Invasive alien species are evaluated to represent  a severe threat to global biodiversity. This research is a case study included in the BONUS BLUEWEBS project which focuses on the food webs of the Baltic Sea. The project is coordinated by the Finnish Environment Institute SYKE.

The case study, implemented by Turku University of Applied Sciences, focuses on the recently colonized alien species, such as the Harris mud crab originated from North America, in native fish species’ diet in the Archipelago Sea area. Based on the results, the positioning of the new alien species in the Archipelago Sea food webs is evaluated and the study also produces information on the distribution and spatial expansion of the species in focus.