Marine life is migrating from the equator to the tropics, according to a recent study published in the Proceedings of the National Academy of Sciences. The study shows that many species known to reside in the equator’s warm waters are migrating to cooler waters. Scientists behind the study have linked this situation to global warming, saying that water at the equator has become too warm for some species.
Traditionally, the equatorial regions are known to have more species diversity than the poles due to abundant food sources and warm waters. However, with the changing climate, environments for marine life are changing, too. As equatorial waters become less hospitable, many species are migrating for better conditions.
Researchers warn that if the situation continues, this migration will have serious ecological effects. The authors note that such a situation happened has occurred before. For example, about 252 million years ago, this type of species migration led to the death of about 90% of all marine species. When species migrate to other regions, they can affect the area’s natural food chain and overburden the environment. In turn, this can lead to the death of weaker species.
Though global warming has not affected the equatorial regions as heavily as other parts of the globe, it still significantly impacts the area. Over the past 50 years, the equator has witnessed a temperature rise of about 0.6 degrees Celcius. While modest compared to temperature changes in polar regions, the equator’s rising temperature can be detrimental because “tropical species have to move further to remain in their thermal niche compared with species elsewhere.”
A 2015 study published in Nature Climate Change predicted that species richness would decline at low latitudes. The recent study found that species richness is greatest at around 30 degrees North and 20 degrees South. This could mean that many species are migrating from the equator to the cooler subtropics, and they may move even further if global warming continues.
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