mesotrophic
adjective
me·so·tro·phic ˌme-zə-ˈtrō-fik 
ˌmē-,
-sə-,
-ˈträ-fik
of a body of water
: having a moderate amount of dissolved nutrients compare eutrophic, oligotrophic
Example Sentences
Recent Examples on the Web This leaves the deep-water mesotrophic reefs—which are less likely to suffer from bleaching and may be critical for reef recovery—under-studied. 
Jessica Wynne Lockhart, Smithsonian, 17 Oct. 2019
Jessica Wynne Lockhart, Smithsonian, 17 Oct. 2019 Word History
First Known Use
1911, in the meaning defined above