Detailed Explanation:

Answer: Option 4 — 1 only

The Aral Sea has shrunk immensely due to extensive water diversion for irrigation from its feeder rivers (Amu Darya and Syr Darya) since the 1960s, losing over 75% of its area. The Black Sea, while facing pollution and ecological challenges, has not dried up or shrunk significantly. Lake Baikal experiences natural water level fluctuations but has not undergone severe drying like the Aral Sea.

✅ Statement 1 – Correct: The Aral Sea has shrunk by over 75% since the 1960s due to Soviet-era irrigation projects diverting its feeder rivers.
❌ Statement 2 – Incorrect: The Black Sea faces pollution and oxygen depletion issues but has not experienced significant shrinkage or drying.
❌ Statement 3 – Incorrect: Lake Baikal, the world's deepest freshwater lake, has not dried up or shrunk immensely despite some natural water level variations.

📝 Short Notes: Major Water Bodies Under Environmental Stress

• Aral Sea (Central Asia): Once the world's fourth-largest lake, it has lost ~90% of its volume since 1960 due to Soviet irrigation schemes. This has caused desertification, increased salinity, loss of fisheries, and creation of the Aralkum Desert with toxic dust storms.
• Dead Sea (Middle East): Shrinking at about 1 meter per year due to water diversion from the Jordan River and mineral extraction industries.
• Lake Chad (Africa): Has shrunk by ~90% since the 1960s due to climate change, drought, and irrigation demands from surrounding countries.
• Lake Urmia (Iran): Has lost ~80% of its surface area due to dam construction, agricultural water use, and prolonged drought.
• Lake Baikal (Russia): The world's deepest and oldest freshwater lake, containing ~20% of Earth's unfrozen freshwater. Faces pollution threats but remains stable in size.
• Black Sea: Faces eutrophication, anoxic zones, and pollution but maintains its overall size and water volume.