Experience in using the methods of catastrophe theory in describing the dynamics of phytoplankton in the Vistula lagoon of the Baltic Sea

Abstract

Ideas and methods of catastrophe theory are widely used to analyze “regime shifts” in ecosystems. In this work, the analysis of the seasonal dynamics of phytoplankton in the Russian part of the Vistula Lagoon of the Baltic Sea is carried out on the basis of using the simplest possible model of the catastrophe theory − cusp catastrophe. The total phytoplankton biomass is considered as a state variable. The use of one of the methods of multivariate analysis − principal components method − made it possible to carry out the entire analysis depending on a small number of parameters. A calculation of the control parameters values is carried out using the factor loadings of the main components for the data that characterize the hydro-physical and hydro-chemical regimes as well as the level of biogenic loading on the aquatic ecosystem of the lagoon. It was found that, depending on the specific situation, the same factor or different combinations of factors can play both a stabilizing role and be the cause of destabilization.