| Summary: | Human activities drive degradation and biodiversity loss of freshwater rivers globally. One of the major threats to rivers are channelization, which straightens the river and eliminates the heterogenic habitats as opposed to a natural river system. In the timespan of late 1930s to early 1990s experienced Bognelv, heavy modifications to prevent erosion, increase adjacent land and to control the water level during flood. The present study is the second study identifying the macroinvertebrate community in Bognelv down to species, and thus, the first study to evaluate and quantify the temporal development of the macroinvertebrate community composition and their responses to the restoration measures conducted to Bognelv in Finnmark County, Norway. The restoration process of Bognelv started in 2006 and has since experienced several restoration measures and adjustments of existing measures. The latest adjustment was conducted in 2019, before my visit in Bognelv. Following the study from 2015 I sampled macroinvertebrates by means of kick-sampling. My study found a higher Shannon-wiener index diversity in 2019 compared to 2015. Furthermore, the environmental variables influencing the macroinvertebrate community in 2019 was found to be large woody debris, vegetation coverage of the river closest to the shoreline, moss coverage, depth, velocity, and pools. Similar to 2015, water depth and velocity of current was found to be among the important influential variables. Regarding the restoration measures, I compared macroinvertebrate density and diversity between restoration measure and control. I found side channels to have the highest species richness potential, stations with pools had the highest density. Moreover, the modified channelization station and the channelized control stations followed the same density trend, but channelization showed a significant higher species richness potential. Thus, the overall results showed tendencies towards the restoration measures not providing enough effect on the heterogeneity to ...
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