SEDIMENTATION IN LAKE ONALASKA, NAVIGATION POOL 7, UPPER MISSISSIPPI RIVER, SINCE IMPOUNDMENT<sup>1</sup>

Korschgen, Carl E.; Jackson, Gerry A.; Muessig, Laura F.; Southworth, Deborah C.

doi:10.1111/j.1752-1688.1987.tb00799.x

Cited by 10 publications

(3 citation statements)

References 3 publications

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“…These backwater habitats vary in flushing rate, temperature, turbidity, nutrient availability, water depth, and vegetative cover (De Jager & Houser, 2012; Houser et al, 2013) and are critical for limnophilic organisms both as refugia from high water velocity and as reproductive areas (Giblin, 2017; Rutledge, Hupfeld, Gainer, Kim, & Phelps, 2020). Backwaters are essential for fisheries nursery habitat (Sheaffer & Nickum, 1986), fisheries overwintering habitat (Knights, Johnson, & Sandheinrich, 1995), sediment and nutrient assimilation (James, Richardson, & Soballe, 2008), aquatic vegetation production (Burdis, DeLain, Lund, Moore, & Popp, 2020), zooplankton production (Burdis & Hoxmeier, 2011), mussel habitat (Tucker & Atwood, 1995), and waterfowl habitat (Korschgen, Jackson, Muessig, & Southworth, 1987).…”

Section: Introductionmentioning

confidence: 99%

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Giblin

Larson

King

2022

River Research & Apps

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High densities of cyanobacteria in aquatic ecosystems can cause impacts to ecosystem services because they serve as a poor-quality food resource, produce toxins and can indirectly cause a variety of other negative impacts to water quality. There are many hypotheses about the potential environmental drivers of variation in cyanobacterial abundance and toxicity, but these hypotheses have rarely been considered in combination and rarely been examined in large river ecosystems. Here, we use monthly data from backwater habitats of the Upper Mississippi River (UMR) to evaluate associations between environmental conditions and cyanobacterial abundance and toxicity (microcystin and anatoxin-a) that would be expected based on several hypotheses. Backwaters in the Mississippi River vary in flushing rate, temperature, turbidity, nutrient availability, water depth, and vegetative cover. We find support for hypotheses that suggest physical conditions in backwaters (flushing rate, temperature, turbidity, rooted vegetation cover, and water depth) and nutrient availability influence cyanobacterial abundance and toxicity. We then used structural equation modeling to incorporate several hypotheses into a causal modeling framework, which indicated that backwater connectivity (flushing) strongly influences cyanobacterial abundance via the regulation of water temperature, and that nutrient availability strongly influences the presence of microcystin concentrations above our detection limit. Our data suggest that management of backwater connectivity could influence cyanobacterial abundance and toxicity in UMR backwaters.Reconnecting backwaters (via alteration of levees) could serve as a local adaptation to minimize the effects of climate change and excessive nutrient loading.

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Section: Introductionmentioning

confidence: 99%

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Giblin

Larson

King

2022

River Research & Apps

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“…Estimates of sedimentation rates in backwater areas are variable, averaging ca. 1-4 cm/year (Eckblad et al, 1977;McHenry et al, 1984;Fischer and Claflin, 1995), though other studies suggest sedimentation rates may be somewhat lower (Korschgen et al, 1987;Rogala and Boma, 1996). The presence (or absence) of plant community succession in UMR backwaters has not been well studied, but in some areas sediment accumulation has resulted in progressive loss of open water and an increase in emergent and terrestrial vegetation (Bhowmik and Adams, 1989;Tazik et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

Changes in backwater plant communities from 1975 to 1995 in Navigation Pool 8, Upper Mississippi River

Tyser

Rogers

Owens

et al. 2001

Regul. Rivers: Res. Mgmt.

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Water elevation in the Upper Mississippi River (UMR) is highly regulated by an extensive system of locks and dams. Completion of this system in the 1930s created productive, biologically diverse backwater habitats. The status of plant communities in these backwater areas may now be threatened by several factors, including sediment accumulation, recreational use, and navigation traffic. Aerial photography, taken in 1975 and from 1991 to 1995, was used to describe vegetation changes occurring in four UMR backwater areas of Navigation Pool 8. The objectives were to determine (1) if changes occurring in these areas are consistent with hydrarch succession, (2) if the diversity of their plant communities has declined since 1975, and (3) how a large flood event that occurred in 1993 affected the composition and diversity of plant communities in these areas. Three general cover classes were recognized, representing an aquatic to terrestrial gradient. Coverages of specific vegetation types were estimated and evaluated using two indices of community diversity (vegetation richness and the Shannon diversity index). Though some vegetation changes were consistent with expected successional patterns (e.g. increased terrestrialization), other changes were not (e.g. loss of marsh vegetation). Diversity indices and coverages of most aquatic macrophytes declined from 1975 to 1991/1992 but then increased following the 1993 flood. The results suggest that disturbance-diversity concepts, including the flood pulse model, are applicable to the vegetation dynamics of these systems. Published in

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“…1) River, inundated in 1937 during the construction of a 9-foot (2.7 m) navigation channel and associated locks and dams (Korschgen et al 1987b). Water flows into the lake through two chutes from the Mississippi River channel running along the west side of the lake; from the southern chute, Sommer's chute, the lake may receive up to 80% of its water (Pavlou et al 1982).…”

Section: Study Areamentioning

confidence: 99%

The distribution of Vallisneria americana seeds and seedling light requirements in the Upper Mississippi River

Kimber¹,

Korschgen²,

Valk³

1995

Can. J. Bot.

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Vallisneria americana declined in backwaters of the Upper Mississippi River, U.S.A., after a drought in 1988. To determine whether viable seeds of V. americana occurred in the seed bank of navigation pool 7, Lake Onalaska, the upper 5 cm of sediment was collected from 103 sites in May 1990. These sediment samples were kept in pots at a depth of 0.4, 0.8, and 1.2 m in an outdoor pond for 12 weeks. Vallisneria americana seeds germinated from sites throughout the lake, and some seedlings produced overwintering buds by the end of the study. Seeds, spores, or fragments of 12 other species of aquatic plants also germinated. Seed germination trials with fresh and stored seeds in both greenhouse and ponds in which light availability was reduced with shade cloths indicated that seed germination was insensitive to light level. To determine the light requirements for seedling survival and bud production, sediment from Lake Onalaska was incubated in ponds under neutral density shade screens reducing light to 2, 5, 9, and 25% of full sun. Seeds germinated under all shade treatments but survival was significantly higher in the 9 and 25% light treatments, and bud production was restricted to these light levels.

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SEDIMENTATION IN LAKE ONALASKA, NAVIGATION POOL 7, UPPER MISSISSIPPI RIVER, SINCE IMPOUNDMENT¹

Cited by 10 publications

References 3 publications

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Changes in backwater plant communities from 1975 to 1995 in Navigation Pool 8, Upper Mississippi River

The distribution of Vallisneria americana seeds and seedling light requirements in the Upper Mississippi River

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SEDIMENTATION IN LAKE ONALASKA, NAVIGATION POOL 7, UPPER MISSISSIPPI RIVER, SINCE IMPOUNDMENT1

Cited by 10 publications

References 3 publications

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Environmental drivers of cyanobacterial abundance and cyanotoxin production in backwaters of the Upper Mississippi River

Changes in backwater plant communities from 1975 to 1995 in Navigation Pool 8, Upper Mississippi River

The distribution of Vallisneria americana seeds and seedling light requirements in the Upper Mississippi River

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SEDIMENTATION IN LAKE ONALASKA, NAVIGATION POOL 7, UPPER MISSISSIPPI RIVER, SINCE IMPOUNDMENT¹