Metabarcoding
Unfortunately, some problems during the PCR-procedure in the lab
appeared that resulted in less fish individuals with a sequenced gut
content. We identified 32 aquatic and 17 terrestrial species in the gut
content of the 31 fish individuals analyzed (Appendix 1). Fish
individuals feed on 1-8 different species and perch, irrespective of the
location, had the most diverse diet (5 ± 3 species), in contrast to
roach (3 ± 2 species), and bleak (2 ± 1 species) (Table 2). No
terrestrial species were identified in the gut content of fish caught
downstream of the dam and no terrestrial species were identified in the
gut content of roach upstream of the dam either, thus, not allowing any
statistical comparison (Table 2). However, in locations upstream the
dam, terrestrial species were ingested by bleak
(1 species ± 1) and perch (4
species ± 1) and this result was significant for the latter species (Z =
6.137, P = 0.013, Table 2).