Coral Bleaching in Hawaii

Image: Hawkfish in bleached Pocillopora coral


The Hawaiian archipelago is one of the most isolated groups of islands in the world. This is probably the reason why the few marine organisms that have reached this place evolved into new species and are found nowhere else in the world. These kinds of species are called endemics, and the occurrence of these unique species is known as endemism. Many scientists consider Hawaiian coral reefs to be one of the highest endemic tropical marine ecosystems on earth, giving these reefs and their unique biodiversity such an important conservation value. As we saw a couple months ago on our last XL Catlin Seaview Survey expedition to Hawaii, these reefs that are dominated by a few coral species, the main providers of structure and microhabitats, are in turn occupied and utilized in many different ways by other marine life.



Coral bleaching


Right now, as consequence of unfavorable warming conditions, these corals are going through one of the most significant bleaching events in their recent history. Coral bleaching occurs when there is a break down between the coral and their algae symbiotic, as result of the warmer temperatures.  The algae, which provides many benefits, leaves the coral, resulting in a bleaching effect on the coral´s tissue. Bleached corals are structurally weaker and more susceptible to diseases, and in most cases corals died. This means that at the moment, these corals that maintain Hawaiian reef communities, are in danger of dying. All these factors could result in the loss of endemic species.


For the moment, we are concerned about the number of corals we are seeing that have turned completely white; nevertheless, we are hopeful for the recovery of these corals as many of them are still alive and there could be good chance of survival.



Importance of action


The fate of these priceless creatures is hinging on the actions we make now. We may not be able to stop coral bleaching completely, but we can give these communities an opportunity to recover and even resist thermal stress through local conservative action. Bleaching does not have to be a death sentence.


It is important to keep in mind that different actions could be taken by each of us, regardless of our role in the society, to ensure the protection and survival of our coral reefs. Even those who live far from the coasts can help protect coral reefs. The things we do to reduce our carbon footprint not only save energy, but also help combat climate change and maintain appropriately cool ocean temperatures.


Ways to conserve coral reefs include: reducing local stress by conserving and improving water quality, protecting fish life, disposing of trash properly, practicing responsible diving or snorkeling, and helping to monitor the reefs. This would give the corals the best fighting chance against climate change.  Of all of these, the main strategy should be to increase ecological monitoring, as it is an important management tool in the coral reef resistance to bleaching and provides ways to develop successful strategies to mitigate the dangers of bleaching on marine life that depend on coral reefs.