HeRA: A New Tool for Assessing the Invasiveness Potential of Non-Native Species

With over 140 species of primary freshwater fish, including 73 that are endemic, Greece is recognized as a biodiversity hotspot in Europe. However, like freshwater systems worldwide, these ecosystems face serious threats, particularly from the introduction of non-native species. This ongoing increase in invasive species has heightened scientific and policy-maker awareness, as such introductions can lead to population declines and even extinctions of native fish. In response to this growing concern, various risk assessment tools have been developed to evaluate the potential hazards posed by non-native species, both those already established and those likely to be introduced. These tools are critical for informing policy decisions and managing biological invasions effectively. In the current study, a new tool, the Hellenic Risk Assessment (HeRA), is proposed. Unlike its predecessors, HeRA places greater emphasis on assessing the biological traits of introduced species and incorporates region-specific considerations tailored to the Mediterranean basin. Its scoring system evaluates both the likelihood of a species establishing itself and its potential environmental impact, making it a valuable resource for stakeholders in prioritizing management actions and making informed decisions regarding the import of live fish species.