Kreislauf zwischen Autotrophen und Heterotrophen. Autotrophe können Kohlendioxid (CO2) und Wasser nutzen um Sauerstoff und komplexe organische Verbindungen zu bilden. Dies hauptsächlich durch den Prozess der Photosynthese. Alle Organismen können solche Verbindungen nutzen um ihrerseits CO2 und Wasser durch zelluläre Atmung zu bilden.
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The Brown Pelican (Pelecanus occidentalis), an endangered species, feeds on schooling fish near the ocean's surface by plunging beak-first from the air. The chemical DDT almost caused the demise of the brown pelican back in the 1960's. Pelicans exposed to DDT laid eggs with thin or non-existent shells, which broke during nesting, thus reducing the number of surviving offspring. Since DDT was banned in 1972, brown pelicans have made a remarkable recovery. There are permanent brown pelican nesting colonies on both Anacapa and Santa Barbara Islands.