Ocean plants, like all other plants in the world, need sunlight to survive. In deeper parts of the ocean, there is less plant life because sunlight cannot penetrate through the dense waters. Therefore, either most plants grow in shallow waters, where sunlight can easily penetrate, or they float on water, constantly receiving direct sunlight.
One of the largest marine plants and the fastest growing plant in the world, Kelp is a type of seaweed found in cold seas. It is brown with long ruffled tentacles like arms that attach easily to rocks.
In some areas of the sea, where the Kelp density is high, the areas are called Kelp forests, and are considered amongst the most thriving ecosystems on the planet. Areas with less kelp density are called Kelp beds.
Kelp has some amazing evolutionary characteristics that allow them to survive underwater.
The body of the kelp (known as thallus) is held strongly to the ground by its huge root like mass called the holdfast. This root only performs the task of an anchor, and does not deliver nutrients as normal roots do.
The second part of the plant that allows it to stand straight in high-pressure water is its spine, similar to a plant stalk, called the stipe. The stipe lengthens upward and supports the entire plant’s framework.
The stipe has leaves attached to it and extending outward, called fronds. These fronds provide the foundation for all the plant’s nutrient needs like photosynthetic activity.
Another great adaptation of the Kelp is its gas-filled bladders, called pheumatocysts. These are located near the stipe, at the bottom of the fronds, and act as floating devices keeping the plant in its upright position.
When these bladders are active, the plant is able to rise to the ocean’s surface to capture light in order to start the photosynthetic process.
The Kelp can withstand turbulent currents, and in fact thrives in such conditions, as they provide a steady stream of nutrient rich water, coming from the depths of the ocean floor.