The inventory of benthic macroinvertebrate species was carried out in some streams of the Mefou catchment area, from August 2021 to August 2022, in order to determine the biological groups that make up the population ...The inventory of benthic macroinvertebrate species was carried out in some streams of the Mefou catchment area, from August 2021 to August 2022, in order to determine the biological groups that make up the population and characterise these environments. The dataset acquired during this study made it possible to update the existing database and contribute to the knowledge of the biological groups associated in these environments, and to provide additional information on the existing ones in relation to bioindication. Overall 80 families were identified and, on the basis of frequencies of occurrence greater than 75%, 22 families were retained as potential biological indicators. The remarkable diversity of insects and the low abundance of Diptera reflect the low degradation of environments and the good quality of water. The high diversity indices obtained reflect the maintenance of the favourable ecological conditions that favours the development of a balanced and, integrated biological community capable of adapting to changes.展开更多
The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar...The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar Convention as of global importance. It is not only a refuge for birds and wildlife but also has seen the emergence of fishery and tourism since. Understanding of its behavior with respect to the quantitative and qualitative aspects of water resources is important for future use and management, especially for further development of fishery and ecotourism. The factors influencing changes in quantity and quality of ААLS water were studied between 1993 and 2011. Starting from 1993 the water level and water volume of the lake progressively increased. The spatio-temporal distributions of pH, dissolved oxygen, ammonium, nitrite, nitrate, phosphate, chloride, and biochemical oxygen demand (BOD5) during 2003-2005 and 2009-2011 were determined. On the basis of the conducted hydrological and hydro-chemical research fishery development in ААLS is recommended. The question is posed what requirements have to be in met in the future in order to guarantee the prolonged existence of the lake at a suitable water quality.展开更多
With the aim of assessing the benthic macroinvertebrates’ diversity, a study was carried out in some tropical forest streams of the Nyong River catchment in Cameroon from February 2019 to February 2020. A total of 16...With the aim of assessing the benthic macroinvertebrates’ diversity, a study was carried out in some tropical forest streams of the Nyong River catchment in Cameroon from February 2019 to February 2020. A total of 167 samples were carried out from 13 stations during 13 months. Some environmental variables were measured. These parameters varied more or less from station to station but significantly at the temporal level. In this study, 13,690 benthic macroinvertebrates belonging to 4 phyla, 7 classes, 16 orders and 93 families were collected. The benthic macroinvertebrates were more abundant and more diversified in the stations whose waters are well oxygenated and present a moderate current compared to the stations with a very weak current. The diversity varied significantly from 1.33 ± 0.14 bits/ind to 2.00 ± 0.35 bits/ind and the high values were found in stations with multiple substrates and well-oxygenated waters. Temporally, the diversity varied significantly from 1.10 ± 0.16 bits/ind in NM sampling station in February 2020 to 1.87 ± 0.1 bits/ind in the OB sampling station in September. In addition, the settlement was more abundant during the short dry season, more precisely during the month of August (1471 individuals) but richer during the long dry season during the month of February (54 families). The distribution of the abundances of the benthic fauna in the different stations made it possible to identify five typological groups using the rarefaction curves, the ascending hierarchical classification and the principal component analyses. Each of these five groups is characterized by a specific taxonomic richness, composition and abundance.展开更多
文摘The inventory of benthic macroinvertebrate species was carried out in some streams of the Mefou catchment area, from August 2021 to August 2022, in order to determine the biological groups that make up the population and characterise these environments. The dataset acquired during this study made it possible to update the existing database and contribute to the knowledge of the biological groups associated in these environments, and to provide additional information on the existing ones in relation to bioindication. Overall 80 families were identified and, on the basis of frequencies of occurrence greater than 75%, 22 families were retained as potential biological indicators. The remarkable diversity of insects and the low abundance of Diptera reflect the low degradation of environments and the good quality of water. The high diversity indices obtained reflect the maintenance of the favourable ecological conditions that favours the development of a balanced and, integrated biological community capable of adapting to changes.
文摘The Aydar Arnasay Lakes System (AALS) is an artificial lake system which was created in 1969 by diverting flood water from Chardarya reservoir. It has developed into a wetland of 4000 km2 area recognized by the Ramsar Convention as of global importance. It is not only a refuge for birds and wildlife but also has seen the emergence of fishery and tourism since. Understanding of its behavior with respect to the quantitative and qualitative aspects of water resources is important for future use and management, especially for further development of fishery and ecotourism. The factors influencing changes in quantity and quality of ААLS water were studied between 1993 and 2011. Starting from 1993 the water level and water volume of the lake progressively increased. The spatio-temporal distributions of pH, dissolved oxygen, ammonium, nitrite, nitrate, phosphate, chloride, and biochemical oxygen demand (BOD5) during 2003-2005 and 2009-2011 were determined. On the basis of the conducted hydrological and hydro-chemical research fishery development in ААLS is recommended. The question is posed what requirements have to be in met in the future in order to guarantee the prolonged existence of the lake at a suitable water quality.
文摘With the aim of assessing the benthic macroinvertebrates’ diversity, a study was carried out in some tropical forest streams of the Nyong River catchment in Cameroon from February 2019 to February 2020. A total of 167 samples were carried out from 13 stations during 13 months. Some environmental variables were measured. These parameters varied more or less from station to station but significantly at the temporal level. In this study, 13,690 benthic macroinvertebrates belonging to 4 phyla, 7 classes, 16 orders and 93 families were collected. The benthic macroinvertebrates were more abundant and more diversified in the stations whose waters are well oxygenated and present a moderate current compared to the stations with a very weak current. The diversity varied significantly from 1.33 ± 0.14 bits/ind to 2.00 ± 0.35 bits/ind and the high values were found in stations with multiple substrates and well-oxygenated waters. Temporally, the diversity varied significantly from 1.10 ± 0.16 bits/ind in NM sampling station in February 2020 to 1.87 ± 0.1 bits/ind in the OB sampling station in September. In addition, the settlement was more abundant during the short dry season, more precisely during the month of August (1471 individuals) but richer during the long dry season during the month of February (54 families). The distribution of the abundances of the benthic fauna in the different stations made it possible to identify five typological groups using the rarefaction curves, the ascending hierarchical classification and the principal component analyses. Each of these five groups is characterized by a specific taxonomic richness, composition and abundance.
