Title: Natural History of the Galapagos Islands

1. Title: Natural History of the Galapagos Islands Nothing gets lost, nothing is created, everything transforms. -Lavoisier

2. Map of the Islands

3. Las Islas Encantadas= The Enchanted Islands Resources • Pierre Constant Marine Life of the Galapagos • Good maps and drawings = p12 • Julian Fitter Wildlife of the Galapagos • page 7 = Conservation Plea • page 8 = Introduction • 2 major conservation issues: • Introduction of invasive species • Population increase

4. DOMINANT GALAPAGOS THEMES: • ISOLATION • STRONG CURRENTS • INACCESSIBILITY • ARID CONDITIONS • SANCTUARY • EXPLOITATION • BIODIVERSITY • EVOLUTION • CONSERVATION

5. Biodiversity • Galapagos organisms are very susceptible to competition from introduced species from S. America, etc • CDRS on Santa Cruz in Puerto Ayora focused on conservation • In early years, eradication of goats from Sante Fe (by 1975 all were gone), Espanola and Pinta and rats from Pinzon was a priority • Successful captive breeding program of tortoises and now land iguanas

6. goats are biggest problem, other mammals are pigs, dogs, cattle, donkeys, horses, cats, rats and mice • invertebrates are fire ants, blackfly, wasps • plants include quinine tree, guayava, elephant grass • expensive to eradicate--need human and financial resources • As population grows (5% annually), islanders must help protect islands and provide answers for conservation

7. General Setting of the Islands • Stretch over a 320 km (174 mile) axis from east to west • 600 miles west from coast of Ecuador • Made of 19 islands and 42 + islets or surfacing rocks • Islands are purely oceanic • Archipelago is entirely volcanic

8. Geology of the Islands • Islands are situated on the confluence of three of the earth’s tectonic plates • Pacific, Cocos and Nazca • The three plates are pushed apart by convection currents caused by heat deep inside the earth • The Galapagos drifts southeasterly at the rate of about 4-6 cm a year • Hot Spot!

9. Tectonic Plates

10. Hot Spot Theory • Hot spot has a fixed position • A hot spot is related to a weakness of the oceanic crust which leads to fissures on the ocean floor • Under the Nazca plate, the hot magma is always in motion due to convection currents • The hot spot creates a magmatic plume when the hot magma contacts the cold ocean water to build a platform • Platform grows and grows….into a cone

11. Hot Spot Theory continued • A volcanic cone is created which in a few years reaches the surface of the ocean • This new island joins the others on the slow-moving “conveyer belt” • Once drifted away from the hot spot, an island experiences little or no more volcanic activity and the now dormant volcano is eroded away by wind and sea

12. More hot spot…or is it “mantle plume” • Islands originated through hot spot activity no earlier than 3-5 million years ago • Hot spot also responsible for forming Hawaiian islands

13. Galapagos Plumology

14. Age of the Galapagos • Oldest islands in east and youngest to west • Espanola is oldest • Fernandina is youngest (hence volcano in 2009)

15. Climate • Galapagos are desert islands • Are considered subtropical • Located on equator but don’t have equatorial climate therefore have micro-climates • Climate is largely determined by ocean currents • 2 seasons • warm, wet season from Jan to June • cool, dry season from July to Dec known as garua (mist)

16. Oceanic Currents • In cool season, the cold Humboldt (aka Peruvian) current flowing from the southeast keeps the islands cooler than you would expect on the equator and the mist garua condenses in the air • In warm season, annual rains for first 3 months, SE winds and Humboldt vanish. Warm waters come from Panama and Columbia • Upwelling from currents allows for nutrients to be pumped to surface for plants to grow and the food chain to survive

17. Distribution of Currents (also on page 212 Fitter)

18. El Nino-La Nina Phenomenon • Some years, warm water coming from north increases around around Christmas time • In 1982-1983, a big Nino brought nine months of rain, increased humidity, suffocating heat, increased sea temp. therefore increase in animal mortality • Another in 1997-1998 • Nina is counter event with cold period…good for marine life

20. Facts about El Nino • As many as 50% of sea lions and marine iguanas dies • Increased rainfall promotes plant growth and rising sea levels cause loss of beaches resulting in major habitat change

21. Human History of the Galapagos • 1535 = Bishop of Panama, Tomas de Berlanga’s ship was swept off course; he described giant tortoises and iguanas • 1570 = Abraham Ortelius, Flemish, draws the first map of the Insulae de los Galopegos (Islands of the Tortoises) • 1600-1720 = Buccaneers use islands as bases for raids on Spanish ports; eat turtles, use wood

22. 1790 = Alessandro Malaspina, Sicilian, leads first scientific mission to islands; records are lost • 1793 = James Colnett, English, explores whaling on islands; Post office barrel established in Floreana • 1795-1895 = Heavy exploitation endangers species; whales population destroyed, tortoises eaten • 1813 = David Porter, U.S., destroys British whaling fleet

23. 1819 = Major eruption of Fernandina volcano • 1830-1832 = Ecuador becomes an independent republic and annexes the islands; establishes a penal colony on Floreana • 1835 = Darwin visits the islands (only there 5 weeks of his 5 year voyage..visited San Cristobal, Floreana, Isabela, James Islands)

24. 1836-1940 = attempts at colonization 1850-1860 = Britain and US attempt to lease or purchase islands with no success

25. 1928 to mid 1930’s = Floreana Island was inhabited by Ritters, Wittmers and Baroness of Vienna and Paris= murder mystery= Galapagos Affair • 1934= Ecuador enacts the first protective legislation for the islands • 1957 = Choose site for CDRS • 1959 = Ecuador declares all islands except already colonized are a national park; the Charles Darwin Foundation is formed

26. 1968 = Conservation programs begin; Fernandina erupts and its calderan collapses • 1969 = Organized tourism begins • 1982-1983 = El Nino events cause changes in population of organisms • 1985 = Fire set by humans burns more than 200 sq km of S. Isabela Island • 1986 = Ecuador govt establishes Marine Reserve • 1997-1998 = Another El Nino

27. MORE NATURAL HISTORY… • FOUND IN REFERENCE SECTION OF YOUR COURSE READER: • “A Traveler’s Guide to the Galapagos Islands” by Barry Boyce • Good information for Introduction Section of your Paper = pages 7-37….mark this with sticky note