The pods are in your favor
Your chances are high during Spring Whale Watch Week
Photo by Morris Grover
By Michael Edwards
For the TODAY
In one year, gray whales swim from Baja California’s balmy calving bays, to the Arctic’s nutrient-rich seas, and back again. The 12,000-mile journey is the longest migration of any mammal on Earth, and residents and visitors to the Oregon Coast have front row seats to this biannual phenomenon.
After a 13-month long gestation period, the gray whale mother births a 15-foot long, 1,000-pound calf into Baja California’s 72-degree waters. Kevin Shelly, a whale watching boat captain for 27 years, said that “the calves in San Ignacio Lagoon were playful. They breached, rolled and swam right up to the side of the boat. The mothers floated just below the surface. They looked right at us, but were never aggressive.”
Though Mexico’s warm waters are ideal for rearing whale calves, the lagoons are food deserts. Thousands of miles away, in the frigid north, a mud-entombed food bonanza awaits.
On a blustery day in early March, before the leviathans’ arrival, I spoke with Justin Duering, the Oregon State Parks Interpretive Ranger at Depoe Bay’s Whale Center, about the specifics of the gray whale migration.
“Beginning in late March, 10 whales per hour pass by the center,” he said. Unlike the whales that enter the bay in May to feed on mysid shrimp, these Alaska-bound travelers “swim along the coastline beyond the mile-marker buoy.” Sexually immature whales and pregnant females lead the procession north. “Because of their massive caloric requirements, we see pregnant whales early. Pregnant mothers have to get to the Arctic and begin feeding as soon as possible.”
Duering added that “mothers with calves are the last to pass by in late spring.” This is because despite its impressive size, the newborn calf does not have adequate blubber to insulate itself from the north Pacific’s frigid waters. While baby grows fat and strong in Mexico, gulping down 50 gallons of milk per day, mother fasts, drawing on her fat stores for sustenance.
Migrating gray whales encounter many obstacles. Ships entering and exiting busy Pacific Coast ports pose collision hazards and the drone of diesel motors creates a disorienting underwater soundscape that increases the whales’ production of the stress hormone, cortisol. Heavy rains cause overflows in municipal wastewater facilities. The contaminated runoff closes beaches to surfers, but gray whales swim five miles per hour through the sludge and plastic debris. Whales regularly get entangled in fishing gear, and despite the mothers’ notoriously ornery resistance, calves are preyed upon by orcas.
By the time she and her baby arrive in the Bering Sea in June, mother will have lost 40 percent of her body weight. While in the Arctic, she will eat a ton of amphipods, or sand fleas, every day. The gray is the only whale that scoops up the ocean’s substrate and strains water and mud through its baleen strands, swallowing only the scrumptious sand fleas. By October, mother will hopefully regain her pleasantly plump figure. This however, is increasingly not the case.
Since 2019, there have been a high number of emaciated gray whales found stranded along the Pacific Coast. Recent studies cited by NOAA suggest that the amphipod population in the Arctic is decreasing, and that the whales aren’t getting enough to eat.
These days, spring comes early to the Arctic, the sea ice retreats and an explosion of phytoplankton ensues. Without the protective cover of the pack ice, storms make a froth of the sea and the zooplankton population skyrockets. Zooplankton feast on the phytoplankton before it settles into the muddy sea floor. This means that the amphipods have less to eat, which leads to fewer amphipods. Fewer amphipods means less food for whales.
In 2016 there were an estimated 27,000 gray whales in the Eastern North Pacific. In 2022, that number fell to less than 17,000. Scientists are hopeful that the gray whale population and the tonnage of Arctic amphipods has reached an equilibrium, and that the dramatic die-off will wane.
Despite the myriad challenges that the species faces, it's worth noting that in the 1970s, gray whales had been hunted to the brink of extinction. The abolition of commercial whaling and the gray whale’s subsequent resurgence represents one of the major accomplishments of the Endangered Species Act, is a monument to international cooperation, and probably most of all, is a product of the animal’s dogged refusal to fade into oblivion.
Spring Whale Watch Week begins on Tuesday, March 28, and runs until Sunday, April 2. Between 10 am and 1 pm, Oregon State Parks’ volunteers will staff 17 prime whale viewing sites along the Oregon Coast, including several along the Central Oregon Coast. The volunteers will answer questions and help visitors spot whales. For information on specific observation sites near you, go to stateparks.oregon.gov.