fuge

/F Y UW1 JH/
noun
  1. 1

    Any local environment that has escaped regional ecological change and therefore provides a habitat for endangered species.

  2. 2

    (aquaculture) A separate section of a fishtank that shares the same water supply, used for denitrification, plankton production, etc.

Source: https://en.wiktionary.org/wiki/fuge, https://en.wiktionary.org/wiki/refugium