As seas warm, the Galápagos Islands are facing a giant evolutionary test. El Nino and La Nina are naturally occurring cycles that have always affected species living in the Galapagos Islands. The problem though is that global warming is raising the baseline temperatures and this results in much higher temperatures in both the sea and in the air. And this is threatening all of the fauna and flora on these islands.
The Galapagos Islands are located in the Pacific Ocean west of Ecuador in South America.
Nicholas Casey, a New York Times correspondent based in Colombia, and Josh Haner, a Times photographer, traveled to the Galapagos to see how global warming is affecting the Islands where Darwin first began to put his ideas about natural selection and evolution together.
A long article about what Casey and Haner found in the Galapagos Islands was published in the New York Times on December 18, 2018. Below is a very much streamlined version of this article. To read the entire article click the link at the bottom of this page. There are a lot of very good photographs of the animals of the Galapagos in this article.
“In the struggle against extinction on these islands, Darwin saw a blueprint for the origin of every species, including humans.”
“Yet not even Darwin could have imagined what awaited the Galápagos, where the stage is set for perhaps the greatest evolutionary test yet.”
“As climate change warms the world’s oceans, these islands are a crucible. And scientists are worried. Not only do the Galápagos sit at the intersection of three ocean currents, they are in the cross hairs of one of the world’s most destructive weather patterns, El Niño, which causes rapid, extreme ocean heating across the Eastern Pacific tropics.”
“Research published in 2014 by more than a dozen climate scientists warned that rising ocean temperatures were making El Niño both more frequent and more intense. Unesco, the United Nations educational and cultural agency, now warns the Galápagos Islands are one of the places most vulnerable to the impacts of climate change.”
“To see the future of the Galápagos, look to their recent past, when one such event bore down on these islands. Warm El Niño waters blocked the rise of nutrients to the surface of the ocean, which caused widespread starvation.”
“Large marine iguanas died, while others shrank their skeletons to survive. Seabirds stopped laying eggs. Forests of a giant daisy tree were flattened by storms and thorny invasive bushes took over their territory. Eight of every 10 penguins died and nearly all sea lion pups perished. A fish the length of a pencil, the Galápagos damsel, was never seen again.”
“That was in 1982. The world’s oceans have warmed at least half a degree Celsius since then.”
“David J. Anderson, a biologist at Wake Forest University who studies the blue-footed booby, a seabird, said the ravages of El Niño were a surprise when he began working on the islands in the 1980s.”
“”Now we are wondering, how frequent do these things get? El Niños have a bulldozer effect,” he said. “And they are happening more and more.””
“Though the Galápagos lie at the heart of the geographic tropics, it’s hard to guess that, standing on one of the islands, because of a vast current that flows north from southern Chile. That stream, the Humboldt Current, keeps the islands cool and rainless most of the year, unusual given that the Equator crosses through the archipelago. It means the islands are subtropical in climate, a rare place where penguins and corals exist side by side.”
“But sometimes the cool Humboldt Current suddenly slows.”
“The ocean waters start warming rapidly, heating up as much as 2 degrees Celsius, or 3.6 degrees Fahrenheit, within months. Storms begin to strike the islands with rain and flash floods. And, as if overnight, the Galápagos become warmer: It is the start of El Niño, Spanish for “the boy child,” a reference coined by Peruvian fisherman because the changes can occur around Christmas.”
“”The Galápagos marine system is analogous to a roller coaster,” said Jon D. Witman, a professor of biology at Brown University who studies coral ecosystems in the Galápagos, noting that the spikes of hot temperatures were followed by spells of falling temperatures, known as La Niña.”
“The problem with global warming, Dr. Witman said, is that the baseline from which these swings occur is rising as the ocean temperatures do. This, as the intensity and frequency of El Niño is increasing.”
“Rising ocean temperatures mean less algae, the main source of food for marine iguanas. Scientists say they believe that the reptiles may reabsorb parts of their skeleton in order to decrease their size and increase their chances of survival on a smaller diet. Stress hormones may trigger the process, but little more is understood about how the iguanas adapt. Nevertheless, the changes could be central to their survival as El Niño cycles become more frequent.”
“Evolution has led other animals in different directions, which could now prove fatal as ocean temperatures rise.”
“When sea temperatures rise, the sardine population around Isabela Island drops. In the 1982 El Niño, nearly every large adult male fur seal died of starvation. Most of the sea lion pups born that year died as well because parents couldn’t feed their young, according to a study by Fritz Trillmich, a behavioral ecologist.”
“”It’s like if our generation didn’t have kids,” said Robert Lamb, a doctoral candidate in ecology and evolutionary biology at Brown University.”
“The blue-footed boobies once lived principally on sardines. But for reasons unknown, sardine populations plummeted in 1997 and the fish remain scarce, forcing the birds to eat other fish. When sea temperatures rise during El Niño, these other fish also start to disappear.”
“”They basically stop trying to breed,” Dr. Anderson, the Wake Forest biologist, said of the boobies. He said the pattern had become more frequent in parallel with El Niños.”
“”One hundred years from now, I would not be surprised if the blue-footed boobies were gone” if current trends continue, Dr. Anderson said.”
“Similar behaviors are seen in other aquatic birds here. Galápagos penguins, which are only found on these islands, stop breeding when the water reaches 25 degrees Celsius, or about 77 degrees Fahrenheit.”
“While warmer temperatures often spell doom for native species that evolved to the Galápagos’ cool subtropical climate, invasive species flourish.”
The image at the top of this page is a Sand Hill Crane which was photographed in The Bosque del Apache Wildlife Preserve in New Mexico.