tailieunhanh - ECOTOXICOLOGY: A Comprehensive Treatment - Chapter 34

Thực phẩm điều tra web có một lịch sử tương đối dài trong nghiên cứu ecotoxicological. Mùa xuân im lặng của Rachel Carson (1962) đặt đại bàng hói và các loài chim khác của con mồi ở trên cùng của kim tự tháp dinh dưỡng của Elton và giới thiệu giáo công cộng quan trọng, nhưng thường bị hiểu lầm, khái niệm về biomagnification. Kể từ khi xuất bản cuốn sách có ảnh hưởng của Carson, nghĩa là hàng trăm nghiên cứu đã báo cáo nồng độ các chất gây ô nhiễm trên mức độ dinh dưỡng và cố gắng. | 34 Fate and Transport of Contaminants in Ecosystems INTRODUCTION Food web investigations have a relatively long history in ecotoxicological research. Rachel Carson s Silent Spring 1962 placed bald eagles and other birds of prey at the top of Elton s trophic pyramid and introduced the lay public to the important but often misunderstood concept of biomagnification. Since the publication of Carson s influential book literally hundreds of studies have reported concentrations of contaminants across trophic levels and attempted to relate trophic position to biomagnification. The goal of this chapter is not to provide a comprehensive review of these studies which have been adequately described in several recent publications Barber 2003 Borgâ et al. 2004 Fisher and Wang 1998 lannuzzi et al. 1996 Zaranko et al. 1997 . Instead the primary goal of this section is to characterize the ecological factors that influence transport of contaminants through ecosystems. Because of the difficulty developing reliable food web models researchers are keenly aware that predicting food chain transport requires more than an understanding of the physicochemical properties of contaminants. Quantification of feeding habits of organisms especially those with mixed diets or that show ontogenetic changes is often challenging. The structure of food webs and the dynamics of energy and contaminant flow also vary greatly among locations. Consequently predictive models have become increasingly sophisticated as investigators attempt to quantify the influence of ecological factors such as feeding habits food chain length and habitat characteristics on contaminant transport and biomagnification. The inclusion of these ecological factors into transport models represents a major improvement in our understanding of how contaminants are distributed in ecosystems. However knowing the concentration of contaminants in a particular species or trophic level tells very little about the consequences of .