The word plankton originates from the Greek word for “wandering.” Refers to the diverse group of plants and animals that spend some or all of their life cycle drifting in the water of oceans or freshwater lakes. Plankton is abundant and important within the marine environment. Most fo the Earth’s biomass, the mass of living organisms, consist of plankton adrift in the oceans. Ninety-eight percent of marine species are bottom dwelling, but the vast majority of the ocean’s biomass is planktonic. Many of these organisms are capable of locomotion, but are generally unable to move independently of currents and waves. This lack of strong swimming ability separates plankton from nekton, which include organisms that can control their movement in the water. Some planktonic organisms can be quite large, however, plankton are generally smaller than nekton. Plankton can be classified based on their feeding styles.
Phytoplanktons are a very important part of ocean life. The carbon dioxide in the atmosphere is in balance with carbon dioxide in the ocean. During photosynthesis, phytoplankton removes carbon dioxide from sea water and release oxygen as a by-product. This allows the oceans to absorb additional carbon dioxide from the atmosphere. If fewer phytoplanktons existed, atmospheric carbon dioxide would increase.
Phytoplankton also affects carbon dioxide levels when they die. Phytoplankton, are composed of substance that contain carbon. Dead phytoplankton can sink to the ocean floor. The carbon in the phytoplankton is soon covered by other material sinking to the ocean bottom. Deforestation contributes to the accumulation of carbon dioxide in the atmosphere by reducing vegetation that takes up carbon dioxide. Carbon dioxide acts as a “greenhouse” gas in the atmosphere, and therefore may contribute to global warming. Sources of carbon dioxide in the Earth’s atmosphere include decomposition of organic matter, the carbon dioxide that animals and people exhale, volcanic activity, and human activities such as burning of fossil fuels and wood.
In the pelagic...