Epipelagic Zone (Sunlight Zone)

Assembled from 14 blocks · 2 evidence · 5 related

1. Story
2. The uppermost pelagic layer, conventionally surface to about 200 m. It is the only zone where enough sunlight penetrates to sustain net photosynthesis, so essentially all primary production in the open ocean happens here. The 200 m figure is a convention marking the approximate base of the photic zone in clear open water; it is not a physical boundary, and in turbid coastal water the productive layer can end in tens of metres. Light does not switch off at any depth - it attenuates continuously and roughly exponentially.
3. Knowledge
4. Epipelagic Zone (Sunlight Zone)
5. Mesopelagic Zone (Twilight Zone)
6. Connections
7. Mesopelagic Zone (Twilight Zone)
8. Marine Snow
9. Epipelagic Zone (Sunlight Zone)
10. Bathypelagic Zone (Midnight Zone)
11. Bioluminescence
12. Evidence
13. Sunlight does not penetrate below roughly 1,000 m; the aphotic zone below that comprises the bathypelagic (1,000-4,000 m), the abyss (4,000-6,000 m) and the hadal (6,000 m and deeper). Attenuation is continuous, and these depths are stated as conventional bands, not measured discontinuities.
14. The water column is conventionally divided into five zones - sunlight (epipelagic, 0-200 m), twilight (mesopelagic, 200-1,000 m), midnight (bathypelagic, 1,000-4,000 m), abyssal (abyssopelagic, 4,000-6,000 m) and hadal (below 6,000 m).