The elevation and slope determines the length of time its exposed. Organisms living in pelagic waters also put up with changes in salinity, temperature etc. and inhabit the coastal areas etc. which fit their adaptations. Other zones include the surface waters of the coastal areas called the neritic zone and the waters of the ocean called the epipelagic zone. The open ocean is less productive than the neritic zone which contains plant plankton, fish larva, invertebrate larva that will eventually end up near the coast. Each level on the pyramid represents a trophic level.
Autotrophs absorb sunlight energy and transfer inorganic mineral nutrients into organic molecules.
The energy stored in the organic molecules is passed to consumers in a series of steps of eating and being eaten and is known as a food chain. Each step represents a trophic level and the complex food chains within a community interconnect and is known as a food web. The final trophic level that connects consumer to producer is that of the decomposers. They live on dead plant and animal material and the waste products excreted by living things. The nutritional activity of these replenish nutrients that are essential ingredients for primary production.