Search “ocean zones” on-line, and you will note lots of of illustrations that depict the identical vertical profile of the ocean. The skinny, prime layer is the “daylight” or epipelagic zone, which receives sufficient gentle for photosynthesis by phytoplankton, algae and a few micro organism. Beneath it’s the twilight zone, the place the sunshine fades however remains to be sturdy sufficient for some animals to see by and the place many animals make their very own gentle by way of bioluminescence. Subsequent is the midnight zone, with no measurable gentle, adopted by the relentlessly chilly abyss. Lastly, there are the extremely deep seafloor trenches generally known as the hadal zone, named after Hades, Greek god of the underworld.

On this traditional view, the quantity of sunshine and the water strain—which will increase steadily with depth—largely outline which creatures dwell the place. These elements are necessary, however so are water temperature, salinity, quantities of oxygen and nitrogen, and the altering currents. Knowledge collected worldwide have revealed that ocean dynamics, and ocean life, are much more complicated than we thought, stunning us many times as we discover.

Classic ocean cutaway depicts the ocean as a layer cake of five zones that are defined by depth and are uniform worldwide.

Credit score: Jen Christiansen

Spilhaus projection shows oceans as an interconnected system. Ocean conveyor belt and 5 data collection locations are labeled

Credit score: Skye Morét; Supply: “The International Significance of the Southern Ocean and the Key Function of Its Freshwater Cycle,” by Michael P. Meredith, in Ocean Problem, Vol. 23; 2019 (reference)

California coast upwelling chart reveals the dynamic nature of temperature, salinity, oxygen and nitrogen values over time.

Credit score: Jen Christiansen