Environmental Science Report: Keystone Species of Galapagos Islands

This report provides an overview of the Galapagos Islands ecosystem, focusing on the keystone species, specifically the tortoise. It highlights the importance of keystone species in maintaining ecological balance and discusses the negative impacts of invasive species, such as goats, on the tortoise population and the broader ecosystem. The report details the threats faced by endangered species, including the giant tortoise and land iguanas, and the Galapagos penguin, and the causes of their population decline, which include disease, habitat degradation, and climate change. It concludes by outlining the measures taken to mitigate these threats, such as conservation parks, captive breeding programs, and population control of invasive species, emphasizing the ongoing efforts to protect and preserve the unique biodiversity of the Galapagos Islands. The report references several sources to support its findings.

Here we have chosen Amazon rainforest as biome and Galapagos Islands as ecosystem
Keystone species:
Dominant and native species of concerned ecosystem are called keystone species. Keystone
species maintain ecological balance of their habitat. They play a larger role in ecosystem
balance as compare to other species. If their population decreases it will result in huge loss to
ecosystem. Tortoise is a keystone species of Galapagos Island. (Mittlestaedt, Noemi, &
Graham, 2014) Keystone species play an important role in protecting the ecosystem.
Importance of keystone species: Keystone species helps in maintaining ecological balance of
ecosystem for example Tortoise maintain ecological balance of their habitat by dispersing
plant seeds, trampling areas of vegetation and grazing on plants. They are also play a vital
role in ecosystem by opening up new area for vegetation.
Invasive species:
Goat is an invasive species to Galapagos Island. Goats were brought to the islands by pirates
who used to eat them. Later on goat population kept on increasing under favourable
conditions of the Galapagos Islands and eventually they became a threat to the tortoise
community.
Negative impact: Goats have greater browsing efficiency than tortoise which results in food
scarcity for tortoise. Tortoise cannot compete with goats when it comes to grazing therefore
they are threat to Galapagos island’s ecosystem. At least four species of tortoise became
extinct after introduction of goats to the islands one of the example is Abingdon tortoise.
Steps to mitigate negative impacts of invasive species: The Galapagos National Park Service
is constructed in order to conserve and to help in captive breeding of tortoise, transportation
of tortoise to similar ecosystem and goat’s population was reduced by introducing dogs in the
islands.
Endangered species to the islands:
The ecosystem like Galapagos Islands is a natural, living laboratory with minimal human
disturbance until recently. There are large number of species who are endangered to the
island such as giant tortoises, land iguanas, Galapagos penguins, flowering plants, lichens,
insects and land snails to finches and rats. (Swash Andy & Still, 2011)
Causes of decline in species population: Three endangered species which are discussed here
are Galapagos penguins, land Iguanas and giant tortoise whose reason for population decline
is mentioned below.
Giant tortoise: this species is listed as endangered species under IUCN as it population has
declined 90% in last decade. Main threat faced by these species is disease, habitat

degradation due to human activity and introduction of herbivorous species like Goats, Sheep
and cattle.
Land Iguanas: These animals are also crawler like tortoise and face the same threats like
them. Introduction of herbivorous species, human encroachment and disease
Galapagos penguin: Main threat to Galapagos penguin is climate change because they are
conformer (cannot regulate their body temperature with change in temperature of
surrundings). Other threats are human interference, introduction of herbivorous etc.
Measures taken to mitigate threats: Conservation parks are created such as Galapagos
national park service, captive breeding of endemic species, transportation of these animals to
similar areas, reducing population of grazing animals like sheep, goat and cows and by
reducing human activities like farming, fishing and hunting. (Harpp,, Paul, & Jackson, 2014)

References
Mittlestaedt, E. , Noemi, H. & Graham, D. (2014). Introduction, in The Galapagos. A Natural
Laboratory for the Earth Sciences, 1(ISBN 9781118852415), 1–3, 42.
Harpp, K. , Paul, H. & Jackson, M. (2014). Galapagos and Easter: A Tale of Two Hotspots,
in The Galapagos. A Natural Laboratory for the Earth Sciences, 2(ISBN
9781118852415.), 27–29.
Swash, Andy & Still, (2011). Birds, Mammals & Reptiles of the Galapagos Islands. (2nd
ed.). East Sussex, UK.: Pica Press. 15-28.