Illinois Natural History Survey 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.