HR: 14:45h
AN: NB13D-06 INVITED     [Abstracts]
TI: Using Ecological Theory and Historic Surveys to Assess Water Quality When Reference Sites are Unavailable.
AU: * Griffiths, R W
EM: bugman@execulink.com
AF: University of Guelph, Dept of Zoology, Guelph, ON N1G 2W1 Canada
AB: In large areas of southern Ontario, local reference or minimally impaired sites are no longer available largely as a result of extensive deforestation and agricultural practices over the past 1.5 centuries. For example in Essex County, less than 2 percent of the original forest cover is remaining and all streams have been "improved", i.e. deepened and channelized, to assist drainage. Published and unpublished historic benthic studies and surveys have been conducted by various researchers, e.g. Dr. F. Ide, and agencies, e.g Department of Lands and Forest, in Ontario since 1910 and thus may assist in establishing reference conditions in some areas. Meanwhile, using the principle of longitudinal zonation, benthic species can be associated with specific habitat reaches, e.g. creeks, streams, rivers, based on historic and current studies. Although we lack theory to predict specific composition of communities at a site, we can establish a "candidates list" for each habitat reach under reference conditions. When the candidate species are abundant within a habitat reach, water quality conditions approximate reference conditions. A reduction in the proportion of candidate species implies water quality impairment, whereas a lack of candidate species implies degraded water quality conditions.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly