The Re‐establishment of Meromixis in Hemlock Lake, Michigan, After Artificial Destratification

Fast, Arlo W.; Tyler, P.A.

doi:10.1002/iroh.19810660503

Cited by 6 publications

(5 citation statements)

References 8 publications

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“…1 m above ground (Steinberg and Schrimpf, 1982), both the bubble plume and the resulting water current never came into direct contact with the sediment surface, where -despite an oxic bottom water zone (>2 mg L -1 O 2 ) -anoxic conditions prevailed. This is in concordance with the findings of many aeration experi- ments (Fast and Tyler, 1981;Bailey-Watts et al, 1987;Gächter and Wehrli, 1998;Grochowska and Gawronska, 2004;Teranes and Bernasconi, 2000). As well, it is evident from the O 2 data of the water column that bottom waters in Fischkaltersee turned hypoxic very quickly each time the aeration ceased.…”

Section: History Of Eutrophication and Restoration Effortssupporting

confidence: 90%

Fifty years of eutrophication and lake restoration reflected in sedimentary carbon and nitrogen isotopes of a small, hardwater lake (south Germany)

et al. 2013

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This study analyses the response of the carbon and nitrogen isotopic composition of sedimentary organic matter to rapid human-induced eutrophication and meromixis as well as subsequent restoration efforts [in-lake phosphorus (P)-Precipitation, P-remediation of the well inflow and multiannual destratification] in a 46-yr sediment core sequence (1963-2009) from Fischkaltersee, a small hard-water lake (S-Germany). In addition, the sediment record was compared with detailed data on water column chemistry during almost (1977-2009) the recorded history of eutrophication and trophic recovery of the named lake. While the onset of eutrophication resulted in an abrupt positive excursion (+2.4‰), the overall reaction of δ¹³C_SOM to ongoing eutrophication and meromixis as well as to permanent hypolimnion aeration and trophic recovery is a continous negative trend (-3.7‰) with the most depleted signatures (-38.8‰) present in the youngest part of the core. This negative trend was not influenced by multiannual hypolimnion aeration, which although oxygenating bottom waters (>2 mg O₂ L^–1), did not reverse the increasing anoxis in the sediment, as is indicated by an declining Mn/Fe ratio. Hence, we conclude that in Fischkaltersee δ¹³C_SOM was controlled by photoautotrophic input only during an early phase in the eutrophication process. The signal of intensifying microbially mediated carbon cycling processes in the sediment, i.e. methanogenesis and methanotrophy, was superimposed on the primary productivity signal by crossing a certain TP threshold (approx. TP=0.04 mg L^–1). Sedimentary δ¹⁵N values exhibit an overall increase (+3.4‰) in reaction to the eutrophication process, while trophic recovery produces a continous decrease in the signal (-2.7‰). Linear correlation of δ¹⁵N to nitrate utilisation in the epilimnion, however, is rather weak (R²=0.33). Comparison between sediment δ¹⁵N values and water column data reveals that two negative shifts in the isotopic signal (-1‰/-0.6‰) around 1980 and 1984 respectively, can be attributed to the existence of significant amounts of ammonium (up to 2 mg L^–1) in the trophogenic zone. Coincident drops in nitrate utilisation (-20%/-53%) indicate phytoplankton assimilation of ammonium. As the artificial aeration did also not affect δ¹⁵N, we conclude that water column denitrification never contributed significantly to the sedimentary N isotope signal

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Section: History Of Eutrophication and Restoration Effortssupporting

confidence: 90%

Fifty years of eutrophication and lake restoration reflected in sedimentary carbon and nitrogen isotopes of a small, hardwater lake (south Germany)

et al. 2013

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“…Lake La Cruz has the requisites to produce biogenic meromixis: it is located in a wind-sheltered basin, it has a maximum depth of 24 m, a relative depth of 18 % and a mean depth of 13 m, much higher than that of other lakes (around 8 m) that also exhibit biogenic meromixis like Valkiajärvi (Meriläinen, 1970), Skjennungen and Store Aaklungen (Kjensmo, 1967), Hemlock (Fast and Tyler, 1981) or Waldsea (Hammer and Haynes, 1978). All the above mentioned factors favour the maintenance of the meromixis.…”

Section: Discussionmentioning

confidence: 99%

Untitled

2001

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The main limnological characteristics of the biogenic meromictic Lake La Cruz, a small karstic lake located on a dolomitic substrate, are outlined below. The lake owes its chemical stratification mainly to high concentrations of bicarbonate and calcium in the permanent monimolimnion, located below a depth of 19 m. A massive precipitation of CaCO 3 crystals ("whiting"), occurring in the euphotic zone every summer, leads to further sedimentation and redissolution in deep waters with enhanced CO 2 concentrations. Other ions, like magnesium, ammonium, reduced iron, silicate, etc. also contribute to the chemically-induced stability of the monimolimnion. The patterns of stratification during two consecutive thermal stagnation periods (1987 -1988) were influenced by different climatological conditions. Depending of the year, the location of the pycnoclines varied; the rainier spring of 1988 favoured a much shallower location of the oxic-anoxic boundary and a much higher primary production reflected by larger oxygen peaks. This greater phytoplanktonic development in upper waters occasioned a shadowing effect on purple and green phototrophic bacterial populations growing in anoxic waters poor in sulphide.

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“…It was the first reservoir shown to be chemically stratified in Tasmania (Tyler & Buckney, 1974;Fast & Tyler, 1981;Tyler, 1980Tyler, , 1981. Morphometric parameters are summarised in Table 1.…”

Section: Description Of Study Areamentioning

confidence: 99%

“…In 1970 the monimolimnetic pool was swept out of Lake Barrington by a flood, but it rapidly reformed (Fast & Tyler, 1981;Tyler & Buckney, 1974). Measurements in 1976 suggested that the pool was being eroded by an interflow (Fig.…”

Section: Lake Barringtonmentioning

confidence: 99%

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Chemical stratification and partial meromixis in reservoirs in Tasmania

Bowling

Tyler

1990

Hydrobiologia

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During the first summer after impoundment, chemical stratification occurred in four deep, steep-sided reservoirs of the Pieman River Power Development, Tasmania, under the influence of thermal stratification and anoxic hypolimnia caused by decaying vegetation in the flooded river valleys. Marked increases occurred in temperature, conductivity, pH, and in concentrations of dissolved iron, manganese, calcium, magnesium and bicarbonate in the sulphuretted, reducing, waters which accumulated as monimolimnetic pools adjacent to the dams. This partial, incipient meromixis persisted only in Lake Murchison, where a shallow monimolimnetic pool remained three years later. In the other reservoirs of the Pieman scheme it decayed after one or two years. Reservoir morphometry, degree of shelter, nature of major inflows, and alignment with respect to prevailing winds, are primary factors determining the persistence or eventual decay of chemical stratification in the respective impoundments. In Lake Barrington, another meromictic Tasmanian reservoir, the initial chemical gradient decayed and virtually disappeared, but was reestablished with greater severity than on any previous occasion. The severity of partial meromixis may wax and wane in relation to seasonal or longer-term meteorological events.

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The Re‐establishment of Meromixis in Hemlock Lake, Michigan, After Artificial Destratification

Cited by 6 publications

References 8 publications

Fifty years of eutrophication and lake restoration reflected in sedimentary carbon and nitrogen isotopes of a small, hardwater lake (south Germany)

Fifty years of eutrophication and lake restoration reflected in sedimentary carbon and nitrogen isotopes of a small, hardwater lake (south Germany)

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Chemical stratification and partial meromixis in reservoirs in Tasmania

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