Gray whales are known for being hardy and resilient — “the jeeps of the ocean,” as retired U.S. National Oceanic and Atmospheric Administration biologist Wayne Perryman calls them — but something has gone badly wrong, says an article published on anchorage daily news website.
First hint of trouble
In 2019, things got weird. Beginning in January, Baja researchers and tour operators noticed gray whales were arriving there about two weeks later than usual. Nearly a quarter seemed atypically skinny — with their blowholes sunken into their backs like deflated, skin-covered bowls — and their vertebrae protruding along their spines.
They also noticed very few mother-calf pairs — a pattern seen in Baja 20 years ago, the last time there was a significant die-off of gray whales. It was a worrisome indication that something was wrong.
As the whales started to leave the lagoons on their normal northern migration, they began to die.
That month, 12 washed up, mostly along the coasts of Baja.
By the end of February, another 21 had stranded, largely along the Mexican coastline.
Then the pace picked up. In March, 42 more died, this time along a coastal belt that stretched from Mexico to Washington. These included a young male in Long Beach Harbor, two young females on the beaches of Angel Island in San Francisco Bay, and a carcass found floating near an oil platform off the coast of Eureka — so decomposed that researchers couldn’t identify the age or sex.
During April and May, as the whales migrated north, 74 more died, bringing the total to 149. On May 30, the National Oceanic and Atmospheric Administration announced it was investigating the die-off as an “unusual mortality event.”
And as the whales finally reached their Arctic feeding grounds, they began washing up in droves — a total of 214 by the end of the year.
As they were perishing in large numbers, the whales were also acting strangely.
In spring 2019, dozens started appearing in San Francisco Bay — some lingering, some acting as if they were trying to feed. Although their presence delighted urban dwellers, it alarmed others, including Bill Keener, a whale expert at the Sausalito-based Marine Mammal Center, who has studied whales for years.
Deborah Fauquier, a veterinary medical officer for the National Marine Mammal Health and Stranding Response Program, said the annual number of strandings along the west coast of North America has steadily decreased since 2019. However, the number of deaths is still abnormally high, with 172 in 2020 and 92 so far this year.
Fauquier said it’s daunting to figure out the cause of such a large mortality. Even determining the cause of a single whale’s death is a major undertaking, she added.
Over the last three years, NOAA has reported that 268 of the whales it analyzed were discovered in a state of advanced decomposition, making it impossible to tell what happened. Other variables made it difficult to pinpoint a single cause of death.
For instance, all whales are highly sensitive to unnatural ocean noises. Such noises — for instance, seismic air guns or revving outboard engines — could have driven startled or frightened whales into shipping lanes, where they then got hit.
The two newcomers watched as the area’s kelp forests have progressively disappeared, and they documented the changed timing of the gray whales’ migration. Based on their data, the number of migrating whales had dropped from a high of roughly 1,100 in 2015 to a 2019 low of about 800.
But was it just some form of natural variation? Scientists note that Eschrichtius robustus — the scientific name for gray whales — have long shown themselves to be resilient, and adaptable.
Back from the brink of extinction
Gray whales were once found in oceans worldwide, with an estimated peak population along the eastern Pacific of roughly 26,000.
They undertook enormous journeys, and still do. In 2015, one radio-tagged female traveled from the Russian-held seas of Sakhalin Island (where a small population of western north Pacific gray whales still lives) to Mexico and back in 172 days, logging almost 14,000 miles — at that time, the longest recorded migration of any mammal.
In past centuries, other populations of grays were known to comb the Atlantic coastlines: On the western side, they summered along Labrador, on the Canadian island of Newfoundland, and Greenland, swimming south to Florida for the winter; in the east, they congregated around Iceland and the Svalbard archipelago during the feeding months, traveling to the Mediterranean and North Africa for rest and relaxation.
A small population of roughly 200 still roams the western Pacific waters, from Russia’s Sakhalin Island, where Exxon Mobil has a major development, south to the Korean Peninsula.
Among Baja tour operators, legend has it that Pancho and Ranulfo’s father, Pachico Mayoral — then just a 31-year-old fisherman who lived with his five kids and his wife in San Ignacio Lagoon, 560 miles southeast of Tijuana — was the first to realize the whales were friendly.
Soon, he was taking a small number of intrepid tourists and researchers out to see them.
Before long, his neighbors also saw a business opportunity. Together, they established a nascent ecotourism business — with visitors from across the world coming to interact with the ballenas.
In 1988, the Mexican government named the region a protected biosphere. In 1993, it was declared a UNESCO World Heritage Site. The Mexican government limits the number of boats allowed in the lagoon at any given time to 16, restricts the amount of time each boat can spend on the water and regulates fishing to certain times of the year.
The tourists “come here and they touch them, and they start to cry. Or they break into song,” said Ranulfo Mayoral, who has watched tourists interact with whales for most of his life. “The people come here for this out-of-body, almost extraterrestrial experience. They go crazy.”
A gantlet of ocean perils
The lagoons of Baja have long served as gray whale sanctuaries, especially for younger ones at risk of attacks by orcas, their main predators.
But as they journey up the coast to the Arctic’s northern Bering Sea and Chukchi Sea, they face an array of hazards beyond those they historically navigated.
Over the last 30 years, global shipping experts estimate maritime traffic has more than tripled. Some projections forecast it could grow 1,200% more by 2050.
In a study published this year, a research team found that a variety of whales face risk of ship strikes. That was illustrated in May, when two fin whales came to port in San Diego, plastered to the hull of an Australian warship.
But of all whales in the Pacific, grays are the most likely to be struck by ships, the study concluded. “Risk appeared greatest during south- and northbound migration when much of the gray whale population is moving through waters near shore” — places with “high vessel densities,” the study found.
According to a NOAA database, 205 gray whales were killed by vessels between January 2016 and December 2020 in the eastern Pacific.
Possibly because their feeding patterns are changing, gray whales are showing up more frequently and in greater numbers in confined bodies of water, such as San Francisco Bay — where 12 this year have been found dead since early March — and the ports of Southern California.
Researchers, such as Calambokidis, think the whales may be looking for new food sources — digging through the shallow sediments of the protected inlets along their migration route, including San Francisco Bay, Long Beach Harbor and Washington’s Salish Sea.
Ships, boats and submarines can also harm whales indirectly. As their motors and engines whir and their numbers increase, these vessels add to a cacophony of underwater sounds.
Gray whales don’t emit melodious sounds like those of the symphonic humpbacks, recordings of which are often heard echoing throughout New Age salons and yoga studios. Instead, they squeeze out “croaks,” “burps” and congalike “bongs,” which describe some of the species’ six distinct calls.
Those calls — and the ability to hear them — are essential for the survival of these creatures, especially for mothers trying to find their calves and working with them to locate food or avoid predators.
Orcas — also known as killer whales — are part of this gantlet, but they’ve posed serious threats to whales long before modern times. Scientists are still studying this predator-prey relationship but say there’s little evidence that orca attacks are increasing.
Another unknown peril is disease — a fatal virus or bacteria that is being transmitted among gray whales. Research indicates that whales can become susceptible to pathogens if their immune systems are compromised by other stressors, including noise, boat traffic and polluted runoff.
In the Arctic, ‘things are really off’
As spring moves to summer, eastern Pacific gray whales make their way north to the cold waters off Alaska and Russia. These Arctic seafloors have long been their most important feeding grounds, allowing them to bulk up before their migration back to Baja.
Yet the waters of the north have grown warmer in recent decades, and the whales’ food availability has also changed, said Moore, the University of Washington scientist. For instance, in the northern Bering Sea, the crustaceans they once targeted — a species of amphipod — have declined in abundance, she said, forcing grays to consume other species found farther to the west and north.
It remains unknown whether the whales’ new diet is as nutritious as their previous one. But a few whales have been seen feeding in areas of the Arctic where they’ve not been observed before — such as the Canadian coast of the Beaufort Sea.
In the whales’ summer habitat near the Arctic, climate change is hitting harder than anyplace in the world.
In 2012, there was 44.3% less ice than the 1980-2010 average. By 2020, it was 38.9% less, according to records kept by the National Snow and Ice Data Center.
Fisheries in the region were once defined by the northern and southern parts of the Bering Sea — with the northern part colder and home to fish such as Arctic cod. The southern part was saltier, warmer and filled with species such as walleye pollock and Pacific cod.
In recent years, those zones have converged, coinciding with a 99% reduction in Arctic cod numbers and a 900% increase in Pacific cod in the northern Bering Sea, according to federal trawl data.
As the investigation continues, these creatures continue to confound the experts. In 2010, a gray whale was seen swimming off the coast of Israel, and in 2013, another was spotted from beaches in the southern African nation of Namibia. And just this last April, a gray whale affectionately referred to as “Wally” was seen swimming around the Bay of Naples in Italy — a sight not seen since ancient Roman times.
It’s not clear how these whales got so far adrift, although researchers speculate the warming temperatures and diminishing sea ice in the Arctic may have led these rogue whales astray.
Summary
- Gray whales are known for being hardy and resilient — “the jeeps of the ocean,” as retired U.S. National Oceanic and Atmospheric Administration biologist Wayne Perryman calls them — but something has gone badly wrong.
- whales started to leave the lagoons on their normal northern migration, they began to die.
- In a study published this year, a research team found that a variety of whales face risk of ship strikes.
- In the whales’ summer habitat near the Arctic, climate change is hitting harder than anyplace in the world.
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Source: adn.com
