About the Authors

Peter T. Fretwell

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Validation, Writing – original draft, Writing – review & editing

ptf@bas.ac.uk

Affiliation British Antarctic Survey, Madingley Road, Cambridge, England, United Kingdom

Jennifer A. Jackson

Roles Conceptualization, Investigation, Methodology, Writing – original draft, Writing – review & editing

Affiliation British Antarctic Survey, Madingley Road, Cambridge, England, United Kingdom

Mauricio J. Ulloa Encina

Roles Resources, Writing – original draft, Writing – review & editing

Affiliation Aquatic Animal Rescue and Conservation Unit, National Fisheries and Aquaculture Service of Chile, Valparaiso, Chile

Vreni Häussermann

Roles Resources, Writing – original draft, Writing – review & editing

Affiliations Pontificia Universidad Católica de Valparaíso, Facultad de Recursos Naturales, Escuela de Ciencias del Mar, Avda. Brazil, Valparaíso, Chile, Huinay Scientific Field Station, Valparaíso, Chile

Maria J. Perez Alvarez

Roles Resources, Writing – original draft, Writing – review & editing

Affiliations Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Santiago, Chile, Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad de Chile, Santiago, Chile, Centro de Investigación Eutropia, Santiago, Chile

Carlos Olavarría

Roles Resources, Writing – original draft, Writing – review & editing

Affiliation Centro de Estudios Avanzados en Zonas Aridas (CEAZA), La Serena, Chile

Carolina S. Gutstein

Roles Resources, Writing – original draft, Writing – review & editing

Affiliations Lab. Ontogenia y Filogenia, Depto. Biologiía, Fac. Ciencias, Universidad de Chile, Santiago, Chile, Consultora Paleosuchus Ltda, oficina C, Providencia, Santiago, Chile

Competing Interests

Consultora Paleosuchus Ltda loaned equipment for the aerial survey of the Gulf of Penas and employs Carolina S.Gutstein. We are extremely grateful for satellite images provided by DigitalGlobe (Maxar). Carolina S.Gutstein is employed by VH thanks the Blue Marine Foundation and the Huinay Foundation for their support. This does not alter our adherence to PLOS ONE policies on sharing data and materials.” (as detailed online in our guide for authors http://journals.plos.org/plosone/s/competing-interests). If this adherence statement is not accurate and there are restrictions on sharing of data and/or materials, please state these. Please note that we cannot proceed with consideration of your article until this information has been declared.