Coral Reefs and Climatic Change
Corals themselves are tiny animals which belong to the group cnidaria (the “c” is silent)which also include hydras, jellyfish, and sea anemones. Corals are not mobile but stay fixed in one place. They feed by reaching out with tentacles to catch prey such as small fish and planktonic animals. Corals live in colonies consisting of many individuals, each of which is called polyp.
It was believed in the Middle Ages that sea fish were created to balance with the stars in the sky and were consequently equally numerous.
TODAY IN THE 21ST CENTURY THIS CAN NO LONGER BE SAID TO BE TRUE. HUMANKIND IS DESTROYING THE MARINE ECOSYSTEMS.
- Corals are amongst the oldest eco systems on Earth and the largest living structure on the planet.
- They cover less than 1% of Earth’s surface but are home to 25% of all marine life
- They protect our shorelines from erosion
- Provide food and livelihoods for 500 million+ people
- Used in treatment of cancer, HIV, cardiovascular diseases and ulcers
- Corals porous limestone skeletons have been used for human bone grafts
- 1/3 of our corals are now threatened with extinction. At present destruction rates 70% of the world’s coral reefs will be destroyed by 2050
Rising Temperatures (Global Warming)
- This puts strain on corals which then eject the algae (zooxanthellae) that live in their soft tissue, providing nutrients and energy for photosynthesis. Algae also give corals their bright rainbows of colours. Without algae the coral becomes bleached and open to disease.
Atmospheric CO2 (Ocean Acidification)
- Oceans become increasingly acidic as they absorb Carbon Dioxide from the atmosphere. Coral reefs have limestone foundations and the acidity is responsible for them dissolving, which has a critical affect on a corals ability to grow.
With the exception of amphibians corals are at higher risk of extinction than all the terrestrial animals groups…they are also the most sensitive to climatic changes.
Destruction of their habitats, overfishing, ocean warming, increased risk of acidification and millions of tonnes of nutrient run-off all play a part in this situation.
Global Dead Zones
Regions of coastal seawater that have been deprived of oxygen as a result of fertilisers and sewage overspill, consequently, can no longer support life. Twice as many such zones have developed since 1960. Coupled with rising Carbon Dioxide levels not only shallow-water marine life, but also numerous deep-sea species will also suffer and die.
- SWEDEN – cyanobacteria is blooming resulting in the Baltic Sea becoming a deadly, toxic brown sludge.
- HAWAII – Massive stacks of fetid, contaminated green-brown algae dumped on the ocean coasts.
- FLORIDA – Red tides of toxic algal are killing of hundreds of marine mammals….
- CARIBBEAN – 80% of reefs are suffocated by algae…..
Climate change, coupled with ocean warming, is likely to result in a global collapse of coral reefs within the next few decades. There is clear census of scientific opinion that it is essential to reduce greenhouse gases if coral reefs are to survive.