Invasive Species Risk Assessment in Freshwater Ecosystems

Invasive species risk assessment in freshwater ecosystems encompasses systematic evaluation of the likelihood and potential severity of non-native organisms establishing, spreading and causing harm in rivers, lakes and wetlands. Such assessments integrate biological, environmental and socio-economic data to prioritise species for management and inform policy. Core elements include initial screening procedures to rank invasion potential, predictive modelling of species distributions under current and future climate scenarios, appraisal of ecological impacts on native communities and ecosystem services, and evaluation of the feasibility and effectiveness of control measures. Recent advances have improved transparency and repeatability by embedding expert judgement within structured frameworks, refining threshold values calibrated to habitat types and climatic zones, and integrating empirical techniques such as stable isotope analysis. Collectively, these developments support proactive, evidence-based management of aquatic invaders to safeguard biodiversity and resource services globally.

Research from Nature Portfolio

Recent studies have employed stable isotope analysis to quantify the ecological effects of invasive fish in high-value freshwater systems. One investigation modelled hypothetical introductions of European perch into a biodiverse Turkish lake, using carbon and nitrogen isotope ratios to demonstrate selective predation on native fish and significant diet overlap with the resident apex predator. The findings highlighted potential cascading impacts on food-web structure and underscored the need for stringent regulation of species translocations. An earlier landmark report combined stomach‐content and isotope data to reveal that a large freshwater apex predator exhibits both individual dietary specialisation and broad generalism, traits that underpin its ecosystem dominance. These studies illustrate how coupling empirical isotope methods with community analyses refines risk assessments and anticipates ecosystem responses to biological invasions.

Invasive Species Risk Assessment in Freshwater Ecosystems publication trend

The graph below shows the total number of articles in invasive species risk assessment in freshwater ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Risk assessment: A structured process to estimate the likelihood and potential consequences of biological invasions to inform management decisions.

Stable isotope analysis: A technique measuring ratios of isotopes (e.g. carbon, nitrogen) to trace dietary sources and trophic interactions within ecosystems.

Ecological niche modelling: A computational method predicting species’ potential distributions by correlating occurrence records with environmental variables.

Screening kit: A standardised decision-support tool composed of criteria and questions for ranking the invasion potential of species.

Threshold calibration: The adjustment of risk-score cut-offs to distinguish between risk categories, tailored to specific taxa or climatic regions.

References

1. Predicting the potential implications of perch (Perca fluviatilis) introductions to a biodiversity-rich lake using stable isotope analysis. Scientific Reports (2023).
2. European catfish (Silurus glanis) as a freshwater apex predator drives ecosystem via its diet adaptability. Scientific Reports (2017).
3. A global review and meta-analysis of applications of the freshwater Fish Invasiveness Screening Kit. Reviews in Fish Biology and Fisheries (2019).
4. A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions. The Science of The Total Environment (2021).
5. Risk management to prioritise the eradication of new and emerging invasive non-native species. Biological Invasions (2017).
6. Beyond protocols: improving the reliability of expert-based risk analysis underpinning invasive species policies. Biological Invasions (2017).