Paper No: 01Ecosystem Structures & Functions Module: 30 -Types of Aquatic Ecosystems-I : Freshwater Ecosystem 1Ecosystem Structure and Functions Development Team Prof. R.K. Kohli Principal Investigator & Prof. V.K. Garg & Prof. Ashok Dhawan Co- Principal Investigator Central University of Punjab, Bathinda Dr. Renuka Gupta, YMCA University of Science and Paper Coordinator Technology, Faridabad, Haryana Dr. Sharda R. Gupta, Ex Professor Content Writer Kurukshetra University, Kurukshetra Content Reviewer Prof. V.K. Garg Central University of Punjab, Bathinda Anchor Institute Central University of Punjab 1 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem Description of Module Subject Name Environmental Sciences Paper Name Ecosystem Structures & Functions 30 - Types of Aquatic Ecosystems-I : Freshwater Ecosystem Module Name/Title Module Id EVS/ESF-I/30 Pre-requisites To learn about freshwater aquatic Objectives Limiting Factors, Thermal stratification, aquatic organisms, Lentic systems, Keywords Lotic Water systems, Freshwater Wetlands, 2 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem GLOSSARY Atoll: A coral reef that encircles a lagoon partially or completely, a special kind of fringing Reef. Benthos: All the organisms living on and in the seabed which is known as the ‘benthic zone’. Bioluminescent: An organism that produces its own light. Catchment Area: This refers to an area from which all precipitation flows to a single stream or set of streams. Chemosynthesis: A biological process that involves the use of inorganic substances such as hydrogen sulphide as a source of energy to convert carbon and nutrients into organic matter. Coastal zone: Warm, nutrient-rich, shallow part of the ocean that extends from the high-tide mark on land to the edge of the continental shelf. Continental slope: The seaward border of the continental shelf, where the seabed drops sharply into the deep sea. Crustacean: A group of mostly aquatic animals with hard shells and multiple legs. Crustaceans include crabs, lobsters, shrimps and barnacles. Cultural eutrophication: Accelerated nutrient enrichment of aquatic ecosystems that causes major shifts in plant and animal life. Echinoderms: Living organisms including starfish, sea urchins and sea cucumbers, which are found only in the marine environment? Epilimnion: The warmer part of the lake with small temperature gradient. Epipelagic zone: The lighted area of the ocean up to 200m depth, also called photic zone. Estuaries: where fresh water of rivers meets the salty water of the ocean. Euphotic zone: Upper layer of a body of water through which sunlight can penetrate and support photosynthesis. Eutrophic lake: Lake with a large supply of plant nutrients, mostly nitrates and phosphates. 3 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem Hydrothermal Vents: occur in volcanically active areas of the seafloor like mid-ocean ridges, where tectonic plates are pushing and pulling above magma hotspots in Earth’s crust. Hypolimnion: this refers to the cooler part of the lake. Intertidal zone: The area of the coastline between the levels of low tide and high tide. Limnetic zone: Shallow-water zone of a lake or sea, in which light penetrates to the bottom. Limnology: The study of freshwater bodies and the organisms that live in them. Littoral zone: Shallow water of a lake, in which light penetrates to the bottom Mangroves: Salt-tolerant trees found in the coastal zones of tropical areas. Marsh: It is a type of wetland, where water covers ground for long periods of time, dominated by grasses and other herbaceous plants. Nekton: Strongly swimming organisms found in aquatic systems. Oceanic: The regions of the sea which are located beyond the continental shelf. Oligotrophic Lake: Lake with a low supply of plant nutrients. Open Sea: The part of an ocean that is beyond the continental shelf. Pelagic zone: This refers to the entire ocean water column of the open sea.. Phytoplankton: Small, microscopic plants that drift with the water currents. They live in the upper layers of the aquatic ecosystems and use photosynthesis to produce food. Plankton: Small plant organisms (phytoplankton) and animal organisms (zooplankton) that drift with the water currents in aquatic ecosystems. Profundal zone: This constitutes the deep water zone of lakes with light very low or absent. Only heterotrophic organisms occur in this zone. Seamounts: This refers to undersea mountains formed by volcanic activity rising at least 3,500 ft above the seafloor, most occur in chains at hot spots or along plate boundaries. The bathypelagic zone: this zone reaches to about 4,000m depth of the oceans. 4 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem The neritic zone: This refers to the portion of the world's oceans stretching from the edge of the intertidal zone to approximately the edge of the continental shelf. The Abyssal-Benthic zone: The water at the bottom of the ocean, water is very cold (2oC), > 4000m deep. The epipelagic euphotic zone: It is the sunlit upper layer of the ocean. The mesopelagic zone: This stretches from 200 to about 1,000m depth of oceans. Watershed: Land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river). Zooplankton: Microscopic animal plankton, small floating herbivores that feed on phytoplankton. Zooplankton: Microscopic animals that float with the water currents in aquatic systems. Zooxanthellae: Microscopic algae living within the tissues of reef building warm water corals. 5 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem Interesting facts (i) Lake Baikal in Siberia, Russia is the oldest, largest, and deepest freshwater lake in the world. It contains 20% of the world's total unfrozen freshwater reserve. (ii) Lake Vostok, in Antarctica, is one of the largest subglacial lakes in the world. On top of the lake is an icecap four kilometers thick. The ice actually insulates the water, preventing it from freezing. (iii)The Loktak Lake in Manipur, India is famous for a unique ecosystem called ‘Phumdi’, the floating mats of soil and vegetation. The largest area of the Phumdi in the Loktak lake is in the Keibul Lamjao National Park, which is home to endangered brow-antlered deer,the Sangai. (iv) The Okavango Delta in Botswana is the largest freshwater marsh in the world. It is a unique example of the interaction between climatic, hydrological and biological processes. The Okavango Delta is home to some of the world’s most endangered species of large mammal, such as the cheetah, white rhinoceros, black rhinoceros, African wild dog and lion. (v) Seagrasses are found in shallow salty and brackish waters in many parts of the world, from the tropics to the Arctic Circle except Antarctica. Seagrasses belong to a group of plants called monocotyledons. (vi) The Great Barrier Reef is located on the north-east coast of Australia, contains the world’s largest collection of coral reefs. (vii) Hot springs on the ocean floor are called hydrothermal vents. The heat source for these springs is the magma (molten rock) beneath submarine volcanoes. First seen in 1977, hydrothermal vents occur in volcanically active areas of the seafloor like mid-ocean ridges, where tectonic plates are pushing and pulling above magma hotspots in Earth’s crust. 6 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem A view of Loktak lake at Manipur ( Photo Dr Amrabati Thokchom) 7 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem Fig. 30. 4. (a)A view of Renuka lake located in foothills of Siwaliks in Sirmaur district in western Himalaya ( Photo Dr Balkar Singh ) ; (b) Brahamsarovar Pond At Kurukshetra (Photo Dr SR Gupta) 8 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem A view of Loktak lake at Manipur ( Photo Dr Amrabati Thokchom 9 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem Figure 30. 6. Water stream from The Great Himalayan National Park (GHNP) area in the state of Himachal Pradesh ( Photo Dr Balkar Singh) 10 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem The river Yamuna at Kalesar Forest Reserve ( Photo SR Gupta) 11 Ecosystem Structures & Functions Environmental Sciences Types of Aquatic Ecosystems-I : Freshwater Ecosystem .