BLUE WHALES aka Ballenas Azule (March 1992)

By Michael Ellis

I had the good fortune to be in the Sea of Cortez, a.k.a. the Gulf of California last month. In our 92-foot long range fishing boat we were exploring the waters and islands in this section of the world sometimes called Mexico’s Galapagos. Just offshore of the ancient city of Loreto, the original capital of the Californias founded in 1697, we found a group of blue whales. We were in channel between Isla Carmen and mainland Baja where I have often seen many different species of whales in the past. On this particular day we saw fin, Brydes, humpback, and blue whales as well as bottlenose and common dolphins. Few places in the world can boast this diversity of whales.

The reason that whales concentrate in the lower and mid-part of the Sea of Cortez is simply that that’s where the food is. When Cortez first sailed into the area he named it La Mar Vermillion, the Vermilion Sea. It was red because of the abundance of krill that colored the water. The krill, of course, is what the big whales feed on. Krill is the Norwegian word for types of crustaceans known by their scientific name as Euphasids or Thysanoessids. During the winter, upwelled water comes from the depths of the Sea of Cortez bringing nutrients to the surface. This water is like compost and it fertilizes the top layer of the ocean creating a tremendous bloom of small plants, the phytoplankton. These are fed on by small animals, the zooplankton. The zooplankton is then eaten by schooling fish, some seabirds and some kinds of whales. You know the rest of the story.

Blue whales are unique among the great whales in that they feed exclusively on krill. Other whales like fin and humpback will eat fish if available. Blue whales are the largest animal that has ever lived on the planet. You could fit five brontosaurs in one blue whale or 25 African elephants or 1600 human beings or about 2000 fifth-graders. In the Antarctic a blue whale was killed that reportedly weighed 130 tons and was 110 feet long! But no more, those big ones were all wiped out by the whalers. The blues we watched that afternoon I estimated to be about 75 feet long, still big by any standard.

We could watch them on the boat’s sonar as they dove beneath us straight down to over 275 feet. We presumed that that was where the food was concentrated. One whale rolled over on its back right near us and we could see the pleats or throat grooves. There are 60 of these that expand just like an accordion when the whale takes a huge gulp of water and krill. The grooves go all the way back to their belly buttons. Full of water they look like gigantic tadpoles. Blue whales often turn on their side when feeding open their mouth at about 50-degree angle and scoop up a big mouthful. They then use the muscular tongue to force the water out through the 400 baleen plates leaving the trapped krill behind. The tongue then sweeps the food into the gullet. Blue whales must eat about four to eight tons of krill, that is over 60 million of these small crustaceans, every single day.

The fastest growing living thing has to be a blue whale fetus and nursing baby. It begins as a single egg at inception and 12 months later at birth weighs 5,550 pounds and is 23 feet long. And then the baby drinks 50 gallons of milk every day gaining an incredible nine lbs. per hour! When it is finally weaned at the age of seven months it weighs 50,000 lbs. and is 52′ long!

Blue whales have been protected from whaling since 1966. Their recovery has been steady but slow. Like most of the great baleen whales blues travel toward the poles to feed in the summer and toward the equator to breed in the winter. And they are found in all the oceans of the world. And it is not necessary to travel far to see these magnificent creatures. Upwelling creates a very rich coastal environment in our neighborhood. Nearly every summer and fall, blue whales feed around the Cordell Bank, the Farallon Islands, off Half Moon Bay and Monterey Bay, sometimes in huge numbers. I have seen as many as 15 at one time.

But even something as big as a blue whale has a predator, besides man. A pack of 40 killer whales, orcas, was seen attacking a full grown blue whale. They bit the flukes and lips causing the animal to bleed profusely and weaken. Then the orcas moved in for a very large meal. Amazing.

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August 6, 2009