Thanks to a realistic computer model, scientists were able to decipher why the Galapagos Islands maintain their unique habitats
January 14, 2021
Scientists discovered the reason why, despite having low rainfall and vegetation, the volcanic Galapagos Islands can maintain their unique wildlife habitats. To reveal the secret, they used a realistic high-resolution computer model to study the regional ocean circulation around the archipelago.
The Galapagos are located in the eastern equatorial Pacific Ocean about 900 kilometers from the American continent and are an iconic biological hotspot of global importance. The islands are famous for their unique wealth of endemic species, which inspired Charles Darwin’s theory of evolution and today support one of the largest UNESCO World Heritage Sites and Marine Reserves on Earth.
Scientists have known for decades that the regional ecosystem is sustained by the upwelling of cold, nutrient-rich deep waters, which feed the growth of phytoplankton on which the entire ecosystem thrives.
However, despite its critical role in life support, little was known so far about upwelling control factors. Determining the effect of these controls and their climate sensitivity is essential to assess the resilience of the regional ecosystem to modern climate change.
The research that provides new data in this regard was published in Scientific Reports. It was carried out by scientists from the University of Southampton, the National Oceanography Center and the San Francisco de Quito University in Ecuador.
This computer model that they used showed that the intensity of the upwelling – as the phenomenon of ascent to the surface of deep water masses is called – around the Galapagos is driven by local winds to the north, which generate vigorous turbulence in the fronts upper ocean west of the islands. These fronts are areas of strong lateral contrasts in ocean temperature, similar in character to atmospheric fronts on weather maps but much smaller.
The turbulence drives the upwelling of deep water to the surface of the ocean. That is what provides the Galapagos with the necessary nutrients to sustain its ecosystem.
“Our findings show that the upwelling of the Galapagos is controlled by highly localized interactions between atmosphere and ocean. It is now necessary to focus on these processes by monitoring how the islands’ ecosystem is changing and mitigating the ecosystem’s vulnerability to 21st century climate change.” . Explained Alex Forryan, from the University of Southampton, who conducted the research.
Alberto Naveira Garabato, also from the University of Southampton and director of the project supporting the research, added: “This new understanding of where and how the injection of nutrients from the deep ocean into the Galapagos ecosystem occurs is informing ongoing plans to expand the Galapagos Marine Reserve, and improve its management against the growing pressures of climate change and human exploitation. “
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© SOS Galápagos, 2021