In the context of ecosystem productivity, marine upwelling zones are important as they increase the 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/correct?

Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water. The increased availability in upwelling regions results in high levels of primary productivity and thus fishery production. Approximately 25% of the total global marine fish catches come from five upwellings that occupy only 5% of the total ocean area. Upwellings that are driven by coastal currents or diverging open ocean have the greatest impact on nutrient-enriched waters and global fishery yields.