Yakutian char | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Salmoniformes |
Family: | Salmonidae |
Genus: | Salvelinus |
Species: | S. jacuticus |
Binomial name | |
Salvelinus jacuticus Borisov, 1935 | |
Salvelinus jacuticus, commonly known as Yakutian char, is a species of freshwater fish in the salmon family. It is endemic to the mountain lakes in the Lena Delta, Russia. [1] It was reported that the population of the species declined due to overfishing and the rise of temperature in the arctic region. [2]
Yakutian char feed on the larvae and pupae of chironomid flies. [3] The species may grow to a recorded length of 20cm (7.9 inches). The fish usually have a long dark grey body with orange spots on the sides. The species is benthopelagic, residing at or near the bottom of the lake. [4]
Russia, or the Russian Federation, is a country spanning Eastern Europe and Northern Asia. It is the largest country in the world by area extending across eleven time zones. It shares land boundaries with fourteen countries. It is the world's ninth-most populous country and Europe's most populous country. The country's capital and largest city is Moscow. Saint Petersburg is Russia's second-largest city and "cultural capital". Other major urban areas in the country include Novosibirsk, Yekaterinburg, Nizhny Novgorod, Chelyabinsk, Krasnoyarsk, Kazan, Krasnodar and Rostov-on-Don.
The 1770s was a decade of the Gregorian calendar that began on January 1, 1770, and ended on December 31, 1779. A period full of discoveries, breakthroughs happened in all walks of life, as what emerged at this period brought life to most innovations we know today.
The white-tailed eagle, sometimes known as the 'sea eagle', is a very large bird of prey, widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae which includes other diurnal raptors such as hawks, kites, and harriers. One of up to eleven members in the genus Haliaeetus, which are commonly called sea eagles, it is also referred to as the white-tailed sea-eagle. Sometimes, it is known as the ern or erne, gray sea eagle and Eurasian sea eagle.
The Deutscher Jugendliteraturpreis is an annual award established in 1956 by the Federal Ministry of Family Affairs, Senior Citizens, Women and Youth to recognise outstanding works of children's and young adult literature. It is Germany's only state-funded literary award. In the past, authors from many countries have been recognised, including non-German speakers.
There are numerous effects of climate change on agriculture, many of which are making it harder for agricultural activities to provide global food security. Rising temperatures and changing weather patterns often result in lower crop yields due to water scarcity caused by drought, heat waves and flooding. These effects of climate change can also increase the currently-rare risk of several regions suffering simultaneous crop failures, which would have significant consequences for the global food supply. Many pests and plant diseases are also expected to either become more prevalent or to spread to new regions. The world's livestock are also expected to be affected by many of the same issues, from greater heat stress to animal feed shortfalls and the spread of parasites and vector-borne diseases.
Woody plant encroachment is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause biome shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Bush encroachment is often considered an ecological regime shift and can be a symptom of land degradation. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally.
The African humid period is a climate period in Africa during the late Pleistocene and Holocene geologic epochs, when northern Africa was wetter than today. The covering of much of the Sahara desert by grasses, trees and lakes was caused by changes in the Earth's axial tilt; changes in vegetation and dust in the Sahara which strengthened the African monsoon; and increased greenhouse gases. During the preceding Last Glacial Maximum, the Sahara contained extensive dune fields and was mostly uninhabited. It was much larger than today, and its lakes and rivers such as Lake Victoria and the White Nile were either dry or at low levels. The humid period began about 14,600–14,500 years ago at the end of Heinrich event 1, simultaneously to the Bølling–Allerød warming. Rivers and lakes such as Lake Chad formed or expanded, glaciers grew on Mount Kilimanjaro and the Sahara retreated. Two major dry fluctuations occurred; during the Younger Dryas and the short 8.2 kiloyear event. The African humid period ended 6,000–5,000 years ago during the Piora Oscillation cold period. While some evidence points to an end 5,500 years ago, in the Sahel, Arabia and East Africa, the end of the period appears to have taken place in several steps, such as the 4.2-kiloyear event.
This is a list of several significant scientific events that occurred or were scheduled to occur in 2021.
Retrogressive thaw slumps (RTS), are a type of landslide that occur in the terrestrial Arctic's permafrost region of the circumpolar Northern Hemisphere when an ice-rich section thaws. RTSs develop quickly and can extend across several hectares modifying Arctic coastlines and permafrost terrain. They are the most active and dynamic feature of thermokarst—the collapse of the land surface as ground ice melts. They are thermokarst slope failures due to abrupt thawing of ice-rich permafrost or glaciated terrains. These horseshoe-shaped landslides contribute to the thawing of hectares of permafrost annually and are considered to be one of the most active and dynamic features of thermokarst—the "processes and landforms that involve collapse of the land surface as a result of the melting of ground ice." They are found in permafrost or glaciated regions of the Northern Hemisphere—the Tibetan Plateau, Siberia, from the Himalayas to northern Greenland, and in northern Canada's Northwest Territories (NWT), the Yukon Territories, Nunavut, and Nunavik and in the American state of Alaska. The largest RTS in the world is in Siberia—the Batagaika Crater, also called a "megaslump", is one-kilometre-long and 100 metres (330 ft) deep and it grows a 100 feet (30 m) annually. The land began to sink, and the Batagaika Crater began to form in the 1960s, following clear-cutting of a section of forested area.
The following scientific events occurred or were scheduled to occur in 2023.