University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 Ecosystem Recovery Analysis of Amos Palmer Drain, in Milan, Michigan By: Laura Fields-Sommers April 8, 2011 Undergraduate Honors Thesis Program in the Environment University of Michigan Dr. Catherine Riseng 1 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 Abstract The purpose of this study was to determine how the North Branch of Amos Palmer Drain (Wayne County, Michigan) stream ecosystem changed after a mining company stopped discharging waste water into the stream in 2003. Macroinvertebrates, stream morphology, habitat, and water chemistry samples were collected in 2010 at a site on Amos Palmer Drain and other similar sites within the watershed and were compared to samples collected at the same locations from 1997, 1999 and 2002 using t-tests, correlations and box plots. At NB of Amos Palmer Drain, significant increases were found in the number of families from 1997 to 2010, and average tolerance scores of the macroinvertebrate community from 1997, 1999, and 2002 to 2010. Significant decreases were found in all of the flow measurements, pH, and conductivity between 1999 and 2002, and 2010. Macroinvertebrate assemblage changes were likely due to changes in overall habitat, caused primarily by a decrease in flow to a more natural flow regime with levels reflecting conditions found in similar sites in the watershed. The variables measured were comparable to other local sites of similar size. Evidence supports the hypothesis that the NB of Amos Palmer Drain has reverted back to its state prior to mining drainage, though the state of the site previous to pollution was not assessed. Introduction Streams are thought to be among the most threatened ecosystems on our planet (Hawkins and Vinson, 1998). Humans have historically used streams to dispose of unwanted materials including trash, sewage and industrial waste. Chemicals and toxins enter the watershed in rain water runoff as well. The physical state of streams is often altered by channelization, removal of the riparian buffer, alteration of stream flow, and alteration of watershed landuse (Sahagian and 2 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 Vorosmarty, 2000). Streams also may be highly vulnerable to climate change, through its anticipated impact on the hydrological cycle (Chen and Shen, 2010; Arnell, 1999). Some researchers believe the hydrological cycle will be intensified with climate change, due to changes in evaporation and precipitation rates (Arnell, 1999). Many aspects of the environment, economy, and society are dependent on water resources (Zabihollah, 1999; Arnell, 1999). In less than 15 years, it is estimated that 62% of the world’s population of eight billion will live in countries experiencing water stress (Arnell, 1999). Information about the ecological quality of water resources is critical to understanding the state of our environment and understanding our environment is critical to protecting our economy and society (Carlisle et al., 2009). In order to effectively manage bodies of water, it is important to quantify changes and alterations (natural or anthropogenic) which have significant impact on ecosystems (Doledec and Statzner, 2010). Assessment of biological integrity is an integral part of watershed management plans (Davies and Jackson, 2006; Doledec and Statzner, 2010). Here I define a stream system with biological integrity to be an adaptive system with a full, balanced range of functions expected of a system with minimal human influence, commonly referred to as “reference condition” (Davies and Jackson, 2006; Doledec and Statzner, 2010). Aquatic fauna are useful tools for studying the biological integrity of an aquatic system because they integrate ecosystem changes over time (Doledec and Statzner, 2010). Macroinvertebrates in particular are accepted to be one of the most useful fauna for assessing biological integrity and have been commonly used to determine the health of freshwater systems (Brand et. al, 2008; Chon et. al, 2009). The state of macroinvertebrates communities can reveal a past disturbance such as a pollution event even when all chemical traces in the water are gone (Doledec and Statzner, 2010). 3 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 An important process which influences the state of an ecosystem is disturbance. Disturbance can be defined as a discrete temporal event that severely disrupts the structure and functions of an ecosystem (Brown et al., 1988). Natural disturbance regimes are common in most ecosystems; however, repeated human disturbance has made streams some of the most threatened systems on earth (Hawkins and Vinson, 1998). This study examines the capacity of a stream to recover from a typical human disturbance. London Aggregates operated a limestone quarry in Milan, Michigan, and discharged effluent into the Amos Palmer Drain which was found to have flow, and concentrations of total dissolved solids (TDS), hydrogen sulfides, and dissolved oxygen (DO) that exceeded the limits set by their National Pollutant Discharge Elimination System (NPDES) permit under the Clean Water Act of 1992 (CWA, 1992; PIRGIM, 2005; Tobler, 1997). The Intercounty Citizens Action Group (ICAG: made up of residents from London and Augusta Townships) described this stream as milky white water without life during periods when London Aggregates was discharging effluent (Tobler, 1997). In 1998, London Aggregates was sued by the ICAG and the Public Interest Group in Michigan (PIRGIM) for 2,700 violations of the CWA (Gearheart, 2009; PIRGIM, 2005). In 2003, the court handling the lawsuit found London Aggregates to be at fault and subsequently the mining company closed (PIRGIM, 2005). Roughly seven years have passed since London Aggregates stopped discharging effluent into Amos Palmer Drain. I hypothesized that this time period was sufficiently long enough for the ecosystem to improve its biological integrity. I expected that the water quality would have improved and macroinvertebrate assemblages would have diversified. I tested my hypothesis by sampling macroinvertebrate assemblages, water chemistry, habitat, and stream morphology. I compared samples from 2010 to samples collected from 1997, 1999, and 2002 when the effluent 4 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 was being discharged. I also sampled neighboring streams that did not receive effluent to test if Amos Palmer Drain, near the site of limestone effluent discharge, had recovered in comparison to the state of streams with similar characteristics in the same watershed. Looking at this incidence of human disturbance and comparing the ecosystem from the time of the disturbance to the current condition gives insight into the time it takes for a stream ecosystem to recover from limestone mining practices. Materials and Methods Site Description Amos Palmer Drain is a small, intermittent tributary of Stoney Creek in Wayne County, Michigan (Table 1, Figure 1). Sampling was conducted at seven sites in the upper portion of the Stoney Creek watershed, which were located east of Milan. Chosen site locations both matched sites from previous studies and roughly matched landscape conditions with the NB of Amos Palmer Drain watershed (Gustavson and Ohren, 2005). However many of the sites did not overlap with all of the studies and therefore data was not available for every site for every year. In all of the studies every site was located within the Stoney Creek drainage system. The NB of Amos Palmer Drain is a small intermittent stream with a drainage area of 6.10 km2 (Table 1). I sampled macroinvertebrate communities and habitat only in intermittent upstream sites and tributaries (sites 1-5) with drainage areas less than 25 km2 (Table 1, Figure 1). Stream morphology and water chemistry were sampled in intermittent streams and downstream sites (sites 6-8), which could be classified as river sites and were considered too large (drainage areas over 200 km2) to compare biological samples (Table 1; Figure 1). Sampling was scheduled to be conducted in August of 2010 but was pushed back to October, because the smaller, intermittent 5 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 sites (sites 1-5) were nearly dry and would have been incomparable to samples from the earlier studies taken in wetter seasons. Amos Palmer Drain was the lowest tributary on Stoney Creek sampled. The site 1 was located on the north branch of Amos Palmer Drain, close to where the limestone effluent was discharged and had one of the smaller drainage areas (Figure 1, Table 1). Site 2 was the closest site to the NB of Amos Palmer Drain, located on the south branch of Amos Palmer Drain and it had the smallest drainage area, 2.63 km2 (Table 1). The site nearest the headwaters of Stoney Creek was site 3 and it had the largest drainage area of the sites sampled for macroinvertebrates (24.86 km2). Sites 4 and 5 were located on separate tributaries from site 3 and had similar drainage areas (Table 1, Figure 1). Sites 6, 7 and 8 were located on the central branch of Stoney Creek. Sites 7 and 8 were located downstream from Amos Palmer Drain convergence with Stoney Creek. Historical Data London Aggregates discharged effluent from mining operations into the north branch of Amos Palmer Drain from 1992 until 2003 (PIRGIM, 2005; Tobler, 1997). I obtained historical biological, water chemistry, and habitat data from two sources: the University of Michigan’s fluvial ecosystems class in 1999 and 2002 (Wiley, personal communication, 2010), and the Michigan Department of Environmental Quality’s 1997 survey. The 1999 and 2002 surveys were conducted in March and the 1997 survey was conducted in July. This historical data on Stoney Creek, collected during the time of the London Aggregates unauthorized effluent discharge was compared to data collected in 2010, seven years after the mining discharge ended. Landuse data were obtained from summarized Anderson Level variables in ArcView GIS and 6 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 drainage area data were calculated by the Michigan Department of Natural Resources using 1:100,000 scale topographic maps (Brenden et al., 2006). Field Methods Latitude and longitude coordinates for each site were taken with a GPS unit (Garmin, Nuvi). Sites were about 25m stretches of stream starting from where the road crossed the stream. Habitat characteristics in percentage of stream area, including riffles, back water, undercut bank, submerged vegetation, overhanging vegetation, rocks, log pieces, and leaf packs were recorded along with the percentage of total bank cover of riparian vegetation represented, including forest, shrubs, forbs/grasses, and bare soil. Habitat characteristics were estimated visually. Water samples were taken in jars that were washed with stream water three times, kept on ice for travel and placed in a refrigerator until analysis could be conducted. However, the samples were misplaced and due to time constraints could not be recollected. Water temperature (YSI-58), dissolved oxygen concentrations (DO; YSI-58), pH (Hanna-HI98127), and TDS (TDSTestr, low) were measured with meters on site. Stream width, depth, and flow velocity were measured (YSI- 2000) at one meter intervals along a single transect, established 5 to 10 meters from the road. These measurements were used to calculate mean depth and discharge. General substrate composition was visually estimated and recorded. Macroinvertebrate Analysis Macroinvertebrate samples were collected following rapid bioassessment methods (Catherine Riseng, personal communication, 2010; Fluvial Ecosystems, University of Michigan, 1999 and 2002). Samples were collected using kick screens, D-nets, and hand picking in all observed habitats. Depositional and erosional habitats were sampled proportionately to their 7 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 occurrence. Each site was sampled for one hour with two people; fifteen minutes total were devoted to collecting specimens and forty five minutes were devoted to processing these samples. Each sample was emptied into a white tray, picked for all living macroinvertebrates, preserved in 70% ethanol, and returned to the lab for identification and enumeration. Locations sampled at each site were recorded. Invertebrates in the samples were classified to family to match historical samples (Hilsenhoff, 1995). Tolerance score, behavior, common habitat, and functional feeding group were assigned to families (Berg et al., 2008; Hilsenhoff, 1988; EPA, 2010). Tolerance score refers to a number assigned from 1 through 10 that indicates how tolerant of poor conditions such as low oxygen and pollution a taxa is, with 10 being extremely tolerant and 1 being extremely intolerant (Berg et al., 2008; Hilsenhoff, 1988). Behavior is the type of life an insect lives including burrowing, clinging, sprawling, skating, climbing, and swimming. Habitat indicates where they live, including depositional, erosional, lotic, lentic, and surface habitats. Functional feeding group refers to the way an insect feeds including collectors, predators, gatherers, filterers, shredders, scrapers, and piercers. Ephemeroptera, Plecoptera and Trichoptera were grouped together and their presence was used as an indicator of good dissolved oxygen conditions in the stream. When families were without a tolerance score, I used the average of the generic tolerance scores within that family; if the metrics did not agree I used Hilsenhoff (1988). Data Analysis I conducted simple t-tests to determine if there were any significant changes in the variables measured across all of the sites over the years (PASW-18, 2009). The 2010 samples were compared to each of 1997, 1999, and 2002’s samples separately. I examined change at the NB of Amos Palmer Drain by comparing 2010 data to each of the previous years, using simple t- 8 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 tests for each variable. I also graphed the linear relationship between conductivity and number of families for the 2010 samples using scatter plots with fitted linear least squares regression lines and 95% confidence intervals (PASW-18, 2009). Line graphs and box plots were used to visualize the variation in variables across sites and years. Variables used in correlation analyses were transformed using natural log for simple linear regressions to conform to normality assumptions. All of the tests were run at 95% confidence levels. Results Stream Habitat and General Characteristics Most of the Stoney Creek watershed was dominated by agricultural landuse, ranging from 38% to 72% with average of 56% (Table 3.). Agricultural drainage tiles were found at site 6 and were likely present at other sides. Substrate was generally uniform (silt) in the all streams surveyed, except site 4 which was sandy. Many of the smaller sites (sites 1-4) were intermittent streams and were nearly dry in August. Water was not flowing at the NB of Amos Palmer Drain downstream of the road, and the site had wetland characteristics with marsh flora such as cattails, rushes and sedges. On the upstream side of the road, however, stream flow was visible and no vegetation was in the channel. The water color had a slight brown tint that was seen in all of the sites sampled in 2010, noticeably different from the milky white color described by ICAG (Gearheart, 2009), which was due to the addition of limestone washed effluent from London Aggregates. The NB of Amos Palmer Drain had the lowest agricultural landuse percentage (38%) and the highest urban landuse percentage (15%). The NB of Amos Palmer Drain had the most backwater habitat, since it was ponded, and 90% overhanging forb and grass vegetation was present. 9 University of Michigan Ecosystem Recovery Analysis of Amos Palmer Drain, Laura Fields-Sommers Under Graduate Honors Thesis in Milan, Michigan April 2011 Site 2 also had a large portion of overhanging (60%) and emergent vegetation (60%) and was one of the shallowest sites (about 50 cm deep). It had straight, steep banks that appeared to have been altered for flood prevention. The silt substrate was nearly completely covered in undecomposed leaves and there was such limited habitat variation that sampling was ended 15 minutes early. Site 3 on the other hand, had a high variety of habitats including backwater, overhanging vegetation, and log pieces (Table 3). Site 4, along with being the only site to have sandy substrate, had even more habitat variety than site 3 with backwater, undercut bank, overhanging vegetation, leaf packs and it was the only site with riffles (Table 3). The channel at site 5, like site 2, was filled with undecomposed leaves, that mostly covered the edges of the channel and an island in the middle. This site also had undercut banks, submerged vegetation, overhanging vegetation and log pieces (Table 3). Site 6, 7 and 8 were larger and were perennial. Site 6 had the most diverse habitats of the river sites, but also contained garbage such as sharp pieces of metal and buckets. Site 7 was surrounded by woods and site 8 was next to a subdivision. Stream Morphology Overall, average velocity and average depth were lower at all sites in 2010 than 2002 but not significantly different (Table 2, Table 6). In the NB of Amos Palmer Drain depth significantly decreased by 0.16 m from 0.24 m, velocity significantly decreased by almost half from 0.24 m/s to 0.16 m/s, and discharge was drastically reduced from 0.36 m3/s to 0.002 m3/s from 2002 to 2010. The flow of previous years was artificially high from London Aggregates’ additional load of limestone wash, which was four to five times above their permitted discharge (Gearheart, 2010). 10