Whale of an Opportunity : Scientists Excited as Giant Mammals Flock to Waters off Channel Islands

Edward Cassano considers himself fortunate to have witnessed one of nature’s more unusual spectacles: a blue whale and blue shark feeding side by side.

It’s an impressive sight, if not a comical one: A massive whale lunging through a red cloud of krill, its mouth agape, taking in an enormous amount of the tiny, shrimp-like crustaceans. And the slender shark, at its side, chomping away at the planktonic critters, which are futilely trying to scurry out of the jaws of death.

“That was unbelievable,” Cassano recalls of his recent observation. “We pulled the boat right up, and this blue shark comes by the whale opening and closing its mouth, and krill are jumping out of the way. I mean that’s been reported [to have happened], but it’s just amazing to see.”

Perhaps. But for Cassano, manager of the Channel Islands National Marine Sanctuary, the entire summer has been amazing.

Blue whales, as many as 200, for the fifth year in a row have taken up temporary residence in the nutrient-rich waters surrounding the northern Channel Islands, mostly within sanctuary boundaries.

That in itself is amazing, considering that, while there were once an estimated 300,000 blue whales, there are believed to be only between 5,000 and 10,000 left, a reduction blamed almost exclusively on overzealous whalers in the first half of this century.

And blue whale sightings were considered very rare off California before 1966, when they became protected by the International Whaling Commission.

How times have changed.

Now there are believed to be 2,200 whales in a “California population” that utilizes a large area between Mexico--possibly as far south as Costa Rica--and Northern California.

Of those, 200 or so are currently traveling between Monterey and the Channel Islands area, living high on the hog, swilling up krill as if there is no tomorrow.

“In their world, this is like a block in their neighborhood,” Cassano says of the Channel Islands. “They’re, like, going to the corner deli--they’re hanging out here, and then they’ll move on.”

Until they do, however, they are providing quite an opportunity for whale watchers and scientists.

“Yesterday, in heavy fog, we saw a dozen whales and we had no more than quarter-mile visibility,” Fred Benko, captain of the Condor out of Santa Barbara’s Sea Landing, said Monday. “We had 125 passengers aboard and two blue whales turned and headed toward us, and both of them threw their flukes [tail-fins] in the air. The roar that came up from the crowd was amazing. Even the whales must have heard it.”

If so, perhaps they also heard the spiel Benko has been giving his passengers since he began alternating whale-watching trips with fishing trips since the whales arrived in force in 1992.

They are treated not only to up-close encounters with blue and humpback whales--and fin whales, minke whales, killer whales, dolphins, sea lions and several species of marine birds for that matter--but enough whale trivia to last a lifetime:

--That blue whales measure up to 85 feet and can weigh 150 tons.

--That newborn calves can be 25 feet long and weigh 7 1/2 tons, and can gain as much as 300 pounds a day and grow to 55 feet within six months.

--That a blue whale’s heart is as big as a Volkswagen Beetle and pumps more than 10 tons of blood through the mammal’s massive body; and that a blue whale’s tongue is as big as an African elephant, weighing up to six tons.

As for krill, they may be small, but to the blue whale they’re plenty filling.

Benko might also explain that a blue whale’s stomach can hold a ton of krill and that the whale usually feeds four times a day, meaning it is capable of eating four tons of krill a day.

“It lunges through that krill at 10 knots, and its mouth opens so wide you can see its pleated throat,” Benko says. “The strain on its jaw must be enormous.”

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The California population of blue whales is believed to be the largest in the world, larger even than that off Antarctica, whose historic population of 180,000 blue whales has been reduced to as few as 1,000.

Nobody is sure where the other blue whales are at the moment, but the accessibility of part of the California population nonetheless is affording scientists an opportunity to learn a little more about an animal whose natural history they know very little about.

This summer, as part of a long-term cooperative project between state and federal agencies, scientists and researchers spent several weeks on the water studying the blue whale’s habitat and prey. The project ended Aug. 2 and will begin again next summer, provided the whales return.

“We’re all coming together to try to understand a very complicated environment,” Cassano says. “Right around here you’re seeing the surface of the ocean. But that’s all you’re seeing. Below us is a very complex ecosystem.

“In that ecosystem there are many different animals. One of the animals is the blue whale, which is the largest animal ever to live, and that includes dinosaurs. The focus of the study is trying to understand this animal’s habitat. What is going on here? What is bringing these animals to the sanctuary?”

The obvious answer is krill, which is abundant in the region because of strong winds and constant upwelling of nutrient-rich water off Point Conception, which causes the plankton to bloom, which in turn provides a food source for krill, which attracts the whales.

But to scientists, this is not enough.

This summer they came armed with six vessels ranging in size from the 180-foot research ship David Starr Jordan to the 36-foot sailboat Star Rover, manned by a researcher from UC Santa Cruz trying to attract the mammals with simulated whale calls.

They came with equipment to measure temperature, salinity and basically to study the whale’s habitat from surface to bottom. They came with bio-acoustic equipment to measure the density and depth of krill swarms.

And they came with tagging and tracking equipment to measure the depth and duration of the whales’ dives.

This, all but perhaps a few of the scientists agree, was the most exciting aspect of the research because it meant racing after the whales in a small inflatable boat, as in whaling days, and firing an object into their backs.

Only in this case the object wasn’t a deadly harpoon but a harmless small electronic tag--fired from a crossbow--that penetrates only a few inches into blubber and self-releases after data is gathered in a time-depth recorder within the tag.

“We hit one the other day and just nailed it,” says David O. Brown, who documented the effort for the sanctuary. “It plopped right into the whale and it didn’t flinch, it didn’t quiver. It dives, and surfaces again, which means it was not spooked. If it’s spooked, man, it’s gone.”

Complete results of the study have not been released, but the scientists have noted that blue whales tend to congregate in areas where there are shelf breaks that drop to great depths. These areas are also likely to attract krill.

One of the tagged whales dived more than 600 feet to get to a “prey layer” of krill, but most of the whales observed dived to about 300 feet in eight- to 10-minute intervals to get to the krill.

What is odd, scientists also note, is that krill tend to stay very tightly grouped and in fairly deep water during the day, rising to the surface only at dusk to disperse and feed on phytoplankton.

Staying below, where they are less likely to be seen, and close to together, in an attempt to appear larger, is a defensive mechanism against certain predators, but it is an act of suicide against blue whales, which can take out nearly a ton merely by flapping their flukes and opening their mouths.

“This indicates that whales are not the major predators,” says Donald Croll, assistant research biologist at UC Santa Cruz. “That’s not an effective strategy to get rid of whale predation.”

Nor, in some cases, is it an effective strategy to avoid the snapping jaws of the blue shark.

NOTEWORTHY

The tuna season may not have developed as hoped south of San Diego, but there have been few complaints in the past week or so as yellowtail and dorado have been swarming under practically every offshore kelp paddy south of the border.

“When you get the right paddy the whole ocean explodes,” says Capt. Rick Podolak of the vessel Holiday.

They are not tuna, but the yellowtail and dorado are doing a nice job of picking up the slack in business for the San Diego fleet.

The tuna, for the most part, remain well south and out of range of the one- and 1 1/2-day boats. The multiday boats are encountering some, but not many. There are some exceptions, however. The Qualifier 105, on a four-day trip, recently boated 70 yellowfin and two 100-pound-plus bluefins to go with 325 yellowtail and 97 dorado.

Other catches of note include two swordfish--a 233-pounder aboard the Legend, and a 222-pounder, after a 7 1/2-hour fight, aboard the Sea Trek IV. Some albacore are still being caught off the Central California coast, but fishing remains spotty at best.

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There are still openings for the Balboa Angling Club’s 20th annual Ladies’ Billfish Tournament on Aug. 24. Details: (714) 476-2345.