Direct (fishing) and indirect (climate change) human impact on the fish communities of the Curonian Lagoon. Predator-prey interactions based on individual size. Estimation of changes in the size distribution in different age classes by applying size-based ecosystem models using Mizer package in R. Identification of possible mechanisms causing changes in fish sizes. Assessment of the Curonian Lagoon ecosystem according to the resilience of fish communities to disturbances (exploitation, temperature fluctuations, pollution). Changes of trophic chains and the emergence of trophic cascades in trophic networks. Estimation of maximum sustainable yields to increase future fish biomass and yields.
Annotation of the dissertation
Curonian Lagoon is one of the most productive water bodies in Lithuania. Many commercially and recreationally valuable fish species are found here. To maintain fish biomass, which is important for humans and other organisms, it is necessary to maintain ecosystem balance and energy transfer efficiency. The aim of this research is to investigate the consequences of direct (fishing) and indirect (climate change) human impacts on the fish communities of the Curonian Lagoon using dynamic deterministic size-based ecosystem models using “Mizer” package in the R software environment. Introducing different fishing and temperature scenarios into the model will allow us to determine how possible changes in fishing effort can affect fish communities and their resilience to climate change. During the research, it is planned to assess the consequences of the reduction of the largest predatory fish individuals, to determine the changes in the number of different fish species and the distribution of their biomass in different size classes over time, to evaluate the changes in trophic chains and the resilience of existing fish communities to disturbances (fishing, temperature fluctuations, pollution).