Does forestry contribute to mercury in Swedish fish?

Tens of thousands of Swedish lakes have fish with unacceptably high levels of mercury. Recent research from Sweden, Canada and Finland indicate a connection between forestry operations and the input of mercury and/or the much more toxic methylmercury species to aquatic ecosystems. While these studies raise the question of whether forestry is a significant contributor to the problem of mercury in freshwater fish, there is not enough information to provide a satisfactory answer as to how important forestry actually is for the mercury contamination in freshwater fish, or what management options might exist to mitigate an eventual contribution to the mercury problem by silviculture.

The Royal Swedish Academy of Agriculture and Forestry (KSLA) hosted a two day workshop addressing these issues. This special issue of KSLA’s periodical presents the consensus document that resulted from that meeting, as well as summaries of some of the presentations. While many issues remain, we hope that these results of the conference will be a step on the way to a more satisfactory understanding of forestry’s role in the unacceptable levels of mercury so commonly found in the fish of boreal lakes, and how to mitigate that problem.