Eli Gross, a naturalist for the international birding tour company Alvaro’s Adventures, was surprised to identify upwards of 70 Guadalupe fur seals offshore of Monterey Bay during a charter on August 13, 2023.
Figure 1: A map showing the 5 locations where the offshore Gualdalupe fur seal sightings occurred. Source: https://ebird.org/tripreport/151286
Initially, naturalists on board assumed that the pod consisted of northern fur seals (Callorhinus ursinus), whose offshore range along the West Coast extends from Southern California to the Bering Sea, according to NOAA Fisheries. After looking closely at identifying photographs, Gross instead identified the seals as the threatened Guadalupe fur seal (Arctocephalus townsendi) due to their smaller size and elongated snouts. The Guadalupe fur seal is much less common along the central and northern California coast, with small breeding populations on offshore islands in Baja California and the Channel Islands.
Figure 2: Two Guadalupe fur seals. Photo taken under permit MULTI 2022-004. Credit: Alvaro’s Adventures.
According to company founder Alvaro Jaramillo, the Guadalupe fur seals were associated with a large warm water area that resulted in a number of unusual sightings, including two Craveri’s Murrelets and three booby species (Nazca, Brown, and Red-footed), all of which appeared to be feasting on a large school of Pacific saury.
As warm water events in the region become more frequent with climate change, scientists expect many marine species to experience a northern range shift. For Monterey Bay National Marine Sanctuary, it is important to understand these shifts so that coastal managers can adapt strategies to protect species, ecosystems, and ecosystem services for future generations.
Figure 3: A bob of Guadalupe fur seals; “bob” is a term that can be used to describe a group of seals. Photo taken under permit MULTI 2022-004. Credit: Alvaro’s Adventures.
Citations:
NOAA Fisheries. “Guadalupe Fur Seal”. 2022. Accessed August 23, 2023 from https://www.fisheries.noaa.gov/species/guadalupe-fur-seal
NOAA Fisheries. “Northern Fur Seal”. 2022. Accessed August 23, 2023 from https://www.fisheries.noaa.gov/species/northern-fur-seal