Metal contamination and its effect on primary production measurements1

Minute amounts of trace elements can affect phytoplankton metabolic processes. Consequently, 14 C primary productivity measurements may be adversely affected by contaminant metals inadvertently added during sampling and handling procedures. We analyzed various components used in the standard 14 C method for metals; significant amounts of contaminants were found in many of the stock solutions used in this procedure and in associated containers. 14 C uptake rates were lower under contaminated conditions than those with clean techniques. The latter are described in detail; their adoption is urged for more accurate and precise estimates of this fundamentally important process.