The Manner in Which Organisms Concentrate Pollutants

This paper provides an overview of the processes that control chemical contamination of marine life in the sea. A decade ago the Stratton Commission concluded that one of the least understood processes of pollution is the manner in which organisms concentrate pollutants. In a sense, the answer is, and was, simple: marine life either accumulates contaminants directly from the water by absorption through external tissues (gills, skin, etc.) or the contaminants are assimilated from the diet. Although we were not involved with Commission proceedings at the time, we presume the question concerned which process dominated in the sea itself - uptake from water or uptake from food? Further, we presume that the question was asked not for its scientific merit but because the answer could profoundly affect the Nation's directions in establishing quality criteria and developing safe waste disposal management strategies. If, for example, water dominated the transfer process then water quality criteria suitable for minimizing bioaccumulation could be relied upon as a regulatory tool for chemicals in aquatic and marine environments. However, if diet was the prevailing source and assimilation in the gut the prevailing "manner" of uptake then criteria would have to include a clear understanding of dietary pathways in the marine environment. Below, we attempt to demonstrate that, with our current knowledge, this question about the manner of uptake at the individual level is practically - but not entirely - irrelevant. Our report is not intended to be a literature review. Rather, we felt we would best serve the purpose of this conference by providing a short but comprehensive restatement of the question based on our knowledge of highlights from research over the past decade, in addition, the reader is advised that this paper is (1) a companion to the oral presentation, which will focus in more detail on several of the processes briefly reviewed here and (2) a companion to the accompanying paper on effects by Boesch [1].