Cooperator: Wisconsin Department of Natural Resources
Project Chief: Steven R. Corsi
Location: Statewide
Project Number: BQY23
Period of Project: July 2001–September 2006
updated 2/20/07
Problem
The state of Wisconsin has recently implemented a federally mandated program
that requires cities with populations greater than 10,000 to develop stormwater-management
plans. The intent is to eventually regulate stormwater as a point source of pollution
by setting limits on the quantity and quality of runoff entering receiving waters.
The critical problem that needs to be addressed is the degree to which toxicants
found in urban runoff need to be regulated in order to protect the biological
integrity of receiving streams. One question that needs to be addressed: is there
a threshold level of watershed imperviousness below which regulation of toxicants
in stormwater runoff is not needed? Another question that needs to be answered
is: at what field concentration of potential toxicants do we see adverse effects
in stream-dwelling organisms? This will permit regulatory effort to be more effectively
focused on problem areas and problem chemicals.
The Wisconsin Department of Natural
Resources would use this information to identify areas where regulation of toxicants
in runoff is necessary to protect, enhance, or restore aquatic communities. Municipalities
will need this information to most economically and effectively comply with these
impending regulations.
Objective
The purpose of this study is to examine the relation of watershed imperviousness
in urban river systems to measures of toxicity in aquatic organisms. More specifically,
the objective is to determine the toxicity of urban river systems to P. promelas
as measured in 21-day spawning tests using in-situ caged fish.
 Approach
In-stream fish exposures involve the following details: (1) in-stream fathead
minnow exposures consist of tests at 3 to 7 streams per time period with
1 test chamber per stream and one control chamber in the laboratory; (2) chambers
consist of 6 cartridges with a pair of adult fathead minnows (one female and
one male) per cartridge; (3) each stream tested fits into a matrix of different
urban influences; and (4) Site visits are made each day to check on the condition
of the minnows, and collect data. (Placement of chambers coincides with the NAWQA
EUSE topical study.)
The overall goal is to conduct this test for
21 days at each of 30 different sites with varying degrees of urbanization. Toxic
response as measured by spawning success will be compared to the degree of urbanization.
Progress (January 2006 to June 2006)
Data analysis was conducted on the results from 11 stream tests from the summer
of 2005. Preliminary results indicate that dissolved oxygen in the stream correlates
with egg count. Egg count also had correlations with several biotic indices computed
from EUSE test results.
Plans (July 2006 to December
2006)
Fourteen sites will be monitored during the summer of 2006 and data analysis
will be conducted during the fall of 2006. The final group of sites will be monitored
during the summer of 2007 with final data analysis and reporting conducted from
October 2007 through September 2008.
Reports
A final report will be written after the summer of 2007 and submitted
to an appropriate journal.
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