Mesopelagic Zone (Twilight Zone)

Assembled from 16 blocks · 2 evidence · 10 related

1. Story
2. Conventionally about 200 m to 1,000 m. Sunlight is present but far too dim for photosynthesis to exceed respiration. This is the layer where surface light finally runs out: NOAA states that sunlight does not penetrate below roughly 1,000 m, the top of the permanently dark aphotic realm. The zone hosts the vast vertically-migrating biomass that rises toward the surface at night and sinks by day, and bioluminescence rather than sunlight becomes the dominant light source through most of it.
3. Knowledge
4. Mesopelagic Zone (Twilight Zone)
5. Bathypelagic Zone (Midnight Zone)
6. Connections
7. Epipelagic Zone (Sunlight Zone)
8. Bathypelagic Zone (Midnight Zone)
9. Bioluminescence
10. Mesopelagic Zone (Twilight Zone)
11. Abyssopelagic Zone (Abyssal Zone)
12. Marine Snow
13. Giant Tube Worm (Riftia pachyptila)
14. Evidence
15. 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.
16. 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).