The Galápagos Islands are the home of thousands of unique species. In fact, those islands were where Charles Darwin began writing about his findings on evolution. But at least one of these species is in jeopardy because of warming ocean temperatures.
Within the next century, rising ocean temperatures around the Galápagos Islands are expected to make the water too warm for sardines to tolerate.
Why is that important? Sardines are a key prey species for many seabirds including the Nazca booby.
Wake Forest University biologists published a study in the August 23 issue of the journal PLOS ONE about this phenomenon. They used decades of data on the diet and breeding of the Nazca booby to understand how the absence of sardines could affect the booby population.
They studied the diet, breeding, and survival of Nazca boobies as part of their study at Isla Españnola in the Galápagos Islands for more than 30 years. In 1997, halfway through their study, sardines disappeared from Nazca booby diet samples, replaced by flying fish.
Flying fish are less nutritious than sardines, and as researcher Emily Tompkins, lead author of the study, said, as flying fish replaced sardines in the birds’ diet, “reproductive success was halved.”
“If the current links between diet and reproduction persist in the future, and rising ocean temperatures exclude sardines from the Galápagos, we forecast the Nazca booby population will decline,” Tompkins said.
David Anderson, a professor of biology and co-author of the study, said, “Few connections have been made between ocean warming and population effects in the tropics, making this study significant.”
But the Nazca booby isn’t the only creature that could be harmed by rising ocean temperatures. The study suggests that other Galápagos predators that do well when sardines are available will have to adjust to a new menu within the next 100 years.
So many species have gone extinct or become highly endangered due to global climate change—probably including species we never even discovered—that it behooves us to act to stop, or at least slow, climate change. Given the United States’ exit from the Paris Climate Agreement, it’s up to other nations, and states and cities within the U.S., to step up and do something about this increasing danger to the survival of all animals, including humans.