Big Blue Neighbors

By OCinSite At-Large | February 17, 2012 10:03 AM

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When Dave Rastovich, the famous Australian surfer and whale advocate, reached the halfway point of his TransparentSea Voyage from Santa Barbara to San Diego, he witnessed the thrill of a lifetime. Just off the coast of Newport Beach, Dave and his small team of intrepid adventurers came face to face with a pod of blue whales. Perhaps sensing Dave’s noble quest, the whales came right up alongside them, almost as if to say “hello” and “thank you.”

Blue whales are the largest creatures on earth, maybe the largest that ever lived, and last fall they congregated off our coastline in numbers higher than anyone can remember. Hundreds of blue whales had come together off of Southern California to feed on an explosion of krill—the small shrimp-like crustaceans that make up most of their diet.

At times during the fall, dozens of blue whales were visible right off Laguna’s coast. Blue whales can be distinguished from our more typical passerby, the gray whale, in a few ways. For one thing, the blue whales show up at times when we don’t typically see gray whales off our coast because their southern migration hasn’t yet reached this far south. Also, blue whales are twice the size of gray whales, often reaching more than 80 feet. The most obvious difference is their spout. Blue whales have a spout that is narrower and much taller than gray whale spouts, and the puff of water vapor tends to linger and stay visible for a longer time.

Blue Whale Basics

The largest blue whales (Balaenoptera musculus) are found in the Southern Hemisphere, where they can reach more than 100 feet in length. The longest blue whale ever recorded was a 108-foot adult female caught during whaling efforts in Antarctica. Those found in the Northern Hemisphere tend to be smaller, but can still reach up to 80 feet in length. Females are larger than males of the same age—the largest perhaps weighing as much as 150 tons (300,000 pounds), comparable in size to a Boeing 737. 

Blue whales have a long and comparatively slender shape compared to other whales and a broad flat “rostrum,” or nose. Their dorsal fin on their back is proportionally smaller than other baleen whales, and true to their name, they have a mottled blue-gray color pattern.
Blue whales are baleen whales, meaning that they have hundreds of large, brush-like overlapping plates in their mouth. During feeding, the whale can take a huge volume of water and food into its mouth, expel the water and trap the food in the baleen to eat.  During the feeding season, the blue whale gorges itself, consuming four tons (8,000 pounds) of krill or more a day.

Blue whales may be found in all oceans of the world but are more common in the Southern Hemisphere than in the Northern Hemisphere. They migrate to more temperate waters, like those found off of Southern California, during the winter months to mate and give birth.

Blue whales are most often seen in smaller numbers off of Southern California during the early fall and often appear by migrating northward just outside the Channel Islands. They are fast, strong swimmers, capable of reaching 30 miles per hour when alarmed, but they usually cruise along at about 12 miles per hour.

Although they may be found by themselves or in small groups, it is more common to see blue whales in pairs. They are sometimes seen in larger groups, but last fall, their appearance so close to the mainland and in such high numbers was unprecedented.

Back From the Brink

Due to their enormous size and speed, blue whales were not targeted by early whalers because they couldn’t catch them with hand harpoons. It wasn’t until the invention of engine-powered vessels and exploding harpoons in the late 1800s that blue whales could be effectively hunted. Blue whales were hunted mostly as an oil supply, as a single large blue whale could yield up to 120 barrels (5,000 gallons) of oil. Once the whaling industry began to focus on blue whales after 1900, thousands were slaughtered. The killing of blue whales peaked in 1931 when almost 30,000 whales were killed.

At that point, blue whales became so scarce that whalers focused on other, more abundant species. While whale populations are hard to measure with accuracy, it is estimated that prior to whaling, there were approximately 350,000 blue whales in the world. That population was reduced by 99 percent before the International Whaling Commission protected them globally in 1966. Blue whales are also listed as endangered under the Endangered Species Act and protected by the Marine Mammal Protection Act.

Presently, there are an estimated 3,000 to 4,000 blue whales in the Northern Hemisphere and more than 2,000 just along Southern California. Recovery has been extremely slow for blue whales compared to other whale species, and there is evidence that their recovery has slowed over the last couple of decades. 

The appearance of so many blue whales so close to the coast is exciting for spectators, but troublesome for the whales themselves because they are often in heavily used shipping lanes and are increasingly at risk of being hit and killed by large vessels using West Coast ports.

Obstacle Course in the Ocean

Today, ship strikes are one of the biggest threats to blue whales along the California coast. While the average number of blue whale mortalities from ship strikes has historically been low, the number of strikes is rapidly increasing.

In September 2007, four blue whale deaths due to ship strikes were reported in the Santa Barbara channel. It is not well understood why, but blue whales seem particularly vulnerable to ship strikes, especially at night when they tend to spend more time at the surface than other whales.

In response to this alarming trend, the Los Angeles-based American Cetacean Society continues to support research to better understand the risks associated with ship strikes and looking at ways to shift shipping lanes to reduce the number of ship strikes.

The Santa Barbara-based Environmental Defense Center has taken things a step further and has threatened legal action if federal agencies do not require slower speeds for vessels and ensure that recovery plans are carried through.

A Beautiful Sight

If you head out whale watching in the future, keep your eye out for a long, sustained spout to witness the stunning majesty of the world’s largest mammal, and remember, this species is at risk due to our past and present actions.

As Dave Rastovich recounts, “At one stage the pair surfaced right next to my kayak and looked us in the eye. To have the biggest heart come and say hello is a very humbling experience. For this to happen right outside of America’s busiest cargo port is a contrast that wasn’t lost on our group.”