Marine and coastal ecology — UPSC Prelims PYQs

Which of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience? 1. Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts. 2. Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones. 3. By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities. Select the answer using the code given below:

Consider the following: 1. Butterflies 2. Fish 3. Frogs How many of the above have poisonous species among them?

Consider the following statements regarding the Indian squirrels: 1. They build nests by making burrows in the ground. 2. They store their food materials like nuts and seeds in the ground. 3. They are omnivorous. How many of the above statements are correct?

With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by removing uneaten fish feed. 2. Biofilters convert ammonia present in fish waste to nitrate. 3. Biofilters increase phosphorus as a nutrient for fish in water. How many of the statements given above are correct?

“Biorock technology” is talked about in which one of the following situations?

Consider the following kinds of organisms: 1. Copepods 2. Cyanobacteria 3. Diatoms 4. Foraminifera Which of the above are primary producers in the food chains of oceans?

What is blue carbon?

Why is there a great concern about the ‘microbeads’ that are released into the environment?

Consider the following statements: 1. The Barren Island volcano is an active volcano located in Indian territory. 2. Barren Island lies about 140 km east of Great Nicobar. 3. The last time the Barren Island volcano erupted was in 1991 and it has remained inactive since then. Which of the statements given above is/are correct?

Consider the following statements 1. Most of the world’s coral reefs are in tropical waters. 2. More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia and Philippines. 3. Coral reefs host far more animal phyla than those hosted by tropical rainforests. Which of the statements given above is/are correct?

At one of the place in India, if you stand on the seashore and watch the sea, ‘you will find that the sea water recedes from the shore line a few kilometres and comes back to the shore, twice a day, and you can actually walk on the seafloor when the water recedes.’ This unique phenomenon is seen at

Biological Oxygen Demand (BOD) is a standard criterion for:

It is possible to produce algae-based biofuels, but what is/are the likely limitation(s) of developing countries in promoting this industry? 1. Production of algae-based biofuels is possible in seas only and not on continents. 2. Setting up and engineering the algae-based biofuels production requires high level of expertise/technology until the construction is complete. 3. Economically viable production necessitates the setting up of large-scale facilities which may raise ecological and social concerns. Select the correct answer using the code given below:

With reference to ‘dugong’, a mammal found in India, which of the following statements is/are correct? 1. It is a herbivorous marine animal. 2. It is found along the entire coast of India. 3. It is given legal protection under Schedule I of the Wildlife (Protection) Act, 1972. Select the correct answer using the codes given below.

Which of the following have coral reefs? 1. Andaman and Nicobar Islands 2. Gulf of Kachchh 3. Gulf of Mannar 4. Sunderbans Select the correct answer using the code given below.

What would happen if phytoplankton of an ocean is completely destroyed for some reason? 1. The ocean as a carbon sink would be adversely affected. 2. The food chains in the ocean would be adversely affected. 3. The density of ocean water would drastically decrease. Select the correct answer using the codes given below:

In the context of ecosystem productivity, marine upwelling zones are important as they increase 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 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?

Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of 1. Its escape into the outer stratosphere. 2. The photosynthesis by phytoplankton in the oceans. 3. The trapping of air in the polar ice caps. Which of the statements given above is/are correct?

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: