“In 2007 UNESCO listed the Galapagos as threatened, as a number of the most unusual creatures found on the islands were in decline.”
By Dr. John J. Hidore
August 11, 2017—-The Galapagos Islands are located about 600 miles west of the coast of Ecuador. There are 13 major islands in the group, in addition to dozens of smaller rock outcrops. They were discovered in 1535 by sailors engaged in exploration. These islands are a unique treasure on our Planet.
The Galapagos Islands have been designated a UNESCO Heritage Site. When explorers first described the islands to people on returning to their home ports, most people did not believe the stories that were told.
The Galapagos Islands are significant for a variety of reasons. First, there is no other island ecosystem like it. They are home to many species of plants and animals not found anyplace else on the planet. The animals include blue footed boobies and marine iguanas. Second, it is the setting for the work of Charles Darwin in formulating the theory of evolution that was published as The Origin of Species. Charles Darwin visited the islands in the year 1835. At the time, the islands were known as Las Encantatas or the enchanted ones.
Climate Change is Altering Life on the Islands
Global warming has already raised the temperatures over the islands. The islands generally receive little rainfall. Parts of the islands depend on cool season fog to provide condensation for plants. Additional warming may eliminate this weather pattern which is the only source of moisture for vegetation is some areas. Increased rainfall that may come with a changing climate may also lead to the decline in many species of plants.
The warmer conditions are causing vegetation zones to move to higher elevations. The rising temperature is also affecting the ratio of males to females in some turtles. Warmer temperatures tend to produce more female offspring, a phenomenon that has been observed at different locations around the world.
The mean temperature of the surrounding ocean of the islands is rising. Like other regions that lie astride the equator, coral bleaching has now been observed to occur in the reefs around the islands. The bleaching is an indication of not only global warming of the atmosphere, but of the warming of the tropical oceans. While corals live in warm water they will not live in water that is even a few degrees above their optimum temperature range. As the ocean warms they are also expected to become more acidic. This will increase the rate at which minerals are dissolved from the reefs.
Sea level has been rising and is expected to rise even more. The only question is how much more it will rise. Estimates of sea level rise by 2100 vary with the highest estimates rising 30 inches. Rising sea level may destroy many of the mangrove forests which are home to some unique species of birds including some species of finch.
There is a second problem which may be a greater threat than climate change to the uniqueness of the islands. This is the introduction of plants and animals not native to the islands. It is believed there are now more than 1400 introduced species on the islands of which more than half are plants.
Many of the introduce species have been accidentally introduced. Probably among the first were rats, which jumped ship over the years. The rats thrived and the population grew rapidly. Many other species of insects and plants were probably introduced at the same time. The accidental introduction continues as other species of plants and animals come to the islands along with the importing of merchandise.
Other species of plants and animals have been deliberately introduced. Among the first were domestic goats. They were often kept aboard ship for the purpose of supplying meat and milk for a ship’s crew. On the Galapagos some of the goats escaped to become wild. Their numbers increased and they began devastating the natural vegetation. In recent years major programs to eliminate the goats have been initiated, especially on the smaller islands. In 2006, for example, a massive effort was mounted to eliminate some introduced species from several islands.
Largely due to problems related to the invasion of species, in 2007 UNESCO listed the Galapagos as threatened, as a number of the most unusual creatures found on the islands were in decline. This includes sea lions which depend on a declining food supply off shore. The changing of the plant communities is a threat to many native birds. Some of the very species of finches which were the foundation of Darwin’s theory of evolution are in danger of becoming extinct.
On the plus side, most native species are expected to survive if invasive species can be controlled. But again, additional climate warming may eliminate the weather pattern necessary for plant and animal survival!
The Galapagos Islands
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