I recently got my results from WGS for aquatic plants and the results of FastQC show that per sequence GC content and Kmer content failed (see results attached). Basic statistics show a %GC of 25.

I am thinking that the GC content failure could be a result of DNA from other organisms like algae and fungi, which would make sense given the natural habitat where the plants where collected (river rapids).

I am new at handling NGS data so could anyone tell me the possible reasons why the Kmer count failed and if should/could do something about it before assembly?

Thank you in advance