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 :

1. Harmful algal blooms (HABs) are often triggered by an excess of nutrients (especially nitrogen and phosphorus) in the water, a process known as eutrophication. 2. Statement 1 is correct: Estuaries act as conduits for river systems, often carrying high loads of nutrients from agricultural run-off, sewage, and industrial discharge into coastal seawaters. This discharge provides the nutrients necessary for algal blooms. 3. Statement 2 is correct: During the monsoon season, run-off from the land increases significantly, washing fertilizers, pesticides, animal waste, and sewage from various sources into rivers and coastal waters. This pulse of nutrients can fuel the rapid growth of algae. 4. Statement 3 is correct: Upwelling is a natural process that brings cold, deep, nutrient-rich water to the surface. While essential for marine productivity, intense or persistent upwelling can concentrate nutrients in surface waters, contributing to conditions favorable for algal blooms, sometimes including harmful species. Therefore, all three factors listed can be causative factors for the increase in harmful algal blooms in the seawaters of India.