Weekly Report ~ August 21, 2023 – August 27, 2023
A Pair of Minke Whales and a Dolphin Trifecta Week with Risso’s, Bottlenose, and Common Dolphin!
Early one morning, off Aliso Canyon, close to a pod Common Dolphin, was a pair of Minke whales. With one following the other, we watched as they were likely tracking the dolphin to join in feeding on small bait fish.
Risso’s dolphins in small groups have been observed beyond the continental shelf. These cetaceans generally prefer deeper offshore waters and have been seen in groups from 10-30 foraging, simultaneously diving as a group with a dive time of about 3-5 minutes. Surface behaviors included flipper slapping, tail slapping, and breaching.
Offshore Bottlenose Dolphin pods have been estimated to have up to 100 members. During most of these sightings, these dolphins with several calves seemed to be on the move, and some groups were occasionally feeding. Active pods displayed high breaches in our wake while others were bow-riding. There were multiple sightings of Coastal Bottlenose Dolphins usually in groups of 2 to 6. One day as we were leaving on our last trip, we had a pair of coastal bottlenose dolphins in the Dana Point Harbor. They turned up the outer channel and began foraging in the shallow water, and as we turned to leave, they both simultaneously breached off our bow.
Common Dolphin encounters included several massive pods called “superpods” or “megapods” containing a thousand or more dolphins with subgroups of nursey pods, which include females with calves and groups of about 10-20 clearly feeding while others engaged with our vessels. Multiple groups would come together, forming mega-pods of well over 1,000 members. These impressive pods of common dolphins seemed to go on for miles. There were several dolphin stampedes as this dolphin looked like they were sprinting across the water, racing each other as they porpoised or leaped out of the water in harmony. Seeing so many tiny calves synchronizing with their “mom” and keeping up with “their” pod is always a beautiful sight.
Risso’s, Bottlenose, and Common Dolphin are considered small-toothed whales and often found near a continental shelf like in the Southern California Bight. Here, upwelling can bring nutrients to the surface, potentially feeding bait fish, which are prey for these dolphins.