Science Water Systems Types

Fresh Water Zones

Upper, Middle and Lower

Upper Zone

Top, shallow part of the fresh water, consisting of plants and animal life, like algae, insects, snails, and small fish, and receives the most sunlight.

Middle Zone

Just below the top layer of the fresh water, where sun penetration is much less now. Contains open water its home to plankton, larger fish like bass and trout and other aquatic life that rely on photosynthesis for food.

Lower Zone

Located below the reach of all sunlight, meaning its colder and darker and lower oxygenation. It supports mainly decomposers like bacteria and fungi. along with bottom-dwelling organisms like worms and octopuses.

Salt Water Zones

Estuary, Intertidal. Continental Shelf, and Oceanic, each requiring organisms to adapt to varying temperates, salinity, light, pressure.

Estuary Zone

Where

Continental Shelf Zone

The submerged, gently sloping extension of the continent under shallow seas. It receives lots of sunlight, making it highly productive with abundant plankton, fish, seaweed, and coral reefs. Important fishing grounds are found here

Oceanic Zone

The vast open ocean beyond the continental shelf, divided into pelagic (open water) and deep-sea environments. Organisms in this zone must adapt to varying temperatures, limited light (especially in deeper layers), high pressure, and lower nutrient levels, Examples include tuna, sharks, jellyfish, and deep sea creatures.