Research Project Summary Information
The Effects of Watershed and Stream Liming on Mercury in Surface Waters and Biota of Honnedaga Lake(27239)
USGS National Center MS270
The Adirondack region of New York has been identified as a mercury (Hg) “hot spot” where high levels of the neurotoxin methyl-mercury (MeHg) have been measured in fish, birds, and other biota. Most of the Hg present in biota of the region is likely introduced to the landscape by dry and wet deposition that originates from a mix of local, regional, and global emissions. Past research in the Adirondacks and elsewhere has identified higher levels of Hg in surface waters and biota associated with lower pH values. The reasons for this Hg-pH association are unclear, however several potential mechanisms have been identified.
A new liming study of tributaries to Honnedaga Lake in the southwestern Adirondacks has recently begun pre-treatment data collection with partial support from NYSERDA. Honnedaga Lake has been chronically acidic, but has recently shown signs of some recovery and harbors a unique strain of Heritage brook trout. These brook trout have previously shown low reproductive success that would likely be improved through the expansion of spawning habitat by mitigation activities such as the liming of tributary watersheds. Elevated Hg in fish has also been demonstrated to negatively affect fish reproduction and recruitment. Thus, the poor recruitment of Honnedaga Lake brook trout associated with acidic conditions may be exacerbated by elevated Hg levels.
The liming study is being conducted in the Honnedaga Lake watershed, where a large amount of information is available on water chemistry, fisheries, and forest management that dates back prior to the onset of acid rain. Three (3) tributary watersheds have been selected for the liming study. These tributary streams are episodically acidic. Two of these streams will be limed in the summer of 2012 and the third will serve as an untreated reference stream. Detailed stream flow and chemistry data are being collected at each of these 3 tributary streams.
The US Geological Survey will conduct background data collection for this project beginning in Spring 2012 and continue through Fall 2012. This initial sample collection will represent largely pre-liming conditions designed to provide background values and some seasonal information on Hg in macroinvertebrates, fish, and surface waters. Water samples will be collected in Fall 2012 and will represent initial post-liming conditions. The streams to be limed will be sampled at each of two locations, upstream and downstream of the planned liming application, and the reference stream will be sampled in one location.
In addition to improving surface water chemistry in acidified surface waters to levels sufficient to improve fish recruitment and other aspects of biological integrity, there is also reason to believe that liming may act to decrease Hg concentrations in surface waters and their resident biota. The Honnedaga liming study provides a unique opportunity to also investigate these effects. If liming can be demonstrated to decrease Hg concentrations while simultaneously improving species richness and expanding habitat for acid-sensitive species, this would provide additional justification for considering liming as a restoration management tool in select Adirondack and Catskill surface waters.
USGS National Center MS270
Dept of Interior P.O. Box 71362
Philadelphia, PA 28272
Environmental Monitoring & Research
NYSERDA Contact Information
R&D - Environment & Energy Res