The only lizard that conquers the ocean is facing a double threat

Nature · Published 23 October 2026 Swipe more like this →

In short: Marine iguanas are evolutionary marvels, having transitioned from land-dwelling lizards to sea-foraging specialists. But today, this unique adaptation is becoming a liability as they face a dual crisis of climate-driven starvation and an escalating black market for exotic pets.

The marine iguana represents a remarkable evolutionary success story in the Galapagos Islands. Originally terrestrial creatures that consumed greenery, they adapted to the volcanic archipelago by developing the unique ability to forage underwater. They are currently the only lizards on Earth capable of living and foraging at sea, primarily by consuming seaweed and intertidal macroalgae. These creatures were shaped by the relentless winds of desolate volcanic isles. Their transformation was a pivotal moment in the crucible of evolution.

However, this specialized niche is under extreme pressure from a 'super' El Niño event that began warming equatorial waters in May 2026. This warming is decimating the macroalgae—the iguanas' primary food source—leading to mass mortality. Scientists have observed the population shrinking in size and dying from starvation or exhaustion as they swim longer distances to find remaining food. A 2013 autopsy of 80 deceased iguanas revealed undigested red and green algae, highlighting a struggle for nutrition. Researchers are currently pursuing four promising leads to solve this mystery. Seawater studies have failed to yield any substantive results regarding their decline.

Compounding these environmental pressures is a 'strange uptick' in black-market trafficking. In May 2026 alone, Ecuadorian officials discovered dozens of iguanas being smuggled in handbags and suitcases to supply the exotic pet trade. While the species is globally classified as vulnerable by the IUCN, 10 out of the 11 known subspecies are locally categorized as endangered or critically endangered. Because each subspecies is highly evolved for specific islands, rescued animals require DNA testing to ensure they are returned to their correct ancestral homes. Smuggling attempts have already resulted in at least one confirmed death among confiscated animals. Authorities and scientists joined forces in 2015 to redouble conservation efforts.

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