The indicators in the Nature Index of Norway are particularly sensitive to the influence of climate on harvesting of marine ecosystems (Framstad, 2015). According to this index, there have been no major changes nor but a slight improvements in the biodiversity of the coastal zone of Mid-Norway during the last 25 years (Fig. The slightly improved condition towards 2010 is due to improved phytoplankton biomass and numbers of harbor seal (Phoca vitulina), while the weak decline since 2010 is due to a small decline in the stocks of Atlantic herring, sand eel (Ammodytes ssp.)