scholarly journals New data regarding ecology of freshwater pelagic amphipod Macrohectopus branickii and other crustaceans of plankton from the southern part of Lake Baikal

2021 ◽  
Vol 7 ◽  
pp. 39-48
Author(s):  
Dmitry Yu. Karnaukhov ◽  
Ekaterina M. Dolinskaya ◽  
Sofya A. Biritskaya ◽  
Maria A. Teplykh ◽  
Yana K. Ermolaeva ◽  
...  

In this study, we present a list of crustaceans traced in plankton of the southern basin Lake Baikal in addition to some details regarding ecological peculiarities of the only known freshwater pelagic amphipod Macrohectopus branickii. The amphipod is an active predator among major parts of the Lake Baikal food chain. Its role in the lake’s ecosystem is similar to that of Antarctic krill and mysids in Europe and North America water bodies. As an active swimmer, M. branickii performs daily vertical migrations. Besides, the species also has horizontal migrations and migrating swarms, including time during breeding period, that hamper species studies. We were interested in clarify some features of the species ecology. As a material we used samples obtained in the 0 to 250 m water layer with a plankton Juday net every 7 to 10 days from 2013 until 2018 as a part of long-term ecological monitoring project of Lake Baikal pelagial. Sampling was conducted in the southern part of the lake off the shore of Bolshie Koty Village. The results showed the presence of one peak of young during breeding period, which is at its maximum in May. The maximum of the 1 to 6 mm group containing young individuals and males occurs in July, and during the same period, a slight increase in immature females in comparison with the first group can also be seen. This finding might be directly linked to the warming trend in Lake Baikal.

1994 ◽  
Vol 51 (11) ◽  
pp. 2570-2578 ◽  
Author(s):  
T. H. Johengen ◽  
Ora E. Johannsson ◽  
G. Laird Pernie ◽  
E. S. Millard

Results from long-term ecological monitoring studies on Lake Michigan (1983–92) and Lake Ontario (1981–92) were compared with regard to changes in phosphorus loads. In Lake Ontario, total phosphorus (TP) loads decreased from 14 000 t∙yr−1 in 1970 to 7500 t∙yr−1 in 1981, and correspondingly, midlake TP concentration decreased from 25 to 16 μg∙L−1 From 1981 to 1991 TP loads remained around 7500 t∙yr−1; however, TP concentration continued to decline from 16 to 10 μg∙L−1. Similarly, mean summer particulate organic carbon (POC), chlorophyll a (CHLa), and nitrate utilization rate decreased by approximately 40, 20, and 50%, respectively. Conversely, silica utilization rates increased markedly after 1983. In Lake Michigan, TP loads also decreased by around 50% from 1974 to 1990 (2000 t∙yr−1); however, TP concentrations at our 100-m station in the southern basin increased during the study period from around 4 to 8 μg∙L−1 There were no distinct trends in CHLa or nutrient utilization patterns; however, POC levels decreased sharply after 1987. Overall, silica utilization rates in Lake Michigan were 50% higher than in Lake Ontario (14.7 vs. 9.6 μg∙L−1∙d−1), whereas nitrate utilization rates were only half (1.4 vs. 4.1 μg∙L−1∙d−1).


Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 155
Author(s):  
Yan Su ◽  
Ting Liu ◽  
Caiqiao Song ◽  
Aiqiao Fan ◽  
Nan Zhu ◽  
...  

As an essential electrolyte for the human body, the potassium ion (K+) plays many physiological roles in living cells, so the rapid and accurate determination of serum K+ is of great significance. In this work, we developed a solid-contact ion-selective electrode (SC-ISE) using MoS2/Fe3O4 composites as the ion-to-electron transducer to determine serum K+. The potential response measurement of MoS2/Fe3O4/K+-ISE shows a Nernst response by a slope of 55.2 ± 0.1 mV/decade and a low detection limit of 6.3 × 10−6 M. The proposed electrode exhibits outstanding resistance to the interference of O2, CO2, light, and water layer formation. Remarkably, it also presents a high performance in potential reproducibility and long-term stability.


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Lahouari Bounoua ◽  
Kurtis Thome ◽  
Joseph Nigro

Urbanization is a complex land transformation not explicitly resolved within large-scale climate models. Long-term timeseries of high-resolution satellite data are essential to characterize urbanization within land surface models and to assess its contribution to surface temperature changes. The potential for additional surface warming from urbanization-induced land use change is investigated and decoupled from that due to change in climate over the continental US using a decadal timescale. We show that, aggregated over the US, the summer mean urban-induced surface temperature increased by 0.15 °C, with a warming of 0.24 °C in cities built in vegetated areas and a cooling of 0.25 °C in cities built in non-vegetated arid areas. This temperature change is comparable in magnitude to the 0.13 °C/decade global warming trend observed over the last 50 years caused by increased CO2. We also show that the effect of urban-induced change on surface temperature is felt above and beyond that of the CO2 effect. Our results suggest that climate mitigation policies must consider urbanization feedback to put a limit on the worldwide mean temperature increase.


2019 ◽  
Vol 203 ◽  
pp. 56-67 ◽  
Author(s):  
Zhiguo Rao ◽  
Chao Huang ◽  
Luhua Xie ◽  
Fuxi Shi ◽  
Yan Zhao ◽  
...  

Author(s):  
Vanessa Tobias ◽  

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are the result of changing water clarity affecting catchability.


2003 ◽  
Vol 154 (6) ◽  
pp. 219-225
Author(s):  
Stepan Stoyko ◽  
Ivan Delehan ◽  
Nino Kuhn ◽  
Vasyl Lavnyy

Professor Alois Zlatnik (born 1902 in Dvur Kralovy, Czechoslovakia,died 1979 in Brno) was a well-known scientific researcher in the Czech Republic, Slovakia and other European countries. His academic career encompassed forest typology,phytobiocoenology, vegetation ecology and plant taxonomy. His fundamental exploration of the biocoenological structure of the virgin forests of Transcarpathia (Ukraine) commenced in the 1930s. At the same time he can be seen as the founder of long-term forest ecosystem research (ecological monitoring). Zlatnik was also an innovator regarding ecological principles of nature conservation of mountain regions.


Author(s):  
Vanessa Tobias

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.


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