Kelp Forests Collapse as The Blob Returns

October 24, 2018

A large area of warm water in the northern Pacific, nicknamed “the Blob”, hung around for a few years, exacerbating the California drought of the past decade. I covered it in this 2015 video.

Now it’s back – and we’re just starting to appreciate the damage it’s doing.

New York Times:

The underwater forests — huge, sprawling tangles of brown seaweed — are in many ways just as important to the oceans as trees are to the land. Like trees, they absorb carbon emissions and they provide critical habitat and food for a wide range of species. But when climate change helped trigger a 60-fold explosion of purple urchins off Northern California’s coast, the urchins went on a feeding frenzy and the kelp was devoured.


“It would be like one of those beautiful deciduous forests turned into a desert,” said Gretchen Hofmann, a professor of marine ecology at the University of California, Santa Barbara. “But in the matter of five years.”

The dangers extend far beyond this inlet: Kelp forests exist along the cooler coastlines of every continent but Antarctica. And they are under threat both from rising ocean temperatures and from what those warmer waters bring.

The story of the kelp’s disappearance is the story of an interwoven food system breaking down, and in the process threatening people’s livelihoods. Some of the first people to sound the alarm about the purple urchins, Dr. Catton said, were commercial red urchin harvesters.

One of them is Gary Trumper, who has harvested red urchins for more than 30 years. Red urchins, larger than purple urchins, are commercially viable because people eat them — or more specifically, their gonads. The delicacy is better known to sushi aficionados as uni.

But the growing purple urchin population outcompeted the red urchins for the available kelp. Without kelp, the red urchins starved.

That cut the value of Northern California’s commercial red urchin fishery from $3.6 million in 2013 to less than $600,000 in 2016. Many harvesters have moved on. “It’s probably 10 or 15 guys left doing it in the harbor,” Mr. Trumper said, sitting in a bar near the slip in Fort Bragg where he docks his boat. “But there used to be probably 100.”

The trouble began with the starfish. Sunflower starfish, whose appendages can span more than three feet, normally eat purple urchins, helping to limit their numbers.

But in 2013, the starfish mysteriously began dying. There isn’t scientific consensus on why, but Drew Harvell, a professor of ecology and evolutionary biology at Cornell University, said she thought that a virus was at least partly to blame and that warmer waters had exacerbated its effects.

Sea otters, another predator of purple urchins, were hunted to near extinction in Northern California by 19th-century fur traders. Their numbers have not rebounded.

Around the same time as the starfish began dying, a mass of warm water appeared hundreds of miles off Alaska, British Columbia, Washington and Oregon. By 2014 that warm water had moved toward land, stretching from Southeastern Alaska down to Mexico.

The marine heat wave was hotter than anything humans had recorded dating back to the late 1800s. Researchers and locals called it “the Blob.” It would last into 2016.

“Human-caused global warming made it much more likely to get as extreme as it did,” said Nathan Mantua, a physical scientist at the National Oceanic and Atmospheric Administration and an author of a study linking the Blob to climate change. Over 90 percent of the heat trapped on Earth because of the greenhouse gases emitted by humans has been absorbed by the ocean, increasing its temperature.

But kelp prefers cooler waters. The bull kelp found off Northern California release spores in the fall; over the winter, the spores grow into tiny alfalfa-like plants that Dr. Hofmann said look a bit like the character Baby Groot from “Guardians of the Galaxy.”

“We don’t know very much about them because they’re very mysterious,” Dr. Hofmann said. “But we’ve done a little work on them and they do not like high temperatures.”

The Blob also slowed the process of upwelling, in which cooler waters and nutrients move from deeper in the ocean up to the surface.


The Blob is back in 2018

Monterey County Weekly:

The issue was discussed by the Monterey Bay National Marine Sanctuary Advisory Council on April 20, and kicked off with a presentation by Cynthia Catton, a California Department of Fish and Wildlife scientist who has been studying the issue off the Northern California coast.

She shared some alarming statistics about that region: There was a 93-percent loss of kelp in 2014, a 33-percent loss in 2015 and only limited growth in the past two years. The population of purple urchins, meanwhile, exploded.

She laid out the confluence of factors that happened simultaneously, even though scientists haven’t yet proven what caused the dramatic shift. In 2013, sea star wasting disease impacted the entire West Coast, decimating one of purple urchins’ predators. The population of purple urchins – which eat kelp, among other things – exploded in 2014. That same year, ocean temperatures increased on the West Coast; kelp thrives in colder water.

“It was a double whammy against kelp,” Catton said.

Locally, the situation is not as dire as further north, but it’s getting worse.

Reef Check, a citizen science nonprofit that operates globally, has been tracking the Monterey Peninsula’s kelp forests for the past 12 years with the help of volunteer divers. Dan Abbott, Reef Check’s Central Coast regional manager, says there have been “unprecedented changes in the past two years” with the loss of kelp and increased purple urchin density.

“The trend is not slowing down,” Abbott says.

Keith Rootsaert has been diving locally for 30 years, and has volunteered with Reef Check for the past nine. He has seen the transformation: “The urchins have been marching,” he says.

When purple urchins displace kelp and cover the seafloor, they form what scientists call an “urchin barren.” While it’s somewhat counterintuitive that urchins would proliferate in a region with sea otters, which prey on them, the theory, Abbott and Rootsaert say, is that the urchins in the barrens are so malnourished that otters don’t consider them worth eating.

Rootsaert says many divers would love to go underwater and start hammering away at the urchins – literally killing them with a hammer – but that because the region is a Marine Protected Area, it’s not legal.


Even though it likely can’t be blamed for intensifying a “snowy” winter on the East Coast, “the blob” can certainly wreak havoc on ecosystems and marine creatures, Bond told Live Science.

In 2015, the warmer water led to red tide algal blooms and lessened the availability of food and nutrition in that part of the ocean, causing fish to venture far from their typical homes and sea lion pups and seabirds to wash up on California’s coast.

“The lingering effects of the original blob [in 2015] are still being felt in Alaska fisheries,” Bond said. Some of the fish that hatched in those warm waters should be getting big enough to be in the fishery, yet they’re not, he added.

The numbers of Pacific cod and a few other fish have been reduced because they encountered a decreased amount of food early in their life cycle, due to the poor nutrition available in the warm waters.

In 2015, the blob had warmed waters between 2 and 7 degrees F (1 and 4 degrees C) above average. Similarly, in the northern part of the Bering Sea, the current ocean temperatures are around 5.4 degrees F (3 degrees C) above normal, which will impact the “distributions of the fish and how well they do,” Bond said.

But how much of an effect the blob will have in the coming months depends on how long it sticks around.

This high-pressure system will most likely shift and start to break down, causing stormier weather in the state, Bond said. If that happens, stormy weather will mix the warm waters with the surrounding cold waters, weakening the blob.

The current blob doesn’t look as strong as it was in 2015, Bond said, “but you know Mother Nature has some tricks up her sleeve, and she doesn’t always play fair,” he said. “We’ll just have to see.”



11 Responses to “Kelp Forests Collapse as The Blob Returns”

  1. redskylite Says:

    Carbon Brief has just published “State of the climate: New record ocean heat content and a growing El Niño” so the fact the heat anomaly appears to have returned in the northern Pacific ocean should not surprise anyone:

    Ocean heat content (OHC) set a new record in the first half of 2018, with more warmth in the oceans than at any time since OHC records began in 1940.

    That’s one of the headlines from Carbon Brief’s latest “state of the climate” report, a quarterly series on global climate data that now includes temperatures, ocean heat, sea levels, greenhouse gas concentrations, climate model performance and polar ice.

  2. redskylite Says:

    Here an interesting look at the The blob just featured in the National Geographic:

    The blob that cooked the Pacific

    When a deadly patch of warm water shocked the West Coast, some feared it was a preview of our future oceans.

  3. What about the barren tide pools?

    What about the thousands of missing species that used to live there?

    Warm water caused the extinction of just about all species of star fish? Really?

    Fukushima Radiation And Links To Mass Die Off Of Sea Stars, Starfish, Chitons, Abalone, Mussels, Sun Stars, Salmon In Pacific Ocean, S. California To Alaska, Study Confirms Bioaccumulation Of Radiation In Star Fish And Seafood

    It is way to easy and not scientific to focus only on ONE potential cause and ignore all others.

  4. redskylite Says:

    As we wait for inventions and advances that may never materialize – we can only observe and urge action to limit the damage and destruction to our ecosystems.

    Now we pray for those atmospheric filters as we know that clean energy is not enough . . we have been far too slow; far too argumentative; far too denialist; far too obstinate !!

    What’s next ?

    Scientists Push for a Crash Program to Scrub Carbon From the Air

    With time running out to avoid dangerous global warming, the nation’s leading scientific body on Wednesday urged the federal government to begin a research program focused on developing technologies that can remove vast quantities of carbon dioxide out of the atmosphere in order to help slow climate change.

    The 369-page report, written by a panel of the National Academies of Sciences, Engineering and Medicine, underscores an important shift. For decades, experts said that nations could prevent large temperature increases mainly by reducing reliance on fossil fuels and moving to cleaner sources like solar, wind and nuclear power.

    But at this point, nations have delayed so long in cutting their carbon dioxide emissions that even a breakneck shift toward clean energy would most likely not be enough.

    • redskylite Says:

      Climate change: Five cheap ways to remove CO2 from the atmosphere
      Climate change: Five cheap ways to remove CO2 from the atmosphere

      As well as rapidly reducing the carbon dioxide that we humans are pumping into the atmosphere in huge amounts, recent scientific assessments of climate change have all suggested that cutting emissions alone will not be enough to keep global temperatures from rising more than 1.5 or 2 degrees C.

      The Intergovernmental Panel on Climate Change and others have all stated that extracting CO2 from the air will be needed if we are to bend the rising temperature curve before the end of this century.

      These ideas are controversial with some seeing them as a distraction from the pressing business of limiting emissions of CO2.

      But a new assessment from the US National Academies of Sciences, Engineering and Medicine says that some of these “negative emissions technologies” are ready to be deployed, on a large scale, right now.

      • dumboldguy Says:

        These 5 cheap ways to remove CO2 may be cheap but they are unlikely to happen—-as the article mentions, we are already doing many things that go counter to them. We will wait too long, and when the SHTF, the really cheap and easy (and perhaps even effective in the short run) thing that will be done is SRM—-get ready for contrails!

        • grindupbaker Says:

          Actually, I’ve not seen a study that indicates that changes in contrails have any effect on Earth’s GMST. I’m interested in this and searched now & then. Do you have one ?

          • dumboldguy Says:

            I’m joking a bit—-the conspiracy theorists say that the government is using passenger jets to spray all sorts of stuff into the atmosphere—-the most (in)famous one being Rainbow Lady

            I’m talking about the “Pinatubo Effect” that many say will be our only quick means of halting AGW while we do the “other” things that we should have done twenty-five years ago. There’s lots of stuff out there—-google around:


            This one is almost scary—-check out the list of partner organizations under “about” and look at the resources page.


        • rhymeswithgoalie Says:

          I’m talking about the “Pinatubo Effect” that many say will be our only quick means of halting AGW while we do the “other” things that we should have done twenty-five years ago.

          FWIW, the apocalyptic premise for Snowpiercer was a geoengineering effort that went wrong and blocked too much sunlight.

  5. rhymeswithgoalie Says:

    Sea otters, another predator of purple urchins, were hunted to near extinction in Northern California by 19th-century fur traders. Their numbers have not rebounded.

    Well the red-urchin fishermen might not agree, but I think we should do all we can to increase the population of sea otters, if only because they are extremely cute.

    • dumboldguy Says:

      And just as we can’t seem to put a price on carbon, none of the models adequately deal with the value of “cuteness”. Too bad.

      (And otters ARE extremely “cute”. Watched a family of river otters at play along the banks of a river in Yellowstone in 1966—-a veritable circus act—-sorry I din’t have a video or movie camera to capture it).

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