Guillermo Ortuño Crespo is an applied marine biologist specializing in the conservation and sustainable management of highly migratory species and high seas biodiversity.

With a Ph.D. from Duke University, his work bridges science and policy, focusing on improving global frameworks for the high seas and advancing equitable marine conservation.

Guillermo has contributed to numerous international processes, including the UN negotiations on Biodiversity Beyond National Jurisdiction (BBNJ), research on pelagic fisheries and Regional Fisheries Management Organizations and is the co-lead of the IUCN WCPA High Seas Specialist Group.