Scuba Diver Australasia + Ocean Planet
MARINE IGUANA
ASIA DIVE EXPO (ADEX 2014, 2017, 2018, 2019 SPEAKER)
The world’s only oceangoing lizard, the marine iguana is endemic to Ecuador’s Galápagos Islands, with the most numerous colonies inhabiting the bays of Fernandina, Isabella and Santa Cruz Islands. They are land animals but feed mainly on the seaweed and algae that grow in the water. Preyed on by cats, rats, dogs and pigs, they are also threatened by marine plastic pollution. The effects of climate change, such as increases in sea levels and air temperature, are affecting their habitat, food supply and ability to regulate body temperature. Smaller and younger iguanas prefer feeding right off the coast in low tide (to avoid fighting the surge) while larger males dive down for food, using their long, sharp claws to hang onto the rocks while scraping off the algae. Marine iguanas cannot breathe underwater, but can dive as deep as 30 metres and hold their breath for up to an hour when foraging. They dive down once or twice a day, usually in the early afternoon, when the water is warm enough for them to stay on the bottom for longer.
When we started our dive in the shallow waters of Fernandina Island at around 11am, the marine iguanas seemed to be reluctant to get in the water. But within about half an hour, they finally started going down. I could see one dropping down, then another, and as the waters warmed up, the iguanas were everywhere!