Plants adapt in different ways depending on if they are submerged or floating. Floating plants feature a waxy upper surface, which helps to repel water. The upper surface also contains the chlorophyll needed for photosynthesis. Submerged plants employ a different water circulation system; instead of running water though stems, they absorb water and nutrients from the surrounding habitat. The roots of a submerged plant are primarily for anchorage and not for sourcing nutrients. This prevents them from being swept away by the currents.
The marine biome is the largest in the world, covering close to 70 percent of the earth's surface. It is also home to the most diverse collection of life: scientists have discovered over a million plant species living in this biome and estimate that there are still nine times this amount yet undiscovered. Many of the plants in this habitat rely on photosynthesis for nutrition. Algae is a particularly important plant, as it is responsible for the production of nearly half the oxygen on the planet.