Matrai is originally from Chile. Matria has a B.A. from the Universidad de Concepción (1981), an M.S. (1984) and a Ph.D. (1988) from Scripps Institution of Oceanography and the University of California San Diego. Following her Ph.D. she moved to the University of Miami. She became a senior research scientist at Bigelow Laboratory for Ocean Sciences in 1995.