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Cold ocean currents have sheltered the Galápagos Islands from global warming, according to a recent study.
The islands are protected from an otherwise warming Pacific Ocean by a cold, eastward equatorial ocean current. And this current has been gaining strength for decades, noted the study published in the journal PLOS Climate September 7, 2022.
The temperatures in waters along the west coast of the Galápagos have dropped by 0.5 degrees Celsius since the early 1990s, the researchers from the University of Colorado Boulder observed.
“There’s a tug of war between global warming and the cold ocean current. Right now, the ocean current is winning — it’s getting cooler year after year,” said Kris Karnauskas, the lead author of the study, in a press release.
This phenomenon is a cause for cautious optimism for the second-largest marine reserve in the world. The island is a biodiverse ecosystem — home to several endangered species. It is designated as a UNESCO World Heritage Site.
Flora and fauna of the Galápagos could assist reseed failing ecosystems and maintain the region’s fisheries.
Corals do not bleach and die in these waters off the west coast of Ecuador. So, the marine food chain does not suffer, unlike in the warm waters nearby.
“As the Galápagos so far has been relatively unaffected by climate change, it’s worth looking at the Galápagos as a potential site to really try to put some climate change mitigation efforts into,” said Karnauskas.
But, the island group is certainly in need of greater protection from overfishing as well as the pressures of growing eco-tourism.
“The human pressures on this area and the mechanism that keeps it alive are at odds. It’s a major resource that should be protected,” said Karnauskas
From space, the Galápagos may appear to be a collection of minuscule specks in the eastern Pacific Ocean. However, it is their precise position on the equator that makes them significant.
The equatorial undercurrent in the Pacific Ocean is bound to the equator by the force of the planet’s rotation. Under the ocean’s surface, a swift circulation of cold, nutrient-rich water flows from west to east.
Some of this water is forced to the surface when it reaches the Galápagos Islands. The nutrient-rich water triggers photosynthesis and leads to an explosion of food for a wide variety of animals.
The cold ocean current creates a cooler, more stable environment for coral reefs and marine life and birds that often live much closer to the poles. It is described by the UNESCO World Heritage Convention as a “living museum and showcase of evolution.” Galápagos is home to the critically endangered — Galápagos penguin, Galápagos fur seal and Galápagos sea lion.
El Niño poses a threat to the island group. It shuts down the cold current every couple of years, causing penguin populations to collapse. El Niño is a climate pattern that causes unusual warming of surface waters in the eastern tropical Pacific Ocean.
“The worry is if in the future there are changes in this current, it could be really devastating for the ecosystem,” said Karnauskas.
This haven may fade if the oceans continue to warm as they have been.
“Are the Galápagos Islands safe forever? Not quite,” said Karnauskas.