Muthiga was born in Kenya, and spent part of her childhood in Dar es Salaam.
[2] She completed her master's degree at the Florida State University, where she studied the impact of salinity on the photosynthesis of Siderastrea siderea.
[citation needed] In 2000 Muthiga was elected President of the Western Indian Ocean Marine Science Association Board of Trustees (WIOMSA).
[5] In this capacity, Muthiga was made of Chair of the Kenya Sea Turtle Conservation programme.
[8][9] The programme helps to protect 90% of the world's coral species and has surveyed almost 1,000 sites across the Indo-Pacific and Caribbean Sea.