All Cameroonian estuarine systems, like the Kienke estuarine system (urban area of the port city of Kribi), are considered, as everywhere in the world, as unstable and vulnerable coastal ecosystems insofar as they are...All Cameroonian estuarine systems, like the Kienke estuarine system (urban area of the port city of Kribi), are considered, as everywhere in the world, as unstable and vulnerable coastal ecosystems insofar as they are influenced by anthropogenic activities (port facilities, industrial facilities), without forgetting climate change. The present work was initiated in order to assess the influence of the seasonal evolution of physico-chemical parameters on the dynamics of zooplankton in the estuarine system of the Kienke. A study to assess the influence of seasonal evolution of some physico-chemical parameters on Zooplankton population dynamics was conducted from June 2016 to August 2017 in the Kienke estuarine system (Kribi, South Cameroon Region). Samples were collected in five (05) sampling points at the lower stream, at the confluence and then at 100 meters from the bank at sea following a monthly frequency. The Kienke estuary was characterized by spatio-temporal variations of physico-chemical parameters. These parameters are high temperature, relatively high electrical conductivity and salinity, and a relatively basic hydrogen potential (pH). Nutrients (ammonia nitrogen, nitrates and orthophosphates) were relatively low in the Kienke estuary. The organic pollution index (OPI) indicated moderate to high water pollution. At the surface and at depth, during the long dry season (December to February), Zooplankton densities were very low in the Kienke estuarine system. But rather high during the main rainy season (August to October). The results show that 105 species of Zooplankton belonging to 46 families grouped into four orders were identified. At the surface, 52 species of Zooplankton belonging to 23 families and 4 orders were identified, while at depth, 53 species of Zooplankton belonging to 23 families were also identified. The most abundant group was the Copepods represented by the following species: <em>Tropocyclops confinis </em>Kiefer, 1930;<em>Mesocyclops </em>sp. Sars, 1914;<em>Macrocyclops</em> sp. Claus, 1893;<em>Thermocyclops</em> sp. Kiefer, 1929;<em>Parvocalaus elegans </em>Adronov, 1972 and <em>Clausocalanus</em> sp. Giesbrecht, 1888. Overall, there was a predominance of microcrustaceans (Cladocera and Copepoda) over rotifers. The results obtained in this work will be of capital importance for the elaboration of sustainable management policies for the estuary of the city of Kribi.展开更多
The aim of this study was to highlight the effect of tide on the variation of the physicochemical parameter in the Kienké estuary. Six (06) environmental variables were monitored at nine (09) stations with the ti...The aim of this study was to highlight the effect of tide on the variation of the physicochemical parameter in the Kienké estuary. Six (06) environmental variables were monitored at nine (09) stations with the time step of one hour from 7 am to 7 pm on 4th</sup> August 2019. The hovmuller analysis showed that salinity, conductivity, total dissolved solids, and pH values increased during the flood phase and decreased during the ebb phase while oxygen concentration decreased during the flood and increased during the ebb phase. The stratification parameter has shown that the influx of seawater during high tide shifts the Kienké estuary from a well-mixed to a partially mixed environment.展开更多
文摘All Cameroonian estuarine systems, like the Kienke estuarine system (urban area of the port city of Kribi), are considered, as everywhere in the world, as unstable and vulnerable coastal ecosystems insofar as they are influenced by anthropogenic activities (port facilities, industrial facilities), without forgetting climate change. The present work was initiated in order to assess the influence of the seasonal evolution of physico-chemical parameters on the dynamics of zooplankton in the estuarine system of the Kienke. A study to assess the influence of seasonal evolution of some physico-chemical parameters on Zooplankton population dynamics was conducted from June 2016 to August 2017 in the Kienke estuarine system (Kribi, South Cameroon Region). Samples were collected in five (05) sampling points at the lower stream, at the confluence and then at 100 meters from the bank at sea following a monthly frequency. The Kienke estuary was characterized by spatio-temporal variations of physico-chemical parameters. These parameters are high temperature, relatively high electrical conductivity and salinity, and a relatively basic hydrogen potential (pH). Nutrients (ammonia nitrogen, nitrates and orthophosphates) were relatively low in the Kienke estuary. The organic pollution index (OPI) indicated moderate to high water pollution. At the surface and at depth, during the long dry season (December to February), Zooplankton densities were very low in the Kienke estuarine system. But rather high during the main rainy season (August to October). The results show that 105 species of Zooplankton belonging to 46 families grouped into four orders were identified. At the surface, 52 species of Zooplankton belonging to 23 families and 4 orders were identified, while at depth, 53 species of Zooplankton belonging to 23 families were also identified. The most abundant group was the Copepods represented by the following species: <em>Tropocyclops confinis </em>Kiefer, 1930;<em>Mesocyclops </em>sp. Sars, 1914;<em>Macrocyclops</em> sp. Claus, 1893;<em>Thermocyclops</em> sp. Kiefer, 1929;<em>Parvocalaus elegans </em>Adronov, 1972 and <em>Clausocalanus</em> sp. Giesbrecht, 1888. Overall, there was a predominance of microcrustaceans (Cladocera and Copepoda) over rotifers. The results obtained in this work will be of capital importance for the elaboration of sustainable management policies for the estuary of the city of Kribi.
文摘The aim of this study was to highlight the effect of tide on the variation of the physicochemical parameter in the Kienké estuary. Six (06) environmental variables were monitored at nine (09) stations with the time step of one hour from 7 am to 7 pm on 4th</sup> August 2019. The hovmuller analysis showed that salinity, conductivity, total dissolved solids, and pH values increased during the flood phase and decreased during the ebb phase while oxygen concentration decreased during the flood and increased during the ebb phase. The stratification parameter has shown that the influx of seawater during high tide shifts the Kienké estuary from a well-mixed to a partially mixed environment.
