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PubMed2001

Relationships between ambient geochemistry, watershed land-use and trace metal concentrations in aquatic invertebrates living in stormwater treatment ponds.

Stormwater treatment ponds receive elevated levels of metals from urban runoff, but the effects of these pollutants on organisms residing in the ponds are unknown. We investigated the accumulation of Cu, Zn, and Pb by macroinvertebrates collected from stormwater treatment ponds in Maryland serving commercial, highway, residential and open-space watersheds, and determined whether watershed land-use classification influences metal concentrations in macroinvertebrates, sediments, and water. Three types of invertebrate samples were analyzed--molluscs, odonates, and composite. Zn concentrations in odonates from ponds draining watersheds with commercial development (mean = 113.82 micrograms g-1) were significantly higher than concentrations in the other land-use categories. Similarly, Cu levels in odonates from commercial ponds (mean = 27.12 micrograms g-1) were significantly higher than from highway (mean = 20.23 micrograms g-1) and open space (mean = 17.79 micrograms g-1) ponds. However, metal concentrations in sediments and water did not differ significantly among land-uses. The results suggest that despite the high variation in ambient metal concentrations within each land-use category, macroinvertebrates in ponds serving commercial watersheds accumulate higher levels of Cu and Zn. The levels of Cu, Zn, and Pb in invertebrates from all ponds were less than dietary concentrations considered toxic to fish.

Animals↗
PubMed2000

Comparing and assessing acid rain-sensitive ponds.

Changes in pH and temperature were monitored in two freshwater ponds in Southeastern Massachusetts from 1990 to 1993 using a remote-sensing system that collected data on a continuous basis. The sensing system included a combination electrode, pH meter and portable computer powered by a marine battery. Temperature and pH information from the pH meter were acquired every 10 min and stored in the computer. The two ponds, located within 2 km of one another, have a different average pH and sensitivity to acid precipitation. Maquan Pond has an average pH of 6.0 and an alkalinity of 7.4 mg/l, while Furnace Pond has an average pH of 6.9 and alkalinity of 14.9 mg/l. The pH of both ponds varied seasonally and showed diel changes due to the photosynthetic and respiratory activity of aquatic organisms. Precipitation events did not change the pH of Furnace Pond. Maquan Pond on the other hand, did exhibit changes in surface water pH due to specific acidic precipitation events. During certain rainstorms, the pH of Maquan surface waters dropped to values as low as pH 4. In addition to the transient changes in pH, the acid-sensitive pond also exhibited differences in planktonic distribution patterns.

Acid Rain↗
PubMed2003

Water quality characterization and mathematical modeling of dissolved oxygen in the East and West Ponds, Jamaica Bay Wildlife Refuge.

The current study was undertaken to characterize the East and West Ponds and develop a mathematical model of the effects of nutrient and BOD loading on dissolved oxygen (DO) concentrations in these ponds. The model predicted that both ponds will recover adequately given the average expected range of nutrient and BOD loading due to waste from surface runoff and migratory birds. The predicted dissolved oxygen levels in both ponds were greater than 5.0 mg/L, and were supported by DO levels in the field which were typically above 5.0 mg/L during the period of this study. The model predicted a steady-state NBOD concentration of 12.0-14.0 mg/L in the East Pond, compared to an average measured value of 3.73 mg/L in 1994 and an average measured value of 12.51 mg/L in a 1996-97 study. The model predicted that the NBOD concentration in the West Pond would be under 3.0 mg/L compared to the average measured values of 7.50 mg/L in 1997, and 8.51 mg/L in 1994. The model predicted that phosphorus (as PO4(3-)) concentration in the East Pond will approach 4.2 mg/L in 4 months, compared to measured average value of 2.01 mg/L in a 1994 study. The model predicted that phosphorus concentration in the West Pond will approach 1.00 mg/L, compared to a measured average phosphorus (as PO4(3-)) concentration of 1.57 mg/L in a 1994 study.

Animals↗
PubMed1997

Potassium Salts Inhibit Growth of the Cyanobacteria Microcystis spp. in Pond Water and Defined Media: Implications for Control of Microcystin-Producing Aquatic Blooms.

Ten metals were assayed in 21 Indian ponds which comprised three groups: (i) eutrophic alkaline ponds containing <2.5 mM potassium and thick growths of Microcystis aeruginosa or Microcystis flos-aquae during most of the year, (ii) equally eutrophic alkaline ponds containing >2.8 mM potassium and no detectable Microcystis growth, and (iii) oligo- or mesotrophic ponds with various potassium and hydrogen ion concentrations and no persistent Microcystis blooms. The effects of potassium on Microcystis growth were examined in filter-sterilized pond water and in defined culture media. A 50% reduction in the 10-day yield of cultured M. aeruginosa was observed in DP medium and pond water supplemented with 1 and 3 mM KCl, respectively. In contrast, the addition of 2 to 30 mM NaCl did not suppress the growth of M. aeruginosa in either DP medium or pond water. Both 5 mM KCl and 20 mM KHCO(inf3) in J medium strongly inhibited the growth of M. flos-aquae C3-9, whereas 5 to 30 mM NaCl had no effect and 20 mM NaHCO(inf3) was stimulatory. For pond water cultured with a mixture of M. aeruginosa and the duckweed Wolffia arrhiza, M. aeruginosa dominated in unsupplemented water and W. arrhiza dominated in water supplemented with 4.8 mM KCl. Implications for the ecology and control of Microcystis blooms are discussed.

Journal Article↗
PubMed1971

Microbial Flora of Pond-Reared Brown Shrimp (Penaeus aztecus).

Agar plate counts and microbial types are reported for brown shrimp reared in 2-acre natural marshland and in 0.5-acre artificial ponds during June to October 1970. Bacterial counts of pond-reared shrimp ranged from 5 x 10 to 5.5 x 10 per g. At final harvest in October, bacterial counts ranged from 2 x 10 to 5.5 x 10 per g. In marsh ponds, bacterial counts of shrimp and pond water were lowest in August when both water temperature and salinity were high. Coryneform bacteria and to a lesser extent Vibrio were the predominant isolates from fresh pond shrimp. Shrimp stored at 3 to 5 C for 7 days were acceptable as judged by appearance and odor. Between 7 and 14 days of refrigerated storage, bacterial counts increased sharply and about 50% of the samples became unacceptable. Refrigerated storage of pond shrimp caused increases in coryneform bacteria and micrococci and decreases in Vibrio, Flavobacterium, Moraxella, and Bacillus species. Pseudomonas species were not significant in fresh or stored pond shrimp. The microbial flora of pond water usually was dominated by coryneform bacteria, Flavobacterium, Moraxella, and Bacillus species.

Journal Article↗
PubMed2006

Variable hydrology and salinity of salt ponds in the British Virgin Islands.

Caribbean salt ponds are unique wetlands that have received little scientific attention. They are common features of dry Caribbean coastlines, but they are threatened by rapid coastal development. We compared hydrology and salinity of 17 salt ponds in the British Virgin Islands. Ponds were mostly hypersaline (>50 ppt), and they exhibited dramatic salinity fluctuations in response to rainfall and evaporation. Individual ponds varied in their mean salinities and thus experienced different ranges of salinity. Differences in mean salinity appeared to be linked with hydrological characteristics. Hydrological variation ranged from permanently inundated ponds with direct sea connection to those fully isolated from the sea and retaining water only after rainfall. We characterized groups of ponds by their major hydrological characteristics, particularly their period of inundation and their degree of connection with the sea. The resulting classification appeared to reflect a continuum of increasing isolation from the sea, concurring with published geological records from salt pond sediments elsewhere. The patterns of variability and succession described here are applicable to salt pond management interests throughout the Caribbean.

Journal Article↗
PubMed1978

[Phylogenetic studies on some Japanese amphibia by means of immunoelectrophoresis. II. Relationships of some amphibians to Japanese pond frogs (author's transl)].

Since the Japanese pond frogs (Rana nigromaculata and R. brevipoda) are known to be very closely allied with each other in morphological, ecological, physiological or immunological characters, the phylogenetical relationships between the Japanese pond frogs and other 10 species of Japanese amphibians were investigated by means of immunoelectrophoretic analysis of liver extract. The results obtained are as follows: (1) There are conservative antigens which are commonly found in all species of Anura. (2) The Japanese pond frogs have specific antigens. (3) R. nigromaculata and R. brevidpoda are very closely allied with each other. (4) Four species of the genus Rana (R. rugosa, R. catesbeiana, R. ornativentris and R. japonica) are closely related to the Japanese pond frogs. (5) Two species of the genus Rhacophorus (Rh. arboreus and Rh. burergeri) are related to the Japanese pond frogs. (6) R. limnocharis is related to the Japanese pond frogs at the same extent as the genus Rhcophorus is. (7) Tow species of the suborder Procoela (Hyla arbored and Bufo bufo) are only partially related to the Japanese pond frogs. (8) Cynops pyrrhogaster pyrrhogaster of Urodera had only a few common antigens with the Japanese pond frogs.

Amphibians↗
PubMed1999

Results from black tiger shrimp penaeus monodon culture ponds stocked with postlarvae PCR-positive or -negative for white-spot syndrome virus (WSSV).

Commercial, intensive, earthen shrimp ponds (188) in southern Thailand were stocked with postlarvae (PL) of Penaeus monodon that had tested positive or negative for white-spot syndrome virus (WSSV) infection by polymerase chain reaction (PCR) assay. All the PL were grossly healthy. At 2 wk intervals after stocking, shrimp from each pond were examined for gross WSSV lesions and tested for WSSV by PCR. Shrimp from all the ponds stocked with WSSV-PCR-positive PL (Group 0, n = 43) eventually showed gross signs of white-spot disease (WSD) at an average of 40 d after stocking. Of the remaining ponds stocked with WSSV-PCR-negative PL (n = 145), some remained WSSV-PCR-negative throughout the study (Group 5, n = 52), while others (93) became WSSV-PCR-positive after stocking, during the first month (Group 1, n = 23), second month (Group 2, n = 40), third month (Group 3, n = 24), or fourth month (Group 4, n = 6). Crop failure was defined as a pond drain or forced harvest before 14 wk or 98 d of cultivation. For Group 0 the proportion of ponds failing was 0.953, while it was only 0.019 for Group 5. Thus, the relative risk of failure for Group 0 was approximately 50 times that of Group 5. The relative risk of failure for Group 0 was also 3 times that for ponds stocked with WSSV-PCR-negative PL. Obviously, not all WSSV outbreaks resulted in crop failure. Of the 93 ponds stocked with PCR-negative PL that later yielded WSSV-PCR-positive shrimp, 53% reached successful harvest. The study showed that PCR screening of PL and rejection of WSSV-positive batches before stocking could greatly improve the chances of a successful harvest.

Animals↗
PubMed2001

Effect of probiotics on bacterial population and health status of shrimp in culture pond ecosystem.

The artificially manufactured probiotics having beneficial bacteria, Bacillus spp. was applied regularly in a modified extensive shrimp (Penaeus monodon) culture pond, located on the bank of Vellar estuary, Parangipettai. The populations of total heterotrophic bacteria (THB), beneficial bacteria (Bacillus spp.) and pathogenic bacteria (vibrios) were monitored in water and sediment of the pond. The results were compared with a control pond, situated in the same location having same water spread area, stocking density, species managed with same technologies and optimum environmental parameters in which no probiotic was applied. The populations of THB and Bacillus spp. in the experimental pond increased and the vibrios decreased after each application of probiotics. But the result of the control pond showed an increasing trend of the populations of THB, Bacillus spp. and vibrios towards days of culture. The control pond had lower levels of THB and Bacillus spp. and higher levels of vibrios than the probiotic applied (experimental) pond. Also the probiotics maintained optimum transparency and low organic load in the experimental pond as compared to control. In general, water and sediment had almost equal number of Bacillus spp. and vibrios, but sediment had higher THB load than water. The applications of probiotics lesser pathogenic vibrios and enhance beneficial bacilli in the culture leading to improved water quality, promoted growth and survival rates and increased the health status of the shrimp without stress and disease outbreaks. Thus the application of probiotics could lead to disease-free and profitable shrimp culture operations which will be helpful for shrimp farmers as most of them are now-a-days severely affected by microbial diseases.

Animals↗
PubMed2002

Cotreatment of sewage and septage in waste stabilization ponds.

A one year study was carried out in a waste stabilization ponds system where septage and sewage are cotreated. The system consists of two septage ponds which operate alternately followed by two ponds in series which receive the combined effluent. The septage ponds also act as evaporation ponds for the accumulated sludge. The monitoring program was divided in two phases. The results of the first phase indicate that the effluent of septage ponds has an adequate quality to be discharged into the waste stabilization ponds designed to treat sewage and that is possible to use the septage ponds to dry the accumulated sludge. Further investigation is needed to find suitable post-treatment of the sludge in order to use it in agriculture.

Agriculture↗
PubMed2003

Complex dynamics of toxin producing algal species and primary productivity in two water ponds of Faizabad.

In order to develop a method of predicting and assessing pond eutrophication, which is a serious environmental problem, and to propose effective measure of improvement of water quality. The present study was performed to measure water quality variables, primary productivity, chl-a and biomass of toxin producing algal species and fish production. High nutrient influx and toxin producing algal species have been observed during June 1999 to May 2000 in two water bodies [Girija Kund (A) and Maqubara pond (B)] of Faizabad. The maximum chl-a concentration, toxins producing algal species biomass were found to be 415.00 and 515.00 in pond A, while 451.00 microg/l and 541.22 mg/l in pond B, respectively in the case of Microcystis aeruginosa. Ecological parameters to evaluate GPP, NPP and CR were found to be 297.00, 134.000 and 182.00 mgCm3/h in summer season in pond B, respectively which is higher than pond A. A poor association existed between chl-a and GPP. Temporal variation (Photosynthetic rate) in A(max) & P(max) was also observed to evaluate the productivity of pond. Annual fish production potential of the ponds A and B has been estimated to be around 342.00 Kg and 204. 00 Kg, respectively which may be due to the presence of toxin producing algal species.

Biomass↗
PubMed2003

Pond treatment and effluent reuse of sewage from an oil production site in an arid coastal environment.

A pond system consisting of two lines each of an anaerobic followed by facultative and maturation ponds is used to treat site sewage from oil and gas production operations in an arid coastal environment. The performance of the pond system was evaluated together with the suitability of treated effluent for reuse in local irrigation. Effluent from the pond system by-and-large satisfies criteria for irrigation of non-food crop plants with respect to chemical parameters. The primary problem is coliform bacteria levels which are an order of magnitude higher than preferred values. First-order decay rate constants for each pond were calculated from a mass balance model that assumes complete mixing and incorporates the considerable evaporation that occurs in this setting. While the anaerobic ponds of both lines exhibit suitable performance, rate calculations indicate that the facultative and maturation ponds of the East Line are performing better than the West. A tracer study of the facultative and maturation ponds indicates that some short-circuiting is occurring in the West Line. A field experiment of coliform transport in irrigated soil gives indications of short- and long-term risks associated with reuse of the effluent.

Agriculture↗
PubMed2003

Integration of coliform decay within a CFD (computational fluid dynamic) model of a waste stabilisation pond.

CFD mathematical modelling offers the potential to predict the actual flow pattern in a pond rather than generalising its mixing and mass transport as either an ideal flow reactor or, in the case of the non-ideal flow reactor, as a single dispersion number. However, perhaps the greatest benefit that CFD offers over the previous approaches is its ability to directly account for physical influences on the pond hydraulics such as the addition of baffles for example. In addition to solving the equations of fluid flow, CFD modelling also allows incorporation of other equations. The next logical development is, therefore, the integration of a reaction model within its solution domain. This potential has been recognised by several researchers, but to date no such work has been published. The primary aim of this paper was to present a CFD model of a field pond that incorporates the first order decay equation for coliforms. Experimental monitoring of the field pond gave an average effluent concentration of 3,710 f.c./100 mL, while the CFD model predicted 4,600 f.c./100 mL. Considering the pond provides an order of magnitude decrease in faecal coliform concentration, the integrated CFD model has clearly predicted the treatment efficiency very well. The secondary aim of this paper was to demonstrate the potential application of this technique. A typical pond was designed and modelled along with two variations incorporating two baffles and six baffles respectively. As is typically found in pond systems, the standard design suffered from severe short-circuiting with the model predicting a value of 6.2 x 10(6) f.c./100 mL at the outlet. The simulations of the baffled designs illustrate how treatment efficiency was improved by reducing the short-circuiting through the pond. The model predicted values of 6.0 x 10(3) f.c./100 mL for the 2-baffle design and 5.7 x 10(2) f.c./100 mL for the 6-baffle design.

Enterobacteriaceae↗
PubMed2003

Correlation between snails and fish in fish ponds of World Fish Center (ICLARM) with special reference to snail vectors of schistosomiasis and fascioliasis.

The abundance of snail species in earthen fish ponds, irrigation and drainage canals at World Fish Center (ICLARM) in descending order was Bellamya unicolor (50.89%) > Physa acuta (18.94%) > Cleopatra bulimoides (7.6%) > Lanistes carinatus (6.73%) > Bulinus truncatus (5.19%) > Melanoides tuberculata (4.83%) > Lymnaea natalensis (3.14%) > Gabbiella senaariensis (0.9%) > Biomphalaria alexandrina (0.55%) > Lym naea truncatula (0.4%) > Planorbis planorbis and Succinea cleopatra (0.33%) > Ferrissia isseli (0.18%). Dead snails constituted about 5.19% of all the collected specimens. There were dramatic decrease in the total number of pulmonates in fish ponds which contained only Tilapia sp., and a very small number of cat fish, whereas the numbers of prosobranchia snails were much higher in these ponds. In fish ponds which accommodated a variety of fish species, the most dominant snail was B. unicolor followed by L. carinatus. However, pulmonate snails were absent in these ponds. B. truncatus was the only snail species found in concrete tank which contained only young tilapias with a very small size (5-8 cm in standard length). In irrigation canals, the number of snails and diversity was much higher than those in fish ponds. Out of 191 snails collected from inlet irrigation canal, 71 were dead, but in the outside irrigation canals, seven out of 564 snails were dead. P. acuta was absent in all examined fish ponds, but it was alive and in a high number (497 snails) in the outside irrigation canals. The number of snails collected from Bahnasawy drain was remarkably low (128 snails), however the diversity of snails was much higher compared to those in fish ponds and irrigation canals. Snail populations were stable with constant recruitment of young to adult snails for all the studied species.

Animals↗
PubMed2004

[Suspending particulates in rotifer-culturing pond ecosystem].

A comparative study on the structure and dynamics of suspending particulates in static and current water rotifer-culturing ponds showed that the total content of suspending particulates varied from 6.76 to 65.39 mg.L-1, with an average of 11.50 mg.L-1 in static water ponds, among which, organic pariculates accounted for 66.8%, while inorganic particulartes occupied 33.2%. In the organic particulates, both particulate detritus and bacteria accounted for 31%, while phytoplankton and zooplankton occupied 30.5% and 5.3%, respectively. The amount of suspending particulates in current water ponds was 41.83 mg.L-1 in average, among which, organic pariculates accounted for 70.4%, while inorganic pariculates occupied 29.6%. In the organic pariculates, both particulate detritus and bacteria accounted for 39.2%, while phytoplankton and zooplankton occupied 30% and 1.2%, respectively. The content of suspending pariculates in static water ponds was less than those in current water ponds. Rotifer-culturing pond was a special type of ecosystem, where Brachionus plicatilis was the major consumer, its community structure was sample, and the abiotic factors were easy to be changed, which resulted in the dynamics of suspending pariculates content in ponds. The ratio of organic to total pariculates in rotifer-culturing ponds was higher, and the contents of both particulate detritus and bacteria were corresponding to that of plankton.

Animals↗
PubMed2005

Performance of very shallow ponds treating effluents from UASB reactors.

Polishing ponds are units conceived for the post-treatment of the effluents from anaerobic reactors, are designed as maturation ponds, and aim at a further removal of organic matter and a high removal of pathogenic organisms. The paper investigates the performance of four very shallow (H = 0.40 m) polishing ponds in series, with very low detention times (1.4-2.5 days in each pond), treating anaerobic effluent from the city of Belo Horizonte, Brazil. The system was able to achieve excellent results in terms of BOD and E. coli removal, and good results in terms of ammonia removal, allowing compliance with European standards for urban wastewater and WHO guidelines for unrestricted irrigation. The paper presents the values of BOD and E. coli removal coefficients, which were much higher than those found in conventional pond systems. No statistically significant difference was found in the effluent E. coli concentrations from a pond with low depth and low detention time, and another pond in parallel, with double the depth and approximately double the detention time. The results endorse the applicability of the system composed by UASB reactors followed by very shallow ponds in series, with low detention times.

Anaerobiosis↗
PubMed2005

CFD (computational fluid dynamics) modelling of baffles for optimizing tropical waste stabilization pond systems.

CFD modelling of the incorporation of two baffles equally spaced along the longitudinal axis of the pond and with a length equal to 70% of the pond breadth, indicated a potential improvement in the removal of E. coli in a 4-day secondary facultative pond at 25degrees C from 5 x 10(6) per 100 ml in the effluent from a 1-day anaerobic pond to 4 x 10(4) per 100 ml; the reduction in an un-baffled pond was an order of magnitude less effective. The addition of a similarly baffled 4-day primary maturation pond reduced the effluent E. coli count to 340 per 100 ml; the reduction in an un-baffled series was two orders of magnitude less effective. Well designed baffles thus have considerable potential for reducing pond area requirements and hence costs in the hot tropics. These very promising results highlight the need for field studies on baffled pond systems to validate (or allow calibration) of the CFD model used in this study.

Biodegradation, Environmental↗
PubMed2005

Assessment of the waste stabilization pond performance, New Borg El-Arab City.

New Borg Al-Arab city includes 9 residential areas and 4 industrial zones. The four industrial zones are occupied by 266 running factories belonging to different industrial sectors. All the domestic sewage as well as the industrial wastewater is treated at an oxidation pond treatment plant and the plant effluent is used in irrigation of silviculture areas. The plant consists of 2 pond complexes. Each complex comprises 9 facultative ponds, arranged in 3 parallel series. Raw wastewater is pre-treated through screens and grit removal before entering the primary ponds. The study aims at assessment of the performance of the waste stabilization ponds. The results revealed that pre-treatment units were not functioning properly. The retention time was calculated to be 6 days in each pond of the first complex and 3 days in each pond of the second complex. The mean BOD surface loading rate was calculated to be 676 kg/ha/d for the first complex and 1584 kg/ha/d for the second. The plant was hydraulically and organically overloaded. The percentage removal of BOD, COD, SS, and NH3-N had an annual mean of 57%, 56%, 44%, and 39%, respectively for the first complex and 21%, 42%, 39%, and 25%, respectively for the second. Faecal coliforms were reduced by about 1 log10 unit in both complexes. The final pond effluent was not complying with the Egyptian law for reuse in irrigation. The study proposed some recommendations which can improve the efficiency of the plant as well as the effluent quality.

Efficiency, Organizational↗