Neature Talk: Marine Iguanas
February 2, 2021
The Galapagos Islands, a small archipelago off the west coast of Ecuador, are rich in genetic diversity, similar to the American islands of Hawaii.
Along with being home to tortoises, many of which being older than any living person alive today, these islands also harbor Earth’s only marine lizard species, the Galapagos Marine Iguana.
The Galapagos Marine Iguana feeds specifically on sea algae that grows along the shallow ocean floor. While feeding under the water, these iguanas ingest large amounts of salt water, along with the sea algae that they rely on for survival. Due to this, these magnificent marine creatures have developed a remarkably efficient salt gland; this gland allows for them to ingest copious amounts of salt water along with their sea algae. The salt gland will then filter all of the salt out of the iguanas’ blood stream without taking the, now fresh, water with it. The newly fresh water is now able to be used in the iguanas’ bodily processes, just as if it had been freshwater to start with. To expel the salt from their bodies, these iguanas will essentially “sneeze” out the salt.
Due to their strict reliance on one food source, these iguanas have had to use a special survival tactic that allows them to survive on less food during the season that sea algae is not as readily available. The iguanas will shrink by up to 20% in times where there is a severe lack of algae; they are then able to survive on a significantly less amount of food.
Unfortunately for these iguanas, due to having such a small habitat in a very specific location, extinction is a continuous, and very serious, threat. Wild dogs, cats, pigs, and even certain strains of bacteria prey on the young of the iguanas, making the populations of future generations continue to dwindle in numbers. A saving grace for these iguanas is a strict legal protection afforded to the entire Galapagos Islands that prohibits any animal, plant, or rock to be used by a person for profit, and a law that states that for a person to apply for residency on the island, they have had to exhibit respectful living practices on the island for five years.
As always, when asking yourself how to help these creatures that live so far away, the work starts right in your own home. Focus on recycling plastics and other trash that does not break down, be mindful of the amount of non renewable materials you are using in your day to day life, and remember that nature was here long before we were, and for it to still be here long after we are gone, it needs to be treated respectfully.