Guillermo Ortuño Crespo

Ph.D., Marine Geospatial Ecology Lab
M.Sc, Ecosystem-based Management of Marine Systems

2015-2020 Duke University

Postdoctoral Researcher (Stockholm Resilience Center)

Guillermo Ortuño Crespo is a Ph.D. student at Duke University’s Marine Geospatial Ecology Lab. He recently obtained a M.Sc. degree in Ecosystem-based Management of Marine Systems from the University of St Andrews, where his research was focused on the conservation and management of Thunnus thynnus and the use of genetic tools in fisheries management. His main research interests are in the spatial ecology and conservation of highly migratory, straddling species, which raise fundamental questions about their trans-boundary management, particularly in areas beyond national jurisdiction.


Crespo, G.O., Dunn, D.C., 2017, A review of the impacts of fisheries on open-ocean ecosystemsICES Journal of Marine Science, fsx084, doi: 10.1093/icesjms/fsx084, link

Crespo, G.O., Dunn, D.C., Reygondeau, G., Boerder, K., Worm, B., Cheung, W., Tittensor, D.P., and Halpin, P.N. (2018). The environmental niche of the global high seas pelagic longline fleet. Science Advances, 4(8), Eaat3681. DOI: 10.1126/sciadv.aat3681 link

Wright, G., Cremers, K., Rochette, J., Clark, N., Dunn, D., Gjerde, K.M., Harden-Davies, H., Mohammed, E., Ortuño Crespo, G. (2019). High Hopes for the High Seas: beyond the package deal towards an ambitious treaty IDDRI, Issue Brief, N°01/19. link

Crespo, G.O., Dunn, D., Gianni, M., Gjerde, K., Wright, G. & Halpin, P.N. (2019). High-seas fish biodiversity is slipping through the governance net. Nat. Ecol. Evol. link

Tittensor, D. P., Beger, M., Boerder, K., Boyce, D. G., Cavanagh, R. D., Cosandey-Godin, A., Crespo, G.O, Dunn, D.C., Ghiffary, W., Grant, S.M., Hannah, L., Halpin, P.N., Harfoot, M, Heaslip, S.G., Jeffery, N.W., Kingston, N., Lotze, H.K., McGowan, J., McLeod, E., McOwen, C.J., O’Leary, B.C., Schiller, L., Stanley, R.R.E., Westhead, M., Wilson, K.L., & Worm, B. (2019). Integrating climate adaptation and biodiversity conservation in the global ocean. Science Advances, 5(11), eaay9969. link.

Vierros, M.K, Harrison, A.L., Sloat, M.R., Ortuño Crespo, G., Moore, J.W., Dunn, D.C., Ota, Y., Cisneros-Montemayor, A., Shillinger, G.L., Watson, T.K., & Govan, H. (2020). Considering Indigenous Peoples and local communities in governance of the global ocean commons. Marine Policy, 119: 104039. link.

Nereus Fellow Guillermo Ortuño Crespo (Duke University) attended the Climate Impacts on Oceanic Top Predators (CLIOTOP) symposium in Taiwan, where he presented his research on the spatial ecology of pelagic long liners. Guillermo’s research was recently published in a special collection in Science Advances on high seas fisheries.

November 14, 2018 | FisheriesEcology

By Guillermo Ortuño Crespo, Nereus Program Fellow at Duke University

Due to their wide-ranging swimming behaviors, migratory fish, marine mammal, seabird and sea turtle species experience a variety, and an increasing amount, of anthropogenic pressures over the course of their lives. These threats, including climate change, overfishing, and marine pollution, combined with conservation strategies that largely fail to consider spatial connectivity over the life cycle, are resulting in declining populations worldwide.

September 27, 2017 | EcologyBiodiversity

This policy brief is from the Nereus-hosted side event at the Second Session of the International Conference on an internationally legally binding instrument under the UNCLOS on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ), held on March 25, 2019. In it are presentation summaries from Nereus fellows Guillermo Ortuño Crespo (Duke University), Solène Guggisberg (Utrecht University) and alumnus Richard Caddell (Cardiff University).

A Review of the Impacts of Fisheries on Open-Ocean Ecosystems

Guillermo Ortuño Crespo Nereus Annual General Meeting 2016 UBC, Vancouver, Canada May 30 to June 3, 2016

Ecological Connectivity: Implications for Adjacency

Guillermo Ortuño Crespo Preparatory Committee Meeting III on the Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ) United Nations, New York, USA April 4, 2017

Nereus Fellow Guillermo Ortuño Crespo (Duke University) received the ‘2019 Dean’s Award for Outstanding Graduate Student Manuscript’ as the lead author for the paper ‘The Environmental Niche of the Global High Seas Pelagic Longline Fleet’, published in Science Advances.

April 25, 2018 | FisheriesEcology

Nereus Fellow Guillermo Ortuño Crespo (Duke University) writes about the first Global Planning Meeting of the UN Decade of Ocean Science for Sustainable Development that he, fellow Harriet Harden-Davies (ANCORS, University of Wollongong) and policy director Yoshitaka Ota (University of Washington) attended in Copenhagen, Denmark on May 13-15th.

Research fellows Harriet Harden-Davies (University of Wollongong/ANCORS) and Guillermo Ortuño Crespo (Duke University) with Daniel Dunn (Duke University) are co-authors on a policy brief published by IDDRI that aims to strengthen the current high seas management and governance framework to improve marine conservation and sustainability.

Nereus members Guillermo Ortuño Crespo, Daniel Dunn, and Patrick Halpin are co-authors on a new paper published in the journal Nature Ecology & Evolution, ‘High-seas fish biodiversity is slipping through the governance net’. They stress the need to include fish biodiversity in negotiations for the new BBNJ treaty at the United Nations General Assembly and close current legal gaps in existing ocean governance frameworks.

A recent study performed by Nereus researchers showing governance gaps concerning marine biodiversity in areas beyond national jurisdiction (ABNJ) is featured in Science Daily.

The International Seafood Sustainability Foundation (ISSF) awarded Guillermo Ortuño Crespo the runner-up prize for seafood sustainability, for his proposal “Dynamic Habitat Predictions of Two Bycaught Oceanic Shark Species.”

April 25, 2018 | FisheriesEcology

Congratulations to Nereus research fellow Guillermo Ortuño Crespo for successfully defending his Ph.D. dissertation! Here you can read the summary he wrote about his research, as well as his future directions.

Research Associate Marjo Vierros is lead author with a research team that includes Guillermo Ortuño Crespo, Daniel Dunn, Director Yoshi Ota, and Andrés Cisneros-Montemayor on a new study published in Marine Policy, “Considering Indigenous Peoples and local communities in governance of the global ocean commons.”