Individual Behaviour Likely Affects Trappability of an Invasive Species, the Sea Lamprey

We tested if variation in individuals may explain why few Sea Lamprey (Petromyzon marinus) enter traps upon encounter. Trapping is used to control invasive species, but in many cases we see lower than desired trapping success. This is true for Sea Lamprey, an invasive species in the Upper Great Lakes and the target of binational control. We hypothesized that this is due to consistent individual differences in the behaviour of lamprey, where some of those behaviours are more susceptible to trapping. To test this we compared the behaviours of lamprey captured in traps with those captured by electrofishing. We developed behavioural tests to assess if lamprey show individual differences in activity, latency to exit a refuge, and willingness to take risk. Individual lamprey differed consistently in all three of the behaviours measured. Trapped Lamprey were on average more active and more willing to take risk compared to those captured by electrofishing. These results suggest that the design of effective trapping of invasive species requires an understanding of the functional effects of individual behaviours.