Phytoplankton is all cyanobacteria and microalgae (microscopic plants) present in surface water that may be carried by water currents. The study was conducted at two oceanic sites Mehdia and Moulay Bousselham, Rabat s...Phytoplankton is all cyanobacteria and microalgae (microscopic plants) present in surface water that may be carried by water currents. The study was conducted at two oceanic sites Mehdia and Moulay Bousselham, Rabat sale Kenitra region, Morocco, between 2017 and 2018. The objective of this study is to compare the spatiotemporal evolution of certain toxic planktonic species between the two sites. The planktonic species identified all have toxic potency but to varying degrees such as Alexandrium, Dinophysis, Gymnodinum, Pseudonitzschia and Proocentrum. The comparison of the abundance of these taxa in the two sites confirms that the Moulay Bousselham site is characterized by the presence of the most toxic planktonic species represented mainly by Pseudonitzschia in contrast the Mehdia site experienced an abundance of the Proocentrum kind. This situation requires a more detailed study of the essential causes of the proliferation of these species.展开更多
A non-autonomous allelopathic phytoplankton model with feedback controls is considered in this paper. By constructing some suitable Lyapunov type extinction functions, some sufficient conditions for the extinction of ...A non-autonomous allelopathic phytoplankton model with feedback controls is considered in this paper. By constructing some suitable Lyapunov type extinction functions, some sufficient conditions for the extinction of the system are obtained. For the autonomous case, by constructing a suitable Lyapunov function, we show that one species is extinct and the rest species is globally attractive. Our results supplement some known results.展开更多
文摘Phytoplankton is all cyanobacteria and microalgae (microscopic plants) present in surface water that may be carried by water currents. The study was conducted at two oceanic sites Mehdia and Moulay Bousselham, Rabat sale Kenitra region, Morocco, between 2017 and 2018. The objective of this study is to compare the spatiotemporal evolution of certain toxic planktonic species between the two sites. The planktonic species identified all have toxic potency but to varying degrees such as Alexandrium, Dinophysis, Gymnodinum, Pseudonitzschia and Proocentrum. The comparison of the abundance of these taxa in the two sites confirms that the Moulay Bousselham site is characterized by the presence of the most toxic planktonic species represented mainly by Pseudonitzschia in contrast the Mehdia site experienced an abundance of the Proocentrum kind. This situation requires a more detailed study of the essential causes of the proliferation of these species.
基金supported by the Natural Science Foundation of Fujian Province(2011J010007,2013J01011,2013J01010)the Foundation of Fujian Education Bureau(JA12051,JA13361)
文摘A non-autonomous allelopathic phytoplankton model with feedback controls is considered in this paper. By constructing some suitable Lyapunov type extinction functions, some sufficient conditions for the extinction of the system are obtained. For the autonomous case, by constructing a suitable Lyapunov function, we show that one species is extinct and the rest species is globally attractive. Our results supplement some known results.
