At the beginning of September 2025, AQUAPHOENIX partners carried out the first seafloor sampling campaign in Hardangerfjord for Work Package 2 which focuses on assessing the environmental impact of aquaculture emissions and evaluating the effects of sludge removal. The Work Package 2 team brings together researchers from NORCE, NIOZ, and LUKE, working in close collaboration with IMR.
This campaign was conducted on IMR’s research vessel Hans Brattström, extending a planned cruise originally dedicated to water column observations (related to AQUAPHOENIX Work Package 3). During the fieldwork, Einar Bye-Ingebrigtsen and Gunhild Bødtker (both NORCE) collected seafloor samples using a Van Veen grab at multiple locations: next to active fish farms, at nearby reference sites at similar depths, and at two deeper basin stations.
From these samples, the team will study both macrofauna (visible animals living in the sediment) and microbial communities. Macrofauna will be identified using traditional taxonomic counts combined with modern genetic approaches, while sediment microbes will be analyzed using metagenomics, which provides insight into their diversity and function.
The sampling was successfully completed thanks to the excellent support from the vessel crew as well as Eide’s and Lingalaks’ local farmers – and favorable weather conditions.
Next, Work Package 2 will focus on characterizing sludge material in terms of nutrient release and oxygen consumption. We will also collect layered sediment cores for incubation experiments, which will help us understand how matter cycles at the seafloor. Additionally, these cores will allow us to look back in time and reconstruct how aquaculture activities have influenced the fjord’s benthic ecosystem over recent decades.
