Interesting Facts About Plants That Live in the Marine Biome

Ecosystems consist of groups of interdependent organisms and the surrounding environment. Ecosystems are also referred to as biomes, although some scientists use that distinction only for terrestrial ecosystems and exclude aquatic and marine (saltwater) environments from the biome classification. Additionally, biologists now classify many species of algae living in marine environments as members of the Protista kingdom of organisms, although they were once all designated as members of the plant kingdom.

Plants and plant-like organisms that can live in the ocean include mangroves, rockweed, sargassum, sea grass and seaweed. These organisms contain chlorophyll, conduct photosynthesis, and are an integral component of many aquatic biomes. For example, kelp, a type of seaweed, is a major food source for sea urchins, which in turn are kept in check by sea otters, starfish and other predators, all part of an interdependent ecosystem.

The large shrubs and small trees known as mangroves can grow in shallow saltwater environments. Predominantly found in coastal waters, mangroves are true flowering plants. Collectively, all mangroves in one specific area are called a mangal. A group of mangroves provides cover for small animals like birds, frogs, fish, and snakes. Furthermore, a mangal may sustain a varied nursery with several species of animals laying eggs and hatching young within its cover. Interestingly, the root system of the mangrove remains mostly above ground and this species is a rarity among shrubs and trees in that it can thrive in salty and brackish waters.

Ocean algae, i.e., seaweed has evolved a semisolid protective coating that prevents detrimental excess salt water from entering the organism. Seaweeds grow no roots. For example, kelp grows what is known as a holdfast, an organ that develops at the base and attaches to the ocean floor, rocks and other underwater objects for stability. Other ocean plants free-float, their destination determined by wind and water currents. In addition, some species grow a gas-filled appendage that assists in keeping the organisms afloat.

Due to the diversity of the underwater environments of the oceans, species have adapted to thrive under particular conditions. Seaweed species number in the hundreds of thousands, yet most seaweed grows in large groups, often near the surface of the water. According to the NASA Earth Observatory, when phytoplankton, one-celled free-floating algae grow dramatically and suddenly, the event known as a bloom may expand across hundreds of square miles. In massive quantities, the tiny one-celled microscopic organisms are easily recognized on satellite images.