Adapting to Change: How Fish Populations Responds to Ecological Shifts

Abstract

Invasive species are a significant threat to natural biodiversity and human well-being. Despite becoming more commonly considered in the field of biological invasion, studies using long-term time series from Türkiye`s freshwater resources have remained scarce. To fill this gap, we used nine time series from the highly anthropogenically-altered Lake Bafa in Western Anatolia sampled between 1958 and 2019. We investigate how fish populations in Lake Bafa were affected by environmental changes and examined changes in taxonomic and functional diversity of non-native species over time. The analyses revealed an increase in non-native species richness over time. Non-native species did not interfere with native species' niche space, whereas applied models indicate that in this highly altered ecosystem, foremost temperature and salinity shaped the fish community over time, limiting the impacts of non-native species. These results have implications for the fishery of the lake, which include highly valuable catadromous fish species, highlighting the value and importance of long-term data for the study of freshwater ecology to better understand both invasion dynamics and changes in the naturality of ecosystems. These findings further underline the importance of long-term data to create new management strategies for the lake and start restoration processes, thus improving fisheries management.