Professor Emma Johnston smiles outdoors against a sparkling blue waterway and lush coastal hillside. © UNSW Sydney

Professor Emma Johnston © UNSW Sydney

Professor Emma Johnston smiles while wearing a wetsuit and holding scuba diving gear on a sunny wharf beside clear blue water at Sydney Harbour, Sydney, New South Wales. © UNSW Sydney

Professor Emma Johnston at work © UNSW Sydney

A colourful yellow and purple weedy seadragon with delicate, leaf-like appendages floats above a rocky, kelp-covered ocean floor, Sydney Harbour, New South Wales. © Erik Schlogl

Weedy seadragon, Sydney Harbour, New South Wales © Erik Schlogl

A school of small striped fish swims through vibrant, sunlit green sea kelp underwater, Sydney Harbour, New South Wales. © Tamsin Peters

Fish in Phyllospora, Sydney Harbour, New South Wales © Tamsin Peters