Island blog; Marchena

The uninhabited island of Marchena takes its name from a Spanish monk, Fray Antonio Marchena, who was among the first people to visit the island. The island covers an area of 130 km² including a caldera reaching 343m and young lava flows covered in lush vegetation. Although the majority of current day volcanic eruptions in Galapagos occur in the westernmost islands of Fernandina and Isabela, Marchena experienced an eruption in 1991, the first recorded on that island for at least 100 years.

Marchena island is the located in the northern part of the archipelago and is the largest of all the northern islands. It is home to a number of wildlife species, many of which are endangered. The Marchena lava lizard is endemic to the island. Marchena also played a small role in the fascinating human history of Floreana. In 1934, the body of Lorenz, one of the consorts of the Baroness, was found mummified on the beach at Marchena, along with Nuggeröd, the owner of the small fishing boat Dinamita. To read more about the strange goings on of Floreana island involving the Baroness, Robert Philippson and Rudolf Lorenz click here.

However, with no terrestrial visitor sites, Marchena is rarely visited by anyone, including scientists and park wardens, but unfortunately this does not mean there are not problems for the wildlife caused by humans. Feral goats and little fire ant are two species which have had the most detrimental effect on the island and both species were introduced by humans.

Mark Thomas

Mark Thomas

There have been two programmes carried out on Marchena in recent decades in the hope to eradicate the highly damaging invasive species. The programmes for goats and the little fire ant were carried out with minimal human impact; by using Judas goats to control the feral goats and insecticide to control the invasive little fire ant. Goats were first released onto Marchena around 1967 and caused a huge amount of damage to the local wildlife populations. In order to correct this, an eradication program ran from 1970 to 1979. At the end of the programme, the island was declared free of goats. During the Project Isabela years, goats were once again found on neighbouring Marchena but quickly eliminated by park rangers. Judas goats were then released on Marchena as well as other islands to ensure that any potential introduction could be dealt with rapidly.

The little fire ant was first found in Marchena in 1988. An eradication program eventually reduced the size of the known infested area. By 2002 and up to 2007, no fire ants were detected. However in 2007, evidence of the presence of fire ants was observed. A survey in 2008 indicated that a much larger area is infested. The GNP is planning a more thorough survey in the first quarter of 2009 to determine the exact extent of the problem. However recent surveys have found an even larger area of infestation. A key concern for Marchena is the possibility of the further introductions of these or other aggressive exotic species.

Galapagos shark by Jonathan Green

Galapagos shark by Jonathan Green

Marchena is surrounded by exceptional diving and stunning snorkel sites and one of the best places for viewing marine wildlife is Punta Espejo. On the southwest coast there is a large series of grottos and coves that are frequented by fur seals. Punta Espejo on the southeast edge of Marchena is an excellent site for sharks, with hammerhead and Galapagos sharks particularly abundant. Dolphins and sea lions are also present as well as sea turtles, rays, moray eels, garden eels, among others. Bats can also sometimes be observed on the sand as well as across the island. A second dive site, Punta Mejia, is located on the southwestern side of the island where rays, eels, and many fish species can be observed.

Written by Jenny Vidler – Communications and Membership Assistant