Unfortunately, even the remote isolated tropics are not without problems. People used to massively cut down jungles, vegetation, polluting the islands. Especially when the colonialists came, the problems increased.
The colonialists brought rats with their ships. To the rats, the tropical climate suited them, so they quickly swarmed, destroying domestic animals, bird’s nests, fruits and infecting them. The damage is enormous, and today most islands suffer from it, they can’t eradicate rats.
Many nuclear tests were carried out on atolls, massive nuclear detonations caused extensive damage to vegetation, flora and fauna, destruction of the aquatic world, and severe earth tremors that caused the tectonic plates to move, creating dangerous waves, earthquakes, ejecting underground gases and dumping huge icebergs from Antarctica.
Many islands and atolls were used for military purposes for military bases, where they were transformed for military purposes, meaning that palm trees and vegetation were cut to make airports, hangars, pierce land for bunkers, break ridges to make warships and submarines. could pass. Many battles in World War II were fought in the Pacific when the Japanese invaded islands and atolls, further damaging them.
A huge problem is the rubbish that is thrown into the sea and oceans, so under the currents of the sea, the rubbish from around the world (plastics most) is transported and dumped on islands. In some islands, pounds and kilograms of plastic are thrown away every day, which over time turns into plastic sand and pollutes water and soil. Somewhere, tons and tons of plastic bottles and other trash made plastic floating islands.
Some islands have been devastated by the over-exploitation of ores, so they have been deeply dug, vegetation destroyed to reach mines, trains have even been hauled for better transportation of ores to ships.
Erosion is also a problem in many places, the soil becomes barren and an island and especially the atoll begins to sink or some parts.
More about direct examples of those problems can be found here https://tropicalislands.net/direct-examples-of-main-ecological-problems