Rare sightings of Bryde’s whales (Balaenoptera brydei/edeni) in the Southern California Bight

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Bryde’s whales (Balaenoptera brydei/edeni) have been considered an anomalous occurrence in the Southern California Bight (SCB). Thus, they typically have been excluded from species lists associated with SCB management documents. In the last 40 years only two visual sightings of Bryde’s whales were documented in California waters, the last one in 1991 (Carretta et al. 2007). This is despite extensive systematic vessel and aerial surveys and presumed recent recordings of Bryde’s whale vocalizations in the SCB. Bryde’s whales are notoriously difficult to differentiate in the field and from fin (B. physalus) and sei whales (B. borealis), given the subtle differences in physical characteristics. Between August 2006 and September 2010, we photo-documented five sightings of five single Bryde’s whales in the SCB. Two of the five sightings occurred in October 2008 and September 2010 during 33,880 km of aerial surveys. The remaining three sightings occurred during small-vessel surveys that included offshore waters: two in June 2006 and one in September 2010. These sightings combined with other reports of presumed vocalizations suggest that Bryde’s whale numbers may be increasing in the SCB. This may be related to global warming, large-scale oceanographic events (e.g., El Niño and La Niña) and resulting changes in prey availability. However, no clear association pattern was evident between ENSO events and our sightings. The recent sightings reported herein indicate that the Bryde’s whale should be considered as a species present in the SCB and photodocumentation is critical to ascertain species.