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?

1. 1 and 2 only
2. 2 only
3. 2 and 3 only
4. 3 only

Explanation

Only statement 2 is correct

• Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as “upwelling.”
• Upwelling occurs in the open ocean and along coastlines. The reverse process, called “downwelling,” also occurs when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom.
• Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity. Therefore, good fishing grounds typically are found where upwelling is common.

Credit: Oceanservice

• Marine upwelling zones are crucial for ecosystem productivty because they bring nutrient-rich waters from the deep ocean to the surface. These nutrients, support the rapid growth of phytoplankton, which forms the base of the marine food web and significantly enhances marine productivity.

Answer: (b) 2 only | Difficulty Level: Easy