Because they just do, lol.
Some does like phytoplankton and zooplankton.
Phytoplankton (small plants or plantlike organisms floating around in water) require the sunlight to perform photosynthesis.
They use sunlight, carbon dioxide (CO2) and water, in a process called photosynthesis, to produce organic compounds which they use for food and to make their cells. One waste product is oxygen and this makes it possible for animals to live on earth.
Phytoplankton must remain in the photic zone because this upper layer of water is where sunlight penetrates, enabling photosynthesis. By harnessing sunlight, phytoplankton produce oxygen and serve as the primary producers in aquatic food webs, forming the base for marine and freshwater ecosystems. Staying in this zone ensures they can efficiently convert light energy into chemical energy, supporting both their growth and the organisms that depend on them for food.
Producers in the neritic zone include phytoplankton, seaweed, and seagrasses. These organisms use sunlight for photosynthesis to produce energy for themselves and serve as the base of the food chain in this zone.
They live in the sunlight zone
yes, a killer whale or the orca sometimes live in the sunlight zone
Sunlight zone
The Sunlight Zone
the Sunlight Zone
The open water zone reaches down to where sunlight can still penetrate. Organisms that live here include tadpoles, fish, and non deep-rooted plants. Phytoplankton is the most abundant organism here.
Squirrel fish live in the sunlight zone