The effects of acid episodes on Lepomis sunfish recruitment and growth in two ponds in Massachusetts, U.S.A.

1. The effects of transient acidity on the recruitment of Lepomis sunfish were examined in two ponds in Plymouth County, Massachusetts with on-site monitoring systems. One pond had low buffering capacity and was sensitive to acidification and acid spikes, the other had better buffering with no acid spikes. Pond pH was continuously monitored over 3 years.
2. Young-of-the-year (YOY) sunfish were collected and through otolith analysis aged in days since larval metamorphosis. Day-classes were constructed from these age data. The YOY swim-up day-class distribution was more irregular with pronounced gaps in Maquan Pond than in the better-buffered Furnace Pond.
3. The poorly buffered pond, Maquan, experienced irregular acid spikes, defined as a sudden lowering of pond pH from about 6.6 to below 5.3 for an hour or more. These spikes were associated with rainfall ( P < 0.005). Acid spikes were not found at Furnace Pond.
4. The occurrence of acid spikes and diminished day-classes from expected swim-up values were significantly associated, based on pooled data from 3 years at Maquan Pond.
5. Transient acid spikes at Maquan Pond appear to harm Lepomis YOY at the vulnerable stage of metamorphosis, when their gills become fully functional and exposed to the environment.
6. Growth rates of Lepomis YOY were also studied. Length–age and weight–length growth relationships were examined for differences in instantaneous growth coefficients between years and between ponds. Length–age instantaneous growth coefficients ranged from 0.0114 to 0.0176 over five pond-years. The slowest growth rates were in a warm, dry spawning season with the earliest average metamorphosis date.     

The effects of acid episodes on Lepomis sunfish recruitment and growth in two ponds in Massachusetts, U.S.A.

1. The effects of transient acidity on the recruitment of Lepomis sunfish were examined in two ponds in Plymouth County, Massachusetts with on-site monitoring systems. One pond had low buffering capacity and was sensitive to acidification and acid spikes, the other had better buffering with no acid spikes. Pond pH was continuously monitored over 3 years.
2. Young-of-the-year (YOY) sunfish were collected and through otolith analysis aged in days since larval metamorphosis. Day-classes were constructed from these age data. The YOY swim-up day-class distribution was more irregular with pronounced gaps in Maquan Pond than in the better-buffered Furnace Pond.
3. The poorly buffered pond, Maquan, experienced irregular acid spikes, defined as a sudden lowering of pond pH from about 6.6 to below 5.3 for an hour or more. These spikes were associated with rainfall ( P < 0.005). Acid spikes were not found at Furnace Pond.
4. The occurrence of acid spikes and diminished day-classes from expected swim-up values were significantly associated, based on pooled data from 3 years at Maquan Pond.
5. Transient acid spikes at Maquan Pond appear to harm Lepomis YOY at the vulnerable stage of metamorphosis, when their gills become fully functional and exposed to the environment.
6. Growth rates of Lepomis YOY were also studied. Length–age and weight–length growth relationships were examined for differences in instantaneous growth coefficients between years and between ponds. Length–age instantaneous growth coefficients ranged from 0.0114 to 0.0176 over five pond-years. The slowest growth rates were in a warm, dry spawning season with the earliest average metamorphosis date.     

Reproductive strategies of Amazonian stream fishes and their fine‐scale use of habitat are ordered along a hydrological gradient

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Effects of spring acid episodes on macroinvertebrates revealed by population data and in situ toxicity tests

1. While streams in Europe and North America are now recovering chemically from chronic acidification, severe episodic acidification continues to threaten sensitive biota. To appraise further the biological importance of episodic acidification, we surveyed the distribution of the mayfly Baetis alpinus in streams in the Southern Alps (Canton Ticino, Switzerland) in relation to runoff acidity during spring floods. Moreover, to improve mechanistic understanding, in situ toxicity assays were carried out on nymphal B. alpinus during low flows and spring floods, both in streams prone to acid episodes and in well‐buffered controls. 2. Streams surveyed for invertebrates represented three groups which contrasted in susceptibility to episodic acidity. Group one included streams that were acid (alkalinity <0) in spring; group two streams were susceptible to acid episodes because of low base‐flow alkalinity (<200 μeq L^?1); and group three streams were well‐buffered and unlikely ever to be acid. The abundance of B. alpinus was similar among groups during stable flows in winter and summer, but was significantly lower in groups one and two following spring snowmelt. 3. During the bioassays, control streams remained circumneutral to alkaline (pH >6.4). By contrast, episodic streams were circumneutral at low flows, but became acid (pH 4.5–5.6 and total dissolved aluminium to 276 μg L^?1) during intense spring snowmelt. After 15‐day exposures, nymphal B. alpinus survival in the circumneutral control streams exceeded 92% irrespective of flow. In the episodic streams, survival matched the controls during low flows, but declined significantly to 10–20% during acid episodes in spring. Shorter exposure (2–4 days) to pH 5.5–5.7 did not cause significant mortality either during the exposure or over the following 7 days, indicating that B. alpinus might recover from short acid episodes. 4. Our data suggest that the spring distribution of B. alpinus in acid sensitive parts of the Alps directly reflects the toxicity of acid runoff during snowmelt. Our study illustrates that even mild episodic acidification can have significant consequences in Alpine streams for one of the most important invertebrate indicators of acidity.     

Decomposition and macroinvertebrate colonization of aquatic and terrestrial leaf material in alkaline and acid still water

• 1 Decomposition of the leaves of Nymphaea alba L. and Betula pubescens Ehrh. was studied in two ponds of contrasting pH, buffering capacity and trophic level. Rates of carbon loss, concentrations of nitrogen, protein and phenolics and colonization of the leaf material by macroinvertebrates were studied.
• 2 Decomposition of B. pubescens leaves was slower than that of N. alba in both ponds. Protein and phenolic concentrations were higher in the decomposing N. alba material, whereas no significant difference was found for nitrogen concentrations.
• 3 Decomposition of both species was slower in the acid water. The effect of acid water on decomposition rate was similar for both species. Both nitrogen and protein concentrations of N. alba remained higher under acid conditions, whereas no effect of study site was observed on the protein and nitrogen concentrations in B. pubescens litter. The concentration of phenolic compounds was higher in N. alba litter from the acid pond; no such difference was observed for B. pubescens litter. The high concentrations of phenolic compounds in N. alba litter from the acid pond probably induced chemical immobilization (tanning reaction), yielding high concentrations of nitrogen and protein in the litter.
• 4 Diversity of the detritivorous macroinvertebrate fauna on the litter of both species was extremely low in the acid pond, while a relatively high diversity occurred in the alkaline water. Exclusion of large macrofauna inhibited decomposition in the alkaline water, while there was no comparable influence in the acid water.
• 5 The effects of low pH on the decomposition of both terrestrial and aquatic macrophyte litter appeared to be caused by interactive effects of low pH on the microbial decomposition, on the detritivorous macroinvertebrates and, in the case of N. alba, on the resource quality of the detritus.

     

Livestock disturbances in Mediterranean temporary ponds: A mesocosm experiment with sheep manure and simulated trampling

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The role of historic and climatic factors in the distribution of crustacean communities in Iberian Mediterranean ponds

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Dynamics of manganese,cadmium, and lead in experimental power plant ponds

The purpose of this study was to determine the effect of heated power plant water on the uptake and retention of manganese, cadmium and lead in selected aquatic invertebrates, channel catfish, green sunfish, and aquatic macrophytes and to study the distribution of manganese, cadmium and lead in sediments and water of experimental power plant ponds.The study was accomplished by placing fingerling channel catfish and green sunfish in holding pens in two ponds, one an experimental pond and one a control pond. Whole fish and selected organs of channel catfish and green sunfish were analyzed during the study. The experimental pond received heated power plant water and was maintained 4–6° C above ambient temperature during the study. Sediments, water, Odonata nymphs, tubificid annelids, snails, leeches, fingernail clams and duckweed were also analyzed for the metals.A typical distribution profile for manganese, cadmium and lead in power plant cooling ponds was developed.     

Trophic plasticity,environmental gradients and food‐web structure of tropical pond communities

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Diel variations of certain physico-chemical parameters of water in selected aquatic systems

A field study was conducted during the months of October, January, May, and July (1979–80) to examine the diel variations in dissolved O₂ (DO), pH, dissolved CO₂, bicarbonate and carbonate alkalinity, NH₄-N, NO₃-N, and PO₄-P concentration, and conductivity (EC) of the water in six aquatic systems. Water in hyacinth (Eichhornia crassipes) ponds showed very little or no diel or seasonal variations in DO, pH, dissolved CO₂, and bicarbonate alkalinity. Dissolved O₂ concentration of the water under floating hyacinth cover was in the range of 0.2–3.0 µg/ml, while dissolved CO₂ levels were in the range of 10–35 µg/ml. In the aquatic systems with no floating vegetation, i.e., elodea (Egeria densa) pond, cattail (Typha sp.) pond, control pond (filamentous algae and Chara spp.), and eutrophic lake (algae in Lake Apopka), DO and pH of the water increased during mid-day and decreased during the night. Dissolved O₂ levels in these ponds were in the range of 5–20 µg/ml during mid-day and 2–8 µg/ml during the night, while pH of the water was in the range of 8–9.5 during mid-day and decreased to 7–8 during the night. An inverse relationship was observed between bicarbonate and carbonate alkalinity of the water in the aquatic systems with no floating vegetation while no carbonates were detected in the water with floating hyacinth plants. Ammonium N, NO₃-N and PO₄-P concentration of the water in these aquatic systems showed very little or no diel variations.Florida Agricultural Experiment Stations Journal Series No. 2788.     

Acid sensitivity and water chemistry correlates of amphibian breeding ponds in northern Wisconsin,USA

Fifty-one amphibian breeding sites in northern Wisconsin were sampled in two surveys, in 1986 and 1987, to determine the chemical conditions and amphibian inhabitants present. All twenty-one ponds in 1986 and twenty-eight in 1987 were mildly acidic and sensitive to acidification. The pH levels encountered were generally not toxic to the resident amphibians, and may have been related to levels of phenolics in some cases. Soil type and forest canopy coverage appeared to influence the chemistry of these ponds and a direct relationship of amphibian species richness with pond size was found. Only larger ponds were long-lived enough for metamorphosis of amphibian larvae, suggesting an importance for recruitment. They were also the most sensitive ponds and the only ones to enter the chronically toxic pH range for ambystomatid salamanders, possibly placing them at risk to future acid inputs.     

Dilution and acidification effects during the spring flood of four Swedish mountain brooks

The seasonal variation in water chemistry was followed during 1980 and 1981 in four mountain brooks in the southern part of Swedish Lapland. In the area investigated the soil is calcareous and the brook water is very well buffered during the major part of the year, with alkalinity varying between 0.4 and 1.0 milliequivalents per liter and with pH values about 7.5. These years the snow had a pH of approximately 5.2, which was considerably higher than has been reported from adjacent areas in the lower, coniferous region. During snowmelt the water discharge increased drastically, and although the net transport of bicarbonate increased, alkalinity showed low values due to dilution with meltwater. pH decreased, but not further than to 6.3–6.5, far from values reported in 1979 (pH less than 5), apparently due to the comparatively clean snow. A slight deficit in alkalinity, as compared to the nonmarine calcium and magnesium content, points to an acidification impact on the area. During maximum runoff some chemical variables, like aluminium, iron, nitrogen and phosphorus, behaved reversely to what might be expected during dilution and reached maxima in concentrations. It is concluded that the extreme runoff characteristics of high mountain areas make brook water more sensitive to acid precipitation than might be expected when regarding only the calcareous properties of soil and bedrock.     

Production of a fish taxocene in a Texas pond

Synopsis Production rates of seven species of fishes were determined for one year in a 0.95 ha pond. Total annual production of all fishes in the pond was 209 g m^–2y^–1 (after the subtraction of 16.2 g m^–2y^–1 of negative production). Over 90% of the production occurred in the months of June through September, with young-of-the-year fishes contributing 84% of the total. When Y of Y fishes shifted to benthic diets in the spring, the small biomass of benthos available could not sustain the large biomas of fish. Severe competition for the available food then resulted in decreased production rates for the entire fish taxocene.     

Biotic and abiotic parameters that distinguish types of temporary ponds in a Portuguese Mediterranean ecosystem

Temporary ponds are seasonal wetland habitats subjected to extreme and unstable ecological conditions. Some are classified as priority habitats for conservation by the European Union Habitats Directive. Our study area was the coastal plain of southwest Portugal, which spans across 100 km north to south and hosts a large number of temporary ponds as a consequence of climatic and edaphic characteristics. Field sampling of floristic and edaphic data was carried out in 24 temporary ponds every spring between 2005 and 2008. We recorded a total of 174 plant species identified within visually homogeneous plots. We included the data in a geographic information system and classified ponds according to their floristic composition, using a biotic regionalization analysis based on species presence/absence, which is a practical and unambiguous criterion. We found three significantly different groups of ponds which corresponded to an eco-physiognomic pond typology: Mediterranean temporary ponds, marshlands, and disturbed ponds. For the first two pond types we defined characteristic or indicator plant species. We searched also for relationships between pond type and a series of large-scale climatic, geographic, and geological variables, as well as local-scale physical and chemical properties of the soil. Pond type was distinguished by a complex combination of some of these variables, including environmental energy, soil texture, nitrogen content of the soil and pH. A practical way of discriminating between different types of ponds is important so that management and conservation measures can be defined accordingly.     

Determinant landscape‐scale factors on pond odonate assemblages

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Landscape connectivity affects individual survival in unstable patch networks: The case of a freshwater turtle inhabiting temporary ponds

1. The loss of connectivity is among the main threats for species occupying freshwater pond networks. Landscape connectivity can impact the persistence of patchy populations by reducing movement rates among ponds, thereby increasing the likelihood of local extinctions in source–sink systems, and reducing the probability of colonisation following extinctions. In addition, loss of connectivity may also reduce survival rates if individuals have to cross a hostile matrix, though this hypothesis has been rarely tested. Here, we address these issues by evaluating how individual survival and inter-patch movement probabilities of the European pond turtle (Emys orbicularis) are influenced by patch connectivity.
2. The study was carried out in a network of temporary ponds embedded in a heterogeneous agricultural matrix in southwestern Portugal, encompassing a period associated with a severe drought (2003–2005) and another with wetter climatic conditions (2010–2014). We mapped the location of ponds and land uses around each pond, and quantified connectivity among ponds using least-cost distances based on patch location and resistance to movement of different land uses. We then used multistate capture-recapture modelling to quantify how survival and movement of this freshwater turtle were related to different metrics of landscape connectivity, in the wet and dry periods.
3. We captured 221 pond turtles, including 89 juveniles, 58 females, and 74 males. Survival was higher in ponds more connected with other ponds, especially for juvenile turtles. The probability of movement between ponds decreased with increasing least-cost distances. Movement probabilities tended to be higher in the dry than in the wet period.
4. Our results support the idea that landscape connectivity affects both movement and survival rates in a patchy population inhabiting a temporary pond network. These effects are likely to be particularly marked in unstable freshwater systems like ours, where individuals may have to move widely to escape drying ponds during particularly dry years.
5. Overall, our findings suggest that focusing conservation efforts solely on protecting discrete freshwater habitats such as temporary ponds may be insufficient, requiring also due consideration of landscape connectivity offered by the surrounding agricultural matrix to assure long-term persistence of patchy populations inhabiting such habitats.

     

Amphibian‐mediated nutrient fluxes across aquatic–terrestrial boundaries of temporary wetlands

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Disturbance from pond management obscures local and regional drivers of assemblages of primary producers

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Review of ammonia-oxidizing bacteria and archaea in freshwater ponds

Aquaculture ponds are simple and unique ecosystems, which are affected intensively by human activities. In this mini-review, we focus our attention on the distribution and community diversity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in pond water and sediments, as well as the possible ecological mechanisms involved. Moreover, we discuss the possibility of increasing the activity of ammonia-oxidizing organisms in order to improve the water quality in aquaculture ponds. Compared with eutrophic lakes, the significantly higher ammonia concentration in pond water does not lead to significantly higher AOB levels, and the abundance of AOA is too low to quantify accurately. Similar to eutrophic lakes, high abundances of AOA and AOB are present in the surface sediments at the same time, where the oxidation of ammonia is performed mainly by AOB. AOB and AOA exhibit significant seasonal variations in aquaculture ponds, which are affected by the temperature, pH, and dissolved oxygen. The dominant AOB species are Nitrosomonas and the Nitrosospira lineage in pond environments. Nitrososphaera or members of the Nitrososphaera-like cluster dominate the AOA species in surface sediments, whereas the Nitrosopumilus cluster dominates the deeper sediments. AOB and AOA can be enriched on artificial substrates suspended in the pond water, thereby potentially improving the water quality.

     

Species distributions and shell characteristics of Pisidium (Mollusca: Bivalvia) in the Colorado Front Range: the role of abiotic factors

SUMMARY.

• 1 Forty lakes in the Colorado Front Range were sampled to examine the relationship between water chemistry and the distributions and shell characteristics of Pisidium species. Alkalinity, pH, and dissolved organic carbon contributed most to the classification of lakes according to the dominant Pisidium species. Alkalinity was also strongly correlated with mean clam weight for populations of P. casertanum, the most common of the five species collected.
• 2 Historical evidence shows a reduction in the number of lakes occupied by clams and a constriction in the distributions of certain species. These changes have occurred mainly in lakes that now have low alkalinity.
• 3 A role for acidification is suggested because the recorded changes in distributions have occurred during the last 20 years, coincident with a general decline in alkalinity in waters of the Front Range.