Data from: Patterns and correlates of non-native inland fishes in the circum-Mediterranean region

The circum-Mediterranean region is a global biodiversity hotspot, home to a highly distinctive freshwater fauna with a large proportion of range-restricted endemic species, many of which are currently threatened. However, these ecosystems are increasingly impacted by biological invasions, particularly by non-native fishes. In this study, we provide a comprehensive, updated inventory and analysis of non-native fishes recorded in inland waters across all countries bordering the Mediterranean Sea, based on an extensive review of scientific literature, online databases, and technical reports. A total of 146 non-native fish species were recorded in circum-Mediterranean inland waters, with Italy, Spain, and France exhibiting the highest numbers of established species. Certain orders, such as Salmoniformes and Esociformes, were significantly overrepresented among established non-native species, whereas others, including Siluriformes and Characiformes, were underrepresented. Establishment rates varied among fish orders and Mediterranean countries. Most introductions came from other European countries, temperate Asia, and North America, primarily through escapes or intentional releases; however, introduction patterns varied depending on the region. Non-native fish species richness showed a strong positive correlation with gross domestic product and the number of dams, underscoring the influence of economic development and habitat modification as key drivers of species introductions. We also discuss the implications for regional biodiversity conservation and highlight the need for coordinated transnational strategies to manage fish invasions effectively across political and ecological boundaries.