NOBROOK Spring 2022

The spring has been a busy time for the NOBROOK project! Each of the experimental stream sections have been habitat mapped this spring and each stretch has been given a score of the quality of trout habitat (THS). This data will allow us to determine the quality of habitat being utilized when we combine this with the telemetry data we have collected through the fall of last year, late winter and early spring of this year.

Furthermore, in June each stretched was electro fished and more fish of both species were tagged and boldness score, the fish that we managed to recapture from last fall’s tagging were also scored this year.

Other than the field work that’s been done in Borås, we also had the chance to visit our collaborator and friend Libor in Lunz, Austria. The plan moving forward is hopefully to work together on some experiments there next summer. In order to get a more detailed perspective of the effects of remvoing brook trout with different behavioural triats we will be conducting these experiments in artificial stream channels located in Lunz. This will be conducted as a supplement to the field based approach taking place in Borås.

The plan for the time being is to examine the behavioral phenotypes of the fish (brown and brook trout that will be caught in Austria), and we will design the enclosures so as to create different subhabitats of different qualities. This will allow us to determine which fish is the most dominant one as the most dominant fish will inhabit the best habitat (i.e. the most stable water flow and best food supply), and we will subsequently remove this fish and observing the response of the remaining population. The enclosures will emulate both sympatric sections with both species, as well as allopatric sections with only brown trout.