Area: 130 km2 or 50 mi2
Maximum Altitude: 343 m or 1125 ft
Human Population: 0
Marchena Island is the largest of the northern islands. The Marchena Lava Lizard is endemic to that island. On the southwest coast there is a large series of grottos and coves that are frequented by fur seals. 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 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.
With no terrestrial visitor sites, Marchena is rarely visited by anyone, including scientists and park wardens. The two programs carried out on Marchena in recent decades include two eradication programs – for goats and the little fire ant. Two marine visitor sites exist – Punta Espejo on the southeast and Punta Mejía on the southwest.
The primary conservation challenges on Marchena have involved introduced species, first feral goats and later the Little Fire Ant. Goats were first released onto Marchena around 1967. The goat eradication program ran from 1970 to 1979, when the island was declared free of goats. During the Project Isabela years, goats were once again found on 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 infestation. 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.
Marine Visitor Sites: Punta Espejo and Punta Mejía
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. Other species include sea turtles, rays, Moray Eels, and Garden Eels, among others. Bats can also sometimes be observed on the sand. A second dive site, Punta Mejía, is located on the southwestern side of the island. Rays, eels, and many fish species can be observed there.
Conservation Site: Fire ant eradication
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.