What lives at that depth?
The ocean is divided by light, not by distance. Below 200 m there is not enough to photosynthesise; below 1 000 m there is none at all.
Almost exactly a sunlight zone
200 m is deeper than 1 of the 9 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| recreational scuba limit | 40 m | 5× | |
| sunlight zone | 200 m | 1× | Where all photosynthesis happens |
| twilight zone | 1,000 m | 0.2× | |
| sperm whale dive | 2,250 m | 1/11.3 | |
| average ocean floor | 3,688 m | 1/18.4 | |
| Titanic | 3,800 m | 1/19 | |
| midnight zone | 4,000 m | 1/20 | No sunlight at all |
| abyssal zone | 6,000 m | 1/30 | |
| Challenger Deep | 10,935 m | 1/54.7 |
Worth knowing
- Below 200 m there is too little light for photosynthesis, so almost everything deeper ultimately eats what falls from above.
- A sperm whale can dive to 2 250 m and hold its breath for 90 minutes, hunting squid in complete darkness by echolocation.
Frequently asked
How deep does sunlight reach in the ocean?
Usable light for photosynthesis stops around 200 m. Some blue light is detectable to 1 000 m, and below that the only light is made by the animals themselves.
What lives at the bottom of the Mariana Trench?
Amphipods, sea cucumbers, xenophyophores and at least one species of snailfish, which is the deepest-living fish known at about 8 300 m.