Which aquatic ecosystems are included in the biosphere?

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Diagram illustrating Earth's environmental spheres, with labeled sections showing the geosphere (land and crust), biosphere (living things), atmosphere (air), and hydrosphere (water), each extending vertically from the Earth's surface. — Biosphere Earth's environment includes the atmosphere, the hydrosphere, the lithosphere, and the biosphere.

Within the context of the biosphere, aquatic ecosystems are broadly categorized into two primary types:

Marine environments: These encompass the ocean and its various habitats, which cover two-thirds of the Earth's surface.12
Freshwater environments: These are inland water ecosystems located on continental landmasses, including bodies such as lakes and rivers.13

These ecosystems are integral components of the biosphere, characterized by complex interactions between living organisms and their nonliving environment. Both marine and inland aquatic systems rely on fundamental ecological processes, including photosynthesis by primary producers and the cycling of nutrients through biogeochemical cycles.145