Final answer:
The Sargasso Sea is the body of water in the middle of the North Atlantic Gyre, known for its clear blue water and floating seaweed, and plays an important role in marine biodiversity.
Step-by-step explanation:
The Sargasso Sea marks the middle of an ocean gyre and is located in the central North Atlantic Ocean. This area is characterized by a calm and relatively stagnant water body situated in the subtropical North Atlantic Ocean and is bounded by ocean currents that form the North Atlantic Gyre.
The gyre encompasses the Atlantic Ocean from eastern North America to Portugal. The Sargasso Sea is known for its clear blue water and floating seaweed (sargassum), and is critical for marine biodiversity, despite being significantly impacted by human activities.