Entire Pond Research Articles

A novel tracer technique for the assessment of fine sediment dynamics in urban water management systems

Urban storm water run off can reduce the quality of receiving waters due to high sediment load and associated sediment-bound contaminants. Consequently, urban water management systems, such as detention ponds, that both modify water quantity through storage and improve water quality through sediment retention are frequently-used best management practices. To manage such systems effectively and to improve their efficiency, there is a need to understand the dynamics (transport and settling) of sediment, and in particular the fine sediment fraction (<63 μm) and its associated contaminants within urban storm water management systems. This can be difficult to achieve, as modelling the transport behaviour of fine-grained and cohesive sediment is problematic and field-based measurements can be costly, time-consuming and unrepresentative. The aim of this study was to test the application of a novel cohesive sediment tracer and to determine fine sediment transport dynamics within a storm water detention pond. The cohesive sediment tracer used was a holmium labelled montmorillonite clay which flocculated and had similar size and settling velocity to the natural pond sediment it was intended to mimic. The tracer demonstrated that fine sediment was deposited across the entire pond, with the presence of reed beds and water depth being important factors for maximising sediment retention. The results of the sediment tracer experiment were in good agreement with those of a mathematical sediment transport model. Here, the deposited sediment tracer was sampled by collecting and analysing surface pond sediments for holmium. However, analysis and sampling of the three dimensional suspended tracer ‘cloud’ may provide more accurate information regarding internal pond sediment dynamics.

Nutrient limitation of phytoplankton in solar salt ponds in Shark Bay, Western Australia

The aim of this research was to examine nutrient limitation of phytoplankton in solar salt ponds of varying salinity at Useless Inlet in Western Australia. These ponds use solar energy to evaporate seawater for the purpose of commercial salt production. A combination of techniques involving water column nutrient ratios, comparisons of nutrient concentrations to concentration of magnesium ions and bioassays were used in the investigation. Comparisons of changes in dissolved inorganic nitrogen to phosphorus ratios and concentrations of dissolved inorganic nutrients against changes in concentrations of the conservative cation Mg2+ indicated that phytoplankton biomass was potentially nitrogen limited along the entire pond salinity gradient. Nutrient addition bioassays indicated that in low salinity ponds, phytoplankton was nitrogen limited but in high salinity ponds, phosphorus limited. This may be due to isolation of phytoplankton in bioassay bottles from in situ conditions as well as to changes in phytoplankton species composition between ponds, and the variable availability of inorganic and organic nutrient sources. The differences in limiting nutrient between methods indicate that phytoplankton cells may be proximally limited by nutrients that are not theoretically limiting at the pond scale. Dissolved organic nutrients constituted a large proportion of total nutrients, with concentrations increasing through the pond sequence of increasing salinity. From the change in nutrient concentrations in bioassay bottles, sufficient dissolved organic nitrogen may be available for phytoplankton uptake in low salinity ponds, potentially alleviating the dissolved inorganic nitrogen limitation of phytoplankton biomass.

人工池でのヒ素の自然浄化

An arsenic removal unit (GSF) was constructed by the Miyazaki University research group in the Marua village in Bangladesh. The sludge drained from the GSF was directed to a sludge tank and allowed to settle down. Then the supernatant in the tank was released to an artificial pond. The water, sediment and sludge samples from the pond and tank were analyzed, and the microbial statuses of the pond and tank were examined. The ORP result was observed to have changed from the reduction state to the oxidation state in the tank within one year from 2005 and 2006. Therewith, the concentration of soluble arsenic and iron in the tank decreased compared with those one year ago. The amount of arsenic included in the entire pond hardly changed in 2005 and 2006. From the result of an enrichment culture using sediment from the pond, monomethylarsonic acid and dimethylarsinic acid were detected in the medium, and the amount of total arsenic compounds in the medium decreased. It is thought that this loss was contributed by biogenic activity induced by inorganic arsenic biomethylation to gasified volatile organic species, such as monomethylarsine and dimethylarsine. These results suggested that the natural attenuation of arsenic in the pond was performed by biologic gasification.

Assembly of zooplankton communities in newly created ponds

Summary1. The creation or severe disturbance of habitat patches is generally followed by a phase of community (re)assembly. After such an event, the trajectory of community assembly in habitat patches may be highly variable because of stochasticity during the dispersal and colonization process. Conversely, assembly patterns may also be deterministic if communities are shaped by prevalent environmental conditions in the habitat patches (species sorting), or by systematic differences in the dispersal capacities of species.2. In this study, we investigated the pattern of community assembly of zooplankton species in 25 newly created ponds at 13 different sites in Flanders (Belgium). Over a period of three consecutive years, we assessed at what rate and with what frequency species of the regional species pool colonized the newly created ponds. We also studied the development of community structure over time and tested whether the dynamics were consistent across different ponds at the different locations. In addition, we characterized the dynamics of metacommunity features, such as alpha, beta and gamma diversity in clusters of ponds.3. Even within the first year after their creation, the new ponds were rapidly colonized by a small subset of species from the regional species pool (Daphnia obtusa, Chydorus sphaericus and Simocephalus vetulus). These species dominated the cladoceran assemblages during the subsequent years. Other species in the regional species pools were only sporadically able to colonize ponds.4. During the entire study period, we observed no significant shifts in species lists or in the occurrences of species among years. The low incidence of the majority of species may be the result of dispersal limitation or the failure of immigrants to establish due to priority effects exerted by the first colonizers. There was, nevertheless, a consistent change in the relative abundance of species, which was most probably mediated by differences in the hatching time among species influencing species composition in the first year.5. In contrast to expectations, we observed no increase in average alpha diversity (local species richness) and gamma diversity (total richness of entire pond clusters) during the course of the study period. Beta diversity was relatively low from the beginning and remained constant throughout the study period. These deterministic patterns can mainly be attributed to the dominance of the three first colonizing species and the low success rate of other species in colonizing the ponds.

The Lily Pond

The Lily Pond (Fig. 18 and Color Plate A No. 1) was prepared as an installation for Burning Man 2002 and, as with many creative works, it began life as something much different than what it eventually evolved into. Born of my desire to create a large-scale interactive environment, the Pond was originally conceived as a large array of electronic devices that would respond both visually and audibly to people passing near them. Function quickly gave way to form upon my realization that there was no reason these devices could not be sculptural as well as functional. Prior experience with botanical sculpture led me and my colleagues to the idea of each device becoming a plant; from there it was a short leap to the concept of the lily pond. The Lily Pond came to consist of nearly 300 lily pads, mounted 22 inches above the ground and covering an area of roughly 3,500 square ft. Each pad is actually a green circuit board, fabricated in the shape of a lily pad and home to the various electronic circuits that give life to the Pond. The pads are arrayed in a hexagonal grid on 4-ft centers. This arrangement allows one to walk amongst the pads, experiencing the illusion that one is wading into a knee-deep pond. The illusion of wading is greatly enhanced at night, when each lily pad projects a diffuse blue glow onto the ground beneath it. As one walks among the pads, they individually modulate their light levels, in effect simulating the movement of ripples on water. These ripples of light propagate out into the pond, where they collide and combine with other ripples. Wanting to expand the concept beyond the basic idea of a pond full of interactive lily pads, we looked to the flora and fauna of a real pond. In the natural environment, objects of inspiration are plentiful; we found abundant material to draw from. We selected a few elements that interested us for inclusion in the first incarnation of the Pond. Roughly two-dozen of the lily pads sport lotus blossoms made of lampworked glass and stainless steel. These flowers are lit from within and slowly fade on and off and change colors. Seven dragonflies, in the form of wire-frame sculptures, inhabit the Pond. The wings of the dragonflies are illuminated with fiber optics and are animated in a way that suggests rapid motion. The glass eyes of the dragonflies are also lit with a soft light that slowly fades on and off. A pond would not be complete without fish, and The Lily Pond is home to several varieties. Five full-sized ceramic koi lurk beneath the surface, their eyes and barbles glowing gently in the night. There are four different schools of trout, also ceramic, as well as a dozen carp, made of kiln-cast glass. The trout and the carp are illuminated with miniature colored spotlights hidden beneath the lily pads. The shore of the Pond is made of several large steel sculptures suggestive of the reeds, ferns and grass that accompany a real pond. These sturdy sculptures also serve as a buffer zone between the vast unknown exterior world and the quiet, contemplative space of the Pond. Breathing life, motion and light into the Pond requires the collision of several different technologies. The light sources used to illuminate the ground are some of the latest generation of light-emitting diodes (LEDs), which are rapidly becoming the most efficient light sources available. In order to produce the rippling water effect, the lily pads “talk” to one another, using infrared technology similar to that found in television remote controls. The ripple effect itself is based upon a relatively new branch of science known as cellular automata. And finally, each lily pad contains its own power source that is recharged every day by a set of photovoltaic solar cells. Thus the entire Pond is wireless and self-sustaining, powered by the sun. The Lily Pond represents a variety of techniques, technologies, materials and creative visions. Collaborators include the Sunbrothers (lotus blossoms and solar cells), Kathleen Fernald (ceramic fish), Michael Christian (shore sculpture), Lee Kobus (glass fish) and Jay Kravitz (glass fish).

Old industrial mill ponds: a neglected ecological resource

The extent and status of the old industrial textile mill ponds within the area around Huddersfield, UK, is examined in relation to planning and development pressures and conservation value. The aquatic macroinvertebrate biodiversity is assessed and the sites classified on the basis of the community present. Many ponds have been redeveloped and lost as a result of the decline of the textile industry. However, some have become important habitats for aquatic organisms and may form a refuge in the urban environment. There is little environmental monitoring of mill ponds and their ecology and little protection from development processes is provided by either central or local government. The dearth of information regarding old industrial mill ponds and the need for a comprehensive survey of the entire pond resource is highlighted at a time when there is increasing pressure to redevelop old industrial sites.

The Use of Sodium Carbonate Peroxyhydrate to Treat Off-Flavor in Commercial Catfish Ponds

Sodium carbonate peroxyhydrate (SCP) was applied to seven commercial catfish ponds in Mississippi to study the effects of treatment on fish flavor and pond ecology. The seven ponds were treated on alternate days in the morning with two doses of SCP at 55 kg hectare−1 (average depth 1-1.6 m). In three of the ponds, a potent 2-methylisoborneol (MIB) producing planktonic Oscillatoria chalybea-like species that was initially present was absent from the water column after treatment. In addition, the fish from two of these ponds were judged on-flavor 7 to 10 days after treatment. The off-flavor chemicals in three other ponds were diminished when measured seven days after treatment and fish were harvested from two of these ponds 10-14 days after treatment. The fish from the other two ponds were harvested 21 days after treatment. In the sixth pond, the predominant algal species was a 2-methylisoborneol producing O. chalybea-like species at 380 cells ml−1 and the treatment was ineffective. The treatment was most successful when off-flavor was less than two months duration and where application of the chemical was accomplished uniformly over the entire pond surface.

Daily oxygen variations in marine fish ponds, Elat, Israel

A computerized data acquisition system (DAS) was deployed in marine fish ponds at Elat, Israel. The DAS recorded dissolved oxygen, pH and temperature in two ponds and in the water inlet to ponds. Wind velocity and solar irradiation were also recorded. During phytoplankton bloom conditions, wide daily variations were observed in dissolved oxygen (between 3 and 16 mg O 2l −1) and in pH (between 8.2 and 8.8). During phytoplankton crash conditions, the amplitude of these variations decreased and the ponds approached anoxic conditions (∼2 mg O 2l −1). Operation of a mechanical paddle wheel during crash conditions overrode the metabolically induced fluctuations and brought the oxygen levels close to saturation with the atmosphere. Using the rate of oxygen decrease during the night, community respiration and oxygen exchange rate with the atmosphere were calculated. Respiration at the beginning of the night was higher by a factor of 4 compared to respiration at the end of the night. Primary productivity for the entire pond community was calculated based on the oxygen rate of change during the day, and compared to standard BOD incubations. This comparison suggests that 65% of the primary productivity was by the phytoplankton and 35% by the benthonic algae and the macroalgae. Based on this study we compare the difference between seawater and freshwater pond systems and consider the implications for aquaculture of phytoplankton dynamics, benthonic algae and macroalgae, paddle wheel operation, and computerized data acquisition.

The Summer Food and Habits of the Chain Pickerel (Esox niger) of a Small New York Pond

to an intelligent management program. As yet few detailed studies of our common game and pan fishes have been made. This is true of the chain pickerel as only fragmentary information is available on many phases of its life history. Most studies of the food of this form are based on analyses of a few specimens from a given locality. A good summary of the literature on the food of Esox niger was presented by Adams and Hankinson (1928: 394). More recently Hunter and Rankin (1939: 194) have compiled some of the published information on three species of Esox (niger, americanus, and lucius). They also presented the results of additional studies on the food of 30 specimens of Esox niger and Esox americanus; unfortunately comparison with the material here presented is hardly possible since these authors combined the data on the stomach contents of the two species. A good opportunity to study the food and habits of the chain pickerel was had during the summer of 1939 when the writer was a research fellow at the Edmund Niles Huyck Preserve at Rensselaerville, Albany County, New York. The studies were made at Lincoln Pond, a small artificial lake, where little fishing has been permitted for a number of years. It is similar to many weedy, warm ponds of eastern New York and New England. The area is approximately 9 acres and the pond is fed by two small inlet streams which, however, were completely dry during the summer of 1939. An aerial view that shows the salient features of the terrain was presented by Raney (1940: 736). The pond is largely edged by a relatively shallow shelf of silt 10 to 30 feet wide that supports a copious growth of emergent grasses and submerged aquatic plants. The depth of water over this shelf averages about a foot. The remainder of the pond varies in depth up to 11 feet as the maximum. It is very weedy and during late July and August the aquatic plants (mostly Elodea) virtually choke the entire pond. The pond is unusually productive of aquatic insects and other invertebrates as well as of fishes. Although fishes were abundant as individuals, only five species were represented and these were all probably stocked since the dam was replaced some years ago. The fishes present besides the chain pickerel were: (1) Golden shiner (Notemigonus c. drysoleucas); (2) common bullhead (Ameiurus n. nebulosus); (3) yellow perch (Perca flavescens); and (4) common sunfish (Lepomis gibbosus). At various times during the summer, collections of young pickerel were made from the grassy shelf around the pond with a 10-foot seine. Large pickerel were taken by angling, by gill nets, and by seining along shore at night with a 6-foot seine. At night the pickerel could be readily found by the aid of a flash-

The Chemistry of Impounded Waters as a Factor in Game Fish Production

Abstract Since 1931, the writer has been engaged in making a survey of small lakes and ponds for the New York Conservation Department Biological Survey. During this time, he has observed and studied a large number of new and old artificial lakes. These studies have included, among other important factors in fish production, an analysis of those chemical conditions that directly affect fish life. Studies were made on Minerva Lake over a period of several years after the construction of the lake. From the many lakes studied, pertinent examples are chosen which indicate that In small newly impounded waters, chemical conditions tend, at first, to be unsuitable for game fish throughout the entire pond and therefore no stocking should be done. As the impounded waters increase in age, an improvement in chemical conditions is noted, but this improvement usually involves only the surface layer of water. Stocking must hence be limited to species tolerant of warm surface temperatures. The colder bottom-waters rarely...

The Animals of the Lemna Association

This is a study of the small animals in an association of one of the smallest flowering plants, Lemna minor, in the vicinity of Ithaca, N. Y. The dominant animal forms are naturally very small, ranging in size from a fraction of a millimeter to scarcely six millimeters in length. Yet, just as with large organisms, the destruction caused by them is compensated by the prolific growth of the plant. The individual plants of Lemna mttinor are, as is well known, very small, flat, leaf-like discs, convex on the upper side and slightly concave underneath. A single water root dangles from the center of each green thallus and helps to maintain the equilibrium of the plant. Being a free-swimming hydrophyte, Lemn1a minor has many air cavities which make it buoyant. Stomata are scattered over the upper surface. From April to October may be considered the active growing period of this species in the latitude of Ithaca, New York, with the peak of rapidity in growth occurring in July and August, when an entire pond may be blanketed with these small plants. Proliferation takes place in one plane, the lateral branches emerging from two clefts or pouches on the margin of the thallus. These new thalli are connected with the parent thallus by short slender stalks and are easily detached by a slight disturbance of the water. New centers of growth are thus established in the pond by the drifting apart of the disconnected offspring. In the fall, when conditions become less favorable for growth, lateral branches develop which lack air spaces and have plenty of reserve food. These winter buds sink to the bottom of the pond where they remain until the water becomes warm again the next spring. Then with the formation of air spaces, they begin their vegetative activities for the summer and rise to the surface. Propagation takes place also by the production of seeds from diminutive flowers (fig. 1). Inasmuch as Leminia mi-nor grows in quiet waters, it is not surprising that many filamentous forms of algae, as well as colonial types, are found among its roots and attached to the under surface of the thalli. Desmids and diatoms likewise abound. The liverwort, Riccia natans, and the spermatophytes, Spir odela and Wolfia, sometimes float about with the Lem-na. Near the edges of ponds grow cat-tails (Typhaceae), bur-reeds (Sparganiaceae), and arrowheads (Alismaceae). Occasionally water-lilies (Nymphaeaceae), water cress (Cruciferae), Elodea, and CeratophyllvUn associate themselves with the duckweeds (Lemlnaceae).