Blue whales are the largest animals ever to have inhabited the planet -- larger, even, than the great dinosaurs -- but these endangered cetaceans are often elusive and the sighting of one whale is generally considered a special treat.However, thanks to the recent upwelling of nutrients and a monstrous bloom of shrimp-like krill off Monterey, Calif., the sighting of a single specimen there might now be regarded as a disappointment.
That's because dozens of the massive leviathans have converged within Monterey Bay to gorge on krill. With them are smaller but more gregarious humpback whales, and various other cetaceans.
Together they've transformed the region into a marine mammal wonderland that is luring tourists, scientists and news crews in unprecedented numbers.
"This past weekend we took out more people than I've ever taken out since I started doing this 20 years ago," said Nancy Black, a prominent whale researcher who runs Monterey Bay Whale Watch."We took out 450 people and that's the capacity we can take out with our two boats going out three times each day. I've never had that many people or that many trips."
Black described the blue whale gathering as a "once-in-a-decade event" that began July 5, when dozens of blue whales appeared to have materialized overnight. She believes the whales who initially discovered the krill used long-distance communication skills to summon other whales. Word quickly spread on shore as well, and whale-watching operations are trying to meet demand by adding extra trips and running essentially from morning to dusk.
Blue whales, which can measure 90 feet and weigh up to 150 tons, are sometimes seen off California during the summer, but rarely in such concentrations that allow for multiple sightings and blows of whale breath that shoot skyward like steam from kettles in almost any direction a person looks.
"It's rare to see so many of them in one place, but to see both species of whales -- blues and humpbacks -- together in one place like that is extremely rare," said Alisa Schulman-Janiger, a researcher with the Los Angeles chapter of the American Cetacean Society.
Black estimated the overall number of whales in Monterey Bay to be 200 "at a bare minimum." The gathering of at least several dozen blue whales is significant considering there are only about 10,000 blue whales worldwide, and only about 2,000 that utilize Eastern Pacific waters between Central America and Northern California.
Blue whales migrate north each spring and summer to fatten up. A single blue whale can devour four tons of krill per day, but Black said enormous clouds of krill -- at times 200 feet thick and spanning for miles -- are still present along the drop-offs of Monterey Bay's vast submarine canyon.
Such bounty appears to have placed all marine mammals in the area in a playful mood. Whale watchers have witnessed humpback whales breaching clear of the water and dolphins and porpoises riding in surface wakes generated by swift-swimming blue whales.
It's worth noting that sporadic blue whale sightings are occurring to the south off Orange County and Los Angeles, and predictable blue and humpback whale sightings are occurring off Santa Barbara. But one needs only to check Black's log book to see that the big feed -- gluttony on a scale that might be unrivaled in the animal kingdom-- is off Monterey.
Black, a marine biologist involved in many research projects, counted 28 blue whales on July 5, and the phenomenon has shown no signs of letting up.
On Sunday, passengers aboard her morning Sea Wolf excursion enjoyed close encounters with 28 blue whales, 22 humpback whales and 150 Risso's dolphins. Those aboard the early-afternoon voyage saw 24 blue whales, 58 humpback whales and 45 Risso's dolphins. Those on he late-afternoon trip saw 15 blue whales, 30 humpbacks whales, 1 minke whale and 60 Risso's dolphins.
On Saturday's morning adventure, the count was almost unbelievable: 14 blue whales, 55 humpback whales, 600 Pacific white-sided dolphins, 2,200 Risso's dolphins, 40 northern right-whale dolphins and seven harbor porpoise.
On Monday morning Black, in a cellphone interview, said other local whale-watching outfits are enjoying similar encounters. As Black spoke, the Sea Wolf had just left a pod of Risso's dolphins and a couple of a couple of friendly humpbacks, and was off to find the blues.
"I have to admit, it's been pretty amazing," Black said.
-- Pete Thomas
Photos: Top image of blue whale feeding on krill courtesy of Alisa Schulman-Janiger; bottom image of humpback whale fluke by Pete Thomas. Video courtesy of ABC
Editor's note: This post also appears on the GrindTV.com Outdoors blog