Recent reports highlight a rapidly spreading disease, yellow band disease, causing significant damage to the coral reefs of Thailand. Experts suggest various factors contributing to this vulnerability, including overfishing, pollution, and rising water temperatures due to climate change.
Understanding Yellow Band Disease
Identified by the distinctive color it turns corals before annihilating them, yellow band disease has been present for decades, wreaking havoc on reefs in the Caribbean. It is triggered by environmental stressors such as increased water temperatures, pollution, sedimentation, and competition from other organisms. These factors weaken the coral, making them susceptible to pathogens like bacteria and fungi. The devastating impact of yellow band disease is irreversible, unlike coral bleaching.
Coral Reefs: A Complex Ecosystem
Corals are marine invertebrates that live in colonies of identical individual polyps. They share a symbiotic relationship with photosynthetic algae called zooxanthellae, where the algae get a safe environment and essential nutrients from the coral, while providing the coral with energy through photosynthesis.
Coral reefs are underwater ecosystems comprised of coral polyp colonies. They are categorised into hard corals, which create hard, white exoskeletons using calcium carbonate from seawater, and soft corals, typically found in deeper waters, attaching themselves to such skeletons.
The Importance of Coral Reefs
Coral reefs offer multifaceted benefits, from maintaining ecological balance to contributing to the economy. They host diverse plant and animal species, regulate the planet’s climate by absorbing carbon dioxide, protect coastlines from erosion and storm damage, and support industries like fishing, tourism, recreation, and even medicine and biotechnology.
Threats Endangering Coral Reefs
Change in climate induces ocean acidification and coral bleaching, causing corals to expel the algae living in their tissues and turn completely white. Pollution in the form of sewage, agricultural runoff, and industrial discharge can result in coral death and disease. Overfishing disrupts the delicate balance of coral reef ecosystems, leading to the decline in coral populations. Coastal development infringes on coral reefs and invasive species can outcompete native ones, disrupting the overall balance.
Initiatives to Safeguard Coral Reefs
To combat threats to coral reefs, various technological interventions have been initiated. Cryomesh involves storing coral larvae at -196°C, which can later be reintroduced to the wild. Biorock technology offers a platform for rapid coral growth, creating artificial reefs.
In India, the National Coastal Mission Programme focuses on coastal conservation, while globally, initiatives like the International Coral Reef Initiative and the Global Coral Reef R&D Accelerator Platform work towards preserving the health of coral reefs.
UPSC Civil Services Examination
Previous years’ questions examining understanding of coral reefs and related technologies include:
– “Biorock technology”: Discussed in connection with restoration of damaged coral reefs (2019).
– Species capable of establishing symbiotic relationships: Include Cnidarians, Fungi, Protozoa (2021).
– Statements on coral reefs: Most reside in tropical waters, more than one-third are located in Australia, Indonesia and Philippines territories, host more animal phyla than tropical rainforests (2018).
– Locations with coral reefs: Andaman and Nicobar Islands, Gulf of Kachchh, Gulf of Mannar, Sunderbans (2014).
– Impact of global warming on the coral life system: Assessment along with examples (2019).