10th Annual Emiquon Science Symposium

Conference AttendeesThe following abstracts and posters were presented at the 10th Annual Emiquon Science Symposium held May 18-19, 2016. The symposium consisted of a field-trip across Thompson Lake to the water control structure, a poster session, and several break-out sessions devoted to identifying and prioritizing research questions.

Poster Abstracts

Estimating Population Size of Select Indicator Fishes at The Nature Conservancy’s Emiquon Nature Preserve Prior to Illinois River Reconnection (.pdf)

Todd D. VanMiddlesworth, Jason A. Deboer, Andrea K. Fritts, Mark W. Fritts, Doyn M. Kellerhals, Richard M. Pendleton, Levi E. Solomon, and Andrew F. Casper

Abstract: Largemouth Bass Micropterus salmoides and Black Crappie Pomoxis nigromaculatus are popular sportfish species, making their study and management a priority for many natural resource agencies and organizations. These species can be used as bioindicators of the relative quality of aquatic habitats, making them an invaluable resource for both managers and researchers assessing the effects of natural and anthropogenic disturbance in aquatic systems. As such, the Upper Mississippi River Restoration program has labeled both species indicators of ecosystem health, and the Illinois Department of Natural Resources monitors these species in lakes and reservoirs throughout the state, including a large disconnected floodplain restoration project known as The Nature Conservancy’s (TNC) Emiquon Nature Preserve. Emiquon has been disconnected from the Illinois River since the early 1900’s, drained and put into agricultural production until 2000, and then restored back to a floodplain lake beginning in 2007. TNC began construction of a water control structure in 2015 that will result in a managed reconnection with the Illinois River. The objective of this research was to establish pre-reconnection population estimates for Largemouth Bass and Black Crappie to benefit TNC managers by allowing them to more precisely evaluate the status of sportfish populations within the Emiquon Preserve. These data will allow for post-reconnection comparisons with the Illinois River and subsequent water level management.


Detection and Disturbance Rates of Waterfowl During Aerial Surveys (.pdf)

Andrew D. Gilbert, Heath M. Hagy, Aaron P. Yetter and Christopher N. Jacques

Abstract: Aerial surveys of waterfowl have been conducted in the Illinois and Mississippi River floodplains since 1948. These traditional surveys provide an index of waterfowl population size and are used to track migration events, set harvest regulations, and for research purposes. New methods are being evaluated to estimate population size by randomizing survey locations and estimating detection probabilities. We used double sampling to determine a correction factor for waterfowl estimates during fall aerial surveys. Immediately before an aerial survey, a ground observer conducted an intensive survey of waterfowl in predetermined locations from an elevated, unobstructed location where probability of detection was assumed to be 100%. Aerial counts were divided by ground counts for all common species and foraging guilds to determine detection probability. Preliminary results indicate that mean detection rate for all waterfowl was 96.0% (SE=7.1). Mean detection rate was 94.4% (SE=8.2) for ducks, 105.2% (SE=11.0) for dabbling ducks, 74.8% (SE=10.5) for diving ducks, 53.3% (SE=7.5) for mergansers, and 92.4% (SE=8.6) for geese. While conducting ground surveys, observers also documented any disturbance to waterfowl caused by aerial surveys. Our preliminary findings indicated that on average 18.4% (SE=2.4) of waterfowl, 12.2% (SE=2.1) of ducks, 11.5% (SE=2.1) of dabbling ducks, 4.5% (SE=1.4) of diving ducks, 13.0% (SE=2.6) of mergansers, and 28.6% (SE=4.0) of geese exhibited a negative response (i.e., flew short distances, swam away, changed behavior significantly) to aerial surveys. Our preliminary findings indicated that on average 5.5% (SE=1.6) of waterfowl, 2.0% (SE=1.0) of ducks, 1.2% (SE=0.8) of dabbling ducks, 0.7% (SE=0.4) of diving ducks, 4.3% (SE=1.4) of mergansers, and 15.1% (SE=3.0) of geese abandoned the survey site and did not return following aerial surveys. With our findings, traditional aerial surveys conducted in the Mississippi and Illinois River floodplains can be used to minimize bias in population estimates associated with aerial survey techniques.


Breeding Ecology of Waterbirds in a Restored Floodplain of the Illinois River (.pdf)

Andrew D. Gilbert, Heath M. Hagy and Ben O’Neal

The Nature Conservancy’s Emiquon Preserve is the most substantial floodplain restoration effort to date in the region, directly restoring, enhancing, and protecting >2,700 ha of former floodplain wetlands and associated uplands in the central Illinois River valley. The restoration has provided critical nesting habitat for many waterbird species, including species of conservation concern such as least bittern, black-crowned night heron and common gallinule. Since 2013, nest searches have been conducted in two distinct wetland vegetation communities, 1) dense emergent and 2) hemi-marsh vegetation. Researchers have evaluated nest density, nest success, and nesting characteristics of marsh birds during June and July of each year. Nest density in hemi-marsh vegetation in 2015 was 0.38 nests/ha resulting in an estimated total of 52 nests, compared to the three year average of 0.78 nests/ha and an estimated total of 105 nests. Nest density in dense emergent vegetation in 2015 was 1.20 nests/ha resulting in an estimated total of 162 nests, compared to the three year average of 0.98 nests/ha and an estimated total of 225 nests. Average nest survival in 2015 was 45% in hemi-marsh and 53% in dense emergent vegetation, compared the three year average of 53% and 58% respectively. Nest density and survival has apparently declined since 2013 and valuable dense emergent vegetation is rapidly declining due to sustained high water levels. During the summer of 2016, with the completion of a new water control structure, Emiquon Preserve will restore water exchange between the floodplain and the Illinois River for the first time since restoration. Vegetation and waterbird communities may have delayed responses to river-floodplain connection and repeated adaptive research will allow researchers to adaptively manage and improve Emiquon Preserve following reconnection using nesting waterbirds as an environmental indicator and sentinel of wetland quality.


Can Geographic Ranges Predict Seedling Success In Tallgrass Prairie Restorations? (.pdf)

David Seidel, Jacob Sherell, Grace Kennedy, and Amy McEuen

Species have dramatically shifted their ranges in response to past global climate changes. Such range shifts may be prevented under current climate change scenarios due to landscape fragmentation and rapid rates of change. Restoration ecologists must choose species to add to restoration sites which is becoming increasingly challenging as current environmental conditions differ strongly from the past. We tested whether species with more northerly distributions were harder to establish through seedling additions compared to species with more southerly distributions. Our study was conducted in the restored tallgrass prairie on the Nature Conservancy’s Emiquon Preserve in central IL during the months of May through August 2015. Six species that failed to establish from the original seed mixture were chosen: three northern species (Agastache foeniculum, Oligoneuron ohioense, and Heuchera richardsonii) on the southern edge of their distribution, and three southern species (Conoclinium coelestinum, Eryngium yuccifolium, and Parthenium integrifolium). Seedling addition areas were established in two different prairies with each site receiving 216 seedlings (36 of each species). We measured survival, growth, and flowering every two to three weeks throughout the growing season. When the Illinois River overtopped the levee in June, one of our seed addition sites was partially flooded and we measured flooding depth for each seedling. We will discuss initial patterns of survival and growth for the first field season and their relationship to flooding, geographic range, and species habitat preferences.


Innovative Conservation Planning and Implementation in Tile-Drained Drinking Water Supply Subwatersheds of the Mackinaw River, Illinois (.pdf)

Krista Kirkham, A. R. Maybanks, A. M. Lemke, M. Day, D. A. Kovacic, M. P. Wallace, K. L. Bohnhoff, J. R. Kraft, A. T. Noto, and R. M. Twait

In 2010, The Nature Conservancy and partners began a new watershed project to demonstrate the effectiveness and cost-benefits of using constructed wetlands and nitrogen management to reduce nitrate loadings to local drinking water that supplies the City of Bloomington, Illinois. Data from GIS, LiDAR topography, soils maps, and aerial infrared photography were used to develop a watershed drainage tile map that helps to guide outreach, implementation, and monitoring of conservation practices. An integrated outreach team comprised of stakeholders and local conservation agencies provide targeted and broad-scale outreach to landowners. To date, four constructed wetlands and several hundred acres of cropland in the watershed have been used in nitrogen management trials. During 2016-2018, three more wetlands are slated for construction, along with a planned expansion of 3000 cropland acres for nitrogen management. Wetlands are currently monitored for nitrate and dissolved phosphorus reductions in tile drainage water, and soil and corn stalk nitrogen testing is being conducted to determine optimum nitrogen application to farm fields. Outreach information will be combined with efficiency data from these conservation practices to determine the potential for nutrient reduction and the economic cost-benefit from using a watershed conservation approach to treat nonpoint source runoff. Collectively, this research will provide a conservation blueprint to the City of Bloomington for planning and development of sustainable funding for watershed conservation.


Rates of Endocrine Disruption in Two Commercial Fishes Along a Downstream Gradient in the Illinois River (.pdf)

Madeleine M. VanMiddlesworth, Andrew F. Casper, Jason A. DeBoer, and Jeffrey M. Levengood

Endocrine-disrupting chemicals can be found in high concentrations in aquatic systems via point source discharges such as waste water effluent. Laboratory exposures suggest feminization of male fishes, e.g. intersex condition and presence of female-specific lipoprotein, vitellogenin (VTG). Field assessments of feral fishes may provide insight into the extent of endocrine disruption within a system. The Illinois River has a notable history of pollution through urbanization. We explored patterns of intersex and VTG levels in male gonads of common carp and channel catfish collected throughout a downstream gradient of sites. Histology identified feminization in male gonads and blood was sampled for detection of VTG in carp. Low rates of intersex were observed in testes from both fish species. Male VTG was consistently low or below detection in all sites. As declining population trends are determined in these commercial species, we should continue to examine the reproductive health of Illinois River fishes.


True Metabolizable Energy of Submersed Aquatic Vegetation for Dabbling Ducks

Sarah Vanderhorst, Heath M. Hagy and Christopher N. Jacques

Aquatic systems in the Midwest have been highly modified since the beginning of the 20th century, including channelization, damming, and dredging of most large rivers (e.g., Illinois, Mississippi, Ohio, Missouri) and disconnection from their natural floodplains with networks of levees. While the loss of submersed aquatic vegetation from hydrologically-connected wetlands and backwater lakes along the Illinois and Mississippi rivers is well-documented, information is unavailable to determine the implications of these losses on energetic carrying capacity for waterfowl, especially dabbling ducks. The objective of this study is to estimate true metabolizable energy of species of submersed aquatic vegetation common to the Upper Midwest for dabbling ducks. We conducted feeding trials using wild-strain mallards (Anas platyrhynchos) during autumn 2015. Feeding trials consist of a 48-hour fasting period followed by precision feeding of one of six species of submersed aquatic vegetation (e.g., Stuckenia pectinata, Ceratophyllum demersum) and a 48-hour period in a metabolic chamber where excreta is collected. We will estimate gross energy of test foods and excreta using a Parr adiabatic oxygen bomb calorimeter and adjust estimates for digestion efficiency to ascertain true metabolizable energy. We expect the true metabolizable energy of submersed aquatic vegetation to be less than that of seeds, tubers, and other hard mast. Our data may aide conservation planners in estimating energetic carrying capacity of semi-permanently-flooded marsh habitats and projecting impacts of wetland management alternatives such as semi-permanently-flooded marsh verses moist-soil management. It will also be useful for assessing the tradeoffs in habitat quality for dabbling ducks considering hydrologic connectivity with rivers and lakes, and as input parameters in models predicting habitat change over time or in response to stressors (e.g., climate change).


Response of Waterbirds and Wetland Vegetation Relative to Key Ecological Attributes at Emiquon Preserve, 2007-2015 (.pdf)

Christopher S. Hine, Heath M. Hagy, Aaron P. Yetter and Joshua M. Osborn

The Nature Conservancy identified key ecological attributes (KEAs) of specific biological characteristics or ecological processes to guide restoration efforts and evaluate success at Emiquon. The historic importance of the Illinois River valley to waterbirds has been well-documented. Consequently, several KEAs at Emiquon were related to waterbird communities and their habitats. Previous studies have suggested waterbird use may serve as an indicator of wetland health or a measure of restoration success. Therefore, we monitored the response of waterbirds and wetland vegetation to restoration at Emiquon during 2007-2015 to evaluate achievement of desired conditions under the relevant KEAs. Our primary efforts included assessing: 1) abundance, diversity, and behavior of waterfowl and other waterbirds through counts and observations; 2) productivity by waterfowl and other waterbirds through brood counts; 3) plant seed and invertebrate biomass as forage for waterfowl during migration and breeding periods; and 4) composition and arrangement of wetland vegetation communities through geospatial covermapping. We present annual monitoring results ranked according to desired conditions under the KEAs as a means of tracking changes in wetland conditions at Emiquon.


Common Carp Age and Growth Trends from the Illinois River (.pdf)

Ryan Ward, Madeleine VanMiddlesworth, Jason Deboer, and Rich Pendleton

The common carp was first introduced into the Illinois River in the late 1800s and has contributed substantially to the commercial fishing industry. However, by 1920 the commercial catch of carp started to show a decline and by 1950 fewer carp appeared to be reaching maturity. In 1983, the Illinois Natural History Survey (INHS) conducted an age analysis of Illinois River carp, compared them to other populations in Midwestern river systems, and attributed a young age structure and slower growth of Illinois carp to lack of food and backwater habitat. In more recent surveys, large, presumably older carp have remained present while young carp have become less prevalent, particularly in collections conducted in the Upper River closest to the Metropolitan Chicago area. This led us to explore the current age and growth trends of carp throughout the Illinois River to determine spatial and temporal differences in population structures.

We collected carp at 3 upper river sites (n=93), 7 lower river sites (n=118), and 1 reference site (n=29) at The Nature Conservancy’s (TNC) Emiquon Preserve, a restored and disconnected backwater of the Illinois River. We recorded total length (mm), weight (g), gonad weight (g), total fecundity and extracted dorsal spines for ageing. We cut the dorsal spines above the basal attachment, placed them under a dissecting microscope, and aged them utilizing side-emitting light to illuminate age rings.

This poster will highlight current spatial and temporal differences in carp population structure and will allow us to compare it to past research. Results found from comparing data may help propel future research on Illinois carp ecology and result in better management for the common carp.

Effects of Hunter Disturbance on Waterbird Distributions at Emiquon Preserve (.pdf)

Heath M. Hagy, Michelle M. Horath, Aaron P. Yetter, Christopher S. Hine, and Randolph V. Smith

Wetland restoration in highly modified landscapes involves balancing target ecosystem functions and values with constraints of landscape and stakeholder context. Often, a restored wetland complex cannot meet all target conditions simultaneously, and tradeoffs must be understood, evaluated, and quantified. We examined the tradeoff between providing migratory bird sanctuary and increasing public recreational opportunities within a restored floodplain wetland complex along the Illinois River. We surveyed the distribution and behavior of waterbirds in response to a gradient of spatial and temporal disturbances from waterbird hunting activities. Using ArcMap and spatial interpolation of waterbird densities as a novel approach to quantify sanctuary area, we estimated that approximately 42% of Emiquon Preserve functioned as sanctuary across disturbance intensities, hunter distribution, and time periods during autumn migration. Waterbird abundance did not increase with short-term temporal sanctuary or decreased hunting intensity. Disturbance distance around hunting locations was 752.1 m, overall, and increased 38.4 m for each additional hunting party. Exclusion distance around hunting locations was greater in areas with greater mean disturbance frequency. We question the effectiveness of short-term temporal sanctuary for waterbirds at the expense of recreational opportunities and advocate our analytical approach to quantify sanctuary area and disturbance buffers without experimentally causing disturbances.

The Impact of Flooding on Water Quality in Restored and Unrestored Illinois River Floodplain Lakes (.pdf)

Daniell Bennett, Alex Johnson, Keenan Dungey, and Michael Lemke

Although part of the complex ecology of dynamic flood-pulsed river systems, flooding dictates the degree of disturbance and extent of river-floodplain connection that is proportional to its duration and magnitude. In a changing landscape under river control and increased alteration, it is difficult to understand the restoration ecology and function, especially when the area is altered by flood. The objective of this analysis of historical data was to compare trends in water quality measurements in Illinois River floodplain shallow lakes that varied in the degree of flooding (i.e., disturbance) and extent of restoration. Water quality variables were compared from a restored lake with limited flooding (Thompson Lake, flood of record 2013; TL13), a restored lake that was connected to the river and flooded (Long Lake, 2013; LL13), a connected and flooded unrestored lake (Big Lake 2002; BL02) and a restored lake on the floodplain that did not flood (LL02). A high concentration of ammonia accompanied flooding in the unrestored floodplain lakes, with no effect in lakes minimally connected to the river. BL02 increased in ammonia after the flood likely due to algal decomposition. Nitrate increased with the flood pulse in connected lakes (BL02, LL13), then decreased to low levels three months post-flood. It appears that nitrate contributed to algal growth given the three month post-flood increase in chlorophyll a in BL02 and LL13. It seems that the river connection is a greater influence on the biotic response of these shallow lakes than is the state of their restoration.

The Evaluation of a Cost-Effective, Digital Approach to Estimate Fecundity in Freshwater Fishes (.pdf)

Rich Pendleton, Andrew Casper, Jason DeBoer, Andrea Fritts, Mark Fritts, Nikolai Klibansky, Levi Solomon, and T.D. VanMiddlesworth

Determining the basic life-history of organisms enhances our ecological understanding and ability to conserve or manage species. However, oftentimes the resources and time needed to document expression of life-history traits can hinder our ability to understand the ecology of a species. Studies of species reproductive traits, such as fecundity, inform researchers and managers of the reproductive potential of a species and offer insight into population dynamics. However, traditional manual counting methods of estimating fecundity in fishes can be costly and laborious. Using methodology developed for marine fishes, we evaluate a cost-effective, automated approach to estimate fecundity using free ImageJ software to determine the validity and accuracy of automated estimates relative to manual count estimates within freshwater systems. We collected three freshwater fishes within an environmentally heterogeneous watershed to determine if estimation methodology (automated vs. manual counts) is influenced by species, size of individual, or location. Strong correlations between methods existed for medium- to large-sized bluegill and largemouth bass, however, little to no correlation existed between the methods for black crappie. Location influenced the strength of the relationship between counting methods, but was predominately an artifact of the size of individuals collected within each location. Currently, automated methodology provides a quicker and relatively accurate way to estimate fecundity for bluegill and largemouth bass, yet refinements must be made to account for smaller individuals and potential differences in ovary physiology and/or egg development among species.