Industrial extraction of natural resources has led to degraded ecosystems, loss of biodiversity, and species extinction. Improved management of resources is now an urgent concern. In Arctic Fennoscandia the effects of resource extraction are of particular concern. In this chapter we use examples from indigenous Sámi reindeer herding in northern Sweden and salmon fishing in the Kemijoki river valley in northern Finland. We show how the emergence of industrial mega systems has led to accumulating industrial land use that now severely encroaches on the ecosystems that reindeer and salmon depend on. The negative effects from encroachments is also further exacerbated by climate change. As a result, the culture-bearing activities of reindeer herding and salmon fishing that have shaped identities in Arctic Fennoscandia for centuries are facing rapidly deteriorating conditions. There are large-scale plans in northern Sweden and Finland to increase mining, wind energy production, and forestry. To avoid, or at least mitigate, long-lasting effects on the ecosystems represented by reindeer and salmon, adequate assessments of cumulative effects from industrial developments are urgently needed.