Gray whales hug the shore to rake the bottom for food

Afew years ago in winter, I sailed my boat down the west coast of Mexico’s Baja Peninsula, from Ensenada to Cabo San Lucas. Because the nautical charts of that area are imprecise, we sailed, for safety, about 10 miles offshore.

We didn’t see one gray whale on that five-day trip.

"I imagined them to be practically lined up head to tail here," my friend said.

But last week the whales made it up to me. As I walked Baja’s west coast beaches, the same ones we had sailed past, scores of gray whales showed me their barnacled backs, wavy flukes and newborn calves. The 40-foot-long whales were, well, practically lined up head to tail.

My friend and I hadn’t seen gray whales from the boat because they swim so close to shore. Some I saw last week were only 50 feet or so outside the breakers, so close I worried they might go over the falls and slam onto the beach.

The gray whales’ penchant for swimming so close to shore is unique among the great whales. Researchers for some time weren’t sure of the route that females with calves swam because the scientists did their surveying from planes flying slightly offshore. This missed the many whales swimming just feet outside the surf line.

Like other great whales, grays migrate extraordinary distances each year, traveling between 9,000 and 13,000 miles round trip. One big difference between grays and their baleen cousins, though, is that grays live their entire lives along coastlines. Rarely do gray whales venture farther than six miles offshore, and some swim in water only 10 feet deep.

This is partly because of the whales’ method of eating. Grays turn on one side, usually the right, and drag their jaw through the sand and mud, plowing up the ocean floor. As the whale pushes out sediment and water with its tongue, bottom-dwelling fish and invertebrates get caught in the whale’s baleen plates.

A large, muscular tongue is handy for sifting silt, but it’s one of the grays’ downfalls. Orcas apparently consider gray whale tongue a delicacy. Gray whale carcasses are found missing only their tongues.

Orcas are another reason researchers guess that grays hug the shoreline and give birth in lagoons: Orca sonar might not work well in shallow water.

Because the current generation of gray whales has grown up with whale-hugging humans, some now swim to whale-watching boats for a pat on the head. The rub of human hands might scratch an itch caused by barnacles and sea lice, the parasites that give gray whale skin its distinct bumpy appearance.

In 1972, Mexico created the world’s first whale sanctuaries in the lagoons of Baja. These are among the few places in the world where you can pet a whale.

I’ve not done that yet, but I’ve now walked a beach where grays swam so close that we whale-watchers couldn’t stop exclaiming, "Look! They’re right here!"

Usually a sailboat is the best tool for whale watching, but in this case low tech worked better. For my fine gray-whale day, all I needed were two bare feet and a steep sand beach.

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Reach Susan Scott at www.susanscott.net.