Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The open ocean refers to the vast expanse of seawater that extends beyond coastal areas and continental shelves. It is characterized by deep waters with low nutrient levels and supports a wide range of marine life.
Related terms
Pelagic Zone: The pelagic zone refers to all areas of the ocean that are not close to the bottom or near the coast. It includes both the surface waters (epipelagic zone) and deeper waters (mesopelagic, bathypelagic, abyssopelagic zones).
Phytoplankton are microscopic photosynthetic organisms that float in aquatic environments, including oceans. They form the base of many marine food chains and play a crucial role in carbon fixation.
Upwelling is a process in which cold, nutrient-rich water from deeper layers rises to replace warmer surface water. This brings nutrients to the surface and supports high productivity in certain areas of the open ocean.