galapagos islands

Deeper corals bleaching

December 7, 2023 By EarthWise Leave a Comment

When ocean waters get too warm, corals – which are actually tiny animals – eject the colorful algae that inhabit their tissues. The symbiotic relationship between coral polyps and algae is essential to coral survival When the algae is ejected, previously colorful coral turns white, and the coral can ultimately die. If waters cool off, the algae can reestablish themselves and the coral can regain its color and health.

The world’s oceans have been warming at an unprecedented rate, making coral bleaching and die-off a global phenomenon. It is estimated that half of the planet’s reefs have already disappeared. Some places are worse off than others. For example, almost 95% of coral reefs in Southeast Asia are threatened. Florida’s reefs are especially threatened, particularly since there have been unprecedented marine heatwaves off its coast.

It has long been assumed that deeper reefs, where water is cooler, would remain safe from the effects of warming, but a few years ago researchers recorded coral bleaching some 300 feet underwater along the Egmont Atoll in the western Indian Ocean. At one point, bleaching affected 80% of corals in some areas. This discovery came as a huge surprise to oceanographers. It was probably associated with an El Niño-like phenomenon in the waters and those reefs have mostly recovered in the intervening years.

Fairly recently, researchers have found pristine coral reefs deep down in the waters off the Galapagos Islands, where shallow reefs have largely disappeared. There are likely to be similar reefs in the ocean depths around the world, but scientists are expressing concern that even coral reefs lying deep beneath the ocean surface may not ultimately be protected from the warming seas.

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As Oceans Warm, Coral Bleaching Seen at Greater Depths

Photo, posted June 5, 2023, courtesy of Ryan Hagerty / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Giant Tortoise Is Not Extinct | Earth Wise

July 4, 2022 By EarthWise Leave a Comment

The Galapagos Islands are famous for their tortoises, among many other things. A few million years ago, some giant tortoises from South America were somehow carried across hundreds of miles of ocean to the islands – perhaps on driftwood during storms. Tortoises don’t swim, so any that made to an island could only breed with others on that same island. The result was rapid evolution of tortoise species in the Galapagos. Today, there are 14 different species of giant tortoises there.

Centuries ago, tortoise populations in the Galapagos were decimated by European sailors who hunted them for food. The giant reptiles could be kept alive on ships with little food or water, so they became a great source of meat.

On the island of Fernandina, there was a species of Galapagos tortoise known as the “fantastic giant tortoise.” Only a single one of these was ever found and that was in 1906. It ended up being preserved as a museum specimen.

In 2019, a female tortoise living on Fernandina was located and genome sequencing has only recently been successfully completed for that living specimen and the century-old one in the museum which compared them to sequences of the other 13 species of Galapagos tortoise. That analysis showed that the two were indeed the same species and are distinct from all the others.

The female tortoise, who has been named Fernanda, now resides at the Galapagos National Park Tortoise Center, which is a rescue and breeding facility. She is well over 50 years old. Recent tracks and scat on Fernandina Island provide evidence that there may still be others of her kind. The experts are trying to do what they can to keep the species alive.

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‘Fantastic giant tortoise,’ believed extinct, confirmed alive in the Galápagos

Photo, posted January 1, 2019, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plastic Pollution And The Galapagos Islands | Earth Wise

July 12, 2021 By EarthWise 1 Comment

The proliferation of plastics remains one of the world’s most challenging environmental problems. Plastic pollution can be found in some of the most remote regions of the planet, including atop the world’s tallest mountains and in the deepest depths of the ocean. Even the Galapagos Islands, a volcanic archipelago in the Pacific Ocean, are no exception.

According to a new study by researchers from the University of Exeter, the Galapagos Conservation Trust, and the Galapagos Science Center, plastic pollution has been found in seawater, on beaches, and inside marine animals at the Galapagos Islands.

In the most polluted hotspots, more than 400 plastic particles were found per square metre of beach. The researchers found that only 2% of macroplastic pollution – plastic fragments larger than five millimeters – was identified as coming from the Galapagos islands. All seven of the marine invertebrate species examined – 52% of individuals tested – were found to contain microplastics.

Significant accumulations of plastic were also found in key habitats, including rocky lava shores and mangroves. In fact, plastics were found in all marine habitats at the island of San Cristobal, which is where Charles Darwin first landed in Galapagos.

Most of the plastic pollution in the Galapagos appears to arrive via ocean currents. According to the research team, the highest levels of plastic pollution were found on east-facing beaches, which are exposed to pollution carried across the ocean on the Humboldt Current.

The pristine images of the Galapagos, a world-famous biodiversity haven, might give the impression that the region is protected from plastic pollution. But clearly that is not the case.

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Plastic in Galapagos seawater, beaches and animals

Photo, posted April 12, 2012, courtesy of Ben Tavener via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.