cold water

La Niña has arrived

February 26, 2025 By EarthWise Leave a Comment

After seven months of waiting following the end of the recent El Niño condition, La Niña finally showed up in the eastern Pacific Ocean in early December.

El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide. Normally, trade winds in the Pacific blow west along the equator, taking warm water from South America towards Asia. To replace the warm water, cold water rises from the depths. During El Niño, trade winds weaken and warm water is pushed back east, toward the west coast of the Americas. As a result, areas in the northern U.S. and Canada are dryer and warmer than usual.

During La Niña, trade winds are stronger than usual, pushing more warm water toward Asia. This results in more upwelling of cooler water from the depths. This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada. During a La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the North.

According to the report published in January by NOAA, the La Niña that has arrived is not a particularly strong one. Sea surface temperatures are only about 1.3 degrees Fahrenheit below average in the tropical Pacific. The report also suggests that the La Niña condition may not stick around very long.

The El Niño-Southern Oscillation phenomenon adds a natural source of year-to-year variability in global temperatures. The presence of La Niña for at least part of this year may temporarily keep the lid on rapidly climbing global temperatures.

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La Niña Is Here

Photo, posted November 23, 2011, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Help For Kelp | Earth Wise

April 10, 2023 By EarthWise Leave a Comment

The warming of the oceans has been causing the decimation of kelp forests. The thick canopies covering coastal ocean regions have been wilting in warmer and nutrient-poor water. Making matters much worse has been the explosion in population of sea urchins that thrive in warmer water. The urchins gobble up the kelp, often resulting in so-called urchin barrens, largely devoid of life.

Kelp are considered a foundation species that occupy nearly half of the world’s marine ecoregions. They thrive in cold water, where they form large underwater forests that provide essential habitat, food, and refuge for many species. Kelp are often harvested for use in products ranging from toothpaste and shampoo to puddings and cakes. Including the other services kelp provide, they are associated with billions of dollars in value annually.

On the North American Pacific Coast, a species of sea star consumes sea urchins. However, these creatures are critically endangered. A marine wildlife epidemic known as sea star wasting syndrome, which began 10 years ago, has killed off more than 90% of the sunflower sea star population. A new study by researchers at Oregon State University looked at the ability of sea stars to control sea urchin populations.

Lab experiments showed that sea stars consume urchins at a rate sufficient to maintain and possibly even restore the health of kelp forests. The study shows that there is a clear link between the population crash of sea stars, the explosion in sea urchin populations, and the decline in kelp.

The study’s authors are calling for active management and a coordinated sea star recovery program to try to deal with the effects of a disease whose cause has not been determined.

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Sea stars able to consume kelp-eating urchins fast enough to protect kelp forests, research shows

Photo, posted December 14, 2015, courtesy of Ed Dunens via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Crabs | Earth Wise

November 8, 2022 By EarthWise Leave a Comment

Globally, there are more than 6,000 species of crabs. In Alaska’s waters alone, there are 18 species, including 10 that are commercially fished. The perils of crab fishing in this region, including freezing temperatures, turbulent seas, and raising full pots that can weigh well over a ton, have been highlighted for many years in the reality TV series Deadliest Catch.

One of those commercially-fished species is the Alaska snow crab. Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas.

In October, officials in Alaska announced that the upcoming winter snow crab season would be canceled for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years ago, approximately 90% of snow crabs mysteriously disappeared ahead of last season. Officials also canceled the Bristol Bay red king crab harvest for similar reasons for the second year in a row.

The closures dealt a severe blow to crab fishers in the region. According to the Alaska Seafood Marketing Institute, Alaska’s crab fishing industry is worth more than $200 million.

The canceled seasons also raise questions about the role of climate change in the snow crab population crash. While the causes of the decline are still being researched, scientists suspect that warmer temperatures are responsible. Temperatures in the Arctic region have warmed four times faster than the rest of the planet.

As the climate continues to change, the warming waters around Alaska may become increasingly inhospitable to snow crabs and other species.

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Alaska’s Bering snow crab, king crab seasons canceled

Alaska cancels snow crab season for first time after population collapses

Photo, posted November 16, 2010, courtesy of David Csepp / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio