Currents Are King

The islands are teeming with life because of where they formed. They sit at the crossroads of several major ocean currents. The climate depends on these currents. The currents are affected by the winds that push them.

Let’s start with the Humboldt current. It sweeps north from Antarctica and carries cold, nutrient‑rich water.

The Humboldt is a deep‑water current. With powerful trade winds, it creates an upwelling.

At the surface, winds blow ocean water away. Then deep‑sea water rises up to replace it.

When ocean organisms die and decompose, they sink to the bottom as nutrients. Upwelling brings up these nutrients. They provide food for tiny living organisms.

Cromwell current

Peru Oceanic current

South Equatorial current

Humboldt current

PACIFIC OCEAN

GALÁPAGOS
ISLANDS

ECUADOR

South
America

Panama current

Cold water with more nutrients rises up to replace water that is pushed away.

Surface winds push water away from the land.

phytoplankton

UPWELLING

Strong winds and deep currents create upwelling. The ocean becomes plentiful with food.

When Currents Collide

From May through December, the Humboldt current collides with the warm‑water Panama current. This current flows south from Central America. When the currents meet, they create a cool mist. Clouds form, and the islands seem to disappear.

Meanwhile, the Cromwell current moves in from the west. It travels thousands of kilometers from Hawaii. This cold current also carries nutrients to feed the marine food chain.

cactus finch

mistand fog around Isabela Island

And here comes the South Equatorial current. It flows east to west. This is a warm‑water surface current in the Pacific.

Around December, the warm Panama current becomes forceful. It can bring high humidity and heavy tropical rains. These can usher in El Niño!

The waters and currents moving around Galápagos Islands support life.

Disruptive Force

The El Niño current only forms every few years. This current affects weather patterns. It can bring heavy rain and possible flooding. El Niño can last for months at a time.

El Niño can benefit the plant life on the islands by bringing rain. This leads to a population boom for animals that eat them.

During a harsh El Niño, the Humboldt current is cut off. Upwelling cannot happen. That means there isn’t enough food for sea animals. Many die.

The Galápagos is a place where nature fights to stay in balance. It was born of fire. It is fueled by wind and water. It is full of life.

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Galápagos penguins can only be found in the Galápagos Islands.

The Galápagos have three kinds of living things. Native species are found naturally here and elsewhere. The blue‑footed booby is a good example. Introduced species are not from here. People brought them to the islands. The goat is a good example. Endemic species are only found here.

The islands are isolated. So, many plants and animals are endemic. Strange things live here and only here. Lizards that swim. Giant tortoises. Meat‑eating centipedes. Blood‑sucking birds. Walking fish.

Galápagos penguins are the only penguins found north of the Equator. The cool waters carried them here.

leaning in to cool down

The blue‑footed booby can be found in the Pacific, from California to Peru and on the Galápagos Islands.

Galápagos penguins dive in the cold‑water currents to search for food. To manage hot temperatures on land, the penguins lean forward. This shades their feet from the sun. They stretch their flippers out. This releases body heat under their flippers.

Hidden in Plain Sight

The Galápagos hold new forms of life, like the hybrid iguana. It is found on only one island. A hybrid occurs when a male marine iguana mates with a female land iguana.

Liking Lava

The lava cactus is one of the first species to grow on new lava flows. It is only on six islands.

Pucker Up

This Galápagos red‑lipped batfish is odd. It can swim, but it uses its fins to walk, instead. And what’s with those red lips? Who knows?

Before you read

Life Science

Adaptation

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“The iguanas are small, and of a sooty black, which, if possible, heightens their native ugliness. Indeed, so disgusting is their appearance, that no one on board could be prevailed upon to take them as food.”

—Captain James Colnett of the British Royal Navy, 1798

Grooved teeth act like rakes. They scrape algae off rocks.

Black scales absorb heat.

Sharp claws help with climbing and holding on to rocks.

A short, square snout makes eating easier.

While the iguana swims, its back spines
balance its body.

Partially webbed feet
help it swim.

Marine iguanas made an impact on some of the islands’ earliest visitors. When naturalist Charles Darwin first saw them, long after Captain Colnett, he found them unappealing, too. He described them as “imps of darkness.”

These are the only lizards in the world that can live and forage at sea. They are endemic to the Galápagos Islands. Scientists believe that they are descended from land iguanas. They probably floated out to the islands from the continent on logs or vegetation.

Salty Sneezes

Marine iguanas swallow saltwater with their food. Then they need to get rid of salt from their systems. Glands in their noses remove salt from their blood. Then they sneeze it out!

Heat‑Seeking Lizard

Marine iguanas can’t control their body temperatures. They rely on a source, like the sun, to do it for them. If you read last month’s edition of Explorer magazine, you’ll know what the word for this is: ectotherm— a cold‑blooded animal.

Marine iguanas will lose an average of 10 degrees of heat in the cold water. So, before they dive in, they try to soak up enough heat to raise their body temperatures.

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