Impact of Climate Variability and Anthropogenic Activities on Zooplankton Community in the neritic Waters of Alexandria, Egypt.

2014 ◽  
Vol 25 (2) ◽  
Author(s):  
Howaida Zakaria
2021 ◽  
Vol 14 (7) ◽  
Author(s):  
Ahmed M. Heneash ◽  
Ahmed E. Alprol ◽  
Hazem T. Abd El-Hamid ◽  
Mohamed Khater ◽  
Khaled A. El Damhogy

2015 ◽  
Vol 46 (6) ◽  
pp. 1019-1036 ◽  
Author(s):  
Ye Zhu ◽  
Wen Wang ◽  
Yi Liu ◽  
Hongjie Wang

The impacts of climate variability and anthropogenic activities on hydrological processes have been of wide concern in the hydrology community during recent decades. In this study, specific investigations of individual impacts of climate variability and anthropogenic activities on runoff during 1964–2010 are conducted for the upper Huaihe River Basin at Huaibin (HB) and its five sub-catchments. The non-stationary relationship between precipitation and runoff was firstly analyzed, and according to change point detection results, long-term series for each catchment was divided into pre-change period and post-change period, respectively. Then, the climate variability and human activities that occurred in the whole HB catchment were analyzed. Finally, using two quantitative evaluation methods, the individual impacts of climate variability and human activities for each catchment were assessed. The results showed that for the whole HB catchment, runoff changes during the whole post-change period are mainly attributed to climate variability, as for its sub-catchments except the Xinxian catchment. As for decadal behaviors, runoff generally suffered more human-induced impacts in dry decades (1990s) than wet decades (1980s and 2000s). These results reflected the complex role of climate variability and human activities in influencing the runoff regime, which could be considered in local water resources management.


2020 ◽  
Author(s):  
Marie Harbott ◽  
Henry C. Wu ◽  
Henning Kuhnert ◽  
Simone A. Kasemann ◽  
Carlos Jimenez ◽  
...  

<p>Ocean warming and ocean acidification (OA) are increasingly influencing marine life. Parts of the increasing amount of CO<sub>2</sub> in the atmosphere will eventually get absorbed by the ocean, which changes the oceans carbonate chemistry and threatens the ecological competitiveness of calcareous marine organisms. Currently,  the global coverage of studies on the development of pH since preindustrial times is sparse. An important region to study environmental and climate variations is the northwestern coastal part of Cuba where the Loop Current (LC) joins the Florida Current and contributes to the Gulf Stream. The tropical Atlantic is a primary region for the formation of warm surface water of the thermohaline ocean circulation and the Caribbean in particular as a habitat for coral reefs in the Atlantic making them susceptible to changes in water temperatures and carbonate chemistry. This provides a unique chance to study multiple aspects of the implications of anthropogenic activities such as changes in SST, ocean pH, and carbonate chemistry using the coral skeletal geochemistry as an archive of climate and environmental changes. Here we present results from a multi-proxy approach for the reconstruction of environmental change and natural climate variability from a North Cuban Siderastrea siderea coral. The sub-seasonally resolved records indicate interannual to decadal changes in SST and seawater carbonate chemistry since 1830 CE. The comparison with pH will provide clues on whether the regional climate variability has been directly affected by atmospheric CO<sub>2</sub> forcing.</p>


2016 ◽  
Vol 48 (2) ◽  
pp. 416-430 ◽  
Author(s):  
Abubaker Omer ◽  
Weiguang Wang ◽  
Amir K. Basheer ◽  
Bin Yong

Understanding the linear and nonlinear responses of runoff to environmental change is crucial to optimally manage water resources in river basins. This study proposes a generic framework-based hydrological model (Soil and Water Assessment Tool (SWAT)) and two approaches, to comprehensively assess the impacts of anthropogenic activities and climate variability on runoff over the representative Hutuo River Basin (HRB), China. Results showed that SWAT performed well in capturing the runoff trend in HRB; however, it exhibited better performance for the calibration period than for the validation. During 1961–2000, about 26.06% of the catchment area was changed, mainly from forest to farmland and urban, and the climate changed to warmer and drier. The integrated effects of the anthropogenic activities and climate variability decreased annual runoff in HRB by 96.6 mm. Direct human activities were responsible for 52.16% of runoff reduction. Climate (land use) decreased runoff by 45.30% (2.06%), whereas the combined (land use + climate) impact resulted in more runoff decrease, by 47.84%. Land use–climate interactive effect is inherent in HRB and decreased runoff by 1.02%. The proposed framework can be applied to improve the current understanding of runoff variation in river basins, for supporting sustainable water resources management strategies.


Omni-Akuatika ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 151
Author(s):  
Udeme Effiong Jonah ◽  
Emeka Donald Anyanwu ◽  
Diane Akudo Avoaja

Estuaries are influenced by the mixture of river water with seawater; creating unique ecosystems with several physical and chemical processes affecting the water quality. Spatial and temporal assessment of the composition, abundance, and distribution of zooplankton fauna of Uta Ewa Estuarine water system was carried out between May 2019 and February 2020 to assess the effects of anthropogenic activities on the zooplankton assemblage. Water and Zooplankton samples were collected from three (3) stations using standard procedures. Some parameters like water temperature, dissolved oxygen, hydrogen-ion, electrical conductivity, and turbidity were determined in-situ. The ranges of the physico-chemical parameters were: water temperature (24.9-25.3oC), EC (62.3-70.9mS/m), pH (6.5-6.7), turbidity (12.0-28.0NTU), DO (3.8-4.7mg/L), BOD (2.3-3.2mg/L), phosphate (3.2-5.2mg/L), and nitrate (3.0-6.3mg/L). ANOVA showed a significant difference (p<0.05) in the spatial and temporal means values of some parameters. A total of 1,067 individuals from 30 zooplankton taxa and 4 taxonomic groups were recorded. Rotifers (33.4%) were the dominant group, followed by protozoa (32.9%), copepods (20.9%) and cladocerans (13.8%). Station 1 had the highest abundance (388 individuals), station 2 (303 individuals) and station 3(375 individuals). The higher number of individuals (193) was recorded in August 2019. The biodiversity indices pointed to slightly polluted to stable environment. This study showed that the water quality and zooplankton community was influenced by anthropogenic activities both spatially and temporally but season also played a major role in the temporal variation. In conclusion, the water quality was deteriorating due to anthropogenic activities, which in turn affected the structure of zooplankton community. Keywords: Abundance, Assessment, Zooplankton, Physicochemical, Estuary


2021 ◽  
pp. 1186-1194
Author(s):  
E.D. Anyanwu ◽  
◽  
O.G. Adetunji ◽  
S.N. Umeham ◽  
◽  
...  

Abstract. Aquatic ecosystems and biota are often adversely affected by anthropogenic activities. Consequently, zooplanktons have been used to monitor anthropogenic impacts because of their sensitivity to their environment. Water quality and zooplankton community of the Eme River, Umuahia, was assessed between December 2017 and November 2018. The study was carried out in six stations in relation to human activities. Human activities in the watershed were dominated by sand mining. A quantitative filtration method was used for the zooplankton sample collection while standard sample collection and analytical methods were used for the water samples. The zooplankton species recorded were 27 while the most abundant zooplankton group was Rotifera. A known pollution indicator, Daphnia pulex, had the highest number of individuals. The effects of human activities in the watershed were reflected in the results of some of the physicochemical parameters of the river. The zooplankton assemblage and community structure also reflected the effects of human activities in the river. Combined effects of human activities and season contributed to the relatively low zooplankton abundance recorded particularly in some downstream stations. The impacts of sand mining on water quality and zooplankton were more remarkable in the downstream stations (4 6) where the activity was intense while a large number of children swimming and related activities during the dry season had some impacts in station 1. The dominance of indicator and tolerant species indicated that the river was undergoing eutrophication. Sand mining among other observed anthropogenic activities was a major contributor to the nutrient enrichment in the river. The major water quality parameters influencing the zooplankton community structure was revealed by canonical correspondence analysis.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 123
Author(s):  
Na Yao ◽  
Bing Feng ◽  
Meng Zhang ◽  
Liang He ◽  
Huan Zhang ◽  
...  

Industrial activity, dam construction, and agriculture—while important for socioeconomic progress—can severely damage the natural environment. To evaluate the effects of these human activities on the bio-integrity of riverine ecosystems, we examined the Wanan reach of the Ganjiang River (Wanan River basin), which contains the river’s largest reservoir. On the basis of 20 attributes of zooplankton, we constructed a zooplankton index of bio-integrity (Z-IBI) evaluation system using range analysis, discriminant analysis, and correlation analysis. Our research found that these anthropogenic activities can greatly change the composition and number of zooplankton community. The overall health status of this catchment was classified as “good”, and the eco-health situation of the reference, industrial, dam-controlled and agricultural sites were deemed “healthy”, “fair”, “good”, and “fair”, respectively. Our results suggested that the three activities adversely affected the integrity of local aquatic ecosystems. Agriculture was the activity most detrimental to the zooplankton community, followed by industrial production and dam construction. Therefore, we demonstrated that the Z-IBI evaluation system can be applied to reservoir–riverine ecosystems. We also provide guidance on the ecological protection, assessment, monitoring and of reservoir–riverine ecosystems and suggest that additional Z-IBI evaluation approaches be further developed in the future.


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