Context: According to a recent study, cold ocean currents have sheltered the Galápagos Islands from global warming.
Ocean currents are the continuous, predictable, directional movement of seawater driven by gravity, wind (Coriolis Effect), and water density. Ocean water moves in two directions: horizontally and vertically.
Horizontal movements are referred to as currents, while vertical changes are called upwellings or down welling.
This abiotic system is responsible for the transfer of heat, variations in biodiversity, and Earth’s climate system.
Overcoming Global Warming:
The islands are protected from an otherwise warming Pacific Ocean by a cold, eastward equatorial ocean current and this current has been gaining strength for decades.
The temperatures in waters along the west coast of the Galápagos have dropped by 0.5 degrees Celsius since the early 1990s.
There’s a tug of war between global warming and the cold ocean current. Right now, the ocean current is winning — it’s getting cooler year after year.
Importance of Phenomenon:
This phenomenon is a cause for cautious optimism for the Galápagos Islands.
Flora and fauna of the Galápagos could assist reseed failing ecosystems and maintain the region’s fisheries.
Corals do not bleach and die in these waters off the west coast of Ecuador. So, the marine food chain does not suffer, unlike in the warm waters nearby.
As the Galápagos so far has been relatively unaffected by climate change, it’s worth looking at the Galápagos as a potential site to really try to put some climate change mitigation efforts into.
Significance of Ocean Current:
Nutrient-rich Water: The equatorial undercurrent in the Pacific Ocean is bound to the equator by the force of the planet’s rotation.
Under the ocean’s surface, a swift circulation of cold, nutrient-rich water flows from west to east.
Some of this water is forced to the surface when it reaches the Galápagos Islands.
The nutrient-rich water triggers photosynthesis and leads to an explosion of food for a wide variety of animals.
Stability for Coral Reefs: The cold ocean current creates a cooler, more stable environment for coral reefs and marine life and birds that often live much closer to the poles.
Position from Equator: From space, the Galápagos may appear to be a collection of minuscule specks in the eastern Pacific Ocean. However, it is their precise position on the equator that makes them significant.
Impact of Climate Change on Ocean Currents:
Influx of Warm Freshwater: Climate change leading to increases in ocean temperatures, evaporation of seawater, and glacial and sea ice melting could create an influx of warm freshwater onto the ocean surface.
Blocking Ice Formation: This would further block the formation of sea ice and disrupt the sinking of denser cold, salty water.
Excess Heat in Atmosphere: The shallow, speedy currents could ultimately limit how much heat the ocean can absorb, causing more of that excess heat to remain in the atmosphere.
Altering Global Temperatures: These events could slow or even stop the ocean conveyor belt, which would result in global climate changes that could include drastic decreases in Europe’s temperatures due to a disruption of the Gulf Stream.
Affecting Marine Biodiversity: Marine microbes and wildlife could be subjected to shallower, hotter, and faster surface waters.
Challenges arising out of Ocean Currents:
Future of Current: The worry is if in the future there are changes in this current, it could be really devastating for the ecosystem.
Regulation of Overfishing: The island group is certainly in need of greater protection from overfishing as well as the pressures of growing eco-tourism.
Human Pressures: The human pressures on this area and the mechanism that keeps it alive are at odds. It’s a major resource that should be protected.
Adverse Impact of El Niño: El Niño poses a threat to the island group. It shuts down the cold current every couple of years, causing penguin populations to collapse. El Niño is a climate pattern that causes unusual warming of surface waters in the eastern tropical Pacific Ocean.
Way Forward:
Ocean currents can regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth’s surface.
Without currents in the ocean, regional temperatures would be more extreme — super hot at the equator and frigid toward the poles — and much less of Earth’s land would be habitable.
About Galápagos Islands:
An archipelago of volcanic islands.
They are distributed on each side of the equator in the Pacific Ocean.
The second-largest marine reserve in the world and contributed to the inception of Darwin’s theory of evolution.
They designated as a UNESCO World Heritage Site and described as a “living museum and showcase of evolution.”
The island is a biodiverse ecosystem — home to several endangered species.
Galápagos is home to the critically endangered — Galápagos penguin, Galápagos fur seal and Galápagos sea lion.
