Answer: (C)

Explanation: The whitening of coral colonies due to the loss of symbiotic zooxanthellae from the tissues of polyps is called as Coral Bleaching. Zooxanthellae are unicellular algae that provide colour to corals. They also provide food to corals and their deaths lead to breakdown of the symbiotic relationship between them. This breakdown of symbiotic relationship causes starvation and resultant deaths of coral polyps. This condition exposes the white calcium carbonate skeletons of the coral colony.

Causes of Coral Bleaching:

1. Extreme climate conditions: High temperature of water leads to the declination of these corals as they cannot survive in high temperatures. As estimated by scientists, most of the coral reefs of the world will soon decline with the increasing rates of ocean warming.
2. Ocean Acidification: Oceans absorb more carbon dioxide due to a rise in CO2 levels. This increases the acidity of ocean water. This inhibits the corals’ ability to create calcareous skeletons that essential for their survival.
3. Pollution: The toxic pollutants which are dumped directly into the ocean can lead to the poisoning of the coral reefs as it increases the nitrogen level of the seawater, leading to an overgrowth of algae.
4. Sedimentation: Construction along the coasts and islands lead to soil erosion, increasing the sediments in the river. As a result, it can smother corals by depriving them of the light needed to survive.
5. Infectious Diseases: Vibrio shiloi is a bacterium that inhibits the photosynthesis of zooxanthellae. This bacterium becomes more potent with an increase in sea temperatures.
6. Coastal development: Development of coastal infrastructure and tourist resorts on or close by these coral reefs causes significant damages.
7. Human activities: Over-fishing, coral mining, development of industrial areas near coral ecosystems etc. impact coral ecosystem.

Answer: (B)

Explanation: Mangroves are a group of trees and shrubs, sustaining in the coastal regions of the planet. These trees grow in low-oxygen soil with slow-moving water. These ecosystems of tropical and subtropical inter-tidal regions bordering the sheltered sea coasts and estuaries, they stabilize the shoreline and act as a bulwark against encroachments by the sea. Hence, statement 2 is not correct.

Answer: (C)

Explanation: An Umbrella species is a large animal or another organism on which many other species depend. Umbrella species are very similar to keystone species, but umbrella species are usually migratory and need a large habitat. Umbrella species are species selected for making conservation related decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat. In India, the Bengal tiger is the most prominent umbrella species. Hence, both statements are correct.

Answer: (B)

Explanation: Biodiversity as a global issue gained importance at the 1992 Earth Summit in Rio de Janeiro, Brazil where world leaders agreed on a comprehensive strategy for “sustainable development”. One of the key agreements adopted at Rio was the ‘Convention on Biological Diversity’ (CBD) which was signed by vast majority of the world’s governments showing commitments for maintaining the world’s ecological foundations as economic development proceeds worldwide.
The objective of the Convention is conservation of biological diversity; sustainable use of its components and fair and equitable sharing of the benefits arising from the use of genetic resources. The CBD is the first comprehensive global agreement addressing all aspects relating to biodiversity. The institutional framework for CBD’s implementation is provided by the Conference of the Parties (COP). The COP is the governing body of CBD which keeps under review implementation of the Convention, and steers its development COP is the supreme decision making body which has the authority to adopt protocols under the Convention. It also has the authority to amend the Convention itself. Hence, statement 2 is not correct.

Answer: (B)

Explanation: Olive Ridley turtle is the smallest and most abundant of all sea turtle found in the world. It gets its name from its olive coloured carapace, which is heart-shaped and rounded. It is found in warm waters of the Pacific and Indian oceans. It spends entire lives in the ocean and migrates thousands of kilometers between feeding and mating grounds in the course of a year. Though found in abundance, their numbers have been declining over the past few years. It is recognized as Vulnerable by the IUCN Red list. In India, it is protected under the Wildlife (Protection) Act.

• Carcasses of Olive Ridley turtles are washing ashore on Hope Island’s beaches here, indicating that the breeding cycle of the endangered species has been dealt a severe blow this year by mechanised fishing boats.
• As these fishing boats scour the Bay of Bengal coastline, there is gloom among conservationists and forest department officials that this year will be bad for the turtles.
• The turtles, which are protected under the Wildlife (Protection) Act, commence their journey from the Indian Ocean during their mating season in October and November. When they reach the Bay of Bengal, the females lay eggs on the beaches. Even as the destination for a majority is Gahirmatha in Odisha, the sandy stretches of Hope Island of the Coringa Wildlife Sanctuary have turned into a breeding area for a few hundred turtles every year.
• Owners of mechanised boats are not taking precautions to protect the turtles. Most of them are crushed under the boats and succumb to injuries.