El Niño is coming, and ocean temps are already at record highs – that can spell disaster for fish and corals

Marine heat waves can reach the ocean floor as well as surface waters. Sebastian Pena Lambarri via Unsplash, CC BY

by Dillon Amaya, National Oceanic and Atmospheric Administration

It’s coming. Winds are weakening along the equatorial Pacific Ocean. Heat is building beneath the ocean surface. By July, most forecast models agree that the climate system’s biggest player – El Niño – will return for the first time in nearly four years.

El Niño is one side of the climatic coin called the El Niño-Southern Oscillation, or ENSO. It’s the heads to La Niña’s tails.

During El Niño, a swath of ocean stretching 6,000 miles (about 10,000 kilometers) westward off the coast of Ecuador warms for months on end, typically by 2 to 4 degrees Fahrenheit (about 1 to 2 degrees Celsius). A few degrees may not seem like much, but in that part of the world, it’s more than enough to completely reorganize wind, rainfall and temperature patterns all over the planet.

White corals indicate bleaching from heat stress.
Marine heat waves can trigger coral bleaching. Alexis Rosenfeld/Getty Images

I’m a climate scientist who studies the oceans. After three years of La Niña, it’s time to start preparing for what El Niño may have in store.

How El Niño affects the planet

No two El Niño events are exactly alike, though we’ve seen enough of them that forecasters have a pretty good idea of what’s likely to happen.

People tend to focus on El Niño’s impact on land, justifiably. The warm water affects air currents that leave areas wetter or drier than usual. It can ramp up storms in some areas, like the southern U.S., while tending to tamp down Atlantic hurricane activity.

How El Niño forms. NOAA.

El Niño can also wreak havoc on the many marine ecosystems that support the world’s fishing industries, including coral reefs and seagrass meadows.

Specifically, El Niño tends to trigger intense and widespread periods of extreme ocean warming known as marine heat waves.

Global ocean temperatures are already at record highs, so El Niño-induced marine heat waves could push many sensitive fisheries to a breaking point.

The problem with marine heat waves

A marine heat wave is just that: a “wave” of extreme heat in the ocean, not dissimilar to an atmospheric heat wave on land.

At their smallest, marine heat waves can inundate local bays and coves with hotter-than-normal water for a few days or weeks. At their largest, marine heat waves like the Northeast Pacific Warm Blob of 2013-2014 can grow to gargantuan proportions, with regions three times the size of Texas experiencing ocean temperatures 4 to 6 F (about 2 to 3 C) above average for months or even years.

An example of a marine heat wave showing intense heat.
Fierce marine heat waves like this one in 2019 can wreak havoc on sea life off the North American Pacific Coast with temperatures about 4 to 6 F (2 to 3 C) above normal. Dillon Amaya

Warm water might not seem like a big deal, especially to surfers hoping to leave their wetsuits at home. But for many marine organisms that are highly adapted to specific water temperatures, marine heat waves can make living in the ocean feel like running a marathon.

For example, some fish increase their metabolism in warm waters by so much that they burn energy faster than they can eat, and they can die. Pacific cod declined by 70% in the Gulf of Alaska in response to a marine heat wave. Other impacts include bleached corals, widespread harmful algal blooms, decimated seaweeds and increased marine mammal strandings. All told, billions of U.S. dollars are lost to marine heat waves each year.

Marine heat waves flare up for a variety of reasons. Sometimes ocean currents shift warm water around. Sometimes surface winds are weaker than normal, leading to less evaporation over the ocean and warmer waters. Sometimes cloudy places just aren’t as cloudy for a few months, which lets more sunlight in and heats up the ocean. Sometimes both weaker winds and fewer clouds happen at the same time, producing record-breaking marine heat waves.

Where El Niño fits in

In the climate system, El Niño is king. When it dons its fiery crown, the entire planet takes notice, and the oceans are no exception. But the likelihood of increased marine heat wave activity during El Niño depends on where you are.

Along the U.S. West Coast during El Niño, surface winds that normally blow from the north tend to subside. This weakens evaporation and slows upwelling of colder, deeper water. That increases the chances of coastal marine heat waves.

Peruvian fishers have for centuries weathered periods of extreme ocean warming that drive fish away. It wasn’t until the 1920s that scientists realized that these South American marine heat waves were related to the Pacificwide ENSO.

In the Bay of Bengal east of India, interactions between El Niño and a tropical air flow pattern known as the Walker Circulation elevate the risk for marine heat waves.

Seafloor heat waves are another risk

Even if marine heat waves aren’t more obvious at the ocean surface this year, it doesn’t mean all is well down below.

In a recent study, my colleagues and I showed that marine heat waves also unfold along the seafloor of coastal regions. In fact, these “bottom marine heat waves” are sometimes more intense than their surface counterparts. They can also persist much longer. For example, a 1997-1998 bottom marine heat wave off the U.S. West Coast lasted an extra four to five months after surface ocean temperatures had already cooled.

Events like this can be related to El Niño and put a lot of stress on bottom-dwelling species. Bering Sea snow crab landings were down 84% in 2018 after a marine heat wave reached the seafloor.

We’re in (for) hot water

With El Niño on the horizon, what can we expect for this year?

The good news is seasonal forecast models can skillfully predict marine heat waves three to six months in advance, depending on the region. And forecasts tend to be most accurate during El Niño years.

Map showing where marine heat waves are forecast in October 2023.
NOAA’s marine heat wave forecast issued in early April predicting October 2023. NOAA/Jacox, et al. 2022

The latest forecast predicts several active marine heat waves to persist into June-August, including in the North Pacific, off the coast of Peru, southeast of New Zealand and in the tropical North Atlantic.

The same forecasts predict El Niño to ramp up over the next six to nine months, increasing marine heat wave risk in January to March of 2024 for the U.S. West Coast, the western Indian Ocean, the Bay of Bengal, and the tropical North Atlantic.

That said, these predictions are far enough out that things could change. Time will tell whether they hold (hot) water, but we would do well to prepare. El Niño is coming.

Dillon Amaya, Climate Research Scientist, National Oceanic and Atmospheric Administration

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Celebrated squirrel’s legacy lives on for visitors

by Lisa Sheppard, Prairie Research Institute

The male squirrel nicknamed Pinto Bean was popular among students on campus and became a social media star with its own Wiki page. Its age was unknown. Pinto Bean died on Oct. 8, 2022, apparently from being struck by a vehicle.

Pinto Bean, the beloved piebald squirrel that lived and died on the University of Illinois campus, is back. The squirrel’s taxidermied remains are now on display at the Forbes Natural History Building lobby, where visitors can see its rare gray and white coloration that attracted fans and followers at the university.

Photo by Joseph Spencer

The Forbes Building is a fitting location for Pinto Bean after his death, according to Eric Schauber, Illinois State Biologist at the Illinois Natural History Survey (INHS), a unit of the Prairie Research Institute.

“The INHS has been the guardian and memory of Illinois’ biological resources since the 1850s,” Schauber said. “This is another page in that history, and one that is tied to our campus here.”

It is unknown if Pinto Bean had any offspring, but if so, half of its kits would have inherited the distinctive piebald pattern, Schauber said. This condition is a genetic mutation that slows the rate at which melanocytes, cells that produce pigment, increase during embryo development. In this case, there was not enough of these cells to cover the animal, and patches of light and dark fur occurred.  

This gene is prominent in many domestic animals, such as in tuxedo cats that have fur with a black and white pattern.

Pinto Bean’s celebrity is an example of humans’ innate need to bond with nature, Schauber said.

“Even in a human-dominated area, such as a college campus, people are experiencing nature around them in various ways and are connecting with that,” he said. “This is just one instance in which students tend to make a connection with local squirrel populations on campuses all across the country.”

Pinto Bean joins a variety of other natural history specimens and models on display in the Forbes Building lobby at 1816 South Oak Street in Champaign, including a great horned owl, songbirds, insects, reptiles, and amphibians. Fossils preserved in amber are also located there. The centerpiece of the lobby’s display is a bison from Illinois in the 1870s.


Media contact: Eric Schauber, 217-300-7827, schauber@illinois.edu

This story originally appeared on the Prairie Research Institute News Blog. Read the original story.

Migratory birds can partially offset climate change

Read the full story from Cornell University.

A new study demonstrates that birds can partially compensate for climate change by delaying the start of spring migration and completing the journey faster. But the strategy comes with a cost — a decline in overall survival.

Giant snapping turtle ‘Chonkosaurus’ evidence of a much cleaner Chicago River

Read the full story in the Chicago Sun-Times.

The man behind the viral video of a huge snapping turtle nicknamed “Chonkosaurus” catching sunbeams along the Chicago River said the sighting points to the improving health of the historically polluted waterway.

Joey Santore and his friend Al Scorch were kayaking and filming a video on plants growing along the river when they came upon the massive reptile lounging on the water near Goose Island.

Everything about the video screams Chicago, from the previously polluted stream of water to Santore’s recognizable accent as he marvels at the turtle’s size.

Sierra squirrels find their niche amid a changing climate

Read the full story from the University of California – Davis.

A new study of squirrels in California’s Sierra Nevada mountains finds that climate is just one factor impacting where species make their homes in a changing world.

Avian flu outbreaks in marine mammals mark new era for deadly virus

Read the full story at e360.

A highly pathogenic strain of avian influenza has killed thousands of wild birds and is now infecting seals and other marine mammals. Researchers know the virus can jump from birds to mammals, but they are on alert to see if it can be transmitted from mammal to mammal.

Michigan updates list of at-risk birds, adds black tern, six others

Read the full story at Bridge Michigan.

Michigan officials recently took six birds off of the states’ endangered and threatened species list. But it added seven other species.

The last time the list was updated was in 2009. Among the species that newly receive threatened status are the Eastern whip-poor-will, evening grosbeak, golden-winged warbler, Northern goshawk, spruce grouse and upland sandpiper.

Warming Arctic draws marine predators northwards

Read the full story from Hokkaido University.

Marine predators have expanded their ranges into the Arctic waters over the last twenty years, driven by climate change and associated increases in productivity.

Innovative method predicts the effects of climate change on cold-blooded animals

Read the full story from Penn State University.

In the face of a warming climate that is having a profound effect on global biodiversity and will change the distribution and abundance of many animals, a research team has developed a statistical model that improves estimates of habitat suitability and extinction probability for cold-blooded animals as temperatures climb.

Rewilding animals could be key for climate: Report

Read the full story from Mongabay.

A new report published in Nature Climate Change suggests that trophic rewilding, or restoring and protecting the functional roles of animals in ecosystems, is an overlooked climate solution. Reintroducing just nine species or groups of species (including African forest elephants, American bison, fish, gray wolves, musk oxen, sea otters, sharks, whales and wildebeest) would help limit global warming to less than the 1.5°C (2.7°F) threshold set by the Paris Agreement, according to the report.

Animals play a significant role in how much carbon plants, soil and sediments can capture, as they redistribute seeds and nutrients and disturb soil through digging, trampling, and nest-building. The report emphasizes the need for a change in mindset within science and policy to take advantage of the vast potential of wildlife, while working closely with local communities to address social issues that can affect conservation efforts.