Bleached coral and a clownfish

Our Warming Oceans

NOAA have recently declared that a “4th global coral bleaching event” is underway. Sea surface temperatures have set daily records for more than a year, which has prompted severe concerns regarding the health of our planet’s oceans, and the creatures that inhabit them, including coral. Like projects worldwide, our projects (currently located in Seychelles and French Polynesia) are experiencing coral bleaching. Read on to learn more and join the fight!

A Crash Course on Coral

Coral is a soft-bodied animal called a polyp, which lives in a colony of other, genetically identical polyps. Each polyp creates a hard calcium carbonate skeleton, which gives the colony a rock-like appearance. Coral polyps look like their close relatives, jellyfish, and anemones, as they have the same basic cup-shaped body with stinging tentacles that surround a single opening. However, coral polyps use their tentacles to capture food, extending them from the skeleton to catch tiny plankton. Despite this, polyps actually get up to 90% of their energy from a type of algae (zooxanthellae) that lives inside the corals’ tissues. This algae provides energy through photosynthesis and is also what give coral its colour!

Scleractinia (hard corals) colonies form the foundation of the coral reef ecosystem. Tropical coral reefs can be found in equatorial regions, between the tropic of Cancer and Capricorn. They prefer clean, clear water, with temperatures ranging between 21 and 28 degrees Celsius, and shallow depths, above 40m.

Image of Acropora coral close-up

What is Coral Bleaching?

Corals bleach when stressed by high temperatures and UV. As a response to this stress corals expel the symbiotic algae on which they depend for the majority of their food and which also give corals their colour. If the stress continues for several weeks, the coral will die of starvation or disease

Why are Coral Reefs Important?

Corals form the foundation of the entire coral reef ecosystem. Supporting 25% of all marine life and a direct food source for half a billion people. They are the economic backbone and an essential storm defence for tropic island nations. And are providing new medical discoveries with benefits across the globe.

What Threatens Them

Coral reefs throughout the world face many threats, both natural and man-made. However, the warming of our oceans is the most imminent threat to coral reefs. In the last several decades, coral reefs have been hit by three global bleaching events, caused by increases in sea surface temperatures. Coral bleaching occurs when the coral becomes stressed and subsequently expels the algae that lives inside their tissues. Without these symbiotic algae, corals lose their colour and die as they have lost their primary source of nutrition.

If we do not tackle the climate crisis we could lose 90% of our coral reefs by 2050. 

Ways you Can Help

There are lots of small things we can all do to help limit climate change, and to protect coral reefs. These include:

  1. Reduce, Reuse, Repair, and Recycle
  2. Lessen Energy Consumption
  3. Conserve Water
  4. Consume less Meat and Animal Products
  5. Minimise the use of Chemicals
  6. Adhere to Guidelines when Exploring the Natural World
  7. Be an Advocate and Contribute Practically to Conservation

Learn more about our Marine Conservation work here

Learn more about Reef Restoration here

Read more blogs here