True metabolizable energy of submersed aquatic vegetation in semi-permanent marshes for dabbling ducks in the Upper Midwest Final Report Period: 1 July 2015 – 30 June 2018

Joseph D. Lancaster, Aaron P. Yetter, Heath M. Hagy, Margaret C. Gross, Sarah E. McClain, John W. Simpson, Christopher N. Jacques

Research output: Book/ReportTechnical report

Abstract

We completed 186 TME assays with mallards (n = 72) and gadwall (n = 114) between 2015 and 2018. Bioavailable energy (i.e., TME) of submersed aquatic vegetation was highly variable among duck and vegetation species as supported by their interaction in the most parsimonious model (wi = 0.42; R2m = 0.33, R2c = 0.47). For gadwall, mean TME (± SE; kcal/g[dry]) was greatest for Eurasian watermilfoil (0.77 ± 0.32, n = 19), followed by Canadian waterweed (0.70 ± 0.31, n = 20), coontail (0.55 ± 0.28, n = 18), southern naiad (–0.61 ± 0.34, n = 17), wild celery (–0.98 ± 0.39, n = 20), sago pondweed (–1.07 ± 0.33, n = 20). Mallards assimilated greatest energy from Canadian waterweed (1.66 ± 0.26, n = 13), followed by coontail (1.51 ± 0.28, n = 8), southern naiad (1.37 ± 0.39, n = 14), sago pondweed (0.50 ± 0.22, n = 14), wild celery (0.05 ± 0.42, n = 11), and Eurasian watermilfoil (–0.13 ± 0.26, n = 12). There was evidence from a competing model (wi = 0.11; R2m = 0.34, R2c = 0.47) that females acquired 0.52 kcal/g (± 0.34) more energy from vegetation than males and that TME declined 0.20 kcal/g (± 0.16) for every 100 g increase in initial mass. We estimated energetic carrying capacity at 318 random points within 20 wetlands across three years (2015–2017) in the Midwest, USA (Simpson et al. 2017). Across all points, Ceratophyllum spp. was the most commonly encountered genera (n = 188) of submersed aquatic vegetation, followed by Myriophyllum spp. (n = 64), Najas spp. (n = 47), Elodea spp. (n = 41), and Stuckenia spp. (n = 36). These five genera comprised 91.5% of the total energy density across all points and years. Extrapolated energy density estimated at sample points ranged from 0 to 5,624 EUD/ha (푥푥̅ = 426 ± 52) and biomass estimates ranged from 0 to 2,340 kg/ha (dry) (푥푥̅ = 204 ± 22). Evidenced from the best supported model (wi = 0.68; R2m = 0.19, R2c = 0.27), energy density was 195 EUD/ha (85% CI = 39 – 964) greater at managed points than unmanaged points, decreased 2 EUD/ha (85% CI = 1 – 3) for every 100 cm increase in water depth, increased 9 EUD/ha (85% CI = 6 – 12) for every 100 cm increase in Secchi depth, and increased 3 EUD/ha (85% CI = 0 – 11) if emergent vegetation was present.
Original languageEnglish (US)
PublisherIllinois Natural History Survey
Commissioning body Upper Mississippi River and Great Lakes Joint Venture U.S. Fish and Wildlife Service, Region 3, Contract Number F15AP00687
Number of pages32
StatePublished - Dec 21 2018

Publication series

NameINHS Technical Report
No.2018 (42)

Keywords

  • INHS

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    Lancaster, J. D., Yetter, A. P., Hagy, H. M., Gross, M. C., McClain, S. E., Simpson, J. W., & Jacques, C. N. (2018). True metabolizable energy of submersed aquatic vegetation in semi-permanent marshes for dabbling ducks in the Upper Midwest Final Report Period: 1 July 2015 – 30 June 2018. (INHS Technical Report ; No. 2018 (42)). Illinois Natural History Survey.