Sea lions look up from lounging on San Carlos Beach in Monterey on Aug. 22, 2024. Nic Coury/Special to The Chronicle
Sick sea lions can’t vote for the ocean, but you can
Recently, a sick sea lion swam into the marina boat channel by my townhome and died. Shortly afterward, I met an underwater photographer who had been bitten on the head by a sea lion a few days before.
We agreed these were probably cases of domoic acid poisoning. This happens to marine mammals during harmful algal blooms. Humans can also get sick from this neurotoxin by eating contaminated shellfish.
Since last year, marine mammals have been dying in large numbers along California’s coast. When I called the Marine Mammal Center in Marin County to report the sick sea lion, I was told its staff had responded to 500 calls so far that day.
Warming coastal waters are supercharging diseases. One killer is a bacterial infection called leptospirosis, which causes sick and dying sea lions to use their flippers to squeeze their stomachs in pain as their kidneys fail.
Warming water and melting ice have caused documented shifts and crashes in small prey populations — including tiny crustaceans that California gray whales feed on, mostly in the Arctic. The result is widespread starvation. A 2025 study estimated that the gray whale population had declined by more than 30% during the previous six years.
Marine heat waves have also contributed to the collapse of hundreds of miles of California’s kelp forests and the communities that depend on them, both human and wildlife. Last year, the National Oceanic and Atmospheric Administration reported record-high ocean heat because the ocean absorbs 90% of the excess heat generated by the burning of fossil fuels and other human activities.
Now California is experiencing a persistent marine heat wave off its central and southern coast in addition to warming from a historic El Niño that is beginning to show its impact.
When I covered the BP blowout and oil spill in the Gulf of Mexico in 2010, I remember flying over 100 dolphins and a humpback whale trapped and dying in a petroleum slick. Today, oil we drill for on land and offshore is killing marine mammals and other species without any spillage — including California’s kelp forests that sea otters, herring and salmon depend on.
Big Oil’s response has been to appeal to the pro-corporate U.S. Supreme Court to not allow lawsuits from states like California or by municipalities or youth trying to hold these companies financially responsible for climate disasters.
The world had a chance to respond years ago when melting Arctic sea ice put polar bears — also considered marine mammals given how much of their lives are spent at sea — in grave (now near certain) risk of extinction in the wild.
But instead of seeing the historic loss of polar ice as a climate change alarm bell, global governments and corporations saw it as a dinner bell for new shipping routes, resource extraction and power projection.
The world is not on track to meet the Paris climate agreement’s goal of holding warming well below 2 degrees Celsius while pursuing efforts to keep it under 1.5 degrees Celsius — thresholds that scientists have long predicted will move our planet’s life support system from at risk to unmanageably catastrophic.
A decade ago, I wrote a book called “The Golden Shore” about how California, with 40 million people and the world’s fourth-largest economy, is a model for how to live well with our coast and ocean.
Now we have sea lions, gray whales and sea otters, along with thousands of seabirds and fish, washing up dead along our coastline.
Much of the problem traces back to a different species of animal — the fossil fuel industry’s political lapdogs whose critical habitat includes numerous statehouses, the White House and the U.S. Capitol in Washington, D.C.
