National Geographic - Craig Welch
When a deadly patch of warm water shocked the West Coast, some feared it was a preview of our future oceans.
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| Thousands of California sea lions, such as this one on rocks near Canada's Vancouver Island, died in 2014 and 2015. Many starved as they struggled to find food in an unusually warm eastern Pacific. Paul Nicklen |
The first fin whale appeared in Marmot Bay, where the sea curls a
crooked finger around Alaska's Kodiak Island. A biologist spied the calf
drifting on its side, as if at play. Seawater flushed in and out of its
open jaws. Spray washed over its slack pink tongue. Death, even the
gruesome kind, is usually too familiar to spark alarm in the wild north.
But late the next morning, the start of Memorial Day weekend,
passengers aboard the ferry
Kennicott spotted another whale bobbing nearby. Her blubber was thick. She looked healthy. But she was dead too.
Kathi Lefebvre
is talking about the whales as we crunch across a windy, rocky beach,
200 miles north of Kodiak. In a typical year eight whales are found dead
in the western Gulf of Alaska. But in 2015 at least a dozen popped up
in June alone, their bodies so buoyant that gulls used them as fishing
platforms. All summer the Pacific Ocean heaved rotting remains into
rocky coves along the more than 1,000-mile stretch from Anchorage to the
Aleutian Islands. Whole families of brown bears feasted on their
carcasses.
Lefebvre, a research scientist at NOAA's Northwest Fisheries Science
Center in Seattle, Washington, had examined eye fluid from one of the
carcasses in a failed attempt to winnow the cause of death. Now the two
of us are on Kachemak Bay in Homer, Alaska, inching toward a wheezing,
dying sea otter sprawled out on the shore. Otter deaths are skyrocketing
on the shoreline beneath the snowcapped Kenai Mountains, so Lefebvre is
here to see whether the fates of these otters and whales are somehow
intertwined.
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| Jellyfish-like animals known as "by-the-wind sailors" blanket an Oregon beach near an old shipwreck. Some of the same unusual wind patterns and currents that recently warmed the Pacific pushed these floating creatures by the millions onto beaches from Southern California to British Columbia. Photograph by Tiffany Boothe, Seaside Aquarium |
In the past few years death had become a bigger part of life in the ocean off North America's West Coast. Millions of sea stars
melted away in tide pools
from Santa Barbara, California, to Sitka, Alaska, their bodies
dissolving, their arms breaking free and wandering off. Hundreds of
thousands of ocean-feeding seabirds
tumbled dead onto beaches. Twenty times more sea lions than average
starved in California.
I watched scientists lift sea otter carcasses onto orange sleds as they
perished in Homer—79 turned up dead there in one month. By year's end,
whale deaths in the western Gulf of Alaska would
hit a staggering 45.
Mass fatalities can be as elemental in nature as wildfire in a
lodgepole pine forest, whipping through quickly, killing off the weak
and clearing the way for rebirth. But these mysterious casualties all
shared one thing: They overlapped with a period when West Coast ocean
waters were blowing past modern temperature records.
As hotter oceans destroy coral reefs in the tropics and melting ice
alters life in the Arctic, it's been easy to overlook how much warm
water can reshape temperate seas. No more. Between 2013 and earlier this
year, some West Coast waters grew so astonishingly hot that the marine
world experienced
unprecedented upheaval.
Animals showed up in places they'd never been. A toxic bloom of algae,
the biggest of its kind on record, shut down California's crab industry
for months. Key portions of the food web crashed. It's not clear if
greenhouse gas emissions exacerbated this ocean heat wave or if the
event simply represented an outer edge of natural weather and climate
patterns. But the phenomenon left daunting questions: Was this a quirk,
an unlikely confluence of extremes that conspired to make life harsh for
some sea creatures? Or was it, as one scientist says, a "dress
rehearsal"—a preview, perhaps, of what hotter seas may one day bring as
climate change unleashes its fever in the Pacific?
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| Humpback whales feast on fish in Monterey Bay, California. Anchovies were scarce in many areas in 2015, but so many congregated in the bay that Jim Harvey, director of Moss Landing Marine Labs, watched from his window as 50 or 60 whales dined on themat once. "That's not normal," he says. |
While Lefebvre and I are pondering our next move, a radio call comes
in. Another dead otter has surfaced on Homer Spit, five miles away. We
retrace our steps to a dusty parking lot, pile into a pickup, and head
off.
Beginning in late 2013, a bewildering patch of warm water
formed in the Gulf of Alaska. A stubborn atmospheric high-pressure
system, nicknamed the "Ridiculously Resilient Ridge," was keeping storms
at bay. Just as blowing across hot coffee frees heat, winds usually
churn and cool the sea's surface. Instead, heat within this shifting
mass, which University of Washington climatologist
Nick Bond
dubbed "the blob," built up and morphed into a wider patch along North
America's West Coast, where it met warm-water masses creeping north. Sea
temperatures in some places rose seven degrees Fahrenheit higher than
average. Some patches of ocean were hotter than ever recorded. At its
peak the warm water covered about 3.5 million square miles from Mexico
to Alaska, an area larger than the contiguous United States.
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| Lauren E. James, NGM staff. Sources: Nick Bond, University of Washington; Raphael Kudela, university of California, Santa cruz |
Two Long, Hot Years
Starting in the winter of 2013, weak winds failed to stir up and cool the northeast Pacific Ocean. Heat accumulated and then spread along the Pacific coast until late 2015, shifting marine life, shuffling the food web, and fueling a massive bloom of toxic algae. The warm water spread farther, went deeper, and lasted longer than at any other time in recorded history.
Wild, Wild West Coast
Algae typically bloom in a few places for a few weeks every spring. From spring to summer of 2015, as warm waters met nutrients rising from the deep, algae spread from Southern California to Alaska. With the additional heat, these algal blooms lasted longer, and many were highly toxic. |
Warmer Deep Water
Heat extended to ocean depths of 1,300 feet in some places. A temperature rise of even a single degree can disrupt an ecosystem. Heat remains deep in the ocean, even though the surface cooled in late 2015.
A Refuge From the Heat
As waters warmed, wildlife moved into Monterey Bay to feed in cool, nutrient-rich water rising from the deep canyon. In 2015, high concentrations of toxic algae lasted longer than usual, harming animals and making some shellfish unsafe to eat. |
Did planet-warming carbon dioxide from
fossil fuels contribute to this event? No one knows for sure. One
controversial notion suggests that the rapid retreat of Arctic sea ice
is making the polar jet stream wavier, allowing weather systems to persist longer. A more accepted theory pegs this heat to normal atmospheric fluctuations in the jet stream
triggered by warmth in the tropics. But even researchers subscribing to
that theory don't necessarily rule out a secondary role for climate
change. "Is long-term warming somehow the puppeteer controlling things
in the background?" asks Nate Mantua,
at NOAA's Southwest Fisheries Science Center in Santa Cruz, California.
"I haven't seen proof, but it's clearly a prime suspect."
Alaska's Sick and Dying Otters
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| A
dying sea otter takes its last breaths. The population of sea otters in
Kachemak Bay is considered healthy, but the number of strandings near
Homer, Alaska, in 2015 surprised scientists and volunteers, who often
responded to several otter deaths in a day. |
Unscrambling this weird behavior is difficult because the world's
largest ocean is so confounding to begin with. Overlapping patterns that
can last for decades already drive temperature swings. Every few years
or decades the eastern Pacific flips from a food-rich, cold-water place
to something warmer, a cycle called the Pacific Decadal Oscillation. El
Niño, the periodic tropical warming, boosts temperatures in North
America. An ocean freeway, the California Current, ushers cool water
south from Canada to Baja California. Along the way, winds push warm
surface waters offshore, causing upwelling, which draws much cooler,
nutrient-rich seas from below.
All these volatile shifts can redistribute marine life. It just
doesn't usually wind up like this. "When all is said and done, I think
people will see this as the most economically and ecologically
consequential event in our historical record," Mantua says of the recent
warming.
Seeking to understand the magnitude of this episode, I am miles off the Oregon coast, weeks before visiting Alaska. The Elakha, a 54-foot research boat, is cutting through rolling chop beneath a milky sky. Bill Peterson,
in jeans and a weathered craft-beer T-shirt, kneels on deck, face
pressed into a red cooler. It holds the contents of a net his colleagues
just hauled up from the sloshing depths. The NOAA oceanographer is here
to show me how thoroughly the eastern Pacific has changed. "Oh my,
that's ugly," he says. Over his shoulder, I glance down at the bottom of
the ocean food web. I see only slop the color of motor oil. That's his
point.
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| Near Petersburg,
Alaska, a worker examines the dorsal fin of an orca. This animal likely
died of natural causes, but exposure to toxic algae created by unusually
warm water is a suspected cause in the deaths of many humpback and fin
whales. |
Every two weeks for 20 years, Peterson's team has come here to gather
the minuscule plants and animals that form the foundation of one of the
planet's most productive marine systems. The prize course in this
buffet is supposed to be inch-long krill. Shaped like shrimps, they are
gobbled by auklets, cohos, basking sharks, and whales. Anchovies and
sardines eat them and then get wolfed by bigger fish and sea lions. At
this time of year, krill should be abundant, but Peterson's haul reveals
mostly soupy algae and small jellyfish, which provide little
sustenance. His team hasn't seen krill in months. "It's been like this
nonstop," he says.
Higher ocean temperatures have thrown this system out of whack. Not
long after the warmth arrived, shelled octopuses more common in the
South Pacific appeared off Southern California. Tropical sunfish and
blue sharks were caught in the North Pacific. Market squid, common off
California, laid eggs in southeast Alaska. A few venomous yellow-bellied
sea snakes from Central America slithered across beaches near Los
Angeles. Peterson's team caught tropical or subtropical zooplankton
he'd never seen: rainbow-hued, beetle-shaped copepods; minuscule
iridescent creatures from Hawaii; tiny crustaceans with cobalt egg sacs.
He cataloged nearly 20 new species that belonged far away.
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| A mola, or ocean sunfish, chases a by-the-wind sailor. With temperatures in some places reaching seven degrees Fahrenheit above average, many subtropical marine animals, such as this sunfish, came close to Pacific shores. |
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| Dead pelagic red crabs, also known as tuna crabs, crowd the sea surface near Monterey Bay. These crabs appeared in unusually high numbers in 2015, frequently washing ashore and coating California coastlines. |
Compared with krill, these zooplankton were limp-lettuce side salads:
smaller and less nutritious. As this low-cal diet coursed through the
food web, larval walleye pollock, common in the Gulf of Alaska, reached
their lowest numbers in three decades. Halibut caught in Cook Inlet had
mushy flesh—a syndrome associated with poor nutrition. Coho salmon
returned to West Coast streams as malnourished runts. These changes
coincided with other shifts. Sardines, already in decline, decreased so
much that an industry made famous by John Steinbeck's novel Cannery Row
shut down for the first time since rebounding from its collapse in the
1950s. Sardine and anchovy populations are cyclical; their precipitous
drop likely had little to do with warm water. But the impact was more
pronounced because the unusual heat redistributed the remaining fish.
Anchovies, already dwindling, seemed to vanish almost everywhere except
Monterey Bay, where they gathered in great numbers, creating a weird
feeding frenzy. At one point, 50 or more whales dined in the bay at
once. In the Pacific Northwest humpbacks cruised into the Columbia River
in search of food. Birds suffered too. At least a hundred thousand
blue-footed Cassin's auklets, small gray-feathered island nesters that
eat krill, starved to death. It was one of the biggest die-offs of birds
in U.S. history. Then, months later, hundreds of thousands of common
murres died too.
Perhaps most visible were the skinny, sick sea lion pups
that surfed ashore in California, loose fur drooping over bones,
looking like children wrapped in parents' clothes. They collapsed under
porches and parked trucks. One curled into a chair on a hotel patio.
Another slipped into a booth at a seaside restaurant. Without sardines
or anchovies, their mothers ate junk-food diets of squid, hake, and
rockfish, and weaned pups early. More than 3,000 were stranded in five
months.
Chugging back to his office in Newport, Oregon, Peterson is baffled.
After a lifetime studying the sea, he finds this warm ocean unfamiliar
and disorienting, "like looking out the window and seeing a macaw fly
by."
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| A
giant Pacific octopus moves along the coast of British Columbia. Recent
changes in the Pacific temporarily altered migration patterns and food
for many creatures, but it will take years for scientists to fully
understand how marine life was affected. |
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| A dying
wolf eel curls up among dead prawns in Washington State's Hood Canal.
Eels and other animals died when warm seawater washed into the canal in
2014. The canal's southern reaches didn't fully flush, which depleted
oxygen. |
It's not that the blob is the new normal. It isn't. Few if any
of these changes are permanent. Even if they were, it wouldn't mean the
sea was dying. Ocean life will continue. But the blob offers something
of an analogue for future seas under climate change. And marine life in
this sea of tomorrow will look very different.
Warmer temperatures speed fish metabolisms, requiring them to eat more, just as their food declines. Some fish may see tinier bodies, more disease, and, in many cases, falling populations,
according to recent studies. Already, according to the
Intergovernmental Panel on Climate Change, many fish and plankton are
heading toward the poles in search of cooler temperatures. As productive
areas grow scarcer with less cold water, fish and predators will
congregate in fewer places, creating new challenges. During the recent
heat wave, more West Coast whales appeared to get tangled in fishing gear or debris. From 2000 to 2012, rescue crews fielded about 10 reports a year. Forty-eight were confirmed in 2015.
And when creatures show up somewhere new, our relationship with the
sea can shift too. In Pacifica, California, I visit Richard Shafer, a
lanky 58-year-old electrician who free-dives for fish with a speargun.
As the heat wave drove game fish north from Mexico, fishing charters
off Los Angeles had their best season in memory. So in August 2015,
Shafer took a charter to an offshore bank west of San Diego. He speared a
yellowtail, and then a hungry sea lion darted past. Knowing that sea
lions steal big fish, especially in the absence of sardines, Shafer
pulled his yellowtail close and swam toward the boat, only to be bitten on the wrist
by a seven-foot smooth hammerhead. These sharks are rarely seen in
California, and rarely attack, yet there were several encounters in 2015
during what one scientist called "an endless parade of hammerheads"
lured by warm water. The animal severed Shafer's tendon and fractured a
pinkie and knuckle, requiring 40 stitches. Each change in the sea can
trigger another that no one sees coming.
The sky pinks with the dying day as Kathi Lefebvre hops from a
pickup truck onto a pebbly stretch of Homer Spit and stares down at the
dead otter. Sea wash muddies the pale fur of its face. Otters in
previous years mostly died from complications of a streptococcal
infection. This year some of the dead look emaciated, while others look
almost fit. Interns with the Alaska Maritime National Wildlife Refuge
don blue latex gloves and begin an examination. One intern is moved
nearly to tears. Another tells Lefebvre about an otter she'd seen
shuddering in spasms the week before. Lefebvre perks up.
WATCH: An otter shudders and gasps in a spasm.
"The thing you're describing, the tremors in the whole body?" Lefebvre says. "I've seen that. In sea lions."
In 1998, as a Ph.D. student at the University of California, Santa
Cruz, Lefebvre learned that dozens of sea lions were turning up sick and
twitchy. Lefebvre had a hunch why: Each spring, a single-celled toxic
alga called Pseudo-nitzschia blooms in small patches, usually for
a week, maybe two, producing a neurotoxin called domoic acid, which
accumulates in shellfish. When ingested by people, this toxin can cause
seizures, memory loss, even death. It also can harm wildlife. In 1961, a
Santa Cruz newspaper told of a mysterious invasion of sooty shearwaters
"fresh from a feast of anchovies." The seabirds bashed into windows and
died on streets. Alfred Hitchcock used the incident as part of his inspiration for The Birds.
Scientists tracking the mystery decades later unearthed old samples of
plankton pulled from Monterey Bay in 1961. They detected high levels of Pseudo-nitzschia.
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| The Pacific Marine Mammal Center in Laguna Beach, California, took in hundreds of emaciated sea lion pups in 2015. As anchovies and sardines dwindled, thousands of sea lions had to rely on less nutritious food or search harder for prey driven away by warm waters, leading many to starve. |
When Lefebvre found domoic acid in the feces of sick sea lions in 1998, it was the first evidence that this type of toxic
bloom could hurt marine mammals.
And blooms that year were particularly bad. El Niño had brought
withering ocean heat to California, igniting the most ferocious bloom on
record—until last year.
In April 2015 algae bloomed, but instead of dissipating after a few
weeks, the bloom grew into a monster, morphing and shifting, stretching
over 2,000 miles, from California's Channel Islands to Kodiak. No one
had seen anything like it. Some shellfish harvests closed along the
coast. Toxin concentrations were 30 times greater than what would
normally be considered high. Tests found domoic acid in some fish, such
as anchovies, at amounts too dangerous for people to eat, a rarity. The
toxin appeared to sicken hundreds of sea lions, seabirds, porpoises, and
seals. Video from Washington State showed a
sea lion suffering a toxin-induced seizure, something never seen that far north. Blooms dragged into November.
Then there were Alaska's dead whales, primarily fins and humpbacks.
Most were too remote or too far gone to test. A few that washed up in
British Columbia showed traces of domoic acid, but the toxin flushes so
quickly it's impossible to know if the dose was large or small.
Scientists lacked proof, but most shared a theory: Whales ate krill,
copepods, or fish dosed by algal toxins, which killed them outright or
scrambled their brains, hampering navigation and feeding. "Given that
we've ruled out most other scenarios, what is most prominent in my mind
is toxic algae," says
Andrew Trites, director of the Marine Mammal Research Unit at the University of British Columbia.
Standing on Homer Spit, Lefebvre wonders aloud if algae played a role
in killing Alaska's otters. She sets down plastic bags to collect
specimens and pulls on gloves. Leaning over the stiffening otter, she
bends to her work.
True to its B-movie name, the blob began fading in December
2015, its heat sinking deep into the sea with the arrival of a powerful
El Niño. But divining what this heat portends will take years. New
research suggests that heat waves like the blob may become
more common and intense
because of climate change. Scientists foresee "higher extremes, more
unusual events. It gets more chaotic," says Raphael Kudela, an ocean
sciences professor at the University of California, Santa Cruz.
Scientists project that toxic blooms will be more frequent, more
widespread, and more toxic.
That could spell trouble for people too. I meet Dick Ogg in his
paint-splattered khakis, strolling down a wooden ramp at Bodega Bay's
Spud Point Marina. He's rebuilding a hold on the
Karen Jeanne.
The commercial fisherman chases salmon, albacore, and sablefish but
makes his real money gathering Dungeness crab. Yet his boat hasn't moved
much in months. Crab remained unsafe to eat long after toxic blooms
vanished, so California delayed its crab harvest for months, at a loss
of $48 million. The governor sought disaster relief from the U.S.
government. Out-of-work deckhands lived off gift cards and a marina food
bank. The closest Ogg came to fishing was helping regulators catch crab
to test for toxins. "A lot of folks are really hurting," Ogg says
glumly.
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| Market squid,
which typically spawn off California, swim by their eggs near Klemtu,
British Columbia. In 2015 squid eggs in the eastern Pacific were found
as far north as Alaska. |
Yet not all of what the blob produced is a harbinger of something.
Given warming over decades, rather than the blob's span of roughly two
years, plants and animals may adapt or move. Some die-offs might have
happened without the blob. Sea star deaths, while
hastened by the warm water, were actually caused by a virus that hit well before the blob. California sea lion populations may simply have
grown too large.
And more changes are coming. Rising seas are reshaping coastlines. Natural low-oxygen zones in deep waters
are expanding.
Ocean acidification is making life harder for shellfish. Predicting the
future is messy—especially when we barely understand the present.
Lefebvre never solved the otter mystery. By year's end, 304 were
dead—nearly five times the recent average. One-third of the carcasses
that scientists tested were positive for toxic algae. But strep
infection was diagnosed as the primary cause of death for most otters.
Any role that the blob played in exacerbating the infection remains a
riddle. Did algal toxins weaken the animals? Did warm water somehow make
things worse? "We still don't know how all these tweaks in our world
come together," Lefebvre says.
Weeks later, I have a similar chat with
Julia Parrish,
a bird expert at the University of Washington, who has been tracking
the murres' deaths. She doesn't know if the seabirds chased scarce food
to strange places, got mixed up by domoic acid, or were pushed ashore by
winds. "I am still just mystified," she tells me.
And that, more than anything, I now realize, may be our new normal:
the unfathomable gulf between the sea we thought we knew and the one
we're rapidly creating.
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