Effects of the Invasive Fish Species Ameiurus nebulosus on Microbial Communities in Peat Pools

Abstract

Disturbances in the functioning of peatlands, due to growing human impact, climate change and the appearance of alien invasive species, are becoming increasingly common. Analysis of trophic relationships in the predator (invasive alien species)–prey system is extremely important for understanding the functioning of peat pools—small water bodies formed in peatlands by peat extraction. These issues are, as yet, very little understood. The aim of this study was to examine the impact of Ameiurus nebulosus, an alien and invasive fish species dominant in these pools, on the microbial communities and small metazoa (phycoflora, bacteria, heterotrophic flagellates, ciliates, and crustaceans) in peat pools. The laboratory experiment included two groups of treatments simulating natural conditions: treatments without fish and treatments with brown bullhead. The water temperature was manipulated as well. The presence of brown bullhead in combination with climate changes was shown to cause a change in the structure of microbial communities. This is reflected in a decrease in the abundance of planktonic crustaceans and an increase in ciliates. The overlapping effects of alien species and gradual climate warming may intensify the eutrophication of peatland ecosystems and the increase in the proportion of cyanobacteria, thereby affecting the carbon cycle in these ecosystems.

Status and Perspectives of the Ichthyofauna of the Labudovo okno Ramsar Site: An Analysis of 14 Years of Data

“…Even though the values of relative biomass and relative annual production of these species varied from site to site and still vary now (depending on the habitat types the sites represent), it can be seen that the values for biomass and production of Prussian carp in the 2018 samples are between three times (Marina) and ten times (Ðurica) lower than in those of 2008 (Table 2). A similar ratio can be observed for the brown bullhead [26].…”

Abiotic and Biotic Effects on Microbial Diversity of Small Water Bodies in and around Towns

“…Although exotic fish species are relatively small, species such as mosquito fish and tilapia have high abundance rates in all water bodies, and the risk of potential biological invasion by alien fish may be higher. Empirical studies have supported the effects of exotic fish on microorganisms in water bodies [66], and in this study, the impact of the fish population composition on small water bodies may have been indirect, such as by disturbing the suspension of the particulate matter in the ponds.…”