Bryde's whale (Balaenoptera edeni)

Species >> Bryde's whale (Balaenoptera edeni)

Muscle serves a wide variety of mechanical functions during animal feeding and locomotion, but the performance of this tissue is limited by how far it can be extended. In rorqual whales, feeding and locomotion are integrated in a dynamic process called lunge feeding, where an enormous volume of prey-laden water is engulfed into a capacious ventral oropharyngeal cavity that is bounded superficially by skeletal muscle and ventral groove blubber (VGB).

Sighting and stranding data are often used to identify patterns in marine mammal occurrence. Here we evaluate the use of public sighting reports, systematic surveys (where available), and stranding data from 1995-2015 to test how well these reflect trends in nine cetacean species in Puget Sound, Washington, USA. In general we found good agreement in documenting trends in occurrence between one of the sighting sources and strandings for 7 of 9 species, though there were often some species-specific considerations.

In the last few years, several unexpected species have been sighted and stranded in southern Puget Sound. This has included the return of one species, the harbor porpoise, that used to be common but had disappeared for many decades from Puget Sound before returning in recent years, and the occurrence of three species since 2010 that are either unknown or extremely rare this far north.

Given the paucity of confirmed sightings over the last 20 y, and its traditional, more tropical or low-latitude distribution, the Bryde’s whale (Balaenoptera brydei/edeni)1 has been excluded from recent National Marine Fisheries Service (NMFS) stock assessment reports of cetaceans occurring in the Southern California Bight (SCB) (Carretta et al., 2011). The last U.S. Pacific marine mammal stock assessment to include the Bryde’s whale was in 2006 (Carretta et al., 2007).

Blue whales occur widely in the world’s ocean and became a target of commercial whalers in what is termed the modern era of whaling. Largest populations occurred in the southern Hemisphere and the Antarctic blue whale was the most heavily hit by commercial whaling with close to 300,000 killed primarily in the first half of the 20th century. From a world-wide abundance of over 300,0000 their numbers are estimated at close to 10,000 now, more than 40 years after the supposed end of commercial whaling in 1966.