Water, sunlight, temperature, pressure, chemicals and geologic features are some nonliving things in the ocean. Termed abiotic factors, these forces impact life in the oceans and on land.
Water's composition and its movements form complex systems. Currents move bands of variable temperature across regions, affecting the types of organisms in those zones. Upwelling pulls organic nutrients from the deep into shallower waters, supporting the growth of plankton. Wave action and tides change the landscape of shorelines and oceanic topography.
Sunlight is essential to life in the upper oceans. Increased turbidity from pollution or storms limits the availability of sunlight for photosynthesis, reducing viable food sources.
Water pressure increases with ocean depth and requires organisms to possess methods to equalize internal and external pressure. Whales are known to hunt in depths of up to 10,000 feet, collapsing their ribs to reduce lung volume and air pockets.
The availability of chemical components in the ocean, including oxygen, carbon dioxide, nitrogen, phosphorus and sulfur, controls the breakdown and use of any organic materials. In the absence of sunlight, chemosynthesis occurs around deep-ocean vents that release chemicals from the earth's core and produce energy for cellular organisms. Other geological forces, such as earthquakes and volcanoes, create and destroy oceanic land masses.
Ocean topography, such as the existence of ledges and the characteristics of the ocean floor, define the types of fish communities in a particular ecological niche. High ledges host large, diverse assemblies, while sandy plains hold fewer species and lower densities.