DURANTE Cristian Alberto
capítulos de libros
Effects of pollution in aquatic food chains
GONZÁLEZ RAÚL; DURANTE CRISTIAN ALBERTO; ARCAGNI MARINA; JUNCOS ROMINA; SECO PON JUAN; CRESPO ENRIQUE ALBERTO; NARVARTE MAITE
Anthropogenic Pollution of Aquatic Ecosystems
Aquatic (marine and freshwater) ecosystems usually receive different types of pollutants through riverine inflow, discharges of sewage or other wastes, or the atmosphere. Marine coastal areas, rivers, and lakes near industrialized and highly populated zones can contain high concentrations of pollutants. The trophic webs of such ecosystems can be affected by those pollutants, with the inhabitant species manifesting different vulnerabilities for certain compounds. Pollutants can bioaccumulate when ingested at a higher rate than excreted and some can also be biomagnified if accumulated at such higher rates throughout the food chain. Biomagnifiyng substances, such as organochlorines, are usually lipophilic (i. e., they dissolve more readily in nonpolar substances than in water), or, like methylmercury, have a high affinity for proteins. Other pollutants, as for example heavy metals, are mostly associated with water and usually do not biomagnify at all, though they may bioaccumulate to very high concentrations in certain individual organisms. Bivalve molluscs and other filter-feeders usually bioacumulate substances at higher rates because they receive pollutants from suspended particles. Top predators (fish, seabirds, and mammals) in aquatic trophic chains can be affected by biomagnified compounds. In this chapter we discuss the conceptual basis of and terminology used in ecotoxicological studies, and review regional investigations that have focussed on the effects and modes of propagation of contaminants through the food webs in the aquatic ecosystems (both marine and freshwater) in Argentina.