Biological invasions in fresh waters cause biodiversity loss and impairment of ecosystem functioning. Many freshwater invasive species are fish, including the largemouth bass Micropterus salmoides, which is considered one of the 100 worst invasive species in the world. Fast individual growth rates, high dispersal ability, ecological tolerance, and trophic plasticity are among the characteristics contributing to its success. The negative impact of M. salmoides on littoral fish communities is believed to be mitigated by habitat structural complexity resulting from aquatic vegetation and coarse woody debris, while the main limits on its spread seem to be strong water flows and high turbidity, which impairs visual predation. Together with the human overexploitation of its potential fish antagonists, habitat alteration could result in M. salmoides having seriously detrimental effects on native biodiversity. The purpose of this study is to critically review the life history and ecology of M. salmoides, its impact on ecosystems outside North America, and the effects of anthropogenic activities on its spread. This will highlight environmental factors that favor or limit its invasive success, helping to identify management measures that might mitigate its negative effects on freshwater biodiversity.

Lakes worldwide have been strongly affected by several types of human-caused alteration, including changes in water level. This also affects deep lakes, including volcanic ones. Volcanic lakes in the Mediterranean area are of great importance for the local economy, but local human activities can threaten their rich biodiversity. As a European biodiversity hotspot and habitat of endemic species, the volcanic Lake Bracciano (Central Italy) is an ecosystem of primary conservation interest threatened by sharply falling water levels, particularly since 2017. It also plays a key role in human wellbeing by providing important ecosystem services including drinking water, fisheries and various recreational opportunities. Although the lake has historically been considered to enjoy good ecological status, various environmental problems, often amplified by water level changes, have arisen during the last two decades. Given this recent rapid evolution, the lake can be considered an example of a valuable ecosystem at risk as a result of increasing anthropogenic pressures. The aim of this review is to examine the changes that have affected the lake in the last 20 years, considerably reducing its capacity to provide ecosystem services, and to review existing and potential threats in order to better inform the management of such resources.