How Do Deep Sea Plants Survive?

Some deep sea plants survive by rooting themselves close enough to the shore that they can still receive enough sunlight to complete photosynthesis. Since sunlight cannot reach the deepest depths of the sea, however, it is impossible for plant life to survive there. Instead, deep sea life is sustained by chemosynthetic bacteria that rely on the conversion of inorganic molecules into organic matter.

Chemosynthesis is like the sister process to photosynthesis in that they both absorb carbons and transform them into food and energy that is then used by other organic life forms. Where photosynthesis is powered by light, chemosynthesis relies on chemical energy. In the absence of both light and chemical energy, life cannot exist.

An interesting piece of trivia is that before the discovery of chemosynthesis in the 1970s, scientists didn't believe that life on earth could be sustained without the sun. Today however, entire self-sustained ecosystems thrive deep in the depths of the sea. Aquatic animals like shrimp and crabs number in the millions, and giant 2.5 metre tube worms are populous in their own right. Additionally, scientists hypothesise that myriad undiscovered life forms exist in the deep sea, outside the reach of the sun and technology.

Hydrothermal vents are central to these systems. Located in areas where there's some degree of tectonic and volcanic action, these vents regularly or continuously gush magma-hot water into the ocean. This water dissolves the surrounding rock and expels the broken-down chemicals and minerals into the ocean at such a high concentration that it should be toxic.

Because of the presence of chemosynthetic bacteria around these vents however, this chemical and mineral cocktail is instead converted into an ample supply of food and energy to keep these ecosystems viable.

To summarise, plants cannot survive in the deepest regions of the sea because there is no sunlight for them to photosynthesise. Chemosynthetic bacteria functions in the place of plant life to enable deep sea life to thrive.

Most deep sea plants live by digging out the nutrients, which comes from dead plants and animals. Most plants live near hot vents or volcanoes where they can get the nutrients easier by just letting it shoot up.
Some deep sea plants produce their own light, which gives off heat and attracts small creatures, that will soon turn into plant food

The rooting plants have an impact on the physiological processes of plants because of the nutrition of the plant. Deep rooted plants survive famine more and adapt well because water is accessible readily to deep-rooted systems. Thus in conditions, where there are sporadically drought-ridden, varieties or species of plants which have deeper roots are able to yield more compared to others. For plants like wheat, the nitrogen fertilizer is known to increase yield, and the plants thanks to their deep root systems are able to make efficient use of the nutrients during the spells of drought. Deep root systems are ideal for increased photosynthesis, as plants are able to draw in more carbon dioxide from the atmosphere, and also for evaporation of water from the plant surface (transpiration).

They don't undergo the photosynthesis cycle unlike other plants because of the absence of light.They survive entirely by absorbing nutrients present in the soil.The soil is very rich because all dead fish,plankton etc., settles on the deep ocean floor (like an undersea graveyard).

By being cool

Most of them are heterotrophic. They survive on small insects or fishes in the sea. Unicellular bacteria can prepare its own food. Sunlight is not present in deep sea. Thus no autotrophic plants are present I think. Algae survive by the photosynthesis reaction by phtoplanktons..

Eating other organisms

They have adapted to the water life and eat organisms to encourage their strength