Marine　biosphere　monitoring　is　one　of　the　crucial　links　to　the　understanding　and　protection　of　the　marine　environment.　Moreover,　underwater　images　play　an　important　role　in　marine　biosphere　monitoring.　Since　the　capture　and　transmission　conditions　are　extremely　poor　in　complicated　underwater　environments,　images　will　suffer　typical　types　of　distortions　significantly.　Pre-evaluation　of　the　image　quality　to　facilitate　subsequent　processing　becomes　particularly　important.　Traditional　Image　Quality　Assessment　(IQA)　methods　are　normally　developed　based　on　perceptual　quality.　Nevertheless,　images　are　captured　for　understanding　and　analysis　to　achieve　the　purpose　of　intelligent　monitoring.　There　are　barriers　between　traditional　IQA　and　IQA　in　marine　biosphere　monitoring.　To　address　this　issue,　this　paper　focused　on　the　fish　detection　task　which　is　a　vital　task　in　marine　biosphere　monitoring.　An　Underwater　Image　quality　database　for　Fish　Detection　(UIFD)　is　proposed　based　on　the　characteristics　of　the　underwater　environment.　This　database　can　be　utilized　as　a　benchmark　to　develop　and　evaluate　underwater　IQA.　In　addition,　it　can　also　be　used　to　provide　guidance　for　improving　the　performance　of　underwater　fish　detection　algorithms.　©　2021　IEEE.