Introducing the marine iguana – a creature that would surprise any scuba diver fortunate enough to encounter it! These remarkable reptiles have evolved to search for food in the sea due to its scarcity on their island. However, venturing into the ocean is a highly risky endeavor. The waves crash against the rocks, and dangerous currents swirl. Only the larger adults can withstand these forces and venture into the water. Not only are these iguanas skilled swimmers, but they can also dive up to 30 feet on a single breath! Subsequently, they casually traverse the sea floor, feasting on red and green algae, as if it were perfectly ordinary behavior for an iguana.
Remarkably, these creatures are the sole sea-dwelling lizards on Earth. The iguanas in the footage must consume their meals quickly, as their breath is running out, and the cool seawater is rapidly cooling their bodies. Staying submerged for more than 10 minutes would cause their muscles to seize up, presenting the challenge of returning to land!
These extraordinary reptiles exclusively inhabit the Galapagos Islands, an archipelago off the South American coast. The ancestors of the iguanas seen in the footage likely arrived on the islands via floating debris millions of years ago.
Today, they reside on the steep rocky cliffs and low rock ledges in the intertidal zone of the islands. Additionally, they require proximity to sandy areas for egg-laying. This habitat not only provides access to food but also limits the predators that can reach them. Predation comes primarily from hawks, owls, snakes, and crabs, although feral predators like rats, dogs, and cats have unfortunately claimed many lives. Their vulnerability to predation increases when they are cold and unable to move effectively.
Marine iguanas predominantly feed on marine algae. The larger individuals can dive during high tide, while the smaller ones must forage in the intertidal zone during low tide. This highly specialized feeding method leaves them susceptible to changes in marine algal flora. A period of heightened mortality occurred between November 1982 and July 1983 due to abnormal weather conditions, leading to their classification as vulnerable by the IUCN, with their numbers steadily declining.