Comparison of selenomethionine and selenite cycling in freshwater experimental ponds

✍ Scribed by R. V. Graham; B. G. Blaylock; F. O. Hoffman; M. L. Frank

• Publisher: Springer Netherlands
• Year: 1992
• Tongue: English
• Weight: 667 KB
• Volume: 62
• Category: Article
• ISSN: 0049-6979
• DOI: 10.1007/bf00478451

✦ Synopsis

A comparison of the cycling and fate of 758e in an aquatic ecosystem was investigated when selenite or selenomethionine was introduced as an acute release into two experimental ponds. Biotic and abiotic compartments were periodically sampled to measure 75Se concentrations throughout the 318-d experiment. The biotic compartments were periphyton, rooted pondweed (Elodea canadensis), snails (Helisoma sp.), and mosquitofish (Gambusia affinis). Results show that the uptake rates in the biotic compartments for 75Se-selenomethionine were at least an order of magnitude greater than for 75Se-selenite. However, elimination rates for respective biotic compartments were similar. Seasonal sediment 758e concentrations in both ponds decreased simultaneously with increases in 758e concentrations within biotic compartments. This suggests that sediment is a secondary source of 75Se rather than a sink in some shallow freshwater systems.