Dive Dry with Dr. Bill

033: Gray Whales

This is an excellent time to write about the leviathon seen about this time of year in Catalina's waters. No, I'm not talking about the extra pounds I added serving on the cruise ship this winter. I'm referring to 30-40 tons of solid blubber (with a little muscle and bone thrown in) known as the gray whale. Although these whales are not large by whale standards (up to 50 feet, they are dwarfed by blue whales which may be twice as long. I've always had a mild interest in whales, but I never attached the significance that many observers give them as a marquee species. Fortunately the efforts of such people led to a recovery of this species from a post-whaling low of about 2,000 to some 25,-26,000 a few years ago. Whaling for greys stopped for a while following 1913, but was not permanently halted until 1946 when the International Whaling Commision was formed. Although the numbers have dropped by about 7,-8,000 in recent years for unknown reasons, this certainly is one of the success stories in the conservation of endangered species. My real interest is directed towards the creatures these giants feed on... the larger plankton, invertebrates and occasionally small fish. Although we think of baleen whales as plankton feeders, the gray whale actually is a bottom feeder eating amphipods, worms and other invertebrates filterd out with its baleen plates. Think of all the critters that go into making all that blubber! Each whale when feeding may consume over one ton of food a day.

While I was on the cruise ship this winter, I used to tell our passengers a tall tale about the night my college classmate former Vice President Al Gore invited me to the White House for dinner. While sitting there, Hilary said to me "I'm sure you realize Dr. Bill, it takes an ecosystem to raise a whale." I responded "after all, which came first... the plankton or the whale?" Obviously I agreed with her since primitive whales only appeared on the scene within the last 40-50 million years and gray whales much later than that. Long before that, plankton were drifting in the sea adding oxygen to our atmosphere and doing just fine without the presence of these huge vacuum cleaners.

Gray whales live for as long as 70, and possibly much more than 100 years. They undertake the longest migration of any mammal in their round trip between the feeding grounds in the sub-Arctic regions and the calving grounds in lagoons on the Pacific coast of Baja. The round trip is over 20,000 km (12,000 miles). Although they make this migration at an average speed of about 4.5 knots, they may swim in bursts at 11 knots. Females breed every two years, giving birth in alternate years to calves about 15 feet long and weighing 1,500-3,000 pounds. The young calf nurses for about 7 months. While swimming, gray whales surface every 3-5 minutes to breathe. Because their blowholes have two nostrils, the blow is heart-shaped. Killer whales are the only real predator on this species other than man.

Over the last 35 years here, I've noticed that most of the gray whales migrating by Catalina pass on our windward side now rather than the leeward side. I used to watch them swim by Toyon Bay through my telescope, often catching just the whale's eye in my field of view. This shift began in the late 1970's, and many attribute it to the increased year-round boat traffic between Catalina and the mainland. However, in about 1976-1977 following an El Nino, this region experienced the start of a long-term oceanographic change in water temperature. Perhaps this change caused the whales to change course?

When I left for my Jan-Feb stint on board Lindblad Expeditions M.V. Sea Bird, I was determined that I would not touch a gray whale if the opportunity presented itself. Our cruises went between La Paz and Magdalena Bay on the Pacific coast of Baja where about 6% of the gray whale population goes to give birth to their calves. On my first three cruises no opportunity presented itself, although we saw plenty of mothers with newborn calves, adults and youngsters spyhopping or finning, and the adults breaching. The displays were impressive (although they took second place to the humpback whales we observed off the Gorda Banks).

On the last two days I was in Magdalena Bay, the opportunity did present itself... in spades! The first day a 35-ton female headed directly to our Zodiac. Our permit required us to keep a distance of 100 feet from a whale, but they could approach us as close as they wanted. This one definitely desired a "close encounter!" It not only approached us, but came alongside with its blowhole right next to the boat. Fortunately I shielded my video camera shortly after when it became very apparent the whale was about to blow... salt water and whale mucous covered my jacket (but a smile covered my face).

I let the video camera roll as the whale allowed our passengers and biologists to touch it, scratch it and "communicate" with it... as long as they didn't touch the sensitive blowhole, eyes or fins. Then it rolled over on its back and lifted its belly up to the boat for all to touch. Permits limit contact to 30 minutes so our Zodiac driver eventually tried to ease away from the whale. It wouldn't have it... and swam over to the Zodiac, pushed its back up against the boat, and moved us back into position. Finally I couldn't resist. I scratched the creature's belly... and I guess it felt like a hard boiled egg (so people tell me). The next morning we had a repeat performance with the exact same whale and script! All I can say is that good scientists can change their mind when preesented with new facts.

Despite this incredible encounter, I still focus most of my attention on the invertebrates and fishes. What kind of self-respecting "marine" animal has to continually come up to the surface to breathe? Certainly not my plankton, most invertebrates or fish. Besides, it's just a "fluke" if you're lucky enough to see a whale at all!

© 2003 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

Image caption: Friendly gray whale pushing Zodiac and extending pectoral flipper; blow hole of
the gray whale next to the Zodiac; Dr. Bill's hand touching whale's belly;
biologist and guest looking at throat pleats on upside-down whale

This document maintained by Dr. Bill Bushing.
Material © 2003 Star Thrower Educational Multimedia