CICIMAR Researchers Work to Safeguard the Guadalupe Fur Seal

Polytechnic researchers are dedicating their efforts to the conservation of this species, which was once declared commercially extinct.

Key Facts

Although its population has grown to nearly 70,000 individuals and continues to recover, Mexico’s NOM-SEMARNAT-059-2010 still classifies the Guadalupe fur seal as an endangered species.

Declared commercially extinct in 1894 due to overexploitation driven by the value of its fur, the Guadalupe fur seal has managed to establish itself on Las Ánimas Island, located in the southwestern Gulf of California. In recent years, approximately 3,000 individuals have been recorded there, a remarkable development considering that the population in this area did not exceed 20 animals in 2019.

Given the ecological significance of this event and the need to study this emerging colony, researcher Fernando Elorriaga Verplancken, from the Interdisciplinary Center for Marine Sciences (CICIMAR) of the Instituto Politécnico Nacional (IPN), leads the project “Abundance, Habitat Use, Fishery Interactions, and Isotopic Niche of the Guadalupe Fur Seal at Las Ánimas Island (Gulf of California): Implications for Colonization and Conservation within a Protected Natural Area.”

The specialist, based at CICIMAR in La Paz, Baja California Sur, explained:

“This species has demonstrated remarkable resilience because it has gone from a scenario close to ecological catastrophe to becoming a conservation flagship. However, there is still only one well-established breeding colony on Guadalupe Island, which highlights a vulnerability that should not be underestimated.”

For this reason, he emphasized the importance of understanding key population characteristics, including the number of animals, periods of greatest abundance, and the dominant age and sex classes, such as juveniles or subadult males, which vary from year to year. This aspect of the research is conducted in collaboration with CICIMAR researcher Claudia J. Hernández Camacho.

The feeding ecology of these animals is another important area of study. Researchers Xchel G. Moreno Sánchez and Fernando Elorriaga analyze the seals’ prey through the examination of fecal samples collected on land. The research includes the recovery of prey remains as well as contaminants such as microplastics, topics investigated by doctoral student María del Mar Quiroga Samaniego and master’s student Yuly Serrano Rodríguez.

The project also examines health conditions and potential human-related threats facing the colony, particularly interactions with fisheries. This work is carried out by IPN postdoctoral researcher Casandra Gálvez, student Mariana Acosta de la Mora, and Master of Science Miriam Romero Velázquez, all members of Dr. Elorriaga Verplancken’s research group.

The IPN specialist noted that Guadalupe fur seals have also shown an affinity for Farallón de San Ignacio Island, off the coast of Sinaloa, and, to a lesser extent, for San Pedro Mártir Island in the Gulf of California Biosphere Reserve. Understanding the species’ distribution across these areas is therefore an important research priority.

Monitoring the “Mother” Island

Since 2012, Dr. Fernando Elorriaga Verplancken has studied the ecology of the Guadalupe fur seal and directed several research projects focused on seasonal occupancy patterns in the San Benito Archipelago, feeding ecology, and the effects of adverse warm-water events such as El Niño on populations at San Benito and Guadalupe Islands. These events can alter prey availability and feeding behavior.

Together with his CICIMAR research team, the Polytechnic scientist monitors the size of the only well-established breeding colony on Guadalupe Island, with support from the National Commission of Natural Protected Areas (CONANP), through the Guadalupe Island Biosphere Reserve and the Pacific Islands of the Baja California Peninsula, as well as the General Directorate of Wildlife of the Ministry of Environment and Natural Resources (SEMARNAT).

This line of research has resulted in numerous articles published in international scientific journals and graduate theses developed by students, including María José Amador Capitanachi, Casandra Gálvez, Romyna Cruz Vallejo, Miriam Romero Velázquez, Ariadna Juárez Ruiz, and Gema Sierra Rodríguez.

The journey of the Guadalupe fur seal continues, and its colonization of the Gulf of California represents an unprecedented event that further highlights the ecological value of the Sea of Cortez and the need for continued research on this species.

“This will only be possible through the joint efforts and collaboration of specialists and students from different disciplines to generate the knowledge needed to support the conservation of this species and its habitat,” emphasized Dr. Fernando Elorriaga Verplancken.