The year 2018 has been declared as the third International Year of the Reef by the International Coral Reef Initiative. Coral reefs are one of the most diverse ecosystems in the world. They are formed due to a unique symbiotic relationship which forms between polyps, tiny animals with a skeleton made of calcium carbonate and marine algae called zooxanthellae. Coral reefs require sunlight as most reef-building corals contain photosynthetic algae. They grow best in salty waters at depths of 100 meters. They are mostly located between the Tropic of Cancer and Tropic of Capricorn, and areas where warm ocean currents flow out of the tropics.
Formed over thousands of years, they have the highest biodiversity of any ecosystem. Also called “the rainforests of the sea”, reef systems inhabit numerous species of fishes, invertebrates, parasites and underwater plants. These constitute almost a quarter of all the marine species. They help in maintaining a healthy marine food-web. Coral reefs provide coastal protection services by acting as natural barriers against storm surges, typhoons and even tsunami waves. The Belize Barrier Reef, longest reef in the western hemisphere, provides protection to 2/3rd of the mainland coast. Apart from providing these ecosystem services, they serve as an important source of food and livelihood for the coastal communities. They contain essential compounds and are often referred to as the medicine chests of the sea. These are now being used to make medicines for deadly diseases like cancer.
The reef systems are a huge attraction for tourists from all over the world. Activities around beaches and reefs like sightseeing, sunbathing, snorkeling and scuba-diving provide huge economic benefits to the coastal communities. All this adds to the world economy. For nations in the Caribbean islands, coral reef tourism contributes to more than half the GDP of their economies. The Great Barrier Reef, off the western coast of Australia, is the largest reef in the world, only living system visible from the outer space. Around 2 million travelers visit the place every year, supporting 70,000 jobs and contributing $6.4 bn to the Australian economy annually. In the USA, each year coral reefs add $3.4 bn to the economy.
Corals reefs have “endangered” status in the IUCN Red list which is a comprehensive inventory of the global conservation status of biological species. Coral bleaching has emerged the major cause of the dying reefs. It refers to the whitening of corals because the colorful algae living inside the corals get expelled. It happens due to temperature variations and reduced quality of water. It is occurring both due to natural and anthropogenic conditions. Rising sea-surface temperatures due to global warming have resulted in the loss of 50% of reef-building corals globally in the past 30 years. Extreme weather events are on the rise because of climate change. Localised phenomena like ENSO (El-Nino Southern Oscillations, which bring warmer waters to southern Pacific and Indian Oceans) events lead to loss of corals in the Lakshadweep archipelago.
Ocean acidification slows the pace of coral development. There has been a 26% increase in ocean-water acidity since the pre-industrial era which is transforming the entire functioning of the ocean ecosystem. Pollution due to surface run-offs has degraded the water quality needed for the growth of reefs. Ocean garbage (like the Great Pacific garbage patch), agricultural residue run-off containing chemicals and pesticides, coastal erosion etc. block the pores of corals hindering their growth. Overfishing and poaching have led to a further decline in the aquatic population which used to keep the reefs thriving. Fishing techniques like bottom trawling, which dredges the sea floor have destroyed many reefs beyond repair. According to the Special Report on Global Warming of 1.5°C by the Intergovernmental Panel on Climate Change (IPCC), the global body for assessing the science related to climate change, Coral reefs would decline by 70-90 percent with global warming of 1.5°C. 2°C rise would lead to a loss of around 99 percent of the corals. The report highlights that coral reefs are unique and threatened systems in restricted geographic ranges constrained by climate-related conditions and have high endemism.
Many nations are joining hands to find ways to conserve these delicate marine ecosystems. Global Coral Reef Monitoring Network (GCRMN), Global Coral Reef Alliance (GCRA), and International Coral Reef Initiative (ICRI) are currently playing an important role in monitoring the reef zones and raising awareness in the public. Project REGENERATE, a project by IUCN and funded by the United States Agency for International Development (USAID), works towards building capacity for marine management and climate change adaptation of ecosystems, local communities and government in the Maldives. In India, the Ministry of Environment, Forests and Climate Change (MoEFCC) studies coral reefs under the Coastal Zone Studies (CZS) to monitor coral reefs and implement early warning systems for coral bleaching.
Technology is also being explored for the conservation of coral reefs. Satellite oceanography is being applied to map and monitor coral reefs. LarvalBot, an undersea robot, has been developed by Queensland University of Technology (QUT). It disperses microscopic baby corals (coral larvae) and has been deployed on Vlasoff Reef, near Cairns in North Queensland. 3D printed reefs have been dropped in the ocean near the Maldives where it is expected that free-floating coral polyps would attach themselves to it. Australian Institute of Marine Sciences (AIMS) is now using facial recognition, image analysis systems, 3D models, artificial intelligence and machine learning to speed up the identification and monitoring process. Sea Simulator is being used to simulate reef conditions in the year 2100 to discover temperature resilience in corals. It calibrates water and light to create “mini-reef” for breeding corals and sea urchins. Thus, technology can help speed up the process of coral conservation.
The coral reefs are one of the most splendid natural treasure possessed by the world. Its loss can cause ripple effects across economies and non-reversible extinction of thousands of species within the ecosystem. Ecologically destructive practice must be curbed and community-based conservation programs need to be made functional in order to conserve this vibrant ecosystem.
Ankita is a student at Jindal School of Government and Public Policy.
Image Source- KCET