- Scientific name: Acropora millepora
- Habitat: Western Indo-Pacific
- Conservation status: Near threatened
- Threat to existence: Ocean acidification and sea temperature rise
- Fun fact: Cluster coral is very popular in reef aquariums!
Additional source: Wikipedia
Image source: Seamarc Maldives
Staying on the topic of ocean acidification, Kolbert now takes us to the rainforests of the ocean: coral reefs. Specifically we visit a research station in the Great Barrier Reef, long considered one of the most incredible and diverse natural wonders of the world, but in recent years has been more known for its decline than its beauty. Just like the tropical rainforests, coral reefs are the production hubs and biodiversity centers of the ocean. But the other side of that coin is that coral bleaching is the deforestation of the ocean.
What is coral bleaching? To understand coral bleaching, we must first understand the delicate symbiosis that corals depend on. Corals are actually two creatures living in mutualism: the coral polyps and a photosynthetic dinoflagellate called zooxanthellae. Under warmer and more acidic conditions, the zooxanthellae, on which the polyps depend for food, begin to produce toxic side products. In response, the polyps evict their housemates. In the absence of the zooxanthellae, the coral lose their bright colors, hence “bleaching.” It’s a lose-lose situation for the polyps, keep the zooxanthellae and die of poisoning, or kick out the culprits and die of starvation. No coral means all the coral-dependent creatures leave or die, and no coral-dependent creatures mean all the predators dependent on them leave or die. Coral reefs go from being biodiversity refuges to a bleak desert.