Which of the following statements about olive ridley sea turtles is or are correct?

Introduction / Context:
Olive ridley turtles are a flagship marine species and an important part of questions on environment and biodiversity. They are well known for their mass nesting events called arribadas, and conservation efforts in India frequently refer to them. This question lists three statements about olive ridleys and asks you to identify which are correct. To answer, you must know basic biological facts about the species and their nesting sites, especially along the Indian coast.

Given Data / Assumptions:
- Statement 1: Olive ridleys are the smallest and most abundant of all sea turtles found in the world. - Statement 2: They live in warm waters of the Pacific, Atlantic and Indian Oceans. - Statement 3: The Coromandel Coast in India is the largest mass nesting site for olive ridley turtles. - We must determine which combination of statements is correct. - We assume standard conservation and zoological references.

Concept / Approach:
Olive ridley turtles are indeed among the smallest of the sea turtle species and are known to be the most abundant globally. They inhabit tropical and subtropical waters of the Pacific, Atlantic and Indian Oceans, so both Statement 1 and Statement 2 are factually correct. The tricky part is Statement 3, which claims that the Coromandel Coast is the largest mass nesting site. In reality, in India the largest known mass nesting sites for olive ridleys are on the Odisha coast, especially Gahirmatha and nearby beaches, not on the Coromandel Coast further south. Thus, Statement 3 is incorrect, and the correct option must include only Statements 1 and 2.

Step-by-Step Solution:
Step 1: Evaluate Statement 1. Olive ridleys are smaller compared to loggerhead, green and leatherback turtles and are considered the most abundant sea turtle species worldwide, so Statement 1 is true. Step 2: Evaluate Statement 2. Olive ridleys are distributed in warm waters of the Pacific, Atlantic and Indian Oceans, which matches the standard description, so Statement 2 is true. Step 3: Evaluate Statement 3. The largest mass nesting (arribada) centres in India are on the Odisha coast, particularly Gahirmatha and Rushikulya, not on the Coromandel Coast; therefore Statement 3 is false. Step 4: Since 1 and 2 are true and 3 is false, the correct combination is "1 and 2 only".

Verification / Alternative check:
If you recall major conservation areas for olive ridleys in India, the Odisha coast is always highlighted in textbooks and news for spectacular arribadas, with thousands of turtles nesting on a single beach. The Coromandel Coast, which includes parts of Tamil Nadu and Andhra Pradesh, has nesting sites but is not identified as the largest mass nesting region. Also, introductory environment material usually states that olive ridleys are the smallest and most abundant sea turtles and that their range spans three oceans, confirming Statements 1 and 2 as accurate.

Why Other Options Are Wrong:
"1, 2 and 3" is wrong because it includes Statement 3, which incorrectly names the Coromandel Coast as the largest mass nesting site.

"2 and 3 only" is wrong since Statement 3 is false and Statement 1 is an important correct fact about olive ridleys.

"1 only" is wrong because it ignores the correct Statement 2 about the species' wide distribution in warm oceanic waters.

Common Pitfalls:
Students sometimes assume any eastern coast location mentioned in environment news must be the key nesting site and accept "Coromandel Coast" without recalling the more specific name "Odisha coast" or "Gahirmatha". Another error is to overthink Statement 1 and doubt that a widely distributed species can also be the smallest. Instead, rely on memorised standard descriptions from trusted sources and carefully read geographical labels in Statement 3. Distinguishing between general nesting areas and the largest mass nesting site is crucial here.

Final Answer:
Only the first two statements are correct, so the right choice is 1 and 2 only.