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MILJØFORSK-Miljøforskning for en grønn samfunnsomstilling

Return of the otter: Aggravation of human-wildlife conflicts and potential for mitigation strategies for coastal areas under pressure

Alternative title: Oteren er tilbake: Forverring av konflikter mellom vilt og mennesker og potensiale for skadebegrensning i kystsoner under press

Awarded: NOK 14.0 mill.

The Eurasian otter was once extirpated from most of Norway due to hunting, but after being protected it has recently made a comeback in Western Norway. This has reignited a classic human-wildlife conflict, which often occurs when humans and predators compete for the same resources. In this case, otters and fishers both target the prized and endangered Atlantic salmon, whose numbers in many rivers have been dwindling as the coastal ecosystems have come under increasing pressure from human activities. Otters also meddle in the affairs of local industry, eating salmon in fish farms and trespassing in places like airports and public buildings. Some local stakeholders now ask for decisive management action, including culling of otters. However, it is not clear how, where, and when otters actually affect salmon stocks, how various stakeholders view the conflict, or what potential mitigation measures would be effective and acceptable to both stakeholders, wildlife management agencies, and the regional population in general. In the RePress project, we seek to investigate and alleviate the otter-human conflict in the region Sunnmøre in Western Norway. We will quantify otter predation in time and space by tagging salmon with radio tags, and simultaneously tag otters to reveal their behaviour and feeding habits along the rivers. Stakeholder and management perceptions of otters, salmon, and "acceptable" management of coastal ecosystems will be explored through surveys, interviews and local focus groups. Finally, the possibility of scaring otters away from conflict hotspots will be investigated by testing various deterrents along rivers, in a zoo and on aquaculture facilities. Combined, the findings will increase our knowledge of otters and salmon, and how to mitigate human-wildlife conflicts in general.

RePress is an interdisciplinary effort to develop knowledge about coastal ecosystem conflicts. Human-wildlife interactions are major drivers of conflict and the re-establishment of the formerly extirpated Eurasian otter throughout Norway is changing attitudes and perceptions about the ecosystems. Otter recolonization is a success story emanating from the conservation and restoration of coastal areas, but now this recolonization has ignited human-wildlife conflicts with coastal industry and society. Lack of knowledge about the pressures placed on coastal ecosystems by predators is therefore a significant knowledge gap. Our project combines survey methods and focus groups to investigate local stakeholder views on otters and their role in the ecosystem. We leverage this knowledge with biological assessments of a key ecosystem conflict between otters and Red Listed Atlantic salmon in coastal areas using biotelemetry to track otters and salmon in a river in Sunnmøre, a region on the west coast of Norway. Next, we will implement a life course approach to understand how ecosystem user perspectives guide acceptability of management possibilities to handle otter conflicts occurring in salmon rivers as well as for fish farms where otters are seen taking salmon. We will use the knowledge of acceptability to test the effectiveness of possible non-lethal otter deterrents. Non-lethal deterrents have promise to replace unsanctioned culling that is currently ongoing. Non-lethal alternatives will be tested in a controlled area with the Bergen Aquarium as well as in the field with help from the Salmon Rivers in Sunnmøre organization and Hofseth Aquaculture company. The project will have a reference group including members from partner organizations, research partners, the Norwegian Environment Agency, the County Governor, and the Bergen Aquarium to assist with dissemination of project findings and integration of these knowledge tools into operations for industry and management.

Funding scheme:

MILJØFORSK-Miljøforskning for en grønn samfunnsomstilling