Low evenness between phyla/genera MiSeq v4


Just wondering if anybody ever experiences a low evenness in their sequences. I am sequencing gut samples from fish. 5/6 phyla total but one phyla dominates the samples (anywhere from 50-99%)?

I am aware of differences in 16s copy number, but could it just as well be a true reflection of the environment. Lots of otu’s just low evenness?

Wondering if this is common

Thank you

completely plausible. If it’s novel for your habitat you might want to do something quantitative to prove the evenness disparity-i.e. FISH