The study of the relationships between living things and their environment is known as ecology.
Ecology, as a science, deals with interactions of all organisms within the environment. These interactions not only
Encompass between-species interactions (e.g., plant-animal interactions), but also interactions between individuals
Of the same species (e.g., sibling relations; competition for mates; etc.). Another aspect of ecology deals with the
Environmental conditions that result from abiotic factors (environmental conditions produced by organisms are
termed biotic factors). The biotic factors that affect an ecosystem might include the weather, how much water is
available for consumption, what type of soil is present, and whether there is enough oxygen to support aerobic
Each species within an ecosystem has slightly different requirements for maintaining life. The earth presents a
mosaic of different combinations of abiotic factors, providing a myriad of habitats for biotic organisms. As a result,
most organisms are restricted to habitats that have a combination of abiotic factors that allow them to survive.
Ecologists term the different areas biomes and the groups of organisms living there communities. Although the
terms are new to most people, the concept is already present in their minds.
The ecosystems (with their characteristic communities, biogeochemical cycles, and energy flow patterns) are notstatic entities. Depending on how the environment changes, the biomes in that environment will also change.
This progression is known as Succession.
An ecosystem is maintained by a delicate balance of interactions between living organisms (biotic factors) and
abiotic factors. All organisms, including humans, are subject to the ecological laws that govern the relationships of
organisms and their environment. Humans, more than other organisms, have the ability to modify the environment
to their own choosing. Such power must be used with care because its misuse can yield disastrous results.
Acid rain is a side effect of air pollution. Sulfur oxides and nitrogen oxides react with water in the atmosphere to
form sulfuric acid and nitric acid, respectively, which ultimately are returned to earth in rain. The burning of oil and
gasoline produces nitrogen oxides. Sulfur oxides are produced by pollutants from burning coal. Pure rainwater has a pH of 5.6 Rainwater with a pH less than 5.6 is classified as acid rain, but rainwater has been recorded with a pH as low as 1.5. Lakes subjected to acid rain have a lowered pH that severely interrupts the normal functioning of the
aquatic ecosystem. Few organisms can tolerate such conditions.
Organic pollution is largely the result of human activity that increases the quantity of fertilizers, sewage, nitrates,
and phosphates in lakes and streams. Organic pollution provides an excess of nutrients for the ecosystem and leads
to changes in the community of organisms. Polluted waters tend to have a reduced oxygen content, which kills off
desirable heterotrophic species, especially game fish. Aquatic organisms vary in their ability to tolerate organic
The subject of ecology is particularly important for us today because we as humans have finally realized that in order for our planet to remain alive, we must take preventive measures to save it. Pond Ecology takes into account one aspect of planet ponds. Through experiments, readings and discussions, we will learn to look critically at ecosystems, and ecology especially as they relate to ponds.
A pond is characterized as being a small body of water that is shallow enough for sunlight to reach the bottom, permitting the growth of rooted plants at its deepest point. Seldom do ponds reach more that 3.6-4.5 meters (12 to 15 feet) in depth.
An undisturbed pond will age. Even though at first a pond will appear to be lifeless, a new pond will acquire both plants and animals by the different forms of inflowing water. Plants colonize all of the zones and provide food and shelter to a wide variety of animals. Frogs begin to visit and lay eggs.
Ponds are considered to be part of the freshwater habitat-which are divided into flowing water and standing water. The flowing water habitat is divided into rapid and slow streams. The standing water habitat are divided into lakes, ponds, and swamps. Ponds can be even further divided into those with bare bottoms and those whose bottom contain vegetation.
Ponds are noted for their abundant and rich varieties of plant and animal life, which all are maintained in a delicate ecological balance. Life forms range from microscopic bacteria to insects, fish, small animals, and birds. As ponds age, the number of species living in it steadily increases until, finally, the growth of larger plants, algae, and the accumulation of wastes convert it into a marsh or cause it to dry up. This process is known as ecological succession.
The water quality of small water bodies, particular in the urban area of India is under the influence of
the growing population and development. Development results in migration of rural population to urban area. It
is easy for these migrants to settle on the open areas nearby ponds, lakes, canals, etc. where solid and fecal
waste is being dumped in to wast body. Added to this the other sources of pollution of small water bodies are
agricultural runoff, industrial waste wehicle washing cloth washing, cattle and people bathing and garbage etc.
this waste increase pollutants in terms of nutrients, organic matter and toxic substaneces in the water bodies and
disturb its ecosystem.
Sama Talav, an Urban pond in Vadodara City lies at 22.3008Â° N, 73.2036Â° E. The Pond is surrounded by urban roads, petrol pump, party plots, Schools,etc.
Sursagar Lake situated at N and E inside Vadodara City . The Pond spreads in length to an approx. of 250m and breath wise around 150m.
The Lake is surrounded by residential area, temples, commercial complex,etc.
The lake was natural freshwater. The lake is surrounded by temple,
agricultural fields and human settlements. There is a solid water dumping site on fringe of the Lake. The upper
catchment area of the lake includes rural and agricultural area. The inlet and outlet of the lake are open. The
runoff in the monsoon, sewage from the area are disposed into the lake is there is no proper sewage collection
and disposal system gone time to time Intel a water of Dharoi Dam water by the Pipe line system, purpose of
used a water in by water pump and pipe line by construction of building by the water tanker the overflow from
the La flow into nearby canal by open channel and is ultimately disposed into water irrigation in earth without
Since, Lake are favorable habitants for a variety of flora-fauna and anthropogenic society, so itâs regular
Monitoring is necessary for control recently, lot of work has been done on changing ecological behavior of
ponds (mahananda et al. 2005), Kanungo et al., 2006; Gupta et al.,2008;) in the present study, the impact of
biotic activities on physico-chemical characteristics of lake water.
After this project, we will realize that man is highly dependent on the planet Earth for survival just as Earth depends on man. Therefore, this project can be used as one of many activities which focuses on the significance of saving our planet.
The project will help us become aware of the importance of keeping ponds safe from pollutants while witnessing the actual devastation that oil or gas spills cause to our pond communities.
MATERIALS AND METHODS
Two sample side were collected from part A and part B in each season. Total two sample were collected in one season like Winter, summer and monsoon Per parameters. In the sampling period of one year total six samples were collected and analyzed per parameter.
The sample ware collected in the Year of 2015 representing winter, summer and monsoon seasons respectively. The samples where collected in the morning between 8.30 to 10.30am.Collection preservation and analysis of water sample were carried out following standard reference (APHA, 2005). The water samples were analyzed for various physico-chemical parameters, biological parameters and bacterial density as well as diversity.
Analysis of Physicochemical Parameters: The samples were used for the analysis of physico-chemical factors according to the standard methods referred to under:
1. Temperature- I.S: 3025(Part -9):1984
2. pH- I.S: 3025(Part-2):1983 RA 2002
3. Colour- I.S: 3025(Part-4)1983 RA 1996
4. Total dissolved solid- I.S: 3025(Part-17)1984
5. Chloride â”I.S:3025(Part-32):1986& ASTM D512-89(Reapproved 1999)Test method â”B
6. Total hardness â”I.S: 3025(Part-21):1983 RA 2002 Edition 2.1(2001-02)
7. Calcium â”I.S: 3025(Part-40):1991
8. Alkalinity â”I.S: 3025(Part-23)1986 RA-2003
9. Acidity â”I.S: 3025 (Part-22):1986
10. Nitrate â”I.S: 3025(Part-34):1980
11. Phosphate- I.S: 3025(Part-31):1988
The biological parameter induce chlorophyll, phytoplankton, zooplankton and bird diversity microbiological parameter include total bacterial count, colifoms and enumeration of various bacterial species.
The biological parameter induce chlorophyll, phytoplankton, zooplankton and bird diversity microbiological parameter include total bacterial count, colifoms and enumeration of various bacterial species
Atmosphere and water temperature ware measured using standard mercury thermometers. The pH of was measured immediately after collection by using a pre-calibrated cyberscan 100 digital pH meter.
The conductively of the water was measured by using a pre-calibrated digital conductivity mater. In the microbiological analysis the total bacterial count. (TBC) and test for coli- forms were done according of
standard methods for the examination of water and waste water (APHA 2005). The bio-chemical tests for identification of bacterial species were done according to manual of systematic bacteriology.
Plankton includes both phytoplankton as well as zooplankton. Plankton samples were collected from the surface water from pre-decided locations. The sampling stations were located as near as possible to those selected for chemical sampling to ensure maximum. Correlation and concentrated to 250 ml by filtering 20
(mew) mesh size plankton net.
Plankton includes both phytoplankton as well as zooplankton. Plankton samples were collected from the surface water from pre-decided locations. The sampling stations were located as near as possible to those selected for chemical sampling to ensure maximum. Correlation and concentrated to 250 ml by filtering 20
(mew) mesh size plankton net. The concentrated sample ware immediately preserved by addition of 5 ml of 4% formalin, plankton sample were identified up to species level under binocular compound
microscope following standard monograph (Edmondson, 1693).
Cyanobacteria are the pioneer oxygenic, gram negative photosynthetic prokaryotes spread in almost all conceivable habitats. Utilization of cyanobacteria for environmental cleaning is already an emerging area since cyanobacteria metabolize the pollutants or detoxify and degrade them or accumulate and absorb them (Subramanian and Uma1998).There have been positive result to such utility programmes in research done with heavy metals and xenobiotics. A large number of cyanobacteria have been reported to bind a variety of heavy metals to different extents. The role of various by cyanobacteria biosorption in the removal and recovery of heavy metal(s) has been well reviewed and documented (Stratton, 1987; Volesky, 1990; Wase and Foster, 1997; Greene and Darnall, 1990; Gadd 1988).
The first step of the project is to come up with a good title for the experiment. Titles are often stated in the form of a question. Just from reading the title, anyone should automatically know the problem that a child is trying to solve in their experiment. For example: What Effect Does Temperature Have on the Respiration Rate of a Fish . From the title it is known that we are trying to find out if the temperature of water changes the rate at which a fish breathes.
Thinking scientifically, we should try to find possible solutions the problem through researching information about the problem we are trying to solve. The information that we find should aid us all in forming an hypothesis during the third stage of the scientific method, and help us in writing the introduction.
The second stage of the scientific method is titled the introduction. We, in paragraph format, should briefly write some sort of introductory statement which addresses such questions as, why he chose to do the particular experiment and why is it worth spending time on. The child should also include some background information about how the fish breathes or how they react in warm verses cold water, or how they are cold-blooded animals, etc.
The third step of the scientific method requires us making an educated guess about what we are experimenting on. The educated guess is called an hypothesis. Using the previous example, a typical hypothesis for this experiment would be: As the temperature of the water increases, the fish respiration rate would increase also.
In the fourth step called the procedure, we have to list the material that is needed to do the experiment as well as provide the basic details as to how the experiment will be performed. This should be a detailed description and a step by step procedure of how the student could test his problem. Anyone reading the experiment should be able to collect the materials needed to perform the investigation and duplicate the experiment by reading the procedures.
The fifth step called observations. We records any pertinent information about their findings while performing the experiment. Whenever possible the student should use charts, graphs, tables or pictures to depict information.
The final step of the scientific method is the conclusion. Here we analyze the data the has placed in his observations and formulates a conclusion. This section is also be done in a paragraph format. We should also state whether or not his hypothesis was correct.
FUNDAMENTALS OF POND ECOLOGY
A. Habitats In the Pond Community
The place where an organisms live is considered its habitat. Four distinctive habitats can be found within the pond community. These four habitats are the surface film habitat, open water habitat, bottom habitat and the shore habitat.
The surface film habitat is located on the top (surface) of the pond water. It is the habitat of air-breathing floating animals (insects) such as marsh treaders, broad-shouldered water striders, and animals that have special devices that allow them to walk on the surface of water without breaking through such as water striders. Some insects and free-floating animals are adapted to live only on the upper side of the surface film. The animals that dwells on the surface usually feed on the floating plans, insects and other animals that may have been killed or drown and floated to the surface. The surface dwelling animals may even feed on one another. Other animals, along with the larvae of some beetles and flies spend much of their life on the underside of the film beneath the floating plants.
The open-water area mainly consist of the water surrounded by plant life. It ends where vegetation is dense and rooted into the soil. The open water habitat is composed of large, free-swimming organism such as fish, and small microscopic plants and animals called plankton that drift suspended in the water. Phytoplankton (small suspended plants), mostly consisting of algae, are the basic food in lakes.
Small suspended animals such as tiny crustaceans, insect larvae, rotifers, and other invertebrates called zooplankton also live in the open-water habitat and are basic food for pond animals. The availability of plankton vary from season to season, but are most abundant during the spring.
Other animals such as turtles, birds and larger fish comes to the open-water area for food. Some insects, insect larvae, and crustaceans migrate from the bottom towards the surface, but return to the bottom as daylight appears.
Life in the bottom habitat of a pond depends upon the type of bottom a pond may have. For example, if the pond is shallow and has a sandy bottom it could be inhabited by sponges, earthworms, snails and insects. The bottom of quiet, standing water ponds are characterized as muddy or silty, and life represented in these types of ponds are crayfish, and the nymphs of mayflies, dragonflies, and microorganisms. These animals usually burrow into the bottom muds.
If the water in the pond is turbid, conditions at the bottom of the sea is extremely different from that in the opened waters because light does not penetrate to the bottom and plants cannot grow. Due to the lack of vegetation, the availability of shelter for animals is almost null. The amount of dissolved oxygen will be low, and the concentration of carbon dioxide will be high. Despite all of the previously mentioned conditions, animals such as earthworms, small clams, and fly larvae such as bloodworms and phantoms can survive in the deep bottom zone. There is usually a large amount of bacteria in this zone because they can survive off of dead organic matter.
The littoral habitat extends from the waters edge outward as far as rooted plants grow. This is the richest area in the pond community because of the plant life that exist in this area. The observer will find unlimited amounts of biotic life. Typically, there are three distinct borders of flowering plants that makes up the littoral habitat: the emergent plant zone; floating plant zone; and submersed plant zone. If the shore is rocky, plants may not grow in this area. Therefore, some ponds may have two distinct borders of flowering plants.
The emergent plant zone is closest to the shore. The observer will find plants that are rooted to the bottom. Their stems and leaves appear above the surface. The emergent zone should be bountiful with grasses, sedges, rushes, and algae. Along with the plant life, the observer will find animals such as protozoans, worms, insects, snails, and small fishes.
The floating-leaf plant zone is made up of broad, flat-leaved water lilies, water ferns, and duckweed. If the observer picks up one of the leaves, animals such as snails, bugs, and mayflies, larvae and eggs may be located underneath them. A variety of algae can be found in this zone. Most water animals use this area for breeding and nesting.
The submersed plant zone is the area of vegetation that surrounds the center of the pond. The plants in this area all have leaves that are long and slender, or bushy and branched leaves. Pondweed, waterweeds, and hornwarts are some of the flowering plants found in this zone. The flowers of these plants are pollinated above the water surface. The seeds of these plants germinate and the plants develop underneath the water.
B. Food Webs and Chains
As ecosystems have living and nonliving parts. The living, or biotic part, of an ecosystem is known as the ecological community. Living things interact with each other by feeding on one another. Therefore, energy, compounds, and chemical elements are transferred from creature to creature along the food chains.
Food chains group organisms into trophic levels. A trophic level include all the organisms in a food chain that are the same number of steps away from the original source of energy. Therefore, green plants are in the first trophic level and plant eating animals (herbivores) are placed in the second level. The third trophic level consists of carnivores (meat eating animals) that feed on herbivores. The fourth trophic level consists of carnivores that feed on the animals from the third trophic level, etc.
For example, trophic levels that exist within the pond community could be diagrammed as follows:
(1) First Trophic Level green plants such as phytoplankton, algae, microscopic plants, pond lilies, etc. which manufactures food through photosynthesis.
(2) Second Trophic Level herbivores such as mayflies, small crustaceans, nymphs, and certain types of beetles that feed on the plants in level one.
(3) Third Trophic Level carnivores such as fish who consume plants and animals from the first and second trophic levels.
C. The Ecological Makeup Of A Pond
The components of a pond ecosystems are very diverse, but it can be divided into several basic units: (1) abiotic substances; (2) producer organisms; (3) macroconsumer organisms; and (4) saprotrophic organisms.
The abiotic substances that make up the pond includes basic inorganic and organic substances such as water, carbon dioxide, oxygen, phosphorus salts, amino acids and nitrogen. Small portions of the necessary nutrients that organisms need in order to survive in the water is always available. The rate at which these nutrients are released into the water are regulated by the temperature cycle (seasons), the amount and availability of sunlight, and the climatic regimes.
There are two different kinds of producer organisms that make up a pond: (1) small minute and/or microscopic floating plants call phytoplankton. The word phytoplankton comes from the prefix phyto which means plant and the suffix plankton which means floating. If the pond produces a large amount of algae, the water will have a green coloration. This can be hazardous to the pond community. Phytoplankton can be found all over the pond, as long as there is sunlight to sustain its life. Algae are a good example of phytoplankton. The second type of producer organism are the rooted or large floating plants which are found growing in the shallow water area.
Fish, crustaceans, and insect larvae is are examples of the macroconsumer organisms that can be found in a pond. The primary macroconsumers consist of zooplankton and benthos. They are herbivores that feeds directly on living plants and the remains of those plants. The secondary consumers consist of carnivores (insects and game fish) which feeds on the primary consumers.
Saprotrophic organisms are the aquatic bacteria, fungi, and flagellates which are widely distributed throughout the pond. Large numbers of these organisms can be found in the mud at the bottom of the pond where dead plants and animals accumulate. Under the correct climatic conditions, decomposition of the dead matter occurs rapidly. Some saprotrophic organisms are pathogenic because they have the ability to cause diseases in other living organisms. However, most of these organisms only feed on dead organic matter.
THE HYDROLOGICAL CYCLE
The hydrologic cycle, commonly referred to as the water cycle, is closely related to the interrelationship of the biotic and physical environment. Man can not survive without water nor would we have lakes, ponds or streams. The water cycle is continuous movement of water from the atmosphere to the earth and from the earth back to the atmosphere. The water that moves from the atmosphere to the earth is called precipitation. However, the water will return to the atmosphere through evaporation.
During a rain storm, some of the rainwater evaporates as it falls to the ground. But most of the rainwater runs along the surface of the ground and travels to the rivers, streams and ponds. The water running along the surface is known as runoff water. Large amounts of precipitation also enter the soil to become ground water. This water can reach a pond, lake or ocean through springs or underground streams; or it may move upward through the soil during dry periods and pass again into the atmosphere as water vapor. The warm air that rises through the atmosphere contains tiny droplets of water. This water cools as it climbs higher into the atmosphere causing the water vapor to condense into droplets of water which forms clouds. The droplets collect to form drops that eventually fall from the clouds as rain. If the water vapor condenses at a temperature below the freezing point of water, then snow is formed.
Ground water is also a part of the water cycle. The ground holds and receives water from precipitation. However, some of the water moves downward into subsoil and fills the spaces around the rock particles. The upper level of the soil where it is saturated with water is known as the water table. If the soil is over saturated with water, the water will run off the surface instead of penetrating into the soil.
FACTORS THAT EXIST IN THE POND
In order for an organism to live in any given habitat, it must have the necessary materials that it needs for growth and reproduction. Anything that is essential for an organisms survival, and for which there is competition, is called a limiting factor. A deficiency or an over-abundance of any kind can limit the survival of an organisms in a particular habitat. For example, cattails growing along the shore of a lake requires a marshy condition where the water is not too deep. In a pond where the bottom is soft and the water is shallow, cattails cannot survive. However, they can survive at the ponds edge.
Some limiting factors have to do with living things. These limiting factors are called biotic factors. Food is a good example of biotic factors because animals can live only where the kinds of food they eat are available. If limiting factors have to do with nonliving things such as air, temperature, sunlight and water, it is called an abiotic factor. At this time we will examine several biotic and abiotic limiting factors and discuss their affect on the habitats of plants and animals that exist within the pond ecosystem.
Most aquatic organisms have a narrow tolerance to change in temperature and therefore cannot live where drastic temperature changes occur. However some animals are equipped with special mechanisms that helps them to adjust to temperature change. A primary example being cold blooded animals because they can adjust by temporarily reducing their metabolism which results in a suspended state of animation. Once normal temperatures reoccur the animal returns to its normal activity.
Some plants and animals adjust by developing special hibernation phases or forms. Some aquatic plants produce winter buds which breaks off and drop to the bottom of ponds. These winter buds realistically are terminal shoots in which leaves are very close together which acts as a stored food supply. Among animals, various devices are common in order for them to survive the wintry cold waters. Some examples include: winter eggs of certain microscopic animals such as rotifers, cladocerans and rhabdocoels and the cysts of many protists, copeds and annelids.
Other animals may adapt by moving into a different environment. Fishes and snails move away from the from the shore into the deeper water. Most insects go to the bottom of the pond and burrow into the substratum to hibernate. Reptiles and amphibians do the same, but some dig holes in the mud, trash and debris. The majority of freshwater fishes and some amphibians, can withstand fluctuations in temperature and survive temperatures well below freezing in winter and fairly high temperatures in the summer.
The amounts of light that is able to penetrate water is restricted by the amount of suspended material in the water and the color of the water. Light is essential to all green plants in order for them to make food. Likewise, green plants and their stored energy are needed by animals in order to survive.
Excessive algae growth and turbid waters can have a devastating affect on a pond because it hinders the amount of light that can pass through the water. Since the green plants can not receive the necessary amount of sunlight, they will die off, thus causing a decrease of available oxygen and food in the water which will kill animal life in the water.
C. Carbon Dioxide
Most of the carbon dioxide in water comes from the decay of organic materials and from respiration that occurs in both plants and animals. Carbon dioxide is also supplied to ponds dissolved in groundwater and rain. The amount of dissolved carbon dioxide is usually higher at the bottom of ponds. Carbon dioxide is used by plants during photosynthesis. Photosynthesis is the process in which organisms containing chlorophyll are able to use the energy from the sunlight to unite carbon dioxide and water to form the sugar glucose, and other compounds that derived from it, and a source of energy. In doing this they use oxygen and release carbon dioxide in respiration. It is the source of carbon found in proteins, fats, and carbohydrates, the basic food substances of animals.
Carbon dioxide plays an important role in determining the pH, the degree of alkalininty or acidity, of water. It combines with water forming weak carbonic acid which reacts with limestone or dissolved lime to form carbonates and bicarbonates. These compounds serve as buffers that regulate pH. The pH of water often determines what types of aquatic life are found in ponds.
There are two ways in which oxygen enters the water. One method is through photosynthesis of green plants in the water. The second method is by diffusion of oxygen from the atmosphere. The amount of oxygen that the waters retain is dependent upon the temperature, pressure, decomposition and pollution. Clean shallow surface water averages an oxygen content of five to ten cubic centimeters per liter. Cold water will hold more oxygen than warm water; rapid moving waters contain more oxygen than stagnant waters. Water containing decaying organic matter will show a drop in oxygen content because the aerobic bacteria involved in decomposition uses the oxygen.
As the sunlight penetrates the water during the daylight, plants give off oxygen as a by-product of photosynthesis more rapidly than it is used in respiration by living things. Therefore there is a reserve of oxygen built up. At night when photosynthesis ceases, both plants and animals use the reserved oxygen. The oxygen content in ponds fluctuates greatly within a twenty-four hour period. If the oxygen content of water is suddenly reduced, fish will tend to come to the surface in order to gulp air.
D. Nutritional Relationships
Most of the biotic limiting factors involve food. The autotrophs require inorganic nutrients from the environment to synthesis organic compounds. These autotrophs are called food producers. There are three different types of food producers found in the pond: (l) the emergent, rooted plants like water lilies, and cattails found near the shore; (2) the submerged plants like hornworts and eelgrass; and (3) the suspended algae which form the phytoplankton. Microscopic examination of a few drops of pond water usually reveals hundreds of one-celled algae.
Phytoplankton may increase so much that lake water turns to a dark green color. Small crustaceans such as ostracods and copepods feed well on the algae blooms. Since these animals feed on plants, they are called herbivores and are first food consumers of an ecosystem. The energy synthesized and stored by phytoplankton is transferred to the protoplasm of the herbivores. The carnivores, flesh-eating animals are divided into two groups: (l) the first-level carnivores, which eat and use the energy of the herbivores; and (2) the second-level carnivores, which prey on the first-level carnivores
The scavengers feed on dead organisms. They are important in the cycling of chemicals and the transfer of energy to the animals in the ecosystem that feed on them. Crayfish, some snails and fish are some examples of scavengers. The bacteria and yeast are representatives of decomposers in the pond. They break the excretions and tissues of organisms into simpler substances through the process of decay.
Other bacteria present in the mud bottom of the pond and in the soil convert the simpler substances left by the decomposers in to nitrogen compounds, which are used by plants. The bacteria that do this are called transformers. Both decomposers and transformers return nitrogen, phosphates, and other substances to the soil or water so that the plants can begin the cycle again. Matter would not be available for recycling, or reuse, in an ecosystem if decomposers did not exist.
Small amounts of organic pollution may increase the fertility of a body of water if it can be decomposed without seriously reducing the oxygen content. However, if the oxygen content is seriously reduced, anaerobic decomposition will be initiated and undesirable gases will form. Even though ponds may be able to survive some forms of organic pollutions, it is practically impossible for a pond to survive inorganic pollutants such as those from chemical, radioactive wastes, etc… because of their potency.
Sticklebacks, carps, eels, stoneworts and duckweed can survive in polluted waters. Other animals show a wide range of tolerance to organic pollution. Most animals that can survive in highly polluted waters have a high tolerance level in the presence of waters with a reduced oxygen supply. Many of the protists can live in these type of conditions. Many of the bivalves and snails have a high tolerance level for pollution. However, the absence of these and other mollusks from ponds is often a warning of pollution.
Atmospheric Temperature and Water Temperature: Air and water temperature was recorded with the help of a mercury centigrade thermometer while avoiding its direct exposure to the sunlight.
Transparency: The transparency of the water was noted by secchi disc of 20 cm in diameter (painted black and white on the upper surface) and computed by the formula:
T = X+Y
Where, T = Transparency in cms
X = Depth at which the disc became invisible
Y = Depth at which the disc reappeared while pulling the rope upward.
Depth: The measurement of depth was made from the bottom of pond vertically upto the upper surface of water by a meter rod.
Chemical parameters of water
pH: pH of water samples was determined with the help of a portable field pH meter (Hanna).
Dissolved Oxygen: Dissolved oxygen was determined by sodium azide modification of Winklerâs method.