CLIMATE CRISIS
“WE’RE TALKING
ABOUT THE
COLLAPSE
OF AN ENTIRE
ECOSYSTEM,”
SAYS A MARINE
SCIENTIST.
”BECAUSE
IT WAS IN THE
OCEAN, NOBODY
NOTICES.”
66 / ROLLING STONE / APRIL 2020
rise, flooding coastal cities. Ocean circulation
patterns will shift, driving big and unpredict-
able changes in the weather, with scary impli-
cations for the global food supply. The report’s
summary was blunt: “Over the 21st century,
the ocean is projected to transition to unprece-
dented conditions.”M
ONTEREY BAY is a crescent on the North-
ern California coast, a place haunted
by the ghosts of John Steinbeck’s
Cannery Row. The old sardine canne-
ries are now T-shirt shops and tour-
isty restaurants. From the pier, you
can watch sea otters playing in the
surf and, if you’re lucky, whales breeching just
offshore. A deep canyon delivers cold, nutrient-
rich waters into the bay, creating one of the most
diverse ecosystems in the Pacific, including giant
kelp beds that grow along the coast all the way
up to Alaska. In good times, these kelp beds are
teeming with life — otters, seals, sharks, rockfish,
lingcod. “The kelp beds are the rainforests of the
Pacific,” Kyle Van Houtan, the chief scientist at
the Monterey Bay Aquarium, tells me.
But like everything in the ocean, the kelp beds
are changing fast. On a recent Saturday morn-
ing, I pulled on scuba gear and jumped in the
water near Monterey to have a look for myself.
What I saw was not the rainforest of the Pacific.
Instead, I was greeted with nothing but rock and
water and hundreds of purple sea urchins, their
thorny spikes like medieval armor. A voracious
horde had invaded the once-magnificent kelp
forest and devoured everything (“purple urchins
are the cockroaches of the sea,” one scientist told
me), leaving only some empty abalone shells, a
rockfish poking around, and a few pathetic kelp
stipes. And this spot is just one fragment of a big-
ger picture. As a result of the Blob, many of the
kelp forests along the coast from California to
Oregon have vanished, done in by warming and
the army of purple sea urchins, which thrive in
a hotter world.
“If a 200-mile-long stretch of forest in the
California mountains suddenly died, people
would be shocked and outraged,” says Laura
Rogers-Bennett, a marine scientist at the Cal-
ifornia Department of Fish and Wildlife, who
works at the Bodega Marine Lab just up the
coast. “We’re talking about the collapse of an
entire ecosystem. But because it happened in the
ocean, nobody notices.”
Rogers-Bennett was one of the first scien-
tists to understand the impact of marine heat
waves like the Blob. In 2013, she was diving in
Northern California when she saw a sea star that
looked like it was melting. “When I touched it,
its skin came off in my hand,” she recalls. And it
wasn’t just one sea star, she discovered. This was
the beginning of a mass die-off of 20 species of
sea stars in the Pacific from a condition knownas “sea star wasting disease,” which is linked
to warming waters. With the loss of sea stars,
which are one of the main predators of purple
sea urchins, the urchin population exploded
and devoured the kelp forests. “It’s very scary,”
Rogers- Bennett says. “The Blob shows you how
fast a tipping point can happen.”
In the past decade, scientists have detected
marine heat waves around the world: The Med-
iterranean was hit in 2012, 2015, and 2017. In
2018, a marine heat wave appeared off the coast
of New Zealand and helped spike land tempera-
tures to record highs. Along the coast of Tas-
mania, giant kelp once stretched over 9 million
square meters. Today, thanks to warmer water
and an invasion of urchins, the kelp covers fewer
than 500,000 meters. Off the Uruguayan coast,
a blob of hot water covers 130,000 square miles
of ocean, an area nearly twice as big as Uruguay
itself. It has caused a massive die-off of clams
and mussels, an important food source for tens
of thousands of people who live on the coast.
“Last fall, another heat wave started building
in the northern Pacific,” says Andrew Leising,
a scientist at NOAA’s Southwest Fisheries Sci-
ence Center. “It couldn’t come at a worse time —
the fisheries are just beginning to recover from
the Blob.”
Marine heat waves are driving a massive reor-
ganization of underwater life, with many crea-
tures migrating to cooler waters.
“Right now, you can go diving off
the Monterey pier and see spiny lob-
sters,” says Van Houtan. “They are a
subtropical species that are normally
found down in Baja. It’s absurd to see
them up here.” (Attention swimmers:
Van Houtan also says warmer waters
are encouraging juvenile great white
sharks to linger in the area). At the
Bodega Marine Lab, scientists doc-
umented 37 species that had never
been found so far north before. Bull
sharks have been hanging off the coast
of North Carolina, 500 miles north of
their habitat in Florida. Lobsters have
all but vanished from Long Island
Sound. These migrations are radical-
ly changing underwater ecosystems,
as well as the lives of people who de-
pend on healthy fisheries. A recent
study by scientists at the University of
California, Santa Barbara, showed that nations
in the tropics would be hit hardest by fish mi-
gration. By 2100, some countries in northwest
Africa could lose half their stocks as fish move to
colder water. “If you know you are losing a stock,
then the short-term incentive is to overfish it,”
said James Salzman, a professor of environmen-
tal law at UC Santa Barbara and co-author of the
study. “What have you got to lose? The stock’s
going to move anyway.”Marine heat waves are also inflicting mas-
sive damage on coral reefs (where they are often
called “bleaching events”). Reefs are the most
bio-diverse ecosystems on the planet — they oc-
cupy less than one percent of the ocean floor,
but are home to more than 25 percent of ma-
rine life. Reefs are created by millions of coral
colonies that build calcium carbonate skeletons.
For the past 100 million years or so, corals have
thrived in a happy marriage with microscopic
plants called zooxanthellae that live embedded
in their tissues. Zooxanthellae produce 85 to 95
percent of corals’ food through photosynthesis.
In return, corals give the plants protection, nutri-
ents, and carbon dioxide, one of the ingredients
for photosynthetic food production. This mar-
riage, however, is exquisitely sensitive to changes
in ocean temperature. One or two degrees of
warming, and the zooxanthellae become toxic to
the corals. The corals spit them out like an abu-
sive spouse and eventually starve to death, leav-
ing only their bleached skeletons behind.
Australia’s Great Barrier Reef, a UNESCO
World Heritage site and one of the crown jew-
els of the natural world, has been hit hard by
warming. The reef stretches about 1,400 miles
along the east coast of Australia — it’s the larg-
est structure built by living organisms on the
planet, so big it’s visible from space. Since 1998,
the Great Barrier Reef has suffered four bleach-
ing events, including devastating back-
to-back heat waves in 2016 and 2017.
According to Terry Hughes, a marine
scientist at James Cook University in
Queensland, Australia, 93 percent of
the corals in the Great Barrier Reef
have been impacted by some level of
bleaching. “We’ve now added enough
greenhouse gases to the atmosphere
that mass bleaching of the reef is at risk
every summer,” Hughes says. “It’s like
Russian roulette.”IF YOU LOOK at a few drops of ocean
water under a microscope, you’ll see
a wild world of bizarre-looking crea-
tures swimming around, fighting and
devouring each other. Many of these
animals — forams, pteropods — have
thin shells made of calcium carbon-
ate. And thanks to the rising acidity
of ocean waters, their shells — like the
shells and skeletons of many other creatures in
the sea — are slowly dissolving.
Acidification is primarily a consequence of
rapidly rising CO2 levels in the atmosphere. The
IPCC report notes that carbon pollution so far
has decreased the average ocean pH, which is
based on a logarithmic scale, from 8.2 to 8.1,
meaning the ocean is 25 percent more acid-
ic today than before the Industrial Revolution.
If we manage to hold global warming to 2 C,CLIMATE CRISIS