Occurrence of Bythotrephes cederstroemi in inland lakes in northeastern Minnesota as indicated from sediment records

2000 ◽  
Vol 27 (3) ◽  
pp. 1552-1555
Author(s):  
M. Rebecca Forman ◽  
Melbourne C. Whiteside
Keyword(s):  
Inland Lakes ◽  
Bythotrephes Cederstroemi ◽  
Sediment Records

scholarly journals Bythotrephes cederstroemi (Schoedler) in Muskoka Lakes: First Records of the European Invader in Inland Lakes in Canada

1992 ◽  
Vol 49 (2) ◽  
pp. 422-426 ◽  
Author(s):  
Norman D. Yan ◽  
Warren I. Dunlop ◽  
Trevor W. Pawson ◽  
Lori E. MacKay
Keyword(s):  
Food Webs ◽  
Close Monitoring ◽  
Inland Lakes ◽  
South Central ◽  
Bythotrephes Cederstroemi ◽  
Pelagic Food Webs

The large predaceous European zooplankter Bythotrephes cederstroemi is now present in eight large recreational lakes in south-central Ontario, Canada: Lake Muskoka, Lake Joseph, Lake Rosseau, Fairy Lake, Mary Lake, Peninsula Lake, Lake Vernon, and Go Home Lake. These observations represent the first evidence that B. cederstroemi has invaded inland lakes in Canada, and we suggest that close monitoring is now needed to establish whether or not pelagic food webs of the lakes will respond.

scholarly journals Microbial nitrification and acidification of lacustrine sediments deduced from the nature of a sedimentary kaolin deposit in central Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tetsuichi Takagi ◽  
Ki-Cheol Shin ◽  
Mayumi Jige ◽  
Mihoko Hoshino ◽  
Katsuhiro Tsukimura
Keyword(s):  
Nitric Acid ◽  
Lacustrine Sediments ◽  
Kaolin Clay ◽  
Central Japan ◽  
Inland Lakes ◽  
Fe Oxidation ◽  
Stable Isotopic ◽  
Fe Hydroxide ◽  
Kaolin Deposit ◽  
Dilute Nitric Acid

AbstractKaolin deposits in the Seto-Tono district, central Japan, were formed by intense kaolinization of lacustrine arkose sediments deposited in small and shallow inland lakes in the late Miocene. Based on mineralogical and stable isotopic (Fe, C, N) studies of Motoyama kaolin deposit in the Seto area, we concluded that it was formed by microbial nitrification and acidification of lacustrine sediments underneath an inland lake. Small amounts of Fe–Ti oxides and Fe-hydroxide in the kaolin clay indicated that iron was oxidized and leached during the kaolinization. The field occurrences indicate that leached ferric iron precipitated on the bottom of the kaolin deposit as limonite crusts, and their significantly fractionated Fe isotope compositions suggest the involvement of microbial activity. The C/N ratios of most of the kaolin clay are distinctly higher than those of modern lacustrine sediment. Although, the possibility of a low-temperature hydrothermal origin of the kaolin deposit cannot be completely ruled out, it is more likely that acidification by dilute nitric acid formed from plant-derived ammonia could have caused the kaolinization, Fe oxidation and leaching. The nitrate-dependent microbial Fe oxidation is consistent with dilute nitric acid being the predominant oxidant.

scholarly journals Evolution of the Arabian Sea Upwelling from the Last Millennium to the Future as Simulated by Earth System Models

Climate ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 72
Author(s):  
Xing Yi ◽  
Birgit Hünicke ◽  
Eduardo Zorita
Keyword(s):  
Arabian Sea ◽  
Positive Trend ◽  
Last Millennium ◽  
Earth System ◽  
System Models ◽  
Sediment Records ◽  
The Future ◽  
Water Stratification ◽  
Arabian Sea Upwelling ◽  
Earth System Models

Arabian Sea upwelling in the past has been generally studied based on the sediment records. We apply two earth system models and analyze the simulated water vertical velocity to investigate coastal upwelling in the western Arabian Sea over the last millennium. In addition, two models with slightly different configurations are also employed to study the upwelling in the 21st century under the strongest and the weakest greenhouse gas emission scenarios. With a negative long-term trend caused by the orbital forcing of the models, the upwelling over the last millennium is found to be closely correlated with the sea surface temperature, the Indian summer Monsoon and the sediment records. The future upwelling under the Representative Concentration Pathway (RCP) 8.5 scenario reveals a negative trend, in contrast with the positive trend displayed by the upwelling favorable along-shore winds. Therefore, it is likely that other factors, like water stratification in the upper ocean layers caused by the stronger surface warming, overrides the effect from the upwelling favorable wind. No significant trend is found for the upwelling under the RCP2.6 scenario, which is likely due to a compensation between the opposing effects of the increase in upwelling favorable winds and the water stratification.

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