Abstract |
Field evidence for short cycling of organic contaminants, from sources at the air-water interface directly into the zooplankton and fishes, has generally been lacking in the literature. The potential mechanisms, however, have been intensively explored; these are dominated by the formation of organic platelets at the air-water interface and the availability to grazers of other forms of suspended detritus. Susceptibility of the zooplankton to short cycling of contaminants thus depends upon their demonstrated propensity to feed near the surface of the lakes. As contrasted with missing environmental information, experimental evidence for short cycling is clear; the experimental inclusion of small, organic particles along with natural assemblages of nannoplankton increased PCB loading to the zooplankton 2.3 times. Further field evidence on the magnitude of short cycling must be sought, because contaminants soluble in oils influence the entire food chain. (Copyright (c) Internat. Assoc. Great Lakes Res. 1982.) |