Trophic network models and prediction of toxic substances accumulation in food webs

Abstract

The term food web or trophic network defines a set of interconnected food chains by which energy and materials circulate within an ecosystem. The classical food web could be divided into two broad categories: the grazing web, which typically begins with green plants, algae, or photosynthesizing plankton, and the detrital web, which begins with organic debris. In a grazing web, materials typically pass from plants to herbivores to flesh eaters. In a detrital web, materials pass from plant and animal matter to decomposers as fungi and bacteria, then to detritivores, and then to their predators. In water ecosystems, the classical food web is represented by the planktonic and benthic food webs, which are interconnected. Additionally, the “microbial loop” represents an alternative pathway of carbon flowthat leads from bacteria to protozoa to metazoa, with dissolved organic matter (DOM) being utilized as substrate by the bacteria, which include nanoplankton (2–20 μm in size) and picoplankton (0.2–2 μm in size)