Lake Toba is a large natural lake in North Sumatra, Indonesia, occupying the caldera of a supervolcano. The lake is located in the middle of the northern part of the island of Sumatra, with a surface elevation of about 900 metres (2,953 ft), the lake stretches from 2.88°N 98.52°E to 2.35°N 99.1°E. The lake is about 100 kilometres long, 30 kilometres (19 mi) wide, and up to 505 metres (1,657 ft) deep. It is the largest lake in Indonesia and the largest volcanic lake in the world. Toba Caldera is one of twenty geoparks in Indonesia, and was recognised in July 2020 as one of the UNESCO Global Geoparks.
Plankton are the diverse collection of organisms found in water that are unable to propel themselves against a current. The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales.
Zooplankton are the animal component of the planktonic community, having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequently, they drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers.
Tonlé Sap is a lake in the northwest of Cambodia. Belonging to the Mekong River system, Tonlé is the largest freshwater lake in Southeast Asia and one of the most diverse and productive ecosystems in the world. It has been designated as a Biosphere Reserve by UNESCO in 1997 due to its high biodiversity. In the 21st century, the lake and its surrounding ecosystems are under increasing pressure from deforestation, infrastructure development and climate change.
Lake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, the western branch of the East African Rift. Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika. In 1894, German explorer and officer Gustav Adolf von Götzen was the first European to discover the lake.
The Narmada River, previously also known as Narbada or anglicised as Nerbudda, is the 5th longest river in India and overall the longest west-flowing river in the country. It is also the largest flowing river in the state of Madhya Pradesh. This river flows through the states of Madhya Pradesh and Gujarat in India. It is also known as the "Lifeline of Madhya Pradesh and Gujarat" due to its huge contribution to the two states in many ways. The Narmada River rises from the Amarkantak Plateau in Anuppur district in Madhya Pradesh. It forms the traditional boundary between North and South India and flows westwards for 1,312 km (815.2 mi) before draining through the Gulf of Khambhat into the Arabian Sea, 30 km (18.6 mi) west of Bharuch city of Gujarat.
Ashtamudi Lake, in the Kollam District of the Indian state of Kerala. It possesses a unique wetland ecosystem and a large palm-shaped water body, second only in size to the Vembanad estuary ecosystem of the state. Ashtamudi means 'eight hills or peaks' in the local Malayalam language. The name is indicative of the lake's topography with its multiple branches. The lake is also called the gateway to the backwaters of Kerala and is well known for its houseboat and backwater resorts. Ashtamudi Wetland was included in the list of wetlands of international importance, as defined by the Ramsar Convention for the conservation and sustainable utilization of wetlands.
Lake Khanka or Lake Xingkai, is a freshwater lake on the border between Primorsky Krai, Russia and Heilongjiang province, Northeast China.
A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems, which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two ecosystems are examples of freshwater ecosystems.
Hirakud Dam is built across the Mahanadi River, about 10 kilometres (6.2 mi) from Sambalpur in the state of Odisha in India. It is the longest earthen dam in the world. Behind the dam extends a lake, Hirakud Reservoir, 55 km (34 mi) long. It is one of the first major multipurpose river valley projects started after India's independence. Hirakud Reservoir was declared a Ramsar site on 12 October 2021.
Ujjani Dam, also known as Bhima Dam or Bhima Irrigation Project, on the Bhima River, a tributary of the Krishna River, is an earthfill cum Masonry gravity dam located near Ujjani village of Madha Taluk in Solapur district of the state of Maharashtra in India.
Fateh Sagar Lake is situated in the city of Udaipur in the Indian state of Rajasthan. It is an artificial lake named after Maharana Fateh Singh of Udaipur and Mewar, constructed north-west of Udaipur, to the north of Lake Pichola in the 1680s.
Refugio Carapá is a biological reserve in the Department of Canindeyú, Paraguay, on the right bank of the Paraná River. It is one of eight sites earmarked as an ecological reserve near the Itaipu Dam, one of the largest dams in the world, located between Paraguay and Brazil. The reserve is 260 km (160 mi) north of the Ciudad del Este. It was founded in 1984 and is 3,250 hectares.
The Continuous Plankton Recorder (CPR) Survey is one of the longest running marine biological monitoring programmes in the world. Started in 1931 by Sir Alister Hardy and Sir Cyril Lucas, the Survey provides marine scientists and policy-makers with measures of plankton communities, coupled with ocean physical, biological and chemical observations, on a pan-oceanic scale. The Survey is a globally recognised leader on the impacts of environmental change on the health of our oceans.
Forage fish, also called prey fish or bait fish, are small pelagic fish that feed on plankton and other tiny organisms. They are preyed on by larger predators, including larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
Berijam Lake is a reservoir near Kodaikanal town in Dindigul district of Tamil Nadu, South India. It is at the old site of "Fort Hamilton", in the upper Palani hills. The lake, created by a dam with sluice outlets, is part of a micro–watershed development project. Periyakulam town, 18.7 kilometres (11.6 mi) to the SE, gets its public drinking water from the lake. The lake's water quality is excellent.
The Bhadra Dam or Lakkavalli Dam, which has created the Bhadra Reservoir, is located on the Bhadra River a tributary of Tungabhadra River. Bhadra Dam is located in the border of Bhadravathi and Tarikere, in the western part of Karnataka in India. The benefits derived from the reservoir storage are irrigation with gross irrigation potential of 162,818 hectares, hydro power generation of 39.2 MW, drinking water supply and industrial use. The dam commissioned in 1965 is a composite earth cum masonry structure of 59.13 metres (194.0 ft) height with length of 1,708 metres (5,604 ft) at the crest level, which submerges a land area of 11,250.88 hectares.
A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and in the past billion years; basking sharks and copepods are just two examples of giant and microscopic organisms that feed upon plankton.
Mycoplankton are saprotrophic members of the plankton communities of marine and freshwater ecosystems. They are composed of filamentous free-living fungi and yeasts that are associated with planktonic particles or phytoplankton. Similar to bacterioplankton, these aquatic fungi play a significant role in heterotrophicmineralization and nutrient cycling. Mycoplankton can be up to 20 mm in diameter and over 50 mm in length.
Compared to terrestrial environments, marine environments have biomass pyramids which are inverted at the base. In particular, the biomass of consumers is larger than the biomass of primary producers. This happens because the ocean's primary producers are tiny phytoplankton which grow and reproduce rapidly, so a small mass can have a fast rate of primary production. In contrast, many significant terrestrial primary producers, such as mature forests, grow and reproduce slowly, so a much larger mass is needed to achieve the same rate of primary production.
