# The ocean is running a fever, and it's rewriting who lives where > Octopus swarms off England, dead cormorants on California beaches, and 82 percent of the world's oceans running hot at once. - Title: The ocean is running a fever, and it's rewriting who lives… - Summary: Octopus swarms off England, dead cormorants on California beaches, and 82 percent of the world's oceans running hot at once. Marine heat waves hit too fast… - Keywords: marine heat waves, climate change, oceans, el nino, kelp forests, ocean, running, fever, it's, rewriting, lives, where - Source: Mother Jones — https://motherjones.com/environment/2026/09/blob-marine-heat-waves-ocean-life-california-coast-kelp-forests-whales-krill-dolphins - Author: Jim Robbins - Published: 2026-09-12T07:00:00+00:00 - Read time: 3 min - Topics: marine heat waves, climate change, oceans, el nino, kelp forests ## Octopus arrived by accident Common octopus larvae normally die when they drift from the Mediterranean into cold Channel water. Last year they hitched a ride on plankton to England's coast and lived. ## Biggest bloom in 75 years A heat wave off Devon and Cornwall pushed water up to 9 degrees F above normal, and the octopus bloom became the largest since 1950. ## Winners and losers UK octopus landings ran about 7,700 percent above normal, a windfall for fishers. Scallop, lobster and crab catches collapsed. ## New predators moved in Seals, conger eels and dolphins fattened on octopus. Bluefin tuna and sharks returned to British waters for the first time in decades. > It has completely shaken up the food chain. ## This time they don't die Past octopus surges ended when cold water returned and killed them off. Researcher Bryce Stewart says these octopuses are not dying, they are breeding. ## Most of the ocean is hot About 82 percent of the world's oceans are in a marine heat wave right now, and this year set new temperature records. ## What a heat wave does Ocean fevers push fish deeper, bleach coral, trigger mass die-offs, feed algal blooms, and fuel storms that wreck fishing and tourism. ## The oceans took the heat A heat wave means five straight days above the 90th percentile of normal. Oceans have soaked up more than 90 percent of the excess heat humans have added. ## Slow warming, sudden shock Gradual warming gives species time to adapt. Heat waves are acute and leave almost none. Since 1940, days of extreme surface heat have tripled. ## The Pacific's giant The world's largest marine heat wave now sprawls across more than 24 million square miles of Pacific, and a record El Nino is expected to push two more off California. ## How the Blob formed In late 2013 a stubborn high-pressure ridge stalled the winter winds that cool the eastern Pacific. The sun did the rest. By 2014 waters ran 7 degrees F above average. ## The krill vanished In 2015 Ric Brodeur pulled up nets he expected to be full of krill, the base of the food chain, and found almost nothing. > You could fit all the krill from the trip into a little plastic bag. ## Seven thousand whales gone North Pacific humpbacks fell by about 20 percent. Emaciated females lost calves, and the reproductive slump ran until 2021, five years past the Blob's end. ## Underwater rainforests fell Kelp died from Baja to British Columbia, with 95 percent wiped out in Northern California. Red abalone crashed so hard the fishing ban now runs to 2036. > It has a specific temperature threshold where it falls apart and it can't survive. ## Four million murres starved Warm currents scattered the anchovies and sardines that Alaska's common murres eat. Half the population died, and a 2024 study found no sign of recovery. ## A new Blob is here Dying pelicans and cormorants are washing up in Southern California, and a record toxic algal bloom stretches to British Columbia. Scripps says heat wave days now match 2015 exactly. > We are definitely along the same trend now. This is a new Blob. ## Key takeaway Marine heat waves hit too fast for sea life to adapt, and the damage from the last one is still unhealed when the next arrives.