Feeding Humpback Whales and Common Dolphins in Monterey Bay

Calm, glassy conditions settled over Monterey Bay today, providing exceptional visibility on both our morning and mid-day trips aboard Sanctuary. The standout encounter occurred immediately following an aggressive vertical lunge feed, when an adult humpback surfaced right beside the boat before expelling its engulfed mouthful, offering a clear and unusual look at its expanded throat pouch still packed with water and schooling fish.

As rorquals, humpbacks rely on pleated throat grooves running from the lower jaw down toward the navel. These pleats expand dramatically like an accordion, allowing the whale to engulf thousands of gallons of prey-laden water in a single stride before forcing it through the baleen plates. Watching an individual surface and calmly retain that distended mouthful beside the hull is an uncommon look at the mechanical transition between engulfment and filtration. Throughout both departures, whales also displayed intermittent bouts of pectoral slapping, tail lobbing, and several breaches.

In total, we accounted for roughly forty humpback whales actively working the bay. They were frequently flanked by aggregations of California sea lions, numbering around 250 individuals, who often herd and corral the same baitfish schools from below. Mid-day travel also brought us into company with a pod of roughly 100 long-beaked common dolphins, their quick surfacings standing out cleanly against the flat water.

With surface water temperatures holding around 64°F and light winds, the bay remains productive and stable. Days with this level of surface glass provide invaluable, unobstructed opportunities to study the feeding mechanics and spatial dynamics of these mixed-species aggregations.