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Boulder City, WI, United States

VanMiddlesworth T.D.,University of Illinois at Urbana - Champaign | McClelland N.N.,Havana Field Office | Sass G.G.,Escanaba Lake Research Station | Casper A.F.,University of Illinois at Urbana - Champaign | And 2 more authors.
Hydrobiologia | Year: 2016

Biomanipulation, or management actions aimed to structure biological communities to achieve certain goals, has often been used in the restoration of aquatic ecosystems. In 2000, The Nature Conservancy acquired the Emiquon Preserve, which included two former Illinois River floodplain lakes, to restore these ecosystems. Restoration included stocking to establish a native fish community commensurate with historical records. Largemouth bass (Micropterus salmoides, bass) were also introduced to control poor water clarity and invasive common carp (Cyprinus carpio, carp). We summarized fish community characteristics and tested whether bass contributed to water clarity maintenance and limited carp during 2007–2014. The fish community was dominated by species stocked in greatest abundance, 13 of 32 species initially stocked have not been collected, and species diversity increased. No carp were observed in bass diets, water clarity declined significantly, and carp relative abundance increased. Increasing water levels during 2008–2009 diffused bass predation potential upon zooplanktivorous fishes and carp and weakened potential trophic cascading interactions. Our findings suggest that water level management, greater stocking of piscivores to maintain predator densities, prevention of gizzard shad (Dorosoma cepedianum) introduction, and/or a more diverse fish community including other native piscivores may be required to achieve long-term restoration goals. © 2016 Springer International Publishing Switzerland Source

Lamer J.T.,Western Illinois University | Sass G.G.,Escanaba Lake Research Station | Boone J.Q.,Floragenex Inc. | Arbieva Z.H.,University of Illinois at Chicago | And 2 more authors.
Molecular Ecology Resources | Year: 2014

Bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix) are invasive species and listed as US federally injurious species under the Lacy Act. They have established populations in much of the Mississippi River Basin (MRB; Mississippi, Illinois, and Missouri rivers) and are capable of producing fertile hybrids and complex introgression. Characterizing the composition of this admixture requires a large set of high-quality, evolutionarily conserved, diagnostic genetic markers to aid in the identification and management of these species in the midst of morphological ambiguity. Restriction site-associated DNA (RAD) sequencing of 45 barcoded bighead and silver carp from the United States and China produced reads that were aligned to the silver carp transcriptome yielded 261 candidate single nucleotide polymorphisms (SNPs) with fixed allelic differences between the two species. We selected the highest quality 112 SNP loci for validation using 194 putative pure-species and F1 hybrids from the MRB and putative bighead carp and silver carp pure species from China (Amur, Pearl and Yangtze rivers). Fifty SNPs were omitted due to design/amplification failure or lack of diagnostic utility. A total of 57 species-diagnostic SNPs conserved between carp species in US and Chinese rivers were identified; 32 were annotated to functional gene loci. Twenty-seven of the 181 (15%) putative pure species were identified as hybrid backcrosses after validation, including three backcrosses from the Amur River, where hybridization has not been documented previously. The 57 SNPs identified through RAD sequencing provide a diagnostic tool to detect population admixture and to identify hybrid and pure-species Asian carps in the United States and China. © 2013 John Wiley & Sons Ltd. Source

McClell M.A.,University of Illinois at Urbana - Champaign | Sass G.G.,University of Illinois at Urbana - Champaign | Sass G.G.,Escanaba Lake Research Station
Journal of Freshwater Ecology | Year: 2012

The fish assemblage of the Illinois River is monitored annually through a long-term electrofishing (LTEF) program. Through the LTEF program, fish species composition and abundances are examined in six navigation reaches using a fixed site sampling design. We added a series of random sites to the LTEF sampling program in 2005 and 2007 to supplement current monitoring efforts. We used random and fixed site samples to assess fish species richness, relative abundance, and species-specific contributions to catches. We collected 17,537 fish from both sampling designs. Total fish and mean catch per hour was greater for fixed sampling (10,221 and 379.1, respectively) compared to random sampling (7316 and 259.6, respectively). Total fish species richness was 70, with 63 and 62 species collected through fixed and random samplings, respectively. Fish species diversity and evenness was greater for fixed site sampling. Eight fish species were unique to the fixed site design with seven fish species unique to random sampling. Fish assemblage analyses showed that catches for each sampling design contained a similar base set of species. Our results suggest that the goals of specific long-term monitoring programs may dictate the sampling method to be used. Whereas fixed site sampling may be biased toward potentially more and a greater diversity of fishes, random site selection will be unbiased and may provide greater spatial coverage. © 2012 Taylor & Francis. Source

Liss S.A.,University of Illinois at Urbana - Champaign | Lamer J.T.,University of Illinois at Urbana - Champaign | Sass G.G.,Escanaba Lake Research Station | Suski C.D.,University of Illinois at Urbana - Champaign
Journal of Freshwater Ecology | Year: 2016

Hybridization can influence a range of characteristics and outcomes for an organism; however, relatively little is known about evolutionary consequences on nutritional performance. Information on hybrid nutritional performance would provide an understanding of how hybrids interact with their environment and insights into mechanisms affecting survival. Our goal was to test for relationships between hybridization and nutritional performance in invasive bigheaded carps (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), and their hybrids in the Marseilles reach of the Illinois River, Illinois, USA. Silver carp showed better nutritional performance relative to bighead carp. Early generation bighead and silver carp hybrid groups were intermediate to both parental lines, thereby, reducing their nutritional performance, and advanced generation bighead and silver carp groups were nutritionally more similar to their respective parental species. Differences in gill raker morphology and feeding habits among bigheaded carps and their hybrids are plausible mechanisms explaining observed nutritional performance patterns. In addition to providing unique insights about how hybridization influences the nutritional performance of wild organisms relative to parentals, our findings may have management implications for bigheaded carps if interbreeding persists over time and reduced nutritional performance is further manifested by continued hybridization. © 2016 Informa UK Limited, trading as Taylor & Francis Group Source

Gaeta J.W.,University of Wisconsin - Madison | Sass G.G.,Escanaba Lake Research Station | Carpenter S.R.,University of Wisconsin - Madison
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2014

Research testing for the effects of climate change on lentic fishes has focused on changing thermal and dissolved oxygen regimes, but has often overlooked potential influences of altered lake levels on littoral habitat availability and species interactions. Natural littoral structures such as coarse woody habitat (CWH) can be critical to fishes for prey production, refuge, and spawning. Drought-driven lake level declines may strand these structures above the waterline and thereby remove them from littoral zones. A prolonged drought in northern Wisconsin, USA, allowed us to test for effects of lake level decline on CWH and the response of a fish community. During our study (2001-2009), the lake level of Little Rock Lake South declined over 1.1m and >75% of the previously submerged CWH was lost from the littoral zone. The loss of CWH coincided with the forage fish species (yellow perch, Perca flavescens) falling below detection and reduced growth of the top piscivore (largemouth bass, Micropterus salmoides). Our study highlights the importance of lake level fluctuations as a mechanism by which climate change may affect aquatic ecosystems and species interactions. Source

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