What area is known as a large fishing ground ideal for growing plankton?

The Grand Banks is recognized as a significant fishing ground due to its favorable conditions for the growth of plankton, which serves as the foundation of the marine food chain. These shallow areas off the coast of Newfoundland are rich in nutrients, largely from the mixing of warm and cold ocean currents. This mixing promotes a thriving ecosystem where plankton can flourish, attracting various fish species such as cod, haddock, and flounder. The abundance of fish has historically made the Grand Banks one of the richest fishing areas in the world, contributing greatly to the fishing industry in Canada.

The other options do not possess the same level of suitability for fishing due to different environmental factors. For example, the Canadian Shield is characterized by its rocky landscape and is not primarily known for fishing. The St. Lawrence River serves vital transportation and trade functions but is not noted for large-scale fishing comparable to that of the Grand Banks. Hudson Bay, while significant in its own right, typically has different ecological conditions that do not support extensive fishing grounds like the Grand Banks.