CORAL REEFS – GEOGRAPHY

News: Low human activity helps corals despite warm ocean

 

What's in the news?

       Simultaneously mitigating human impacts on land and sea reduced coral loss during an unprecedented marine heatwave in Hawaiʻi and supported coral reef persistence after the heatwave.

 

Key takeaways:

       Coral reef ecosystems are frequently impacted by human activity on land and in the sea; land-based disturbances include wastewater pollution, and sea-based disturbances include overfishing.

       Corals are especially impacted by prolonged periods of warm ocean temperatures, known as marine heatwaves, which can cause coral bleaching and death.

 

Coral Reefs:

       Coral reefs are one of the most biologically diverse marine ecosystems on the Earth.

       Coral reefs play an important role in marine ecosystems and support the habitats of flora and fauna in the sea.

       The vast diversity of animal and plant species that contributes to its system are increasingly at risk due to climate change.

       India with its coastline extending over 7,500 km and subtropical climatic conditions has very few coral reef areas.

 

Importance of Coral Reefs:

1. Sustain biodiversity:

       Ecologically, coral reefs are important because they are the counterpart to the tropical rain forest in terms of species diversity and biological productivity in the Ocean.

       Coral reef enables the formation of associated eco-systems which allow the formation of essential habitats, fisheries and livelihoods.

2. Protect coastlines:

       Coral reefs protect coastlines from the damaging effects of wave action and tropical storms.

3. Nutrition and Habitat:

       Coral reefs provide habitats and shelter for many marine organisms.

       They are the source of nitrogen and other essential nutrients for marine food chains and assist in carbon and nitrogen fixing

4. Economic:

       The fishing industry depends on coral reefs because many fish spawn there and juvenile fish spend time there before making their way to the open sea.

       The Great Barrier Reef generates more than 1.5 billion dollars every year for the Australian economy, from fishing and tourism.

5. Climate change record:

       Coral reefs are climatologically important because they provide an accurate long-term record of the climate change and help in extending our knowledge of seasonal climate variability in many remote tropical oceans.

 

Threats to Coral Reef:

       Coral reef ecosystems around the world have suffered unprecedented degradation in recent decades. Coral reef disturbances include both anthropogenic and natural events.

       Natural causes could include the emergence of reef-destroying mechanisms, "bleaching," and the depletion of essential symbiotics.

       Chemical pollution (pesticides, cosmetics, etc.), industrial pollution, mechanical damage, nutrient loading or sediment loading, dredging, shipping, tourism, mining or collection, thermal pollution, intensive fishing, and so on are examples of anthropogenic causes.

       Natural disturbances that cause coral reef damage include violent storms, flooding, extreme temperature swings, El Nino Southern Oscillation (ENSO) events, subaerial exposures, predatory outbreaks, and epizootics.

       Coral reef bleaching is a common stress response of corals to many of the above-mentioned disturbances.

 

Conservation of Corals:

       Environmental Protection Act, 1986 prohibits the use of corals and sands from the beaches & coastal water for construction & other purposes.

       India is participatory in the Green Coast project.

       Coastal regulation zone rules (CRZ) ban the collection and destruction of corals along with dredging and underwater blasting in and around coral formation.

       Concepts of Marine Protected Areas & Marine National Parks help in coral conservation.

       For example: First National Marine Park Gulf of Mannar (Gujarat), Great Nicobar Biosphere Reserve, Mahatma Gandhi Marine National Park (Andaman) are playing an important role in Conservation of corals.

 

Coral reefs are an important part of the ecosystem. It has not only ecological significance but is an important indicator of environmental health. Recent rise in coral bleaching has raised various concerns and efforts have been made to restore the same.