The area around the equator is known for the greatest diversity of life. There are many species of corals, turtles, sharks, fish, stingrays and many other marine animals in the ocean. The more we head towards the Earth’s poles, the smaller the number of animals in the ocean. For a long time, this global formula was unchanged, but that has now changed. A new study found that the ocean around the equator is too hot for many animal species to survive.

The global pattern for ocean life has changed

A large number of marine animals migrate to colder waters towards the earth’s poles. The culprit is global warming. A similar incident occurred 252 million years ago and resulted in the extinction of 90% of all sea creatures. Mass extinction of species may meet us in the near future. This is the finding of The Conversation magazine.

The global formula was created in graphical form and you can see it in the image below. The number of animal species starts at the earth’s poles and the richness of animal species is at its peak in the equator. The curve is based on the distribution of about 50,000 marine species collected since 1955. Over time, this curve decreases, as you can see in the graph.

Image credit: Anthony Richardson

Sea creatures are still moving away from the equator

The warming of the ocean means that tropical species of marine animals migrate to places where the water temperature for life is better for them. Climate change is having a very rapid impact on life around the equator. The 10 main groups of marine animals were monitored and their number decreased in places where the average annual surface temperature of the sea is above 20 ° C.

“Today, species richness is greatest in the northern hemisphere in latitudes around 30 ° N (off southern China and Mexico) and in the south around 20 ° S (off northern Australia and southern Brazil).” As The Conversation magazine writes.

Will history repeat itself?

252 million years ago, frequent volcanic eruptions caused massive greenhouse gas emissions, leading to great warming, resulting in the death of 90% of marine life. Another great warming was 125 thousand years ago and caused the migration of corals and other sea creatures. The last ice age ended 15,000 years ago, after which there was a huge number of animals on the equator and their number has been declining sharply in recent decades.

The situation is serious

The situation shows us that everything must be done to slow down or stop global warming. The loss of marine animals in tropical ecosystems means that these creatures do not have ecological resistance to environmental change. The migration of tropical marine animals to subtropical zones can significantly disrupt the current ecosystem, add more predators and create a more competitive environment. Such an ecosystem could collapse, lack enough food and die out quickly.

What can people do?

Biodiversity needs to be protected. Only 2.7% of the ocean is protected in fully or highly protected reserves. This number needs to be increased to protect most of the ocean. We need to realize that climate change is happening every day and that we need to fight for climate change.


Anthony Richardson, Pixabay