The Nature Conservancy's Emiquon Nature Preserve Fish and Aquatic Vegetation Monitoring Annual Report

Key Ecological Attributes (KEA’s) for thefish and aquatic vegetation communities are used toevaluate theprogressof the restoration efforts at Thompson and Flag lakes of The Nature Conservancy’s Emiquon Nature Preserve.A total of 19 KEA criteria were monitored monthlybetween 4/21/2015-10/23/2015. Of thosecriteria set by the Emiquon Science Advisory Council, 15were met in 2015. The 2015water transparency values were within the desired range (Secchi depths no less than half the maximum water depth when a site is ≤1.5 m deep). However, when 2015results are compared to 2014, we see that the mean monthly transparencies for April-May were lowerthan the same period in 2014. In contrast,transparencies between June-Octoberwere higherthan the corresponding in 2014. Thus,while KEA criteria are being met, there is still room for improvement.The aquatic vegetation community in 2015 continued to be dominated by native aquatic plant species.Despite the dominance by natives, twoinvasive aquatic plants-Eurasian watermilfoilandcurly-leaf pondweedwere among the species collected in 2015.Eurasian watermilfoil and curly-leaf pondweed, while still not dominant,were found at moresites and at a higherdensity than in 2014.An invasive submersed aquatic vegetation species known as Egeria was collected for the first time in 2014 since restoration but was not observed or collectedin 2015.If this increase in densityof these non-natives is an on-going trend, then consideration may need to be given on how to manage theseinvasive plants.The fish community in 2015continuedto be dominated byan increasing number of native species. Despite this, the KEA goal of collecting ≥25 native fish species was not met.Bluegilldominated our catches in 2015whilecatchesof other desirable native fishes including freshwater drum, grass pickerel, and longnose gar were presentbut lowin numbers. Despite the low numbers of thesenative fishes, these were still the highest catches for these species ever observed at the Emiquon Preserve.Of the 21fish species collectedin 2015,only one non-native speciesconsisting of the common carpwas collected. Total common carp catchwas lower than 2014catches and wasthe lowest catch of this species since restoration.The Nature Conservancyunpublishednot peer reviewe

Fish and aquatic vegetation response to different flood regimes at The Nature Conservancy’s Emiquon and Merwin Preserves: Implications for floodplain connection

On April 25, 2013, the Merwin Preserve levee (99% at 446 ft asl) was overtopped at 447.52 ft asl which matched the historic river stage crest (447.52 ft asl) for the La Grange reach of the Illinois River in 1995. Once overtopped, the Merwin Preserve levee failed and the property filled within hours. The river stage continued to rise and crested at 448.04 ft asl on April 27, 2013, which was 0.52 ft higher than the former 1995 record. The only other time that the Merwin Preserve has been connected to the Illinois River was during a minor flooding event that overtopped the Merwin Preserve levee in 2002. The levee at the Emiquon Preserve, a larger TNC restored floodplain wetland upstream of the Merwin Preserve, has never had floodwater overtop its levee until 2013 when it experienced only a brief influx of river water because its levee is much higher (low spot at 451.3 ft asl and majority at 455.0 ft asl) and remained functional when breeched. The Merwin Preserve, in contrast, underwent a longer and more thorough inundation for 29 days. In addition, the legal requirement to move the water back out of the Merwin Preserve after the river returned to normal stage meant that another breach in the levee closer to the river had to be intentionally created. The levee failure and subsequent planned breeching allowed for the exchange of nutrients and organisms between the river and the Merwin Preserve. Because the goal of these projects is “to restore floodplain native plant and animal communities and to reconnect them to the Illinois River to allow movements of aquatic organisms”, it is important to consider how extreme, but infrequent flood events could potentially impact the dynamics of these and other floodplain restoration projects. Thus, the fish and aquatic vegetation monitoring conducted annually at the Emiquon Preserve was extended to the Merwin Preserve, following the historic spring flood in 2013to better understand how fish and aquatic vegetation respond to natural flood events and river connection within recently restored floodplain projects.University of Illinois at SpringfieldNational Science Foundationunpublishednot peer reviewe

Estimating population size of largemouth bass and black crappie at The Nature Conservancy's Emiquon Preserve prior to reconnection to the Illinois River

Prior to completion of the water control structure at The Nature Conservancy’s Emiquon Nature Preserve (Emiquon), a mark-recapture study was conducted on largemouth bass Micropterus salmoides and black crappie Pomoxis nigromaculatus to estimate the populations of both species. Largemouth bass > 150 mm and black crappie > 100 mm were captured using pulsed-DC electrofishing, fyke nets, and tandem fyke nets and double tagged using T-bar style clear tags. Results of this study show very large populations of both species, with populations of largemouth bass estimated at 21,090 (17,110-27,484) and black crappie estimated at 205,042 (91,198-490,563). Information gained in this study will allow Nature Conservancy managers to make informed decisions on future management actions and allow for potential evaluation of those management actions on two major components of the recreational fishery at Emiquon.Ope

The Nature Conservancy's Emiquon Preserve: Fish and Aquatic Vegetation Monitoring Annual Report

Key Ecological Attributes (KEA’s) for the fish and aquatic vegetation communities have been identified as indicators of the condition and success of the restoration efforts at Thompson and Flag lakes of The Nature Conservancy’s Emiquon Preserve. A total of 19 KEA criteria related to the aquatic vegetation and fish communities were monitored monthly between 4/15/2013-10/25/2013. Of those goals set by the Emiquon Science Advisory Council, 15 were met in 2013. The 2013 water transparency values were within the desired range (Secchi depths no less than half the maximum water depth when a site is ≤1.5 m deep). When 2013 results are compared to 2012, we see that the mean monthly transparencies for April-May were less than the same period in 2012 and transparencies during June-October in 2013 were greater than the corresponding in 2012. Two invasive aquatic plants (i.e. Eurasian watermilfoil and curly-leaf pondweed) were among the many aquatic plant species collected in 2013. Eurasian watermilfoil was found at fewer sites and at a lower density than in 2012. Curly-leaf pondweed was also collected at fewer sites than in 2012, but at the same density during both years. Aquatic vegetation monitoring in 2013 represents the first year since monitoring began that Eurasian watermilfoil rake densities displayed a reduced density. Invasive aquatic plant species will continue to be monitored closely.The fish community in 2013 continued to be dominated by native species. Despite this, the KEA goal of collecting ≥25 native fish species was not met. More time may be needed for less abundant species to become established and/or additional stocking may be necessary in order to meet this goal. Gizzard shad dominated our catches in 2013. Catches of desirable native fishes including bowfin and shortnose gar were the highest ever observed at the Emiquon Preserve. Of the 19 fish species collected, only one non-native species, the common carp was collected and will continue to be monitored closely.The Nature Conservancyunpublishednot peer reviewe

The Nature Conservancy's Merwin Preserve: Fish and Aquatic Vegetation Monitoring Annual Report

Our preliminary results may reveal short/long term responses between the aquatic vegetation and fish communities at the Merwin Preserve in 2013 due to major flooding impacts. Data analysis will soon allow us to identify what these responses are which will allow us to better understand how a large disconnected floodplain like the Merwin Preserve and Emiquon Preserve will respond when it is connected to the Illinois River. The knowledge gained will be invaluable for future floodplain restoration projectsThe Nature Conservancyunpublishednot peer reviewe

The Nature Conservancy's Emiquon Preserve: Fish and Aquatic Vegetation Monitoring Annual Report SERIES INHS 2015 (2)

Key Ecological Attributes (KEA’s) for the fish and aquatic vegetation communities have been identified as indicators to evaluate the progress of the restoration efforts at Thompson and Flag lakes of The Nature Conservancy’s Emiquon Preserve. A total of 19 KEA criteria related to the aquatic vegetation and fish communities were monitored monthly between 4/15/2014-10/23/2014. Of those goals set by the Emiquon Science Advisory Council, 15 were met in 2014. The 2014 water transparency values were within the desired range (Secchi depths no less than half the maximum water depth when a site is ≤1.5 m deep). Moreover, when 2014 results are compared to 2013, we see that the mean monthly transparencies for April-May were greater than the same period in 2013 and transparencies during June-October in 2014 were also greater than the corresponding in 2013. Three invasive aquatic plants including Eurasian watermilfoil, curly-leaf pondweed, and Egeria were among the many aquatic plant species collected in 2014. Eurasian watermilfoil was found at more sites and at a higher density than in 2013. Curly-leaf pondweed was collected at fewer sites and at a lower density than in 2013. Aquatic vegetation monitoring in 2014 represents the first year since monitoring began that non-native submersed aquatic vegetation species known as Egeria has been observed or collected. Invasive aquatic plant species will continue to be monitored closely in 2015.The fish community in 2014 continued to be dominated by native species. Despite this, the KEA goal of collecting ≥25 native fish species was not met. However, native species richness continues to increase since restoration began. Perhaps more time may be needed for less abundant species to become established and/or additional stocking may be necessary in order to meet this goal. Bluegill dominated our catches in 2014 andcatches of other desirable native fishes including spotted gar and shortnose gar were the highest ever observed at the Emiquon Preserve. Of the 21 fish species collected, only one non-native species, the common carp including one hybrid was collected and the total catch of this species in 2014 was much lower than in 2013. Also, no young-of-the-year (YOY) common carp were observed or collected in 2014. Invasive fish species will continue to be monitored closely in 2015.The Nature Conservancyunpublishednot peer reviewe

The Nature Conservancy's Emiquon Preserve: Fish and Aquatic Vegetation Monitoring Annual Report SERIES INHS 2015 (2)

The Nature Conservancyunpublishednot peer reviewe

The Nature Conservancy's Emiquon Preserve: Fish and Aquatic Vegetation Monitoring 6-year (2007-2012) Report

A revised version of Key Ecological Attributes (KEAs) developed in 2006 for fish and aquatic vegetation communities at Thompson and Flag lakes of The Nature Conservancy’s Emiquon Preserve were assessed during 2007-2012. Of 19 relevant KEAs, 13were evaluated in 2007, 15 in 2008, 16 in 2009, 15 in 2010, 18 in 2011, and 16 in 2012 through standardized monitoring of the fish and aquatic vegetation communities. Of the total KEAs evaluated during 2007-2012, goals for 9 were met in 2007, 12 in 2008, 12 in 2009, 11 in 2010, 12 in 2011, and 11 in 2012. Secchi disc transparencies collected monthly (April-October) at three fixed Secchi sites (north YSI pole, pumphouse ditch mouth, pumphouse) and two fixed pelagic fish sites (tandem fyke, tandem mini-fyke)decreased during 2008-2012 indicating reduced water clarity overtime. Two invasive aquatic plant species (i.e., Eurasian watermilfoil and curly-leaf pondweed) were collected during 2008-2012. Eurasian watermilfoil dominated the aquatic vegetation community in 2012in that it was collected at more sites, at a higher density than any other species, and at a higher density than previous years(i.e.,rake densities were higher than any other aquatic plant species rake density or percent cover). In contrast, curly-leaf pondweed was collected at fewer sites and at a lower density in 2012 than previous years. Invasive aquatic plant species will continue to be monitored closely.The fish community collections were dominated by native species during 2007-2012. Despite this, the KEA goal of collecting ≥25 native fish species has not been met. Additional stocking efforts and more time may be needed for less abundant species to become established in order to meet this goal. Also, a planned reconnection to the Illinois River may establish more native species. Catch rates of native fishes including largemouth bass, bowfin, spotted gar, longnose gar, gizzard shad, golden shiner, and the threatened starhead topminnow were the highest ever observed at the Emiquon Preserve during 2012. Increased catch rates of these species may be due to reduced water levels in 2012, which may have resulted in the fish community becoming more concentrated allowing for greater detectability. Gizzard shad are a preferred prey type of largemouth bass and an increased density of gizzard shad may increase organic turbidity by promoting phytoplankton growth through feces deposition and feeding on zooplankton. Gizzard shad may also be a more preferred prey type by largemouth bass compared to Lepomis spp. or invasive common carp and increased density of gizzard shad may reduce the potential for largemouth bass to control common carp establishment. Of the all fish species collected during 2007-2012, only two invasives were collected (i.e.,common carp and goldfish). Common carp catch rates increased from 2007-2011 and decreased in 2012, while goldfish catch rates have remained low. Both species have the ability to reduce water clarity through their foraging behaviors by suspending sediments and nutrients into the water column. Common carp and goldfish also have the potential to be detrimental to submersed aquatic vegetation by uprooting plants and reducing water transparency. A recent study conducted on a similar floodplain lake complex showed that high common carp density can cause a decrease in aquatic plant density and waterfowl diversity and use (Bajer et al. 2009). Invasive fish species will continue to be monitored closely.The Nature Conservancyunpublishednot peer reviewe

The Nature Conservancy's Emiquon Preserve: Fish and Aquatic Vegetation Monitoring Annual Report

Key Ecological Attributes (KEA’s) for the fish and aquatic vegetation communities at Thompson and Flag lakes of The Nature Conservancy’s Emiquon Preserve were assessed from 4/10/2012-10/29/2012. Of 18 relevant KEA’s, 13 were addressed in 2012 by aquatic vegetation and fish community monitoring. Out of 13 KEA’s addressed, 8 were met in 2012. Secchi disc transparencies taken during April-May, 2012 were always less than half the maximum water depth, while all water depths exceeded two times the Secchi disc transparencies during June-October,2012 indicating a decrease in water clarity. Also, mean Secchi disc transparencies taken during April-May decreased from 2011 to 2012, while mean Secchi disc readings from June-October were significantly greater in 2011 than in 2012 further suggesting a decrease in water clarity. Two invasive aquatic plant species including Eurasian watermilfoil and curly-leaf pondweed were collected in 2012. Eurasian watermilfoil dominated the aquatic vegetation community and was collected at more sites and at a higher density than in 2011. This suggests that it has been further propagating and is well established within Thompson and Flag lakes. Aquatic vegetation monitoring in 2012 represents the first year since monitoring began that Eurasian watermilfoil rake densities were higher than any other aquatic plant species rake density or percent cover. In contrast, curly-leaf pondweed was collected at fewer sites and at a lower density than in 2011. Invasive aquatic plant species will continue to be monitored closely.The fish community was dominated bynative species in 2012. Despite this, the KEA goal of collecting ≥25 native fish species was not met. More time may be needed for less abundant species to become established and/or additional stocking may be necessary in order to meet this goal. Golden shiner dominated our catches in 2012. Catches of desirable native fishes including largemouth bass, bowfin, spotted gar, longnose gar, golden shiner, and the threatened starhead topminnow were the highest ever observed at the Emiquon Preserve. This may be due to reduced water levels in 2012, which may have resulted in the fish community becoming more concentrated. An increase in golden shiner catches may be attributed to a successful spawn in 2012, while an increase in starhead topminnow catches may be the result of a successful spawn and/or successful stocking efforts in2012. Undesirable native fish,such as gizzard shad,increased from 2011 to 2012. While gizzard shad are an energetically favorable prey fish for largemouth bass, increased density of gizzard shad may increase turbidity by inducing phytoplankton growth through feces deposition and feeding behaviours (zooplanktivores). Gizzard shad may also be a more preferred prey type by largemouth bass compared to Lepomis spp. or invasive common carp and may reduce the potential to control common carp establishment and induce a trophic cascade. Of the 18fish species collected during 2012, only two invasives were collected including common carp and goldfish. Both have the ability to reduce water clarity through their foraging behaviors by uprooting aquatic vegetation and suspending sediments and nutrients into the water column. A recent study found that common carp can also cause a decrease in aquatic vegetation and waterfowl diversity and use (Bajer et al. 2009). Common carp catches decreased from 2011 to 2012. Goldfish catches were low and were not collected in 2011.Invasive fish species will continue to be monitored closely.The Nature Conservancy and INH

The Nature Conservancy's Emiquon Preserve Fish and Aquatic Vegetation Monitoring Annual Report

Under contract with The Nature Conservancy (TNC), fish and aquatic vegetation monitoring (2007-present) was conducted on Thompson and Flag lakes of the Emiquon Preserve by the Illinois Natural History Survey, Illinois River Biological Station (INHS-IRBS) in order to evaluate a series of key ecological attributes (KEA) relevant to restoration success.This report presents a summary of data collected in 2011.INHSunpublishednot peer reviewe