What would happen if phytoplankton of an ocean is completely destroyed...
Phytoplankton: Phytoplankton is mostly microscopic, single-celled photosynthetic organisms that live suspended in water. Like land plants, they take up carbon dioxide, make carbohydrates using light energy, and release oxygen. They are what is known as primary producers of the ocean—the organisms that form the base of the food chain. Because they need light, phytoplankton lives near the surface, where enough sunlight can penetrate to power photosynthesis. The thickness of this layer of the ocean—the euphotic zone—varies depending on water clarity, but is at most limited to the top 200 to 300 meters (600 to 900 feet), out of an average ocean depth of 4,000 meters (13,000 feet). Phytoplankton comprises two very different kinds of organisms.
- The larger category includes single-celled algae known as protists—advanced eukaryotic cells, similar to protozoans.
- These forms include diatoms and are most abundant near coasts. Occasionally, these organisms form blooms—rapid population explosions—in response to changing seasons and the availability of nutrients such as nitrogen, iron, and phosphorus.
- The other type of phytoplankton cells, more primitive but far more abundant than algae, is photosynthetic bacteria.
- These tiny cells, some only a micron across, are invisible but present in numbers of hundreds of thousands of cells per tablespoon of ocean water.
- Too small to be caught in any net, these organisms were unknown until the 1970s, when improved technology made them visible.
- Scientists now know these bacteria are responsible for half of the ocean's primary productivity and are the most abundant organisms in the sea.
- The group also includes cyanobacteria, which are believed to be among the oldest organisms on Earth and the origin of the photosynthetic organelles in plant cells known as chloroplasts.