Phosphorus is indispensable to life on Earth, as it is involved in the passage of genetic information, energy transfer, and the construction of plant cells. Despite this, the amount of phosphorus available for biological uptake is relatively small, so productivity in many terrestrial and aquatic ecosystems is often limited by phosphorus availability. As a result, human interference in the phosphorus cycle can have severe environmental consequences. For example, phosphorus pollution of water bodies by sewage effluents and drainage from agricultural land can contribute to the growth of toxic blue-green algae, fish deaths, and a drastic reduction in the quality of affected water bodies.