The Galápagos Islands: Geography and Significance

• The Galápagos Islands are a volcanic archipelago in the Eastern Pacific Ocean.
• They are located approximately 1000 km from mainland Ecuador.
• The islands' latitude and longitude are 4°N and 92°W.

Significance of the Galapagos Islands

• The islands are a highly protected area due to their many endemic species.
• They contributed to Charles Darwin's theory of evolution.
• They possess exceptional natural beauty.
• The islands showcase ecological and biological processes, such as natural selection.
• There are geological features present such as volcanic activity.

Major Galápagos Islands

• Some of the 13 major islands include Fernandina and Espanola.
• Fernandina is the youngest island, located at the far west of the archipelago.
• Espanola is the oldest island, located at the far east of the archipelago.
• Espanola has drifted around 160km eastwards over time due to a 'belt'.

Google's Assistance in Managing the Islands

• Google mapped the islands to track the populations and survivability rates of endemic species.
• Google created 'virtual diving' to allow people to explore the marine ecosystems.

History of the Galápagos Islands

• The islands were discovered in 1535 by Tomas De Berlanga.
• De Berlanga reported his findings to King Charles V of Spain.
• The islands were named after the giant tortoises that lived there.
• In the 1800s, buccaneers and whalers used the islands as a base.
• They sought shelter, firewood, and food, slaughtering approximately 100k giant tortoises between 1811-1844.
• Buccaneers were the among the first to map and chart the islands.
• Charles Darwin arrived in 1835 and developed his theory of natural selection.

Darwin's Arrival

• Charles Darwin arrived in 1835 on the HMS Beagle.

Foundation for Natural Selection

• The islands offered a basis for natural selection due to their isolation.
• Endemic species adapted well to the challenges of the terrain.

Main Ocean Currents

• The Humboldt Current from Antarctica and the Panama Current from Central America affect the climate.

Climate Differences from the Equator

• The climate differs due to the confluence of several ocean currents with varying temperatures.
• This creates a mix of warm and cold waters depending on the seasons.
• Rainfall also varies according to season.

Humboldt Current

• It dominates the islands from June to December.
• It comes from Antarctica, bringing cold water, filled with nutrients such as phytoplankton.

Panama Current

• It dominates the islands from January to May.
• It comes from Central America, and is a warm-water current with temperatures around 21°C-27°C.
• It has no nutrients in its waters.

Effects on Ecosystems

• The Humboldt Current benefits the marine ecosystem with nutrients but reduces rainfall, harming land vegetation.
• It's referred to as the 'dry season'.
• The Panama Current benefits the land system with increased rainfall.
• It provides warm temperatures, but reduces plankton numbers, which can harm ocean food sources.
• It is referred to as the 'wet, humid season'.

Dominant Animals During Currents

• Humboldt Current: penguins, sea lions, and seabirds like blue-footed boobies thrive due to cold, nutritious waters.

Rainfall Effects

• Humboldt Current: Reduces rainfall, benefiting marine ecosystems but harming land. Water is around 4°C.
• Panama Current: Increases rainfall; good for land, not ocean. Rainfall is around 25-50cm.

Temperature Effects

• Humboldt Current: Reduces temperatures, with waters around 4°C.
• Panama Current: Increases temperatures to about 21°C-27°C, warming the land and increasing humidity.

Garua

• It is a thick mist covering the highlands, occurring during the cool, dry season with the Humboldt Current.
• It does not bring extra rainfall.

El Nino Southern Oscillation (ENSO)

• It consists of El Nino, La Nina, and neutral conditions that shape climate rainfall patterns.
• It occurs every 2-7 years.
• El Nino and La Nina typically last 9-12 months.

ENSO Phases

• The three phases are El Nino, La Nina, and Neutral.

El Nino

• It causes warmer waters and wetter conditions in the Galapagos.
• Trade winds weaken or reverse, moving warm SST back, creating nutritionless warm water.
• The Central and Western Pacific receive colder temperatures and reduced rainfall occurs in the western Pacific.
• The Western Pacific receives colder temperatures.
• There is more rainfall in the Galapagos.

El Nino's Effect on Marine Animals

• It provides warm and nutritionless water, reducing food sources for marine species like iguanas and boobies.

El Nino's Effect on Land Animals

• It creates more rainfall and moisture, increasing vegetation for land species like the Galapagos Tortoise.
• It creates freshwater pools, benefiting flamingoes.

La Nina

• It shows increased rainfall, temperature, and humidity in the Western Pacific due to stronger trade winds.
• Reduced precipitation and cooler temperatures occur in the Central and Eastern Pacific.

La Nina's Effect on Animals

• It benefits ocean animals by increasing food availability due to cooler temperatures and upwelling.
• It is harmful to land animals due to cold temperatures and reduced rainfall which reduces vegetation.

Neutral State of ENSO

• There is reduced rainfall in the Central and Eastern Pacific.
• There is increased rainfall in the Western Pacific.
• Trade winds are normal rather than strengthened.

Galapagos Flora

• Galapagos flora is divided into the coastal zone, the arid zone, and the humid zone.

Plant Statistics

• There are around 552-614 native vascular species.
• There are approximately 825 introduced species.
• Over 100 introduced species are damaging to the endemic flora.

Vegetation Differences

• Coastal plants: Salt-resistant plants.
• Dry/arid area: Drought-resistant leafless plants.
• Humid highlands: Lush vegetation with giant forests, liverworts, and epiphytes.

Prickly Pear Cactus Adaptations

• Thigmotactic anthers curl upon touch, allowing self-pollination.
• It stores water in its stems and leaves, and it is adapted to frequent droughts.
• Spines protect it from predators, and also provide shade.

Lava Cactus Adaptations

• It colonizes easily.
• It extracts minerals from volcanic ash like phosphorous, potassium, and silica.

Other Galapagos Plant Adaptation: Mangrove

• It is salt-resistant.
• Its seeds are effective travellers as they float along water until they plant themselves.
• They are resilient to floods and droughts.