The littoral zone includes the intertidal zone. Outward from shore, the zones are littoral, neritic, pelagic. The benthic zone includes the ocean floor.

The pelagic zone extends neither to the sea bed nor the shore - it is open ocean. The littoral zone includes the shore and the benthic zone includes the ocean floor. The profundal zone is only present in inland bodies of water, and begins below the limit of light penetration.

Since photosynthesis depends upon solar energy, we can deduce that the zone which is least likely to contain photosynthetic organisms is the zone furthest away from the sun, and thus the deepest, lowest level of the ocean. The intertidal zone and zone of coastal upwelling are in fact closest to the coast and sun, while the pelagic zone refers to water which is further from the coast, but includes the surface (though not the sea floor). And the euphotic zone is the uppermost zone, which indeed received sunlight. Thus the least likely of these zones to contain photosynthetic organisms is the abyssal zone, the part of the ocean deeper than about 2,000 m and the deepest of this group.

The Coriolis Effect in the northern hemisphere spins surface water clockwise. This means the new surface water will be first taken south and east from its emergence at the west coast of North America, to join the clockwise North Pacific Gyre.

It is estimated that roughly 50% of individuals in the United States rely on groundwater for their water supplies. In some countries this percentage approaches 100%.

Agriculture is by far the largest consumer of the usable fresh water on earth, using up roughly 70% of water consumed by humans.

In hydroponics, plants are grown in nutrient-rich water and there is no soil involved in the process. Some water is lost through evaporation, but since it is a closed system, very little water is lost.

Flushing the toilet is the largest contributor to household water consumption, averaging about three gallons of water per flush. 

Seventy-five percent of Earth's surface is water, and the oceans contain ninety-seven percent of Earth’s water. This means that roughly three percent of the Earth's water resides in rivers, lakes, glaciers, and water vapor.

The correct response is littoral. The littoral layer is the layer in a freshwater lake along the shoreline with shallow water. The limnetic layer represent "open water", so this layer is off the coastline and in the middle of the freshwater lake. The benthic layer is along the bottom of the lake (i.e. benthic = bottom). And the profundal layer is the layer at the bottom of deep lakes where the light can't reach the bottom.