Galápagos Marine Iguana

Marine iguanas, known scientifically as Amblyrhynchus cristatus, are the only lizards with the ability to live and forage at sea, and are endemic to the Galápagos Islands. They live for up to 12 years and can grow up a mighty length of one and a half meters.

With a diet consisting of predominantly sea algae, they have a high salt concentration which they filter out of their blood by sneezing out the excess. This often forms visible salt crystals on their snout.

With eleven very similar subspecies found across the archipelago, marine iguanas vary in size and color. An incredible phenomenon occurs during mating season, where males transform themselves from black into all sorts of vivid colors.

Marine iguanas can be seen across many islands in the Galápagos, specifically the coastal regions of Isabela, Fernandina, Española, Floreana and Santa Cruz. In January, you can witness the male's unique mating technique of changing color to attract a mate. Española and Floreana have the most colorful transformation, turning vivid green and red, on Santa Cruz they turn red and black, and on Fernandina they become a more dull green and red.

During mating season, you might spot males fighting for females in a fierce battle across the sand. By May, baby marine iguanas have hatched and can be seen clinging onto their mothers.

You can see the reptiles all year round and are most active during the day, spending their time foraging and basking on sun-soaked rocks.

Marine iguanas hang around the coastal regions of the islands and in the waters. Either on a boat or on land,  you will have a great chance of seeing them. On land, you can spot them relaxing on the rocks, and from a boat you can spot them swimming effortlessly through the water. You might even spot them gliding past you while snorkeling or diving.

Marine iguanas are considered to be a vulnerable species due to various threats that caused by human activity and natural climate processes that are being intensified by climate change. 

Threats

• The introduction of cats and dogs by humans has had a detrimental affect to marine iguana numbers. Juvenile marine iguanas are easy prey against larger predators.
• El Niño years, when climate pattern changes disrupt marine and terrestrial ecosystems, periodically decrease the iguana populations as it cuts short their food supplies.
• Oil spills may also dramatically affect the population, as well as plastic pollution including microplastics in the water.

Conservation Efforts

• The marine iguana is protected under Ecuadorian law and is listed under CITES, an international agreement aimed at regulating trade in wild animals.
• The Plastic Pollution Free Galápagos program is working to assess the risk of marine plastic pollution and its effect on marine iguanas.