Publications by authors named "H Viljugrein"

Salmon lice (Lepeophtheirus salmonis) are parasites on salmonid fish and a density-dependent constraint to the sustainable farming of salmonids in open net pens. To control the parasites, fish farmers in Norway are required to count the number of salmon lice in different developmental stages on a subset of the fish each week. Furthermore, they must ensure that the number of adult female lice per fish does not increase beyond a specified threshold level.

View Article and Find Full Text PDF

Establishing freedom from disease is a key component of surveillance and may have direct consequences for trade and economy. Transboundary populations pose challenges in terms of variable legislation, efforts, and data availability between countries, often limiting surveillance efficiency. Chronic wasting disease (CWD) is a contagious prion disease of cervids.

View Article and Find Full Text PDF

Harvesting and culling are methods used to monitor and manage wildlife diseases. An important consequence of these practices is a change in the genetic dynamics of affected populations that may threaten their long-term viability. The effective population size ( ) is a fundamental parameter for describing such changes as it determines the amount of genetic drift in a population.

View Article and Find Full Text PDF
Article Synopsis
  • The eagle owl population in Norway is critically endangered, raising concerns about the impact of Persistent Organic Pollutants (POPs) on their decline.
  • A study analyzed liver samples from 100 eagle owls (1994-2014) and found extremely high levels of POPs, with 90% of the birds exceeding health risk thresholds.
  • The results indicate that higher contaminant levels are linked to poorer body condition, suggesting POPs may jeopardize the health and survival of the eagle owl population.
View Article and Find Full Text PDF