HypOnFjordFish is a multidisciplinary research project that uses West Norwegian fjords as natural infrastructure to generate new knowledge on the effects of hypoxia on mesopelagic and demersal fish communities. Such information is needed to sustainably manage marine resources, and to select optimal coastal and fjord sites for fish farming. Fish farming represents one of Norway’s largest, and most successful industries. 

Deoxygenation linked to ocean warming is a large and growing concern worldwide. Loss of oxygen has been observed in the open ocean, in coastal waters, enclosed seas and fjords. In coastal areas, excess nutrient inputs, including from fish farms, can exacerbate climate change-driven deoxygenation. More information is needed on how oxygen loss affects marine ecosystems. HypOnFjordFish aims to improve our understanding of the effects of hypoxia on fish physiology, growth, behaviour, and community ecology. 

While studying these questions in open oceanic ecosystems can be challenging, West Norwegian fjords offer unique semi-enclosed systems. Fjords differ in their state of oxygenation due to differences in their bottom topography and sill depths. As such, their gradients of hypoxia are tractable for study and provide natural parallels with open ocean gradients. Each fjord contains an ecosystem with many physical and biological processes similar and relevant to those of large oceanic ecosystems. 

HypOnFjordFish focuses on several fjords with different states of oxygenation. One site, Masfjorden, has repeatedly been sampled over the years, and it is documented that this fjord turned hypoxic in 2016. We have unique data from before and after 2016, enabling study of deoxygenation effects on this well-documented ecosystem. Masfjorden will serve as a comparison with other fjords, including Fensfjorden (well oxygenated), Osterfjorden (intermediate oxygen depletion), and Sørfjorden (concern of becoming hypoxic). 

HypOnFjordFish will employ innovative and multidisciplinary research techniques. In addition to the use of acoustics and multiple net-based sampling methods, we will use advanced technology to examine if trace-element deposition in ear stones from a long-lived deep-water fish provide information about previous periods of low oxygen levels in the fjords. We will also attempt to establish lab populations for two mesopelagic species for studies of physiology and growth.

On this website we will share our progress and findings with the broader scientific community and public audience. HypOnFjordFish is led by researchers at the University of Bergen, and involves an international team of collaborators. Funding is provided through a research grant from the Research Council of Norway.