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Environment Book Summary Presented Bu Aartee Mishra
iv) Nekton: This group contains animals which are swimmers. The nektons are relatively large and powerful as they have to overcome the water currents. cts (a The animals range in size- from the swimming insects (about 2 mm long to the largest animals, the blue whale. v) Benthos: . The benthic organisms are those found living in the bottom of the water mass. Practically every aquatic ecosystem contains well developed benthos. Factors Limiting . The Productivity of Aquatic Habitats Sunlight and oxygen are most important limiting factors of the aquatic ecosystems whereas moisture and temperature are the main limiting factors of terrestrial ecosystem
Abiotic Factors affecting Aquatic Ecosystems Light Solubility of gases varies w/ depth, particulate matter Co2 oceans as carbon sink, leads to acidificatiorn Photosynthetic organisms. Temperature Important component of carbonate shells varies w/ depth and season Convection Food for autotrophs O2 Solubility of solids/liquids Acidity Salinity pollutants Lower pH results in more metals soluble in water Certain level for which organisms adapted
LAKE ECOLOGY Any body of standing water, generally large enough in area and depth, irrespective of its hydrology, ecology, and other characteristics is generally known as lake. Ageing of Lakes .Over periods spanning millennia, ageing' occurs as the lakes accumulate mineral and organic matter and gradually, get filled up. . On the basis of their nutrient content, they are categorized as Oligotrophic (very low nutrients),Mesotrophic (moderate nutrients) and Eutrophic (highly nutrient rich). Vast majority of lakes in India are either eutrophic or mesotrophic because of the nutrients derived from their surroundings or organic wastes entering them.
The nutrient-enrichment of theSno FarameterPof otutroph lakes promotes the growth ofc plantLow algae, aquatic plants and_ various fauna. This process is known eutrophication. Sl.no ParameterOligotrophic Eutrophic High production Aquatic animal production 2. Low High natural 3. Aquatic plant Lovw as High nutrient flux Oxygen in the Present hypolimnion (bottom layer) 4 Absent Lake 'Sudarshan' in Gujarat's Gimar area was perhaps theDepth oldest man-made lake in India, dating back to 300 BC. Tend to be Tend to be deeper shallower 6. Water quality Good Poor for domestic & industrial uses 7. Total salts or Usually Sometimes higher Fewer conductance lower 8. Number of Many plant an d animal species
REMOVAL OF THE NUTRIENTS FROM A LAKE > Flushing with nutrient-poor waters. >Deep water abstraction. :>On-site P-elimination by flocculation/flotation with water backflow, or floating Plant NESSIE with adsorbents. :> On-site algae removal by filters and P-adsorbers. EUTROPHICATION >Greek word - Eutrophia means adequate & healthy nutrition. > Eutrophication is a syndrome of ecosystem, response to the addition of artificial or natural substances such as nitrates and phosphates through fertilizer, sewage, etc that fertilize the aquatic ecosystem.
Time sunlight 1. Nutrient load up: 5. Death of the ecosystem: excessive nutrients from fertilisers are flushed from the land into rivers or lakes by rainwater. oxygen levels reach a point where no life is possible. Fish and other organisms die. aigae layer 3. Algae blooms, oxygen is depleted: algae blooms, preventing sunlight reaching other plants. The plants die and oxygen in the water is depleted nutrient material 2. Plants flourish: these pollutants cause aquatic plant growth of algae, duckweed and other plants. 4. Decomposition further depletes oxygen dead plants are broken down by bacteria decomposers). using up even more oxygen in the water.