YV&C News Desk
The Galapagos 'Islands of Fire'
A place where evolution can be observed In-Situ
Apr. 22, 2007 07:45 PM
“Another feature of these isles is their emphatic uninhabitableness. It is deemed fit for ... the jackel itself; ... but the encantadas refuse to harbour even the outcasts of the beasts. Man and wolf alike disown them. Little but reptile life is here found; tortoises, lizards, ... and that strangest anomaly of outlandish nature, the iguano. No voice, no lo, no howl is heard; the chief sound of life here is a hiss”
—Herman Melville, from las Encantadas, 1841
Born of Fire, the Galapagos Islands are tips of submarine volcanoes, a place where evolution can be observed In-Situ. Hundreds of miles from mainland Ecuador, animals and plants set adrift have somehow found and colonised the desert islands. Floating rafts of vegetation, wind, air currents and oceanic drift all helped this colonisation.
Birds lost from migratory routes landed there, and sea birds carried seeds and invertebrates. Animals came from North, Central and South America, and Caribbean, set adrift in the ocean currents. Californian sea lions and land birds came from North America, while pink flamingos and Darwin finches came from the Caribbean. Land iguanas, giant tortoises, pelicans, cormorants and boobies arrived from South America. Fur sea lions and penguins travelled from the Antarctic.
Then there was Charles Darwin, the most famous of all visitors to the Galapagos’. He arrived aboard the HMS Beagle, on September 15, 1835. The HMS Beagle spent five weeks in the archipelago during which the 26 year old naturalist visited Chatham, Charles, Albemarle and James Islands. He spent 19 days on shore collecting and observing flora and fauna in this ‘living laboratory of evolution’. In 1859, twenty five years after his voyage on the Beagle, Darwin released the first edition of his work ~ ‘The Origin of Species by Means of Natural Selection’ which sparked a scientific and religious revolution.
Our luxury motor yacht; the ‘Letty’, lay off Fernandina Island in the Western Galapagos’, a place where the islands are bathed in the colder nutrient rich waters of the Cromwell Current. The Ship’s Captain; Wilson, took us near shore and equiped with mask and snorkel, we slipped into the cool green waters. Marine iguanas scampered on shore and within seconds we were eyed by a huge green turtle. This place is alive, I though, as a vast school of black-striped salema fishes buzzed past. Marine iguanas swam on the surface, trailing prehistoric tails. On the rocks there were Galapagos penguins, flightless cormorants and colourful Sally Lightfoot crabs.
Fernandina is the youngest of the Galapagos archipelago ~ less than 700,000 years old. The hot spot theory held by geologists today says that there are stationary areas of intense heat in the earth’s mantle that cause the crust to melt and give rise to volcanoes. Now and again, there’s a build up of pressure and a volcanic eruption, producing lava.
In 1968, the caldera of Fernandina changed dramatically when it’s floor, a block, two kilometres round, fell by 350 metres. The caldera was clouded in choking dust and the crater lake disappeared. Some 2000 white-cheeked pintail ducks and land iguanas just disappeared.
Fernandina is still the most volcanically active island in the archipelago with a dome shaped cone rising to almost 1500 metres. It’s caldera is now 900 metres deep and 6 kilometres round.
The Galapagos archipelago consists of 13 major islands, 6 minor islands and 49 smaller rock formations, spread over 17,000 square miles. These equatorial islands, volcanic mountains, erupted above the Pacific Ocean, 600 miles West of the Ecuador. They first broke through the sea floor, 7 - 9 million years ago, and still show volcanic activity ~ 7 volcanoes have erupted in the past 15 years.
The Galapagos Islands sit on top of the Nazca Plate, close to the junction with the Cocos Ridge. The plates shift along the Galapagos Rift and the East Pacific Rise, which is making the islands to move South and Eastward at more than 7 centimetres per year. The Eastern islands are older than the Western ones. Fernandina and Isabela, are the youngest, less than 1 million years old.
We stepped ashore at Punta Espinosa, which means Spiny Point in Spanish. This place is surrounded by six volcanoes on Isabela Island which lies across the Bolivar Channel. Stepping ashore onto black lava, from our panga (the local name for a small dinghy), Sally Lightfoot crabs scuttled on the green algae. A pile of marine iguanas lay sunning themselves on the lava. As their body temperatures increased, they made their way to the ocean to feed, on algae. A whale skeleton lay on sand and an inlet had flightless cormorants.
The flightless cormorants flapped their short wings. Sally Lightfoot crabs and marine iguanas lay all around. Sea lions played in the shallows, and far views of volcanoes made for a fantastic vista. Our natural history guides; Harry Jimenez (alias Loco Harry) and Jose Luis Castillo (alias Pepe) were full of information, making the trips very enjoyable.
The islands climate is greatly determined by the ocean currents. In the cooler dry season ~ July to Dec, the Humboldt Current keep the islands much cooler than you would expect. During the warmer, wet season ~ Jan to June, there’s little rain on the coasts.
The colder waters of Fernandina and Isabela Island are superb for dolphin and whale watching ~ striped dolphins, common dolphins, spinner dolphins and pilot whales. No where have I had such amazing encounters with dolphins as in the Galapagos’.
There must have been 70 dolphins, some which joined the bow of our boat. Jumping into the ocean, I cleared the bubbles in my mask to see dolphins all around and a 2 metre Galapagos shark. So sharks do swim with dolphins! Dolphins were zooming in to see us, often in pairs, peeling off when 2 metres away. The sheer excitement of being in the ocean with so many dolphins, was one of life’s best experiences.