Coral Reef Concerns

Worldwide, coral reefs are in decline from causes such as overfishing, pollution, climate change, and ocean acidification. Healthy coral reefs are diverse ecosystems that support major industries such as fisheries and tourism, provide habitat for thousands of other species, act as a natural buffer against waves and storms in coastal areas, and supply biopharmaceuticals.

Recently, the Zoological Society of London reported that scientists are concerned that reefs may face extinction within this century, primarily due to ocean acidification from rising levels of atmospheric carbon dioxide. The effects of declining coral reefs would be devastating on marine ecosystems. Scientists fear we are nearing a tipping point where reefs would begin an irreversible decline. As Alex Rodgers, scientist with the Zoological Society of London and the International Programme on the State of the Ocean says:

“The kitchen is on fire and it’s spreading round the house. If we act quickly and decisively we may be able to put it out before the damage becomes irreversible. That is where corals are now.”

Dire predictions are being made for coral reefs in the Caribbean over the coming months. Scientists are concerned that the warmer-than-average temperatures will lead to further severe bleaching events. Coral bleaching happens when corals expel zooxanthellae, algae that live within coral cells and provide the corals with color as well as vital nutrients via photosynthesis. Warm temperatures seem to precipitate these bleaching events, and because corals rely on these algae for photosynthesis, bleaching episodes can lead to coral mortality. Corals are able to bounce back from bleaching episodes, but resilience likely depends on the absence of concomitant stressors such as pollution. Careful fisheries management is also hypothesized to help coral reefs recover from bleaching events.

I've only recently discovered the joys coral reefs via snorkeling holidays, and was saddened to read such dire predictions for the future of coral reefs. Aesthetic values aside, we need health coral reefs and healthy oceans. Let's hope changes can be made in time to save coral reefs.

Image of coral reef at Kealakekua Bay, Hawaii; ©Lianne McLeod