Coral Reefs are one of the oldest and most biologically diverse ecosystems on the planet. Appearing first as solitary organisms more than 400 million years ago, corals are extremely ancient animals that evolved into modern reef-building forms over the last 25 million years. Teeming with life, coral reefs cover less than 1% of the ocean floor, but support up to 25% of all marine creatures for food, shelter and breeding sites. Hence, they have often been deemed the “Rainforests of the Sea” for their rich biodiversity, acting as a primary habitat for more than 4000 fish species, 700 coral species and thousands of other plants and invertebrates. Coral reefs are also very important to people. Providing an estimated $30 billion US dollars each year in ecosystems services providing food, protection of shorelines, tourism and even medicine. However, threats to their existence abound and scientists estimate that nearly 60% of the worlds coral reefs are threatened.
The greatest threats to reefs are rising sea water temperature and ocean acidification, linked to rising carbon dioxide levels.
Corals contain a symbiotic algae, known as zooxanthellae, provided with a protective environment and compounds essential for photosynthesis by the coral, whilst in return the algae provide oxygen and remove coral wastes, more importantly they provide the coral with the functional organic products of photosynthesis and supply the unique and beautiful colour of stony corals. Without this symbiosis, corals fail to produce compounds utilized in the synthesis of calcium carbonate, the crucial element needed for growth. With as much as 90% of the corals building blocks reliant upon zooxanthellae. It is with high water temperatures that these microscopic algae are lost – a process known as “coral bleaching”. Prolonged high temperatures can cause severe bleaching, killing colonies and leave them vulnerable to other threats. Increased ocean acidity poses an equally dangerous threat, restricting the formation of calcium carbonate skeletons, which if it gets too high may even break apart the existing skeleton providing reef structure.
People pose just a big a threat, with destructive fishing techniques, over-exploitation, pollution, invasive species and aiding the rise in sea temperatures. There are already many of the worlds reefs declared ‘dead or ‘bleached’ and up to 30% of existing reefs could be killed from pollution and sea temperature rise in the next 30 years. However there is still much that we can do to protect coral reefs, ensuring there are healthy fish stocks and clean water surrounding the reefs, increasing their chance of resilience.
Here are 5 of #FieldBahamas top ways to protect the worlds coral reefs…
You don’t have to be a marine scientist to have a positive impact on coral reef conservation. Simple every day changes can have significant effect on the resistance and resilience of coral reefs and the diversity of fish that rely upon them for survival.