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PubMed2006

[Storage and diurnal change of organic carbon pools in rotifer-culturing pond ecosystem].

This paper studied the storage and diurnal change of various organic carbon pools in two rotifer (Brachinus plicatilis) -culturing ponds with different models in Panjin Photosynthesis Fisheries Limited Company, Dawa County, Liaoning Province from May to June 2001. The results indicated that the mean storage of particulate organic carbon (POC) and dissolved organic carbon (DOC) in static water pond was 5.69 +/- 2.90 mg x L(-1) and 24.56 +/- 2.12 mg x L(-1), and that in current water pond was 9.61 +/- 3.17 mg x L(-1) and 24. 3 +/- 2.91 mg x L(-1), respectively. The ratio of total organic carbon (TOC), DOC and POC in current and static water ponds was 1:0.75: 0. 25 and 1:0.82:0.18, respectively. The pond with a high POC concentration was also with a high DOC content. The diurnal change of POC and DOC in current water pond was bigger than that in static water pond, i. e., the POC concentration in current water pond increased in daytime (from 5:00 to 17:00), while that in static water pond was more stable. The POC concentration in the two ponds was decreased from 15:00 to 23:00 but increased from 23:00 to next 5:00, and its peak time was 17:00 for current water pond and 5:00 for static water pond. The DOC/POC ratio in current water pond was increased gradually in daytime (from 5:00 to 17:00), while that in static water pond was decreased. The DOC/POC ratio in the two ponds was increased at night, and tended to dicline from 23:00 to next 5:00.

Animals↗

PubMed1984

Impact of oil and oil-dispersant mixtures on flora and water chemistry parameters in freshwater ponds.

Oil and oil-dispersant mixtures at nominal concentrations of 100 and 20 ppm, respectively, were added to a series of ponds constructed for the study. In the pond treated with oil, there were no discernible short or long term effects on the phytoplankton. Both oil-dispersant treated ponds exhibited fluctuations in the dominant class of algae while the concentration of oil was greater than in the water column. Once the oil concentrations were below this value, there was no apparent effect. Periphytic material on the sides and bottoms of the oiled and control ponds were similar in mass and composed of a large number of species. Periphyton biomass was at least three times greater in both oil-dispersant-treated ponds with one genus dominating the growth. These conditions persisted in one of the oil-dispersant-treated ponds one year after treatment but those in the other pond had decreased to levels in the control pond at this time. Dissolved oxygen (DO) values decreased to about 4.6 ppm in both oil-dispersant-treated ponds shortly after treatment, but remained at approximately the saturation level in the other ponds for 6 weeks after treatment. Then these lower values gradually increased until they were slightly greater than in the controls. During the late winter months, both oil-dispersant ponds had anoxic zones above the sediment, the extent depending on the contours of the bottom. The DO values in the other ponds were at the saturation level. In the early spring, the nitrate ion-concentrations in control and oil-treated ponds were twice those measured for the oil-dispersant ponds. No discernible differences dependent on treatment were observed for nutrients or other ions monitored on a regular basis.

Chlorophyll↗

PubMedDate not supplied

Accumulation, distribution, and toxicity of copper in sediments of catfish ponds receiving periodic copper sulfate applications.

Copper sulfate (CuSO4) is applied periodically to commercial channel catfish (Ictalurus panctatus) ponds as an algicide or parasiticide. Current understanding of the chemistry of copper in soil-water systems suggests that copper may accumulate in pond sediments, although the forms and potential bioavailability of copper in catfish pond sediments are not known. This study investigated the accumulation and distribution of copper in the sediment of catfish ponds receiving periodic additions of CuSO4.5H2O. All ponds were constructed in Sharkey (very-fine, smectitic, thermic Chromic Epiaquert) soil. Nine 0.40-ha ponds received 59 applications of 2.27 kg CuSO4.5H2O per application per pond over 3 yr; no CuSO4.5H2O applications were made to nine additional ponds. Total Cu concentration in the sediments of CuSO4.5H2O-amended catfish ponds (172.5 mg kg(-1)) was four to five times higher than that in the sediments of nonamended ponds (36.1 mg kg(-1)). Copper accumulated in catfish pond sediments at a rate of 41 microg kg(-1) dry sediment for each 1 kg ha(-1) of CuSO4. 5H2O applied to ponds. Copper in the sediments of amended ponds was mainly in the organic matter-bound (30.7%), carbonate-bound (31.8%), and amorphous iron oxide-bound (22.1%) fractions with a considerable fraction (3.4%; 3 to 8 mg kg(-1)) in soluble and exchangeable fractions. This indicates that Cu accumulates differentially in various fractions, with proportionally greater initial accumulation in potentially bioavailable forms. However, toxicity bioassays with amphipods (Hyallela azteca) and common cattail (Typha latifolia L.) indicated that the effect of exposure to amended or nonamended pond sediments was not different.

Animals↗

PubMed1996

Fate and biological effects of polymeric MDI (4,4'-diphenylmethane diisocyanate and homologs) in small artificial ponds.

The effects from a simulated accidental pollution event in a pond with polymeric MDI (4,4'-diphenylmethane diisocyanate and homologs) on different trophic levels of the aquatic ecosystem were investigated in small artificial ponds. Three 4.5-m3 volume ponds, interconnected with closable locks, were provided with natural lake sediment and ground water. Caged fish (rainbow trout, Oncorhynchus mykiss) were added to each pond, and the interconnecting locks were kept open to establish nearly identical physicochemical and biological conditions. At this stage, the ponds were isolated from one another and MDI was added at a dosage of 1 g/liter on top of the sediment of treated part of the first pond, 10 g/liter to the second pond, and 0 g/liter to the third pond (untreated control). Neither the applied monomer MDI nor its potential reaction product MDA (4,4'-diphenylmethanediamine) was detected in water or accumulated by fish. The MDI polymerized to inert polyurea on the sediment of the test ponds. This polymerization formed carbon dioxide, released as bubbles which floated to the water surface. Some carbon dioxide was solubilized in water and reduced the water pH of about 9 by 2.0 units as an average in the high-dosed pond and 0.7 in the low-dosed pond. This reduction caused some other minor changes in the physicochemical characteristics of the pond water. Neither application rate caused any direct effect on the pelagic community (phytoplankton, zooplankton, fish, macrophytes) of the test ponds. Some minor indirect effects caused by the production of carbon dioxide were observed in phyto- and zooplankton community structures. Also, an increase of macrophyte growth was noted. Organisms living in the untreated part of the sediment (macrobenthos) were affected as a result of physical obstructions in this habitat. These populations, however, regained densities equivalent to the control after some weeks, except for Bivalvia which have too long of a generation time for the test period of this study.

Allergens↗

PubMed2005

Energy flow and subsidies associated with the complex life cycle of ambystomatid salamanders in ponds and adjacent forest in southern Illinois.

Breeding adults and metamorphosing larval amphibians transfer energy between freshwater and terrestrial ecosystems during seasonal migrations and emergences, although rarely has this been quantified. We intensively sampled ambystomatid salamander assemblages (Ambystoma opacum,A. maculatum, and A. tigrinum) in five forested ponds in southern Illinois to quantify energy flow associated with egg deposition, larval production, and emergence of metamorphosed larvae. Oviposition by female salamanders added 7.0-761.4 g ash-free dry mass (AFDM) year(-1) to ponds (up to 5.5 g AFDM m(-2) year(-1)). Larval production ranged from 0.4 to 7.4 g AFDM m(-2) year(-1) among populations in three ponds that did not dry during larval development, with as much as 7.9 g AFDM m(-2) year(-1) produced by an entire assemblage. Mean larval biomass during cohort production intervals in these three ponds ranged from 0.1 to 2.3 g AFDM m(-2) and annual P/B (production/biomass) ranged from 4 to 21 for individual taxa. Emergent biomass averaged 10% (range = 2-35%) of larval production; larval mortality within ponds accounted for the difference. Hydroperiod and intraguild predation limited larval production in some ponds, but emerging metamorphs exported an average of 70.0+/-33.9 g AFDM year(-1) (range = 21.0-135.2 g AFDM year(-1)) from ponds to surrounding forest. For the three ponds where larvae survived to metamorphosis, salamander assemblages provided an average net flux of 349.5+/-140.8 g AFDM year(-1) into pond habitats. Among all ponds, net flux into ponds was highest for the largest pond and decreased for smaller ponds with higher perimeter to surface area ratios (r2 = 0.94, P<0.05, n = 5). These results are important in understanding the multiple functional roles of salamanders and the impact of amphibian population declines on ecosystems.

Animals↗

PubMed2002

Effect of point source removal on mercury bioaccumulation in an industrial pond.

A one hectare pond on the headwaters of a mercury-contaminated creek in Oak Ridge, Tennessee acted as a biochemical reactor for the production of methylmercury, increasing waterborne methylmercury concentrations in the stream below the pond discharge. The flow of the creek was diverted around the pond in order to eliminate this input. Waterborne total mercury, methylmercury, and mercury in fish, were monitored in the pond and stream before and after bypass. Waterborne methylmercury concentration in the creek downstream from the pond decreased over 800% following diversion of streamflow around the pond, but mercury in redbreast sunfish in the pond tailwater did not decline similarly. Within the pond, now isolated from fresh waterborne mercury inputs from the stream, methylmercury concentrations in the water column remained similar to levels present before bypass. However, mercury concentrations in sunfish in the pond decreased approximately 75% following bypass, despite the continued presence of highly contaminated sediments (approximately 50 mg Hg/kg dry weight). We concluded that a decrease in the fraction of 'dissolved methylmercury' in the isolated pond relative to pre-bypass conditions explained the decrease in mercury in fish within the pond. That observation also indicates that mercury associated with pond sediments was relatively unavailable for eventual bioaccumulation when compared to 'fresh' mercury contributed by upstream sources. The lack of a post-bypass decrease in mercury concentrations in tailwater fish was also likely to be associated with the particle-associated nature of waterborne methylmercury exported from the pond.

Animals↗

PubMed2005

The impact of cooling ponds in North Central Texas on dairy farm performance.

The objective of this study was to determine whether measurable differences existed between farms with and without cooling ponds. Data from Dairy Herd Improvement records for 1999 through 2002 were obtained on 42 herds located in North Central Texas. Nineteen herds had installed cooling ponds, whereas 23 herds had not. Monthly somatic cell counts for each herd were obtained from the Federal Milk Market Administrator. Data were analyzed using the PROC MIXED regression model of SAS. Within and across herd groups, milk production from June to October was significantly lower compared with milk production for the rest of the year. Although there was numerically higher average milk production per cow per day throughout the year for herds that used cooling ponds, differences between herd groups that used or did not use cooling ponds were significant only for August production. Herds without a cooling pond had 4.8 kg/d per cow lower production in August than in the cool-season months of November to May (26.4 +/- 0.6 vs. 31.2 +/- 0.5 kg/d), whereas the difference in August production was only 2.9 kg/d per cow in herds that used cooling ponds (29.0 +/- 0.7 vs. 31.9 +/- 0.6 kg/d). Differences caused by seasonal use of a cooling pond in culling, days to first service, days open, percentage of estruses observed, and somatic cell counts were not significant. Bulk tank milk samples cultured for 10 different bacteria showed no difference between cooling pond and noncooling pond herds in 2002. Also, there was no difference in incidence of violations from the Texas Department of Health for herds that used or did not use cooling ponds. However, herds with cooling ponds did have a lower percentage of successful breedings, fewer days dry, and a higher percentage of cows in milk compared with dairy herds that used other forms of cooling. Such differences may or may not be attributed to seasonal use of a cooling pond. Therefore, cooling ponds may provide relief from heat stress without adversely affecting most important measures of herd performance.

Animals↗

PubMed1984

The impact of oil and oil-dispersant mixtures on fungi in freshwater ponds.

The impact of oil and oil-dispersant mixtures on the mycoflora of a freshwater ecosystem was assessed using man made ponds. Data indicated that the ponds were well stabilized before pond treatment. Sufficient Norman Wells crude oil to give 100 ppm was added to each treated pond. The dispersant, Corexit 9527, was initially one-fifth of the oil concentration in the oil-dispersant-treated ponds. After pond treatment, an immediate increase occurred in the number of geoaquatic fungi in the oil-treated pond whereas an increase, followed by a sharp decrease, which was in turn followed by a recovery occurred in the oil-dispersant-treated ponds. The fungal enhancement effects, which were slight, were largely short term in duration (7-83 days). No clear cut medium or long term geoaquatic fungal enhancement effects were observed. The pond treatments had no detectable effect on the vertical distribution of fungi in the ponds. No significant treatment effects were observed on the water mould levels in the treated ponds. No obvious treatment effect was observed on the percentage of viable fungi capable of growth on non-degraded or biodegraded oil as a sole carbon source. Fifteen of 39 selected pond water fungi were able to grow on non-degraded Norman Wells oil. Corexit 9527 incorporated into agar plates inhibited the radial growth of the oil utilizing fungal isolates; EC50 values were determined.

Fresh Water↗

PubMed2004

Distribution pattern of ambient cadmium in wetland ponds distributed along an industrial complex.

Water and sediment samples collected from 18 wetland ponds within and outside industrial areas were examined for cadmium concentration and water quality parameters during the period of January to July 1996. The Cd contents in gill, liver, mantle and shell of freshwater mussel (Lamellidens marginalis) as well as leaves and roots of water hyacinth Eichhornia those occurred in these ponds were also estimated. Cd concentration ranged from 0.006 to 0.7025 mg/l in water and from 7 to 77 microg/gdw in sediments of all the ponds investigated. The amount of Cd occurring in water and sediment was much higher in concentrations in the ponds located in Captain Bheri and Mudiali farm close to industrial areas, compared to remaining ponds located outside the industrial belt. Lamellidens marginalis procured from Mudiali and Captain Bheri ponds showed regardless of size, tissue and season of collection significantly higher Cd concentration than did those from other ponds. Likewise, tissue Cd in Eichhornia collected from Mudiali pond was as high as 125-152 microg/gdw in root and 21-63 microg/gdw in leaves compared to 40-108 microg/gdw in root and 9-43 microg/gdw in leaves in the remaining ponds. Seasonal variability of Cd was clear-cut; the concentration was relatively higher in water and sediment in all ponds during summer than during monsoon season or winter. Size-wise, smaller groups showed the highest concentrations of Cd in all tissues of Lamellidens compared with medium and large size groups. Concentration factor for all tissues of Lamellidens regardless of size and season, was inversely proportional with the ambient Cd concentrations. Concentration factor estimated for all tissues in all ponds and all seasons was in the order: liver>gill>shell>mantle. As all ponds located outside the industrial belt showed Cd concentrations ranging from 0.006 to 0.049 mg/l, it is suggested that these wetlands do not pose serious risk to the environment.

Animals↗

PubMed2002

Changes in soil properties of abandoned shrimp ponds in southern Thailand.

Chemical soil properties between active shrimp ponds and abandoned ones on the Bangkok soil series were compared, at Ranote District, Songkhla Province in southern Thailand. Soil samples were collected at depth intervals of 0-10, 10-20, 20-30, 30-40 and 40-50 cm from pond bottoms at the same ponds used in a former study conducted in 1994, for a total of 6 ponds with 3 sampling sites for each pond. These ponds were active during the previous study in 1994, abandoned in 1996 and investigated by this study in 1999. All the samples were analyzed for exchangeable Ca, Mg, K and Na electrical conductivity (EC), organic matter, S, P and pH, and statistically compared with the analytical results of the previous study. An increase in amounts of Ca, Mg, K, Na and EC in the abandoned ponds as compared with the active ones by 1.3-3.4, 1.4-2.1, 7.0-30.0, 1.2-6.3 and 1.3-10.9 times respectively was observed. That more of these elements were gained than lost each time the seawater was introduced into the ponds, is explained by the 'Element Input/Output Consideration' as proposed herein. Furthermore, a decrease in organic matter, S and P was also observed in the abandoned pond soils, and attributed to the absence of shrimp food and shrimp excreta following the cessation of shrimp raising activities. An unexpected decline in the soil pH of the abandoned ponds was found as well. Aerobic decomposition of organic matter during the absence of shrimp raising activities caused by soil microorganisms triggering SO2 and H2SO4 formation probably played a more significant role than the increase in the amounts of the basic elements (Ca, Mg, K, and Na) eventually reducing soil pH in the abandoned ponds. The significant depletion of the amounts of organic matter in the abandoned pond soils also supports this observation.

Animals↗

PubMedDate not supplied

Comparative performance studies of water lettuce, duckweed, and algal-based stabilization ponds using low-strength sewage.

A bench-scale continuous-flow wastewater treatment system comprising three parallel lines using duckweed (Spirodela polyrhiza), water lettuce (Pistia stratiotes), and algae (natural colonization) as treatment agents was set up to determine environmental conditions, fecal coliform profiles and general treatment performance. Each line consisted of four ponds connected in series fed by diluted sewage. Influent and effluent parameters measured included environmental conditions, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrate, nitrite, ammonia, total phosphorus, fecal coliforms, mosquito larvae, and sludge accumulations. Environmental conditions and fecal coliforms profiles were determined in the sediments (0.63 m), suspensions (0.35 m), and surfaces (0.1 m) of each pond. Acidic conditions were observed in the pistia ponds, neutral conditions in duckweed ponds, and alkaline conditions in algal ponds. Fecal coliforms log removals of 6, 4, and 3 were observed in algal, duckweed, and pistia ponds, respectively, in the final effluents, with die-off rates per pond of 2.7, 2.0, and 1.6. Sedimentation accounted for over 99% fecal coliform removal in most of the algal and pistia ponds. BOD removal was highest in the duckweed system, followed by pistia and algae at 95%, 93%, and 25%, respectively. COD removals were 65% and 59%, respectively, for duckweed and pistia, while COD increased in algal ponds by 56%. Nitrate removals were 72%, 70%, and 36%, respectively for duckweed, pistia, and algal ponds. Total phosphorus removals were 33% and 9% for pistia and duckweed systems, while an increase of 19% was observed in the algal treatment system. Ammonia removals were 95% in both pistia and duckweed and 93% in algal systems. Removals of total dissolved solids (TDS) were 70% for pistia, 15% for duckweed, and 9% for algae. Mosquito populations of 11,175/m(2), 3516/m(2), and 96/m(2) were counted in pistia, algal, and duckweed ponds, respectively. Low turbidity and low sludge accumulation characterized the macrophyte ponds. Performance in the removal of fecal coliforms in the algal-based treatment system and organic load removal in both macrophytes and algal-based treatment systems met the Ghana Environmental Protection Agency guideline values.

Animals↗

PubMed2003

Sludge accumulation pattern in an anaerobic pond under Mediterranean climatic conditions.

The main objective of this study was to observe the sludge accumulation pattern of an experimental, covered, anaerobic pond treating municipal wastewater under Mediterranean climatic conditions throughout a 2-year operational period (1999-2000) in order to form a seasonal sludge accumulation model which may be used to predict the required desludging time, not only of the particular anaerobic pond used in the study, but also for other types of anaerobic ponds and operational situations. The 4-m deep pond was supplied with pre-screened, untreated wastewater from the nearby treatment plant of Thessaloniki, Greece, initially at a flow rate of 120m3/day and later at a flow rate of 150m3/day. The influent characteristics were BOD5 441 mg O2/L, COD 942 mg O2/L and suspended solids (SS) 574 mg/L. BOD5, COD, and SS concentrations of the pond effluent were reduced by 50%, 53%, and 64%, respectively, in comparison with those of the influent. During the operational period, three distinctly different zones were seen to form within the anaerobic pond: The first zone, which formed at the bottom of the pond, consisted of inert, high-density sludge. The second zone, which formed above this, contained a high concentration of volatile (easily biodegradable) sludge. The third upper zone (supernatant), was a liquid layer low in suspended solids. The accumulation of sludge in the pond followed an annual sinusoidal pattern with high values during winter and low ones during summer due to the increased digestion rate. The maximum high-density sludge height observed was 0.7m, or 2% (14 m3) of the total pond volume. The maximum volatile sludge accumulation reached 3.1 m, or 53% (300 m3) of the pond volume. A seasonal sludge accumulation model, based on the sludge inflow and seasonal digestion rates, was used to simulate the annual fluctuation in accumulation rate for the local (Mediterranean type) climatic conditions. Monthly values of accumulation (or digestion) rate of sludge (K(AS)) were experimentally estimated at specific mean monthly air temperatures and approximated by a regression second degree polynomial equation to be used with the model. The predicted desludging interval for our experimental pond was 3 years.

Bacteria, Anaerobic↗

PubMed2002

Sludge accumulation in polishing ponds treating anaerobically digested wastewater.

When ponds are used for wastewater treatment, settleable solids will form a steadily growing bottom sludge layer, which reduces their effective volume. Eventually this sludge must be removed to ensure that the pond maintains the required retention time to keep performing properly. The settleable solids may either be present in the influent or they are formed during the treatment as a result of algal flocculation. An experimental investigation was carried out to evaluate bottom sludge accumulation in a polishing pond used for treatment of UASB effluent. The mass and composition of the bottom sludge formed in a polishing pond was evaluated after the pilot scale pond had been in operation for 1 year and about 60 m3 of digested wastewater had been treated per m3 of pond. The bottom sludge mass represented a solids accumulation of 70 g per m3 of digested wastewater. About half of these solids were the result of settling of influent solids in the first part of the pond, while the other half was attributable to settling of algae, formed in the pond. It is concluded that the bottom sludge growth in a polishing pond is so low, that desludging during the useful life span of the pond will most likely not be necessary. This leads to the important conclusion that excess sludge discharge from UASB reactors (a major factor in operational costs) may be omitted, if a polishing pond is used for post-treatment. The bottom sludge had a high volatile solids concentration (58%) and the macronutrient fractions were also high (3.9% N and 1.1% P of the TSS mass). The bottom sludge was stable and could be dried directly without problems. The hygienic quality of the bottom sludge was very poor: about half the influent helminth eggs during one year of operation were found in the bottom sludge and the faecal coliform concentration was very high.

Animals↗

PubMed2000

Effects of spray-irrigated wastewater effluent on temporary pond-breeding amphibians.

Comparison was made of abiotic conditions, amphibian reproductive outputs, and the survival of embryonic and larval amphibians in wastewater effluent-irrigated and natural temporary ponds in an area in Centre County, Pennsylvania that has been spray-irrigated with secondarily treated, chlorinated wastewater effluent from The Pennsylvania State University for approximately 14 years. Three species of temporary pond-breeding amphibians were studied: wood frogs (Rana sylvatica LeConte), Jefferson salamanders (Ambystoma jeffersonianum Green), and spotted salamanders (A. maculatum Gravenhorst). Comparisons of physico-chemical parameters in 10 wastewater-irrigated and 10 natural temporary ponds over 19 weeks in 1997 indicated that wastewater -irrigated ponds had significantly higher median conductance, pH, ¿Na, ¿K, ¿Ca, ¿Mg, and ¿N-NO(3) and lower ¿dissolved oxygen. Many of the wastewater-irrigated ponds supported large mats of duckweed (Lemna spp.) that completely blanketed the pond's surface by mid-May. There were significantly fewer egg masses of all three species in wastewater-irrigated ponds than in natural ponds in both 1997 and 1998. In situ egg hatching success and larval survival (over a 6-day period) of all species was lower in wastewater-irrigated ponds than in natural ponds. Cumulatively, these studies suggest that wastewater effluent irrigation may impact amphibian populations by reducing the survival of amphibian eggs and larvae.

Ambystoma↗

PubMed2005

Spatiotemporal allozyme variation in the damselfly, Lestes viridis (Odonata: Zygoptera): gene flow among permanent and temporary ponds.

Several insect species seem to persist not only in permanent but also in temporary ponds where they face particularly harsh conditions and frequent extinctions. Under such conditions, gene flow may prevent local adaptation to temporary ponds and may promote phenotypic plasticity, or maintain apparent population persistence. The few empirical studies on insects suggest the latter mechanism, but no studies so far quantified gene flow including both pond types. We investigated the effects of pond type and temporal variation on population genetic differentiation and gene flow in the damselfly Lestes viridis in northern Belgium. We report a survey of two allozyme loci (Gpi, Pgm) with polyacrylamide gel electrophoresis in 14 populations from permanent and temporary ponds, and compared these results with similar data from the same permanent populations one year before. The data suggested that neither pond-drying regime, nor temporal variation have a substantial effect on population genetic structuring and did not provide evidence for stable population differentiation in L. viridis in northern Belgium. Gene flow estimates were high within permanent and temporary ponds, and between pond types. Our data are consistent with a source-sink metapopulation system where temporary ponds act as sinks in dry years, and are quickly recolonized after local population extinction. This may create a pattern of apparent population persistence of this species in permanent and temporary ponds without clear local adaptation.

Animals↗

PubMed1987

Survival of spotted salamander eggs in temporary woodland ponds of coastal Maryland.

Temporary ponds on the Atlantic Coastal Plain in maryland were characterized according to water chemistry, rain input, phytoplankton, zooplankton and use by the spotted salamander Ambystoma maculatum during March-October 1983-1984. Neither the number of egg masses per unit of pond surface (abundance) nor the survival of spotted salamander embryos was significantly correlated (P>0.05) with pond pH. Rainfall during May-July significantly increased the hydrogen ion concentration of 5 of 11 ponds evaluated for the impact of rainfall during the previous 48h and the previous week. Survival of egg masses transferred among eight ponds with pH3.66-4.45 and one pond with pH5.18 was significantly reduced (P<or=0.05) only at pH 3.66. Embryonic survival was negatively correlated (P<or=0.05) with the concentration of aluminium in the pond water. The abundance of egg masses was positively correlated (P<or=0.05) with water temperature and magnesium concentration, and total chlorophyll during the larval period. Yearly variability of pond characteristics (e.g. water chemistry, pond longevity) and amphibian reproduction make it difficult to determine the effects of acidic deposition on the spotted salamander. At the present time, pond longevity, water temperature and possibly, oxygen content, seem more important to spotted salamander reproduction than chemical changes caused by annual acidic deposition.

Journal Article↗

PubMedDate not supplied

Pollutant removal efficacy of three wet detention ponds.

Monthly inflow and outflow data were collected from three wet detention ponds in Wilmington, North Carolina, for a 29-mo period. Two ponds drained urban areas consisting primarily of residential, mixed services, and retail usage, while the third mainly drained residential and golf course areas. One of the urban ponds achieved significant reductions in total nitrogen, nitrate, ammonium, total phosphorus, orthophosphate, and fecal coliform bacterial counts. This pond was characterized by a high length to width ratio, with most inputs directed into the upper area, and extensive coverage by a diverse community of aquatic macrophyte vegetation. The second urban pond achieved significant reductions in turbidity and fecal coliform bacterial counts, but there were no significant differences between inflowing and outflowing water nutrient concentrations. There were substantial suburban runoff inputs entering the mid- and lower-pond areas that short-circuited pollutant removal contact time. The golf course pond showed significant increases in nitrate, ammonium, total phosphorus, and orthophosphate in the outflow relative to the inflow, probably as a result of course fertilization. However, nutrient concentrations in the outflow water were low compared with discharges from a selection of other area golf courses, possibly a result of the outflow passing through a wooded wetland following pond discharge. To achieve good reduction in a variety of pollutants, wet pond design should include maximizing the contact time of inflowing water with rooted vegetation and organic sediments. This can be achieved through a physical pond design that provides a high length to width ratio, and planting of native macrophyte species.

Cities↗

PubMed2003

Waste stabilisation pond developments in New Zealand.

Waste stabilisation ponds have been a popular form of wastewater treatment in New Zealand both for large cities and small communities. Over 100 systems have been constructed ranging in size from over 500 ha to less than 0.1 ha. The largest pond system in New Zealand was at Manukau, Auckland and consisted of four ponds with a total of 530 ha. However, ongoing odour and midge releases and an algae parasite problem plus a requirement to reduce ammonia and total nitrogen in summer, led to the decision to decommission the ponds and allow the area to revert to tidal mudflats. The second largest pond system is at Christchurch and totals 226 ha. In contrast to Manukau, the Christchurch ponds have not caused significant odours and final effluent quality has been good. Christchurch has two parallel trains each with three ponds in series. It is proposed to retain and develop the ponds into a seven cells in series arrangement to reduce short-circuiting. Odour emissions from the Manukau and Christchurch ponds have been measured by the use of olfactometry. Dispersion of odours has been modelled and the extent of "odour travel" determined on a statistical probability basis using actual meteorological data. It can be demonstrated that residential areas can co-exist with ponds, which are not overloaded, with separation distances of 200 metres.

Ammonia↗