Emma Letitia Johnston[1] grew up near the sea, and spent much time swimming, snorkelling and sailing as a child.

However, she decided to focus on biology in her undergraduate degree (Bachelor of Science) at the University of Melbourne, which she completed in 1998 with first class Honours.

[citation needed] Johnston joined University of New South Wales (UNSW Sydney) as an associate lecturer in 2001.

[5] She was Dean of Science at UNSW until July 2022, when she was appointed Deputy Vice-Chancellor (Research) at the University of Sydney.

Her research is conducted in such diverse field environments as Sydney Harbour, Antarctica, the Great Barrier Reef, and temperate Australian estuaries.

[citation needed] Among Johnston's significant research findings is the discovery that toxic contaminants facilitate the invasion of coastal waterways by non-indigenous species.

[11] Johnston was made an Officer of the Order of Australia (AO) in the 2018 Queen's Birthday Honours for "distinguished service to higher education, particularly to marine ecology and ecotoxicology, as an academic, researcher and administrator, and to scientific institutes.