Q140. The Sundarbans are part of the delta formed by which river system?
[DSSSB MTS, 22 April 2026]
(A) Cauvery
(B) Krishna–Godavari
(C) Ganga–Brahmaputra–Meghna
(D) Mahanadi
Answer: (C) Ganga–Brahmaputra–Meghna
Explanation: The Sundarbans lie across the vast Ganga–Brahmaputra–Meghna delta shared by India and Bangladesh. The meeting of river sediments, saline tides and estuarine channels creates ideal mangrove conditions and supports fisheries, wildlife and coastal flood protection.
Q139. Which of these Indian states is well known for extensive mangrove forests?
[DSSSB MTS, 25 February 2026]
(A) West Bengal
(B) Uttar Pradesh
(C) Punjab
(D) Madhya Pradesh
Answer: (A) West Bengal
Explanation: West Bengal contains the Indian portion of the Sundarbans, one of the world’s largest mangrove landscapes. Tidal waterways, brackish water and sediment deposition shape the habitat. Mangroves shield nearby settlements and provide breeding grounds for commercially valuable aquatic species.
Q138. Which Indian island group lying to the southwest of the mainland consists mainly of coral atolls?
[DSSSB MTS, 26 July 2026]
(A) Majuli
(B) Andaman and Nicobar Islands
(C) Lakshadweep
(D) Sagar Island
Answer: (C) Lakshadweep
Explanation: Lakshadweep lies off India’s southwest coast in the Arabian Sea. Its coral atolls develop around shallow lagoons. Unlike river islands such as Majuli and Sagar, Lakshadweep owes its land surface largely to biological carbonate deposition.
Q137. The Lakshadweep Islands are located in which sea?
[DSSSB MTS, 26 July 2026]
(A) Red Sea
(B) Bay of Bengal
(C) Arabian Sea
(D) Mediterranean Sea
Answer: (C) Arabian Sea
Explanation: Lakshadweep is situated in the Arabian Sea, west of Kerala. The island group includes reefs, lagoons and atolls that support marine biodiversity and fishing. Its location is also significant for navigation and India’s island-based maritime economy.
Q136. Which Indian coastal location has particularly favourable conditions for developing tidal-power projects?
[DSSSB MTS, 25 July 2026]
(A) Gulf of Mannar
(B) Western Ghats
(C) Gulf of Khambhat
(D) Indo-Gangetic Plain
Answer: (C) Gulf of Khambhat
Explanation: The Gulf of Khambhat in Gujarat has a large tidal range, making it a frequently identified location for tidal-energy development. Tidal energy converts the regular rise and fall of seawater into electricity, though costs and ecological effects require assessment.
Q135. Which combination represents major threats to wild Pacific salmon populations?
[SSC GD Constable, 9 May 2026]
(A) Industrial runoff alone
(B) Overfishing, habitat degradation and climate change
(C) Predation alone
(D) Reduced genetic diversity only in hatcheries
Answer: (B) Overfishing, habitat degradation and climate change
Explanation: Salmon depend on connected marine and freshwater habitats. Fishing pressure, warmer waters, disrupted river systems and coastal habitat destruction can reduce survival. The question illustrates how conserving marine fish stocks requires protecting wider ecological processes and migration pathways.
Q134. Minamitorishima, associated with reported deep-sea rare-earth deposits, lies in which ocean?
[DSSSB MTS, 28 July 2026]
(A) Indian Ocean
(B) Pacific Ocean
(C) Atlantic Ocean
(D) Southern Ocean
Answer: (B) Pacific Ocean
Explanation: Minamitorishima is a remote Japanese island in the Pacific Ocean. Nearby deep-sea sediments have attracted attention for rare-earth elements. Extracting such minerals is technologically challenging and raises concerns about damage to poorly understood deep-ocean ecosystems.
Q133. Which institute reported detecting airborne microplastics in the Sundarbans region?
[RRB NTPC Undergraduate CBT-I, 7 May 2026]
(A) IISER Kolkata
(B) IIT Kharagpur
(C) National Institute of Oceanography, Goa
(D) Wildlife Institute of India, Dehradun
Answer: (A) IISER Kolkata
Explanation: IISER Kolkata researchers reported microplastic contamination associated with the Sundarbans. Tiny plastic particles can travel through air and water, enter coastal food webs and complicate conservation. This makes pollution monitoring important for both mangrove habitats and fishing communities.
Q132. Which river joins the Brahmaputra system in forming the world’s largest delta?
[SSC GD Constable, 30 April 2026]
(A) Godavari
(B) Ganga
(C) Krishna
(D) Yamuna
Answer: (B) Ganga
Explanation: The Ganga, Brahmaputra and Meghna rivers collectively supply sediment to the enormous Bengal delta. Its seaward margin includes Sundarbans mangroves, estuaries and fishing grounds. River discharge and tidal action together influence coastal habitats and shoreline changes.
Q131. Which feature is NOT normally associated with a mangrove ecosystem?
[DSSSB Court Attendant, 15 June 2026]
(A) Dense vegetation
(B) Submerged or exposed specialised roots
(C) High-altitude mountain terrain
(D) Muddy, silty substrates
Answer: (C) High-altitude mountain terrain
Explanation: Mangroves occur at low-elevation coastlines, especially muddy tidal flats and estuaries. Their specialised roots cope with oxygen-poor sediments. High-altitude mountain terrain lacks the saline or brackish tidal conditions that characterise these productive coastal ecosystems.
