Is trait diversity and consistency key to predicting invasiveness of non-native fish?

Invasive species are organisms that spread, most often human-mediated, from their native range into novel environments where they become established and often cause tremendous ecological and economic damage. Their ecological impact includes competition with native species for space, food, and survival, and the cost associated with damage and control of invasive species is estimated to $7.7 billion annually in the USA alone. 

Eradication of invasive species has proven nearly impossible, so mitigation is best performed by preventing further human-mediated spread, but invasive species also spread naturally from their point of introduction. Understanding how invasive species will impact the environment in the future therefore relies on predictions of their spread; key to this is a multidisciplinary approach: we need to understand how the new environments they will encounter will affect their physiology and behaviour, since changes to these fundamental organismal traits will determine their growth, survival, and reproductive success. 

Since natural selection works on individual traits and favours the combination that produces the highest fitness in a given environment, it is especially important to understand how individuals within species differ in their physiology and behaviour, and how consistent these traits are across different environments. 

This project will investigate if variation among individuals in key physiological (metabolic rate) and behavioural (activity, boldness, aggressiveness) traits can improve our ability to predict how invasive species will spread into new environments. This will be done by measuring metabolic rate and behaviour of individuals of the highly invasive fish – the round goby (Neogobius melanostomus) – under a range of salinities, and by linking variation in these traits to the fish’s performance. The round goby invasion front is currently in the brackish Baltic Sea, near Copenhagen, and the biggest potential barrier for further spread into the oceanic North Sea is believed to be increased salinity. Although some “superior” individuals may be able to withstand the higher salinity and continue the invasion, such elevated salinity tolerance may also reduce their performance due to negative effects on their physiology and behaviour. Investigating if such a trade-off exists is a key focus of this project. 

The results from the project can be used to guide the research of other scientists, refine ecosystem models, and inform management agencies, policy makers, and the public of the impacts of invasive species.

Funding
The project is a Marie Curie Fellowship as part of the EU-funded H.C. Ørsted Fellows Programme - co-funded by Marie Skłodowska Curie Actions, grant agreement no. 713683.

Research area: Fish Biology