Back to search

MARINFORSK-Marine ressurser og miljø

Hypoxia effects on fish in west Norwegian fjords: harnessing the power of multidisciplinary studies

Alternative title: Hypoksiaeffekt på fisk i vestnorske fjordar

Awarded: NOK 12.0 mill.

This project uses West Norwegian fjords as natural infrastructures to generate new knowledge on effects of hypoxia on mesopelagic and demersal fish communities. Such information is needed for sustainable management of marine resources, and for determining optimal coastal and fjord sites for fish farming, representing one of Norways largest, most successful industries. Deoxygenation linked to ocean warming is a large concern worldwide. Loss of oxygen is pronounced in the open ocean, occurring in coastal waters, enclosed seas and fjords. Little is known on how hypoxia affects marine ecosystems. Studies are difficult in open oceanic ecosystems but is more readily conducted in enclosed systems. West Norwegian fjords are unique in this respect. 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. 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 a well-documented ecosystem. It also serves as a comparison with other fjords on the effects of oxygen loss on vertical migration behaviors, fish physiology, trophic interactions, behavioral responses to changes, growth, and consequences for populations and communities. In addition, 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. Outreach from the project is regularly published on the project web page: https://hyponfjordfish.w.uib.no/ where also our work packages are presented. The project has participated on 3 research cruises to the fjords (June of 2020, February 2021 and September 2021). All cruises collecting biological and oceanographic samples for the project. Two PhD students, one post doc researcher and four master students have their research projects on HypOnFjordFish. The HypOnFjordFish team has established international collaboration with the Intergovernmental Oceanographic Commission?s Global Ocean Oxygen Network (GO2NE) Levin and Limburg are members of GO2NE, and Gallo has participated in the GO2NE - VOICE program (variability of the oxycline and its impact on the ecosystem). Salvanes and Levin both contributed to a recent GO2NE-sponsored synthesis titled: System controls of coastal and open ocean oxygen depletion, and Salvanes described fjord hypoxia. GO2NE?s Decade for Ocean Science Program - the Global Ocean Oxygen Decade (GOOD) has goals that align well with HypOnFjordFish and we anticipate that HypOnFjord Fish will be one of the GOOD case studies. Limburg has been testing new analytic instrumentation, and discoveries in Roundnose Grenadier, Coryphaenoides rupestris for HypOnFjordFish. She has performed some preliminary analyses on the new laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) instrumentation at the State University of New York College of Environmental Science and Forestry.

This project will use West Norwegian fjords as natural infrastructure to generate new knowledge on effects of hypoxia on mesopelagic and demersal fish communities. Such information is needed for sustainable management of marine resources, and for determining optimal coastal and fjord sites for fish farms, representing one of Norway’s largest, most successful industries. Deoxygenation linked to ocean warming is a large concern worldwide. Loss of oxygen is pronounced in the open ocean, occurring in coastal waters, enclosed seas and fjords. This includes Masfjord, often visited by our research group. This fjord turned hypoxic in 2016. Little is known on how hypoxia affects marine ecosystems. Study is difficult in open oceanic ecosystems, but is more readily conducted in enclosed systems. West Norwegian fjords are unique for this. 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. Our objective is to study effects of oxygen loss on vertical migration behaviors, fish physiology, behavioral responses to changes, growth, and consequences for populations and communities. We will also explore if patterns of trace-element deposition in otoliths from a long-lived fish could reflect previous hypoxic events. We will compare across fjords that differ in basin water oxygen levels, will use data and samples collected from two fjords (Masfjord and Lustrafjord) during field courses for MSc students, and supplement these with new field campaigns to additional fjords (Lysefjord and Osterfjord). We will also attempt to establish lab populations for two mesopelagic species, but we are aware of that this could be a challenge. For Masfjord, however, we have unique data from before and after the fjord turned hypoxic, enabling study of deoxygenation effects on a well-documented ecosystem.

Publications from Cristin

No publications found

Funding scheme:

MARINFORSK-Marine ressurser og miljø