Statement I : Grand Banks are one of the major fishing grounds of the world due to the presence of a vast continental shelf. Statement I : Planktons grow in the shallow waters.

Statement I is true as the Grand Banks of Newfoundland are among the world's most productive fishing grounds, primarily due to their location on a vast, shallow continental shelf [4]. Statement II is also true and provides the correct explanation for Statement I. Plankton, the primary food source for fish, thrives in shallow waters where sunlight can penetrate to the seabed, facilitating photosynthesis [2]. The continental shelf's shallow nature (often 24–100m deep) ensures that nutrients are accessible and sunlight is abundant, leading to high phytoplankton biomass. Additionally, the mixing of the cold Labrador Current and the warm Gulf Stream in this shallow region further enhances nutrient upwelling and oxygen replenishment, creating an ideal environment for fish to feed and breed [1]. Thus, the presence of the shelf directly enables the plankton growth that supports the massive fish populations.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 30: Climatic Regions > Fishing Off Newfoundland > p. 463
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 31: Ocean Relief > Continental Shelf > p. 479
3. [4] https://kids.britannica.com/kids/article/Grand-Banks/489793
4. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 24: The Cool Temperate Eastern Margin (Laurentian) Climate > FISHING OFF NEWFOUNDLAND, THE MARITIME PROVINCES AND NEW ENGLAND > p. 228