Lessons learned and lingering uncertainties after seven years of chronic wasting disease management in Norway

Chronic wasting disease (CWD) is well known among cervids in North America. Nevertheless, management faced different types and degrees of uncertainty when CWD was first detected in reindeer Rangifer tarandus in Nordfjella, Norway in 2016. We present a timeline of the efforts to control CWD, and identify how the process, measurement, environmental, and implementation uncertainties developed from the onset (2016) to the current situation (2023) after seven years of CWD management. In the 'acute' phase (2016-2019), political ambitions were high and depopulation of the Nordfjella reindeer area involving marksmen aimed at eradicating CWD. Subsequently, increased surveillance and increased male harvest was used to enable early detection or to achieve 'freedom-from-CWD' status of the adjacent populations. The second phase (2020-now) came when cases were detected in the large reindeer population in Hardangervidda. Management authorities postponed culling using marksmen, signifying an important change, with more emphasis on socio-political acceptance and consideration of the negative long-term consequences of conflicts with local stakeholders. The subsequent dialogue processes between scientists and local management ended in joint advice. However, the Ministry set aside all advice in 2022, halting further actions, after pressure and negative media attention. During this period, there was no clear research plan to increase knowledge of CWD to reduce process uncertainty; however, large surveillance investments were made to reduce measurement uncertainty. Despite this, detecting and estimating CWD among reindeer at low prevalence remains a key challenge. Governance challenges have emerged as significant implementation uncertainties, partly due to the uncertain occurrence of CWD.