Ecology: The study of the interrelationships among plants and animals and the interaction between living organisms and their physical environment.
Ecosystem: It is an open system consisting of Biotic (living) and Abiotic (non living) factors interacting with each other and with their surrounding environment. They act as a single unit, works together in environment.
In an open system, exchange of energy and matter with environment takes place, and forms a steady dynamic state.
Biota: Biota is all living elements of an ecosystem or a given area.
Ecosphere: It is the upper layer of lithosphere and the whole of the atmosphere above the troposphere, including biospheric and parabiospheric regions.
Biosphere: It is the part of the earth in which life is permanently possible and which contains all living organisms. It consists of the terrestrial oceans and the surface of continents together with the adjacent atmosphere (i.e. troposphere), with the exception of the polar ice caps and the higher mountain slopes above the snow line. These latter regions, described as parabiospheric, are included along the biosphere itself in a large system, the ecosphere, which also embraces the upper layer of lithosphere and the whole of the atmosphere above the troposphere.
Eutrophication: Natural process of nutrient enrichment that occurs, over time, in the body of water. The resulting biological growth, mainly algae, in the epilimnion (upper layer of water stratified lake) dies and settles to the hypolimnion (lower layer op water stratified lake), where it decays and depletes the oxygen from the water.
It is one of the most significant and worldwide water quality problems. The most important problems are –
1) Changes in fish species occur in the lakes due to low levels of oxygen caused by Eutrophication.
2) Excessive algal growth makes water bodies unfit for recreational purposes.
3) The abundant algal blooms, creates unpleasant taste and odour in water supplies and also may clog the intake pipes and filters.
Plankton: Any small free floating organisms living in a body of water; phytoplankton refers to plant species (algae) and zooplankton to animal species (crustaceans, rotifers, protozoa) feeding on other forms of planktons.
Prey: In a feeding relationship the prey is the animal that is killed and eaten by the other.