A first assessment of cyanobacterial blooms in oligotrophic Lake Superior

Limnology and Oceanography, Journal Year: 2020, Volume and Issue: 65(12), P. 2984 - 2998

Published: Aug. 3, 2020

Abstract Lake Superior is often described as the most pristine of Laurentian Great Lakes, but in past decade Dolichospermum blooms have been observed. Land use adjacent watershed has not changed appreciably during this time, lake warming and climatological variables correspond with presence blooms. Blooms occurred only relatively warm years measured by degree days. Furthermore, two largest blooms, 2012 2018, especially extreme rainfall, providing coincidental evidence that intense storms provide nutrients or living propagules to from watershed. Nearshore water narrow zone where appear shows some riverine influence compared further offshore even absence Nevertheless, chemistry associated bloom 2018 more closely resembled nonbloom nearshore than river water, suggesting develop at least persist outside distinct plumes. Concentrations P N peak density greatly exceeded any waters, indicating a buildup phytoplankton biomass perhaps floating drifting shore also significant factor occurrence. One potentially toxic substance (Anabaenopeptin A) was observed low concentration. At concentration, high seston C : indicated severe limitation while pointed against limitation. If these newly are indeed driven temperature rainfall suggests, may continue.

Language: Английский

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Accumulation of arsenic, mercury and heavy metals in lacustrine sediment in relation to eutrophication: Impacts of sources and climate change

Ecological Indicators, Journal Year: 2018, Volume and Issue: 93, P. 771 - 780

Published: May 30, 2018

Language: Английский

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Recent changes in the spring microplankton of Lake Baikal, Russia

Limnologica, Journal Year: 2019, Volume and Issue: 75, P. 19 - 29

Published: Feb. 5, 2019

Language: Английский

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The not-so-dead of winter: underwater light climate and primary productivity under snow and ice cover in inland lakes

Inland Waters, Journal Year: 2022, Volume and Issue: 13(1), P. 1 - 12

Published: July 21, 2022

As global surface temperatures continue to rise as a result of anthropogenic climate change, effects in temperate lakes are likely be more pronounced than other ecosystems. Decreases snow and ice cover extent duration extended periods summer stratification have been observed lake systems throughout the Anthropocene. However, changing on lacustrine communities remain largely uninvestigated. We examined underwater light associated primary productivity patterns under snow-covered clear-lake 6 inland Minnesota, USA, spanning gradients water column optical properties (blue, green, brown) with trophic status organic material content. In all lakes, influenced not only intensity, but also spectral signature penetrating into column. Specifically, wavelength maximum penetration was shifted towards longer wavelengths green (eutrophic) shorter blue brown lakes. Volumetric often higher anticipated (e.g., ∼1200 mg m−3 d−1; Lake Minnetonka, ice). Carbon assimilation rates were lower types except immediately cleared eutrophic where phytoplankton photoinhibited because intense, short-wavelength light. These findings suggest that changes ongoing change scenarios can affect sensitive aquatic

Language: Английский

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Zooplankton-phytoplankton biomass and diversity relationships in the Great Lakes

PLoS ONE, Journal Year: 2023, Volume and Issue: 18(10), P. e0292988 - e0292988

Published: Oct. 26, 2023

Quantifying the relationship between phytoplankton and zooplankton may offer insight into sensitivity to shifting assemblages potential impacts of producer-consumer decoupling on rest food web. We analyzed 18 years (2001-2018) paired samples collected as part United States Environmental Protection Agency (U.S. EPA) Great Lakes Biology Monitoring Program examine both long-term seasonal relationships across all five Laurentian Lakes. also effects diversity biomass, diversity, predator-prey (zooplanktivore/grazer) ratios. Across Lakes, there was a weak positive correlation total algal biovolume biomass in spring summer. The weaker not consistently within individual lakes. These trends were consistent over time, providing no evidence increasing study period. Zooplankton weakly negatively correlated with lakes, whereas unaffected. did change when we considered only edible fraction, possibly due high most these Lack strong coupling producer consumer be related lagging responses by consumers, top-down from higher-level or other confounding factors. results underscore difficulty predicting higher trophic level responses, including zooplankton, changes assemblages.

Language: Английский

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Anthropocene geochemistry of metals in sediment cores from the Laurentian Great Lakes

PeerJ, Journal Year: 2020, Volume and Issue: 8, P. e9034 - e9034

Published: May 6, 2020

Geochemical analyses applied to lake sedimentary records can reveal the history of pollution by metals and effects remedial efforts. Lakes provide ideal environments for geochemical studies because they have steady deposition fine grained material suitable fixation pollutants. The Laurentian Great are most studied system in this field, well-preserved chronological profiles. To date, important has been considered parts inorganic geochemistry, hampering basin-wide conclusions regarding metal contamination. We filled spatial temporal gaps a comprehensive analysis 11 sediment cores collected from all five Lakes. Hierarchical cluster samples divided analytes into functional groups: (1) carbonate elements; (2) oxides with diverse natural sources, including subgroup known be anthropogenically enriched (Cd, Pb, Sn, Zn, Sb); (3) common crustal (4) related coal nuclear power generation; (5) co-occurring rare earth elements. Two contamination indices (I geo EF) indicated that Na, Co, Mn, Cd, Ta, Cu were each, at some point during Anthropocene, pollutants sediments. Land uses correlated analytes, such as increases contaminant rise catchment population elements (e.g. Ca) agriculture. Certain trends observed basin-wide, atmospheric pollutant which followed associated fossil fuel combustion decline following ban leaded gasoline. Other lake-specific, recent high concentrations Na Lake Superior, likely due road salt applications, late-20th-century peak Ca algal whiting events Ontario. Some exceeded guidelines quality, cases prior European settlement basin, indicating paleolimnological context is appropriate management sensitive environmental changes metals, it clear while there success, results uppermost intervals indicate ongoing problems.

Language: Английский

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The Late Pleistocene–Early Holocene palaeoenvironmental evolution in the SE Baltic region: a new approach based on chironomid, geochemical and isotopic data from Kamyshovoye Lake, Russia

Boreas, Journal Year: 2020, Volume and Issue: 49(3), P. 544 - 561

Published: July 1, 2020

The Kamyshovoye Lake sedimentary record in the southeastern Baltic Sea region was studied to reconstruct climatic fluctuations and abiotic responses them during Lateglacial Early Holocene. New results from chironomid, isotopic, palaeomagnetic geochemical data analyses were correlated with earlier evidence of lithological palynological changes record. section that covered interval between 15 200 6500 cal. a BP . Palaeoclimatic reconstructions showed Younger Dryas there two‐step decrease mean July temperature. temperature dropped by 3 °C period ̃12 650 12 300 , then it another 0.5 minimum 11.5 at 11 900 During Dryas–Holocene transition, increase can be seen over several centuries, inferred chironomid data. Further, curve significant continued until ̃9500 coolings, average values typical for Dryas, while characteristic Allerød only reached around 9700 After 9500 more stable, gradual recorded. short‐term Holocene oscillations are clearly traced sequence, although natural components sometimes asynchronous. In case study, seem sensitive indicator environmental despite absence an evident response onset ̃11 700 Considerable pattern recorded later, 500 coinciding noticeable development vegetation. obtained this study contribute deeper understanding how global trends manifested on local scale.

Language: Английский

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Effects of climate change and industrialization on Lake Bolshoe Toko, eastern Siberia

Journal of Paleolimnology, Journal Year: 2021, Volume and Issue: 65(3), P. 335 - 352

Published: Jan. 23, 2021

Abstract Industrialization in the Northern Hemisphere has led to warming and pollution of natural ecosystems. We used paleolimnological methods explore whether recent climate change and/or had affected a very remote lake ecosystem, i.e. one without nearby direct human influence. compared sediment samples that date from before after onset industrialization mid-nineteenth century, four short cores taken at water depths between 12.1 68.3 m Lake Bolshoe Toko, eastern Siberia. analyzed diatom assemblage changes, including diversity estimates, all geochemical changes (mercury, nitrogen, organic carbon) core an intermediate depth. Chronologies for two were established using 210 Pb 137 Cs. Sedimentation rates 0.018 0.033 cm year −1 shallow- deep-water sites, respectively. discovered increase light planktonic diatoms ( Cyclotella ) decrease heavily silicified euplanktonic Aulacoseira through time related more warmer air temperatures shorter periods lake-ice cover, which pronounced thermal stratification. Diatom beta shallow-water communities changed significantly because development new habitats associated with macrophyte growth. Mercury concentrations increased by factor 1.6 since century as result atmospheric fallout. Recent increases chrysophyte Mallomonas suggested acidification trend. conclude even boreal lakes are susceptible effects human-induced pollution.

Language: Английский

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Hierarchical deep learning model to simulate phytoplankton at phylum/class and genus levels and zooplankton at the genus level

Water Research, Journal Year: 2022, Volume and Issue: 218, P. 118494 - 118494

Published: April 23, 2022

Language: Английский

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Arctic warming drives striking twenty-first century ecosystem shifts in Great Slave Lake (Subarctic Canada), North America's deepest lake

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(2007)

Published: Sept. 20, 2023

Great Slave Lake (GSL), one of the world's largest and deepest lakes, has undergone an aquatic ecosystem transformation in response to twenty-first-century accelerated Arctic warming that is unparalleled at least past two centuries. Algal remains from four high-resolution palaeolimnological records retrieved West Basin provide baseline limnological data we compared with historical phycological surveys undertaken on GSL between 1940s 1990s. We document rapid restructuring algal community composition ca 2000 CE consistent recent increases regional air temperature declines ice cover wind speed, collectively altered habitats for biota. This new regime initiated first observation scaled chrysophytes favoured proliferation small planktonic cyclotelloid diatoms which replaced long-established dominance large filamentous Aulacoseira islandica sedimentary records. Such abrupt transformations primary producers this socioecologically valuable 'northern Lake' may have widespread implications entire food web unknown consequences functioning fisheries, First Nations, Métis other northern communities depend upon, pointing need studies.

Language: Английский

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