By George Yarbrough
August proved to be an exciting month for marine mammal sightings as numerous of the elusive Risso’s dolphins (Grampus griseus) were spotted in the waters around the Queen Charlotte Islands. Over fifteen sightings were recorded with the British Columbia Cetacean Sightings Network (BCCSN) from ocean adventure groups, recreational boaters and warden officials. A number of the Risso’s dolphins enjoyed Bag Harbor and stayed an unusually long time. The first group was spotted on August 12 and congregated in groups of up to 40 individuals in the bay. A majority of the sightings described the mammals as feeding and sometimes breeching in patterns. The diet of the Risso’s Dolphins mainly consists of squid.
These sightings are exciting due to the limited up-close encounters with the species. Relatively little is known about the behavior and biology of the dolphins. However, it is speculated that the species’ preferred habitats occur at deep offshore oceanic shelves in tropical and temperate waters. Making it even more unusual for the whales to be found in in-shore BC waters. The last confirmed sightings in BC occurred in 2003 with relatively few individuals documented.
Being the fifth largest member of the dolphin family (up to 4m) Risso’s dolphins are relatively easy to spot and identify. The coloration of the species widely varies with age. Infants are born with a brownish coloration turning to a charcoal black but maintaining the distinct white patch around their mouth. As they mature the dolphins lighten in color to a gray and in some occasions turn to white. The dorsal fin, which always stays black, and the bulbous head are the helpful features in identifying the animal. The dorsal fin is proportionally the largest throughout the dolphin family, and the head is peculiarly round with a crease down the front. The body of the dolphin is usually visibly scarred. This is mainly thought to be the result of social interactions with other individuals.
As the rain and colder weather slide down to central and southern BC waters it is expected that the dolphins will migrate to warmer temperatures. However you never know what can happen, so keep your eyes peeled for groups of Risso’s dolphins! All whale, dolphin, porpoise and sea turtle sightings can be made here.