There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon?

1. Discharge of nutrients from the estuaries.
2. Run-off from the land during the monsoon.
3. Upwelling in the seas.

Select the correct answer from the codes given below:

The formation of the ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?

In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the:

1. decomposer microorganisms to the surface.
2. nutrients to the surface.
3. bottom-dwelling organisms to the surface.

Which of the statements given above is/are correct?

The “Red Data Book” published by the International Union for Conservation of Nature and Natural Resources (IUCN) contains lists of -

1. Endemic plant and animal species present in the biodiversity hotspots,
2. Threatened plant and animal species.
3. Protected sites for conservation of nature and natural resources in various countries.

Select the correct answer using the codes given below:

Salinization occurs when the irrigation water accumulated in the soil evaporates, leaving behind salts and minerals. What are the effects of salinization on the irrigated land?

The 2004 Tsunami made people realize that mangroves can serve as a reliable safety hedge against coastal calamities. How do mangroves function as a safety hedge?