Zusammenfassung der Ressource
What humans have
done that has affected
the Galapagos islands
- Habitat disturbance
- Increased pollution, building & convertionof
land for agriculture have caused destruction
and fragmentation of habitats
- Forests of Scalesia trees and shrubs have
been almost eradicated on Santa Cruz & San
Cristobal for agricultural land
- Exponential increase of human population
- increases demands on water, energy &
sanitation services which authorities struggle to
meet.
- More waste pollution
produced and oil demands
have increased
- Over-exploitation of resources
- In C19 whaling boats & fur -
traders took up residence,
harvesting whales & seals to
sell internationly
- Species were harvested faster than
they could replenish themselves
- Giant tortoises were take as they could
survive on little food whilst in ships for long
periods of time, before being killed & eaten
- This lead to plummeting
number of tortoises
(over 200K in less than
1/2C
- Depletion of sea
cucumber populations
has a drastic effect on
under-water ecology.
- International market of shark fin has led to
150K sharks each year around the islands
(includes 14 species listed as endangered)
- Introduced species
- Species such as: goats, cats, fruits & vegetable plants
were deliberately brought to the islands. Other
species like insects were carried accidently.
- These species out-competed local species, alien species
can eat native species & destroy native species' habitats,
and bring diseases such as: avian malaria & bird flu
- Goats
- Most damaging species to Galapagos
ecosystem as it eats Galapagos rock purslane
- It out-competes the giant
tortoise for grazing, trampling &
feeding on their food supply &
changes the habitat to reduce the
number of tortoise nesting site
- On Northern Isabella island the goat
has also transformed forest into
grassland, leading to soil erosion
- Cats
- Hunt species like lava lizard & young iguanas
- Red quinine tree
- The red quinine also out competes native Scalesia trees
- The Cacaotillo shrub has almost been eradicated from Santa Cruz
- On Santa Cruz the red quinine tree is aggressively
invasive. Occupying high lands, spreads rapidly, has wind
dispersed seeds. Highland ecosystem has changed from
low shrub & grassland to closed forest canopy