scholarly journals The reasons of genetic heterogeneity of Siberian whitefish Coregonus lavaretus pidschian in the Anabar river

2017 ◽  
Vol 15 (3) ◽  
pp. 20-26
Author(s):  
Dmitry S. Sendek ◽  
Eugenie V. Ivanov

Background. A population genetic study of Siberian whitefish or pidschian Coregonus lavaretus pidschian Gmelin of the Anabar River (North-West Yakutia) has been done to study genetic structure of the species within a river system and for revealing its phylogeographic relations. Materials and Methods. Five samples of pidschian from different parts of the river were analyzed for 30 isozyme loci. Results and Discussion. The results has demonstrated a significant genetic heterogeneity of the species sampled from lower and middle reaches of the river (0.001 < DN< 0.056). The most likely reason for genetic differentiation of the species within the river system is a colonization of the watershed by independent phylogenetic lineages of whitefish. At present the phylogenetic lineages in Anabar River are presented by sympatric ecological forms of the species – eastern-siberian whitefish and glacial-plains whitefish – which maintain their reproductive isolation. The relationships of ecological forms of whitefish dwelling the Anabar River with other populations of the species in Siberia, and possible ways of penetration of discrete phylogenetic lineages of pidschian in the basin of studied river are discussed. Conclusions. A genetic heterogeneity of whitefish from Anabar River should be taken into account while creating adequate intraspecific taxonomy and considered in conducting fisheries and environmental measures.

2018 ◽  
Vol 54 (9) ◽  
pp. 1078-1088
Author(s):  
N. A. Bochkarev ◽  
E. I. Zuykova ◽  
L. A. Pestryakova ◽  
E. S. Zakharov ◽  
V. I. Romanov ◽  
...  

1989 ◽  
Vol 21 (12) ◽  
pp. 1793-1796
Author(s):  
C. P. Crockett ◽  
R. W. Crabtree ◽  
H. R. Markland

The detrimental influence of storm sewer overflows on urban river quality has been widely recognised for many years. One objective of the WRc River Basin Management programme is the development of a river impact model capable of predicting the transient quality changes in receiving waters due to intermittent storm sewage discharges. The production of SPRAT (Spill Pollution Response Assessment Technique) is the first step in the development of such a model. SPRAT incorporates a number of significant simplifications, most notably plug flow and instantaneous mixing, and does not implicitly take into account the effects of dispersion. These simplifications reflect the large errors associated with the model inputs. These errors severely limit the potential accuracy of any river impact model. The model has been applied to the Bolton river system in North West England. The development and application of SPRAT has enabled the requirements for a more sophisticated river quality impact model to be clearly defined, in addition to highlighting the problems associated with gathering suitable data with which to build and calibrate such a model.


2013 ◽  
Vol 7 (42) ◽  
pp. 4940-4948 ◽  
Author(s):  
Margaret Awah TITA ◽  
Alice MAGHA ◽  
KABEYENE Veacute ronique Beyala KAMGANG

2018 ◽  
Vol 45 (1) ◽  
pp. 43-58
Author(s):  
Derek H.C. Wilton

In 1893–1894, Albert Peter Low of the Geological Survey of Canada, along with D.I.V. Eaton and four indigenous assistants explored the Labrador Peninsula, then perceived as one of the last great unexplored wilderness areas of North America. The expedition left Lake St. John (now Lac St. Jean) on June 17, 1893, canoeing across the northeastern edge of the North American continent, arriving at Fort Chimo (now Kuujjuaq) on August 27, 1893. They departed Fort Chimo by steamer for Rigolet on the Labrador coast and the Hudson Bay Company post at North West River in the fall of 1893. On March 6, 1894 the party started up the Grand (now Churchill) River continuing through large central lakes into the Ashuanipi river system in western Labrador, then out via the Attikonak River to the Romaine River and finally the Saint Jean river system to arrive at Mingan on the north shore of the St. Lawrence River on August 23, 1894. Low described their fifteen-month journey as having covered over 8700 km including 1600 km on foot, over 4700 km in canoe, 800 km by dog team and 1600 km by steamer. The report from the expedition provides a compendium on the natural history of the region as well as the first geological maps. In terms of economic and scientific results, the greatest was documentation of the vast iron ore deposits of western Labrador; a world-class mining district that has been producing for sixty-three years since 1954. Low’s account also provides details on the essence of such an epic journey, which stands as a classic in the annals of Canadian geological surveying.RÉSUMÉEn 1893–1894, Albert Peter Low de la Commission géologique du Canada, accompagné du D.I.V. Eaton et quatre assistants autochtones ont exploré la péninsule du Labrador, alors perçue comme l'une des dernières grandes étendues sauvages inexplorées d’Amérique du Nord. L’équipe a quitté le Lake St. John (aujourd'hui le lac Saint-Jean) le 17 juin 1893, a traversé la bordure nord-est du continent nord-américain en canoë, et est arrivé à Fort Chimo (aujourd'hui Kuujjuaq) le 27 août 1893. À l'automne de 1893, ils ont quitté Fort Chimo à bord d'un vapeur pour Rigolet, sur la côte du Labrador, et le poste de la Compagnie de la Baie d'Hudson sur la rivière North West. Le 6 mars 1894, les membres de l'équipe ont remonté la rivière Grand (aujourd'hui Churchill), puis à travers les grands lacs centraux jusqu'au bassin de la rivière Ashuanipi, dans l'ouest du Labrador, puis, par la rivière Attikonak jusqu' à la rivière Romaine et, enfin, le réseau de la rivière Saint-Jean jusqu’à Mingan, sur la rive nord du fleuve Saint-Laurent, le 23 août 1894. L’excursion décrite par Low a duré quinze mois et parcouru plus de 8700 km dont 1600 km à pied, plus de 4700 km en canoë, 800 km en attelage de chiens et 1600 km en bateau à vapeur. Le rapport de l'expédition constitue un recueil sur l'histoire naturelle de la région ainsi que des premières cartes géologiques. En ce qui concerne les répercussions économiques et scientifiques, la plus importante en a été la documentation des vastes gisements de minerai de fer de l'ouest du Labrador, un district minier de classe mondiale, en production pendant soixante-trois ans depuis 1954. Le récit de Low fournit également des détails sur le caractère épique d’une telle expédition, laquelle est un classique dans les annales de la Commission géologique du Canada.


Author(s):  
K. Petrov ◽  

The desertification of the North-Western Caspian plain controlled by the arid and humid rhythms of climate, nature landscapes Sarpinsky lowland and the Black lands, intensity of human activities. Trends in desertification are detected by monitoring the state of vegetation, lands and irrigation systems. It has been established that productivity and species diversity of natural vegetation must be strict regulation of pasture load, agriculture should be carried out with the use of modern farming practices, socio-economic development of the territory should regulate the system of environmental measures.


Sign in / Sign up

Export Citation Format

Share Document