Critical Review Dietary Uptake Models Used for Modeling the Bioaccumulation of Organic Contaminants in Fish

Abstract

Numerous models have been developed to predict the bioaccumulation of organic chemicals in fish. Although chemical dietary uptake can be modeled using assimilation efficiencies, bioaccumulation models fall into two distinct groups. The first group implicitly assumes that assimilation efficiencies describe the net chemical exchanges between fish and their food. These models describe chemical elimination as a lumped process that is independent of the fish's egestion rate or as a process that does not require an explicit fecal excretion term. The second group, however, explicitly assumes that assimilation efficiencies describe only actual chemical uptake and formulates chemical fecal and gill excretion as distinct, thermodynamically driven processes. After reviewing the derivations and assumptions of the algorithms that have been used to describe chemical dietary uptake of fish, their application, as implemented in 16 published bioaccumulation models, is analyzed for largemouth bass (Micropterus salmoides), walleye (Sander vitreus ϭ Stizostedion vitreum), and rainbow trout (Oncorhynchus mykiss) that bioaccumulate an unspecified, poorly metabolized, hydrophobic chemical possessing a log K OW of 6.5 (i.e., a chemical similar to a pentachlorobiphenyl).

Spatially explicit bioaccumulation modeling in aquatic environments: Results from 2 demonstration sites

“…For certain sediment‐associated contaminants, such as heavy organics including PCBs and some pesticides, the processes governing bioaccumulation are well understood based on first principles and have been mathematically well‐defined (Thomann ; Thomann et al ; Gobas ; Arnot and Gobas ). There have been a number of bioaccumulation model reviews (Burkhard ; Imhoff et al ; Barber ) and analyses of sensitivity and uncertainty in trophic transfer (Ianuzzi et al ; von Stackelberg, Burmistrov, Vorhees et al ; Barber ); however, questions remain concerning the ability of these approaches to adequately capture true relationships among sediment and water exposures and resulting tissue concentrations in aquatic food webs (Glaser and Bridges ; Thompson et al ). For example, participants of a Department of Defense workshop (Thompson et al ) identified the “evaluation of food web models in setting remedial goals and long term monitoring requirements” as a critical research area given these food web models represent a critical component of decision making at sediment contaminated sites (Gustavson et al ).…”