Written by Christel Schultz
Located near the equator, coral reef systems are some of the most biologically diverse habitats in the world. Reefs are estimated to cover less than 1% of the earth’s surface and provide homes to 25% of marine life. It’s fitting that coral reefs would be deemed the “rainforests of the sea.”
Like the rainforest, reef ecosystems provide a multitude of benefits. The reef is a tremendous food resource for locals and people around the globe. The actual reef structure minimizes coastal storm impacts and erosion. Colorful corals and sea creatures attract snorkelers, divers, and water enthusiasts. The tourism industry provides jobs for the local community. Plants and animals of the coral reef are used to create medicines . Anti-tumor medication developed from sea squirts, and a pain killer derived from the cone snail, are all ready in use. Healthy and abundant reef systems are too valuable to ignore.
The Great Barrier Reef is the largest coral reef on Earth. It spans over 1,400 miles along the coast of Queensland and covers approximately 133,000 square miles. It is the largest living structure on our planet and is considered one of the seven natural wonders of the world. The ecological significance of this unique and diverse reef system was recognized several decades ago. The Great Barrier Reef Marine Park was established in 1975. Activities and access to areas of the reef have been limited, and in some cases prohibited, ever since. The biodiversity and overall health is constantly monitored.
Climate Change and Coral Bleaching
Despite ongoing efforts to protect and maintain it, climate change has heavily impacted the Great Barrier Reef. Record high sea temperatures documented in 2016 caused a mass coral bleaching event. An estimated 30% of the Great Barrier Reef was affected. Water temperatures were elevated again in 2017. Another 20% of the reef was bleached. Bleaching occurs when water temperatures are elevated by 1 to 2°C for just a few weeks. The bright colors characteristic of the reef are provided by photosynthetic algae (Zooxanthellae). The algae create food and oxygen for the coral. When exposed to high water temperatures, the coral becomes stressed and expels the algae. This creates the white “bleached” appearance. Corals starve in the absence of algae and ultimately die.
Regional bleaching events previously occurred approximately every 27 years. In the 1980s, the frequency increased to every 6 years. Damaged reefs typically take 10 years or more to bounce back when conditions are favorable. The northern extent of the Great Barrier Reef suffered the worst damage. Because it was impacted two years in a row, recovery is unlikely.
The southern extent of the reef did not suffer as badly. A variety of coral species remain in that section. Differing species assist in repopulating the reef. Biodiversity is key. A limited number of species survived in the northern reef. Distance between the two areas may prevent transport of coral species from one to the other. The northern extent needs help.
The Great Barrier Reef is not alone. Reef systems all along the equator experienced bleaching in 2016 and 2017. Minor changes in temperature have a major effect. To learn more about the state of coral reef systems around the world, be sure to see Chasing Coral. This is not over – there is hope!
What is being done?
Transplanting healthy coral began decades ago. Impacted areas are addressed on a small scale. The study of corals in various environments continues. Research provides insight about the resilience of certain species. The Australian authorities responsible for the Great Barrier Reef previously refrained from intervention in the ecosystem. Recent bleaching events changed that approach. Transplanting efforts are underway on a larger scale here. Human intervention has become necessary to ensure the future of our coral reefs.
What you can do…
Coral transplanting and restoration are steps in the right direction. Addressing climate change is essential to protect new coral from the same fate. A global effort is crucial. Together we create a better tomorrow.
10 Ways to Protect the Coral Reef
• Choose sustainable seafood. Learn how to make smart seafood choices at www.fishwatch.gov.
• Conserve Water. The less water you use, the less runoff and wastewater that eventually find their ways back into the ocean.
• Volunteer. Volunteer in local beach or reef cleanups. If you don’t live near the coast, get involved in protecting your watershed.
• Corals are already a gift. Don’t give them as presents. It takes corals decades or longer to create reef structures, so leave them on the reef.
• Long-lasting light bulbs are a bright idea. Energy efficient light bulbs reduce greenhouse gas emissions. Climate change is one of the leading threats to coral reef survival.
• If you dive, don’t touch. Coral reefs are alive. Stirred-up sediment can smother corals.
• Check sunscreen active ingredients. Seek shade between 10 am & 2 pm, use Ultraviolet Protection Factor (UPF) sunwear, and choose sunscreens with chemicals that don’t harm marine life. For more information, visit oceanservice.noaa.gov/sunscreen
• Be a marine crusader. In addition to picking up your own trash, carry away the trash that others have left behind.
• Don’t send chemicals into our waterways. Nutrients from excess fertilizer increases algae growth that blocks sunlight to corals.
• Practice safe boating. Anchor in sandy areas away from coral and sea grasses so that the anchor and chain do not drag on nearby corals.