chromatography (HPLC) method were determined. The developed method was then applied to investigate the degradation behavior of FLU enantiomers in mariculture pond water samples. The results showed that the degradation of FLU enantiomers under natural, sterile, or dark conditions was not enantioselective. Chirality 28:649–655, 2016. © 2016 Wiley Periodicals, Inc.     

Phytoremediation efficiency of Eichhornia crassipes in fly ash pond

The present study was focused on field research to examine the phytoremediation potential of naturally grown Eichhornia crassipes in fly ash (FA) pond. Field results indicate the efficiency of E. crassipes for remediation of heavy metals from FA pond. The bioconcentration factor trend was Cr (3.75) > Cu (2.62) > Cd (1.05), and Cu (1.35) in root and stem, respectively. The survival and abundance growth of E. crassipes in the circumstance of heavy metal enriched FA pond is another highlight of the present research that reveals its toxitolerant characteristics. Thus, this lesson on phytoremediation proved that E. crassipes is a potential accumulator of Cu, Cr, and Cd from FA ponds and is a promising species for FA pond's remediation globally.     

The influence of flatworm predation on zooplankton inhabiting small ponds

Experiments were performed in 1977 to determine which large zooplankton in a series of high altitude ponds can be consumed by the predatory flatworm Mesostoma ehrenbergii. This predator consumes Daphnia at a high rate and the fairy shrimp Branchinecta at a low rate, but does not consume Diaptomus. Experiments were performed in 1978 and 1979 to determined the rate of predation on Daphnia in 30 liter tubs and to determine if predation rate is correlated with surface to volume ratio of experimental containers. There is a clear correlation between surface to volume ratio and predation rate. Determinations of Mesostoma and Daphnia densities were made in a series of eight high altitude ponds, and pond surface to volume ratios were determined. Examination of these parameters lends credence to the argument that Mesostoma predation affects Daphnia dynamics in some circumstances. The results suggest that benthic invertebrate predators may affect zooplankton dynamics, especially in shallow ponds.     

Degradation of softwood [14C lignin] lignocelluloses and its relation to the formation of humic substances in river and pond environments

The fate of lignin in water and sediment of the Garonne river (France) and of a pond in its floodplain was examined using specifically labeled [¹⁴C-lignin] lignocelluloses. No significant differences appeared in the mineralization rate of alder, poplar or willow [¹⁴C-lignin] in running water samples. Conversion of total radioactivity to ¹⁴CO₂ ranged between 18.7% and 24.4% after 120 days of incubation. Degree of ¹⁴C-labeled lignin mineralization in standing water and sediments was clearly lower, especially in submerged sediments, and was correlated with oxygen supply. After 60 days of incubation 3.3% to 7.9% of the ¹⁴C-labeled lignin was recovered in water samples as dissolved organic carbon originating from microbial metabolism. In water extracts from sediment the percentage of dissolved organic ¹⁴C was only 0.4% to 1.3% of the applied activity. In the humic fraction extracted from sediments it did not exceed 4.4% which was much lower than in soils. No significant difference appeared between river and pond conditions for humic substances formation.     

Evolving water quality in a common carp and blue tilapia high production pond

Intensive polyculture of blue tilapia, Oreochromis aureus, and common carp, Cyprinus carpio was conducted to determine their growth capacity and the accompanying water quality transitions in a 376 m² (207 m³) fish pond without aeration or water exchange. A total of 485 fingerlings (290 tilapia and 195 carp) averaging 72 g each (total 35 kg) was stocked and fed commercial floating pellets (36% protein-6%-N) at the approximate daily rate of 3% of the fish biomass six days each week. The total net fish growth was 159.4 kg (4.2 t ha^–1) with an average growth of 199.5 g per fish through the 96 days feeding period — 6 June to 7 September 1984. The s conversion ratio for the commercial feed was 1.3.Physiochemical patterns in the pond water were directly related to the rise and fall of turbidity through the course of the production trial. During one period of low turbidity, a biological inversion was evident with pH and dissolved oxygen measured at higher levels near the pond bottom and increasingly lower toward the surface. It is postulated that settled phytoplankton formed a photosynthetically-active algal mat on the pond bottom. The implications for potential fish kills can be significant.     

Variation in plant species richness in and adjacent to 64 ponds in SE Norwegian agricultural landscapes

All vascular plants, classified by life and growth form into six groups, four groups of hydrophytes (lemnids, nymphaeids, elodeids and isoetids), helophytes, and terrestrial species of pond margins, were inventoried in 64 SE Norwegian agricultural landscape ponds and their adjacent margins. The study sites varied considerably with respect to species richness; 0–4 for each hydrophyte group, 0–9 for helophytes, and 13–77 for terrestrial species. A total of 56 explanatory variables were recorded for each pond and adjacent margin to explain the observed richness variability.     

Biomass productivity of Scenedesmus dimorphus (Chlorophyceae) was improved by using an open pond–photobioreactor hybrid system

The industrialization of microalgae-based biofuel production has been hampered by low biomass productivity of conventional open ponds. In this research, a hybrid cultivation system that combined an open pond and photobioreactor (PBR), with broth circulating between both, was introduced. The hybrid system was tested under indoor and outdoor conditions using the oleaginous microalgal species Scenedesmus dimorphus. When the PBR(s) in the hybrid system reinforced the light supply to the carbon-replete open pond the biomass reached 1.34 g l^–1, 116% higher than in the non-hybrid system. Subsequent studies showed that higher circulation speed and low volume ratio of PBR vs. open pond would further improve the hybrid effects. When applied outdoors at pilot scale, the biomass productivity of the hybrid system increased 46.3–74.3% compared with the open pond and in September was 12.5% higher than that of PBRs. These results indicate that hybrid cultivation might be a cost-effective way to improve the light usage efficiency of current open pond systems.     

Viruses in recreational water‐borne disease outbreaks: a review

Viruses are believed to be a significant cause of recreationally associated water‐borne disease. However, they have been difficult to document because of the wide variety of illnesses that they cause and the limitations in previous detection methods. Noroviruses are believed to be the single largest cause of outbreaks, which have been documented in the published literature 45% (n = 25), followed by adenovirus (24%), echovirus (18%), hepatitis A virus (7%) and coxsackieviruses (5%). Just under half of the outbreaks occurred in swimming pools (49%), while the second largest outbreak occurred in lakes or ponds (40%). The number of reported outbreaks associated with noroviruses has increased significantly in recent years probably because of better methods for virus detection. Inadequate disinfection was related to 69% (n = 18) of swimming pool outbreaks. A lack of required reporting and nonuniform water quality and chlorination/disinfection standards continues to contribute to water‐borne recreational disease outbreaks.