4.6 Indicators
When applying the three indicators proposed for the Swedish Agency of Marine and Water Management (SwAM; Johannesson & Laikre, 2020) we find that the proposed limiting threshold values are exceeded in some of the 29 monitored populations (Figure 7a). However, when considering the metapopulations that these populations belong to, positive trends in other populations of the same metapopulations compensate for the negative trends in several cases. Only two of ten full systems (Figure 7b) show warning signals for the ΔH indicator. MetapopulationN e is however, often below the 500-threshold resulting in warning signals from the N eindicator. We underline that the true meta-N e can be larger in these systems because we have likely not sampled the full metapopulations in any of the present cases. Sampling over substantially larger areas are needed to resolve this issue. On the other hand, the generally low N e estimates observed underlines the vulnerability of these systems – if they become fragmented and isolated, local N e is low and reduced connectivity will rapidly result in elevated rates of diversity loss. Protecting large, interconnected systems are thus important for the conservation and viability of fish in small mountain lake systems. We also apply the indicators for CBD (Figure 7c), and in the present case the results are largely consistent with the results from the national (SwAM) indicators.