Rats That Slash Corals In Chagos
The Chagos Archipelago is a group of 55 islands in the Indian Ocean, between Africa, the Middle East and Asia.
Despite its natural beauty and small population, the biodiversity of this area is being devastated by rats brought in by Europeans in the 18th century.
The Chagos archipelago is known to have been a matter of dispute between nations for centuries : the Napoleonic Wars and the Cold War greatly affected this archipelago.
In the mid-20th century, some of its last inhabitants were expelled so that a military base could be built there.
These inhabitants, known as Chagossians, were the slaves brought to work on the coconut plantations.
However, some stowaways accompanied the vessels: the rats! One of the most harmful invasive species.
the rats in chagos
Although today the archipelago is a protected place, unfortunately it is invaded by rats: of the 55 islands, 37 are taken by this small mammal.
Rats are not native to this group of islands, but today these animals have taken over some of them.
Therefore, seabirds, already threatened by climate change and plastics, have to face another problem: the presence of an invasive species in their breeding area.
According to researchers at the University of Lancaster, the differences between the islands are brutal and, while in some of them the number of seabirds is enormous, in others they have disappeared.
With no natural predators, rats flooded the islands and began to feed on the eggs of these birds, and even their young.
The consequences of rat invasion
The study, which aimed to analyze the biodiversity of 12 of these islands, revealed frightening results: islands with rats have 750 times fewer birds than those that were not colonized by this rodent. And migratory birds stopped visiting these islands.
We mainly talk about birds like the alcatraz, seabirds with the ability to dive and swim.
Frigates and terns also find in these islands one of their greatest sanctuaries, which unfortunately is very threatened.
However, birds are not the only ones affected by this invasion. Without birds, other living things are collapsing, as the nutrients in bird droppings are very important to coral reefs.
So, as incredible as it sounds, the birdless islands are surrounding themselves with a marine desert where life is also disappearing due to the proliferation of rats.
Around the islands invaded by the rodent, half the fish are found, compared to islands where there are no rodents.
According to the team of Nicholas Graham, lead author of the study, nitrogen cycles are 250 times shorter on islands with rats.
One of the main cycles that give life to our planet and that seems to be disappearing in the Chagos archipelago.
Possible solutions for the rat invasion in Chagos
This is another example of how the extinction of fauna is not simply a cause for sadness, but also of utmost concern.
After all, entire ecosystems can collapse, on which humans and many other species depend.
However, we must remember that today all human activity, both vital and economic, involves these flows of nutrients and energy.
This is another proof of how the loss of species will make life very difficult for human beings.
So, the authors of the study propose the extermination of the islands to preserve the fauna and flora of the archipelago.
This process was only carried out on one of the islands and the researchers encourage it to be implemented on the others.
