Butyl benzyl phthalate affects shoaling behavior and bottom-dwelling behavior in threespine stickleback

In this laboratory experiment, the effects on fish behavior caused by butyl benzyl phthalate (BBP) were of interest. We showed that shoaling behavior and bottom-dwelling behavior in threespine stickleback, Gasterosteus aculeatus, were altered as a result of exposure to 0.1 mg/L BBP. Threespine sticklebacks, collected from a freshwater population in central Norway, were exposed to BBP for 26 days. BBP was administered daily through the water. We found that exposed fish aggregated more into one single shoal than control fish. Further, the exposed fish spent more time at the bottom of the test aquarium than the control fish. From these results we conclude that the behavior traits aggregation and bottom-dwelling activity may be suitable and sensitive in detecting effects of BBP in threespine stickleback.