Methane cycling dynamics in sediments of Alaskan Arctic Foothill lakes

Bretz, K. A.; Whalen, Stephen C.

doi:10.5268/iw-4.1.637

Cited by 16 publications

(23 citation statements)

References 93 publications

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“…We suggest that the low CH 4 oxidation rates that we observed in sediment cores from well‐oxygenated lakes reflected limitation of CH 4 oxidation at the sediment–water interface by CH 4 availability. In a subset of the lakes we studied, slurry experiments where CH 4 availability and DO saturation conditions were uniformly high showed no difference in potential CH 4 oxidation rates between deep and shallow lakes (Bretz and Whalen ). However, intact core measurements showed that DO penetrated deeper in sediments of the deep compared to shallow lakes (275 μm vs. 110 μm; Bretz and Whalen ).…”

Section: Discussionmentioning

confidence: 94%

“…In a subset of the lakes we studied, slurry experiments where CH 4 availability and DO saturation conditions were uniformly high showed no difference in potential CH 4 oxidation rates between deep and shallow lakes (Bretz and Whalen ). However, intact core measurements showed that DO penetrated deeper in sediments of the deep compared to shallow lakes (275 μm vs. 110 μm; Bretz and Whalen ). This latter result is consistent with the observation by Gentzel et al () that vertical distribution of methanogen and MOB DNA in the first few mm of the sediment profile reflected the oxygen regime of the overlying water in Lake GTH 112.…”

Section: Discussionmentioning

confidence: 94%

“…CH 4 is also released from sediments by diffusive efflux, especially from lakes with small and seasonally anoxic hypolimnia (Bastviken et al ; Kankaala et al ). Higher potential methanogenesis was observed in sediments from small shallow lakes compared with deep lakes (Bretz and Whalen ). CH 4 produced in sediments may be captured by methane‐oxidizing bacteria (MOB) in oxidizing zones at the sediment–water interface and in the water column, supporting microbial production (Bastviken et al ; Maerki et al ; Jones and Grey ).…”

Section: Study Sitesmentioning

confidence: 99%

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Methane efflux and oxidation, and use of methane-derived carbon by larval Chironomini, in arctic lake sediments

et al. 2015

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We measured sediment methane (CH 4 ) efflux and CH 4 oxidation in intact sediment cores from 17 arctic Alaskan lakes which varied in lake area and depth. We evaluated the relationships between CH 4 oxidation and lake area, depth, and hypolimnetic dissolved oxygen (DO). We also evaluated the relationship between d 13 C of larval Chironomini and CH 4 oxidation and estimated use of methane-derived carbon (MDC) by larval Chironomini. CH 4 oxidation declined exponentially as hypolimnetic DO increased, and Chironomini d 13 C declined exponentially as CH 4 oxidation increased. Mixing model estimates indicated that Chironomini incorporated 0% to 40% MDC between study lakes, dependent on CH 4 oxidation. These estimates overlap broadly with those reported for eutrophic lakes, illustrating that use of MDC is not strictly related to lake productivity, but instead is determined by factors controlling hypolimnetic DO and facilitating CH 4 oxidation at the sedimentwater interface. In the lakes studied here, hypolimnetic DO was determined by basin characteristics. Our results, viewed in the context of other studies elsewhere, illustrate that CH 4 oxidation is a potentially important process supporting consumer production across the full spectrum of lake productivity.

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 94%

Section: Study Sitesmentioning

confidence: 99%

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Methane efflux and oxidation, and use of methane-derived carbon by larval Chironomini, in arctic lake sediments

et al. 2015

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“…The in situ porewater concentrations of the EAs were not measured, except for the Mn concentration in P 0-10 (~27 µM), which is within the typical range (2-40 µM) reported in surface sediments of arctic lakes (Bretz and Whalen 2014). However, in the 0-2 cm surface sediment layer of a boreal (Finnish) high-NO 3 -lake (L. Pääjärvi, NO 3 -> 65 µM in the water above the sediment), the porewater NO 3 -concentration was previously found to only reach 14 µM during the growing season (Rissanen et al 2013).…”

Section: Slurry Preparation and Incubationmentioning

confidence: 99%

“…However, in the 0-2 cm surface sediment layer of a boreal (Finnish) high-NO 3 -lake (L. Pääjärvi, NO 3 -> 65 µM in the water above the sediment), the porewater NO 3 -concentration was previously found to only reach 14 µM during the growing season (Rissanen et al 2013). The porewater SO 4 2-concentration typically ranges from ~20 to ~300 µM in the sediments of oligotrophic and mesotrophic lakes (Holmer and Storkholm 2001), while the porewater Fe concentration has been reported to only reach ~400 µM in previously studied northern lakes (Huerta-Diaz, Tessier and Carignan 1998;Bretz and Whalen 2014). This suggests that all EAs were added in significantly higher concentrations when compared to in situ conditions.…”

Section: Slurry Preparation and Incubationmentioning

confidence: 99%

Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two shallow boreal lakes

Rissanen

Karvinen

Nykänen

et al. 2017

FEMS Microbiology Ecology

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Oxygen dynamics in a boreal lake responds to long‐term changes in climate, ice phenology, and DOC inputs

et al. 2015

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Boreal lakes are impacted by climate change, reduced acid deposition, and changing loads of dissolved organic carbon (DOC) from catchments. We explored, using the process-based lake model MyLake, how changes in these pressures modulate ice phenology and the dissolved oxygen concentrations (DO) of a small boreal humic lake. The model was parametrized against year-round time series of water temperature and DO from a lake buoy. Observed trends in air temperature (+0.045°C yr À1 ) and DOC concentration (0.11 mg C L À1 yr À1 , +1% annually) over the past 40 years were used as model forcings. A backcast of ice freezing and breakup dates revealed that ice breakup occurred on average 8 days earlier in 2014 than in 1974. The earlier ice breakup enhanced water column ventilation resulting in higher DO in the spring. Warmer water in late summer led to longer anoxic periods, as microbial DOC turnover increased. A long-term increase in DOC concentrations caused a decline in lake DO, leading to 15% more hypoxic days (<3 mg L À1 ) and 10% more anoxic days (<15 μg L À1 ) in 2014 than in 1974. We conclude that climate warming and increasing DOC loads are antagonistic with respect to their effect on DO availability. The model suggests that DOC is a stronger driver of DO consumption than temperature. The browning of lakes may thus cause reductions in the oxythermal habitat of fish and aquatic biota in boreal lakes.

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Methane cycling dynamics in sediments of Alaskan Arctic Foothill lakes

Cited by 16 publications

References 93 publications

Methane efflux and oxidation, and use of methane-derived carbon by larval Chironomini, in arctic lake sediments

Methane efflux and oxidation, and use of methane-derived carbon by larval Chironomini, in arctic lake sediments

Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two shallow boreal lakes

Oxygen dynamics in a boreal lake responds to long‐term changes in climate, ice phenology, and DOC inputs

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