The age of humans, termed the Anthropocene, might just as well be considered the age of plastic. The dangerously durable material, made ubiquitous in products and packaging through the late 20th century, has inundated our planet’s environment. Today, miniscule plastic pieces are present in deep-ocean sediment, high-mountain snow and just about every place in between. Plastic waste has also entered the marine food web, and according to new research, baleen whales are ingesting staggering quantities.
Blue whales off the California coast may consume as many as a billion pieces, or up to several tons, of microplastic in the course of a summer feeding season, according to a paper published today in Nature Communications.
The authors of the paper, led by Cal State Fullerton biologist Shirel Kahane-Rapport, focused their research on the California Current Ecosystem. They studied the movements and feeding behavior of 191 tagged whales and combined this information with data from water and prey samples collected at locations between Point Reyes and San Diego.
They found that plastic ingestion in whales occurred almost entirely via trophic transfer – that is, via the prey they eat – rather than filtering it directly from the water through their baleen. The scientists assessed whale engulfment capacity, feeding rates, and densities of prey – especially krill and anchovy. They considered a range of existing estimates of plastic particle occurrence in marine forage species, and they assumed that any krill or anchovy containing microplastic contained just one piece.
“[T]his is likely an underestimate,” they wrote.
Humpback feeding. Photo John Durban, Oregon State University.
Still, after scaling up these numbers, they predicted that a large blue whale could ingest 10 million tiny pieces of plastic every day – a quantity weighing somewhere between 5 and 95 pounds, depending on the size and composition of the plastics. They estimate that krill-dependent whales, like blues and fins, consume vastly more plastic than fish-foraging whales, like humpbacks, that may eat 200,000 pieces of microplastic daily.
Whether these rates of plastic consumption are harming the creatures isn’t yet clear. Prior sampling work has found microplastic particles in whale feces, Kahane-Rapport says. That means at least some of the debris passes through the animals’ digestive systems. However, to what extent small plastic pieces are absorbed from a whale’s stomach and intestines into other tissues and organs – a process called translocation – is not yet known.
“That’s the next question,” Kahane-Rapport says.
Matthew Savoca, a coauthor on the paper, says toxic chemicals can bind to plastic molecules and, by this hitchhiking process, could harm feeding marine life.
“Plastics may be a Trojan horse for other toxins,” he says.
Figure from Kahane-Rapport et al., 2022.
The Ocean Conservancy’s Ocean Plastics Research program manager Britta Baechler, who was not involved in the new study, says it is difficult to understand if, how, and to what extent microplastic ingestion harms marine life. Plastics, she says, represent a category of contaminants almost endlessly diverse in chemical composition.
“Meanwhile, whether an animal will be impacted is also dependent on many variables, like the animal’s size, the type and concentration of microplastics encountered, physical fitness of the animal, and other factors,” she says. Still, she adds, there is “ample cause for concern.” She says microplastic exposure can impair growth, reproduction, and feeding behaviors, and cause weight loss, energy depletion, and cell damage. Microplastic health impacts, Baechler adds, can be physical or chemical in nature.
In 2018, a team of Australian researchers, led by Amanda Dawson of Queensland’s Griffith School of Environment, published results of a study showing that krill ingested and eventually defecated microplastic particles with no observed rates of mortality or bioaccumulation in the animals’ tissues. At face value, these findings are good news, though the authors offered a warning that potential sublethal impacts “should be the focus of further ecotoxicological investigation.”
Shirel Kahane-Rapport and Lauren Kashiwabaracollect microplastics from whales. Photo: Matthew Savoca
These scientists also observed something else – that krill can break ingested microplastics down to the nanoscale. Baechler, familiar with these findings, takes them as a warning.
“This may mean those very small microplastics converted into nanoplastics by the krill could move into the gut of the blue whale and ultimately migrate into other parts of its body,” she says.
The persisting nature of plastic, which continuously breaks down into smaller pieces, makes the prospects of cleaning up the world’s plastic waste all but impossible. Plastic pollution is expected to increase through at least 2050, according to Kahane-Rapport and her colleagues’ new paper. Even if it ended today, problems would persist and “get worse before they get better,” as Savoca puts it.
Kahane-Rapport says she hopes her findings, though grim, lead not to despair but to progress. She says there are ways everyday consumers can minimize their own plastic trail while pressuring industries to curb production.
“A lot of the problems of plastic pollution come from large corporations,” she says. “Don’t buy from them unless they show you an improvement in their behavior and way they deal with their waste.”
She says the model she and her colleagues developed to assess microplastic ingestion rates is publicly available, and she hopes it will facilitate future studies in other parts of the world and ultimately hone the scientists’ understanding of how ingested microplastics affect the marine ecosystem.
Top photo: Blue whale feeding. Photo courtesy Matthew Savoca
A resident of Sonoma County, Alastair Bland is a freelance journalist who writes about water policy in California, rivers and salmon, marine conservation, and climate change. His work has appeared at CalMatters, NPR.org, Smithsonian.com, Yale Environment 360, and the East Bay Express, among many other outlets. When he isn't writing, Alastair can often be found riding a bicycle, pulling weeds from his garden, and holding his breath underwater.
Our magazine’s media motto for many years has been “Where there’s an estuary, there’s a crowd.” The San Francisco Estuary is a place where people, wildlife, and commerce congregate, and where watersheds, rivers and the ocean meet and mix, creating a place of unusual diversity. In choosing to tell the...
Ever since the state and federal water projects were built in the 1930s and 1940s, California has captured snowmelt in foothill reservoirs, and moved the fresh water from dam releases and river outflows to parched parts of the state via aqueducts hundreds of miles long. A convoluted system of ancient...
Though the Clean Water Act did an amazing job of reducing wastewater and stormwater pollution of the San Francisco Estuary, some contaminants remain thorny problems. Legacy pollutants like mercury washed into the watershed from upstream gold mining, PCBs from old industrial sites, and selenium from agricultural drainage in the San...
Hothouse Earth
By Ariel Rubissow Okamoto
Photo by Megan Nguyen
Nothing could be stranger than sitting in the dark with thousands of suits and heels, watching a parade of promises to decarbonize from companies and countries large and small, reeling from the beauties of big screen rainforests and indigenous necklaces, and getting all choked up.
It was day two of the September 2018 Global Climate Action Summit in San Francisco when I felt it.
At first I wondered if I was simply starstruck. Most of us labor away trying to fix one small corner of the planet or another without seeing the likes of Harrison Ford, Al Gore, Michael Bloomberg, Van Jones, Jerry Brown – or the ministers or mayors of dozens of cities and countries – in person, on stage and at times angry enough to spit. And between these luminaries a steady stream of CEOs, corporate sustainability officers, and pension fund managers promising percentages of renewables and profits in their portfolios dedicated to the climate cause by 2020-2050.
I tried to give every speaker my full attention: the young man of Vuntut Gwichin heritage from the edge of the Yukon’s Arctic National Wildlife Refuge who pleaded with us not to enter his sacred lands with our drills and dependencies; all the women – swathed in bright patterns and head-scarfs – who kept punching their hearts. “My uncle in Uganda would take 129 years to emit the same amount of carbon as an American would in one year,” said Oxfam’s Winnie Byanyima.
“Our janitors are shutting off the lights you leave on,” said Aida Cardenas, speaking about the frontline workers she trains, mostly immigrants, who are excited to be part of climate change solutions in their new country.
The men on the stage, strutting about in feathers and pinstripes, spoke of hopes and dreams, money and power. “The notion that you can either do good or do well is a myth we have to collectively bust,” said New Jersey Governor Phil Murphy whose state is investing heavily in offshore wind farms.
“Climate change isn’t just about risks, it’s about opportunities,” said Blackrock sustainable investment manager Brian Deese.
But it wasn’t all these fine speeches that started the butterflies. Halfway through the second day of testimonials, it was a slight white-haired woman wrapped in an azure pashmina that pricked my tears. One minute she was on the silver screen with Alec Baldwin and the next she taking a seat on stage. She talked about trees. How trees can solve 30% of our carbon reduction problem. How we have to stop whacking them back in the Amazon and start planting them everywhere else. I couldn’t help thinking of Dr. Seuss and his truffala trees. Jane Goodall, over 80, is as fierce as my Lorax. Or my daughter’s Avatar.
Analyzing my take home feeling from the event I realized it wasn’t the usual fear – killer storms, tidal waves, no food for my kids to eat on a half-baked planet – nor a newfound sense of hope – I’ve always thought nature will get along just fine without us. What I felt was relief. People were actually doing something. Doing a lot. And there was so much more we could do.
As we all pumped fists in the dark, as the presentations went on and on and on because so many people and businesses and countries wanted to STEP UP, I realized how swayed I had let myself be by the doomsday news mill.
“We must be like the river, “ said a boy from Bangladesh named Risalat Khan, who had noticed our Sierra watersheds from the plane. “We must cut through the mountain of obstacles. Let’s be the river!”
Or as Harrison Ford less poetically put it: “Let’s turn off our phones and roll up our sleeves and kick this monster’s ass.”
4th California Climate Change Assessment Blues
by Isaac Pearlman
Since California’s last state-led climate change assessment in 2012, the Golden State has experienced a litany of natural disasters. This includes four years of severe drought from 2012 to 2016, an almost non-existent Sierra Nevada snowpack in 2014-2015 costing $2.1 billion in economic losses, widespread Bay Area flooding from winter 2017 storms, and extremely large and damaging wildfires culminating with this year’s Mendocino Complex fire achieving the dubious distinction of the largest in state history. California’s most recent climate assessment, released August 27th, predicts that for the state and the Bay Area, we can expect even more in the future.
The California state government first began assessing climate impacts formally in 2006, due to an executive order by Governor Schwarzenegger. California’s latest iteration and its fourth overall, includes a dizzying array of 44 technical reports; three topical studies on climate justice, tribal and indigenous communities, and the coast and ocean; as well as nine region-specific analyses.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.
For the first time, California’s latest assessment dives into climate consequences on a regional level. Academics representing nine California regions spearheaded research and summarized the best available science on the variable heat, rain, flooding and extreme event consequences for their areas. For example, the highest local rate of sea level rise in the state is at the rapidly subsiding Humboldt Bay. In San Diego county, the most biodiverse in all of California, preserving its many fragile and endangered species is an urgent priority. Francesca Hopkins from UC Riverside found that the highest rate of childhood asthma in the state isn’t an urban smog-filled city but in the Imperial Valley, where toxic dust from Salton Sea disaster chokes communities – and will only become worse as higher temperatures and less water due to climate change dry and brittle the area.
According to the Bay Area Regional Report, since 1950 the Bay Area has already increased in temperature by 1.7 degrees Fahrenheit and local sea level is eight inches higher than it was one hundred years ago. Future climate will render the Bay Area less suitable for our evergreen redwood and fir forests, and more favorable for tolerant chaparral shrub land. The region’s seven million people and $750 billion economy (almost one-third of California’s total) is predicted to be increasingly beset by more “boom and bust” irregular wet and very dry years, punctuated by increasingly intense and damaging storms.
Unsurprisingly, according to the report the Bay Area’s intensifying housing and equity problems have a multiplier affect with climate change. As Bay Area housing spreads further north, south, and inland the result is higher transportation and energy needs for those with the fewest resources available to afford them; and acute disparity in climate vulnerability across Bay Area communities and populations.
“All Californians will likely endure more illness and be at greater risk of early death because of climate change,” bluntly states the statewide summary brochure for California’s climate assessment. “[However] vulnerable populations that already experience the greatest adverse health impacts will be disproportionately affected.”
“We’re much better at being reactive to a disaster than planning ahead,” said UC Berkeley professor and contributing author David Ackerly at a California Adaptation Forum panel in Sacramento on August 27th. “And it is vulnerable communities that suffer from those disasters. How much human suffering has to happen before it triggers the next round of activity?”
The assessment’s data is publicly available online at “Cal-adapt,” where Californians can explore projected impacts for their neighborhoods, towns, and regions.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.