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1. Diversity and distribution of sediment bacteria across an ecological and trophic gradient

   https://doi.org/10.1371/journal.pone.0258079  

   Sauer, Hailey M.; Hamilton, Trinity L.; Anderson, Rika E.; Umbanhowar, Charles E.; Heathcote, Adam J. (March 2022, PLOS ONE)

   Mendoza-Lera, Clara (Ed.)

   The microbial communities of lake sediments have the potential to serve as valuable bioindicators and integrators of watershed land-use and water quality; however, the relative sensitivity of these communities to physio-chemical and geographical parameters must be demonstrated at taxonomic resolutions that are feasible by current sequencing and bioinformatic approaches. The geologically diverse and lake-rich state of Minnesota (USA) is uniquely situated to address this potential because of its variability in ecological region, lake type, and watershed land-use. In this study, we selected twenty lakes with varying physio-chemical properties across four ecological regions of Minnesota. Our objectives were to (i) evaluate the diversity and composition of the bacterial community at the sediment-water interface and (ii) determine how lake location and watershed land-use impact aqueous chemistry and influence bacterial community structure. Our 16S rRNA amplicon data from lake sediment cores, at two depth intervals, data indicate that sediment communities are more likely to cluster by ecological region rather than any individual lake properties ( e . g ., trophic status, total phosphorous concentration, lake depth). However, composition is tied to a given lake, wherein samples from the same core were more alike than samples collected at similar depths across lakes. Our results illustrate the diversity within lake sediment microbial communities and provide insight into relationships between taxonomy, physicochemical, and geographic properties of north temperate lakes. 

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2. LAGOS-NE Shallow Lakes: a dataset of lake variables and multi-scaled ecological context variables used to predict and compare trophic status and TP:CHLa relationships between shallow and non-shallow lakes in the Upper Midwest and Northeastern United States.

   https://doi.org/10.6073/pasta/be49507b941815d7a6807a273ee02d1e  

   Cheruvelil, Kendra S.; Webster, Katherine E.; King, Katelyn B.; Poisson, Autumn C.; Wagner, Tyler (January 2022, Environmental Data Initiative)

   We conducted a macroscale study of 2,210 shallow lakes (mean depth ≤ 3m or a maximum depth ≤ 5m) in the Upper Midwestern and Northeastern U.S. We asked: What are the patterns and drivers of shallow lake total phosphorus (TP), chlorophyll a (CHLa), and TP–CHLa relationships at the macroscale, how do these differ from those for 4,360 non-shallow lakes, and do results differ by hydrologic connectivity class? To answer this question, we assembled the LAGOS-NE Shallow Lakes dataset described herein, a dataset derived from existing LAGOS-NE, LAGOS-DEPTH, and LAGOS-CLIMATE datasets. Response data variables were the median of available summer (e.g., 15 June to 15 September) values of total phosphorus (TP) and chlorophyll a (CHLa). Predictor variables were assembled at two spatial scales for incorporation into hierarchical models. At the local or lake-specific scale (including the individual lake, its inter-lake watershed [iws] or corresponding HU12 watershed), variables included those representing land use/cover, hydrology, climate, morphometry, and acid deposition. At the regional scale (e.g., HU4 watershed), variables included a smaller set of predictor variables for hydrology and land use/cover. The dataset also includes the unique identifier assigned by LAGOS-NE(lagoslakeid); the latitude and longitude of the study lakes; their maximum and mean depths along with a depth classification of Shallow or non-Shallow; connectivity class (i.e., whether a lake was classified as connected (with inlets and outlets) or unconnected (lacking inlets); and the zone id for the HU4 to which each lake belongs. Along with the database, we provide the R scripts for the hierarchical models predicting TP or CHLa (TPorCHL_predictive_model.R), and the TP—CHLa relationship (TP_CHL_CSI_Model.R) for depth and connectivity subsets of the study lakes. 

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3. Fossil Diatoms Reveal Natural and Anthropogenic History of Jackson Lake (Wyoming, USA)

   https://doi.org/10.3389/esss.2023.10065  

   Dilworth, John; Stone, Jeffery R.; Yeager, Kevin M.; Thigpen, J. Ryan; McGlue, Michael M. (February 2023, Earth Science, Systems and Society)

   Jackson Lake supplies valuable cultural and provisioning ecosystem services to the Upper Snake River watershed in Wyoming and Idaho (western USA). Construction of Jackson Lake Dam in the early 20th century raised lake level by ∼12 m, generating an important water resource supporting agriculture and ranching, as well as tourism associated with Grand Teton National Park. Outlet engineering drastically altered Jackson Lake’s surface area, morphology, and relationship with the inflowing Snake River, yet the consequences for nutrient dynamics and algae in the lake are unknown. Here, we report the results of a retrospective environmental assessment completed for Jackson Lake using a paleolimnological approach. Paleoecological (diatoms) and geochemical datasets were developed on a well-dated sediment core and compared with available hydroclimate data from the region, to assess patterns of limnological change. The core spans the termination of the Little Ice Age and extends to the present day (∼1654–2019 CE). Diatom assemblages prior to dam installation are characterized by high relative abundances of plankton that thrive under low nutrient availability, most likely resulting from prolonged seasonal ice cover and perhaps a single, short episode of deep convective mixing. Following dam construction, diatom assemblages shifted to planktic species that favor more nutrient-rich waters. Elemental abundances of sedimentary nitrogen and phosphorous support the interpretation that dam installation resulted in a more mesotrophic state in Jackson Lake after ∼1916 CE. The data are consistent with enhanced nutrient loading associated with dam emplacement, which inundated deltaic wetlands and nearshore vegetation, and perhaps increased water residence times. The results of the study highlight the sensitivity of algal composition and productivity to changes in nutrient status that accompany outlet engineering of natural lakes by humans and have implications for water resource management. 

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4. Bacterial community structure of microbial pinnacles in ice-covered Lake Vanda, Antarctica

   https://doi.org/10.1080/15230430.2023.2276578  

   Grettenberger, Christen L; Sumner, Dawn Y; Wall, Kate; Hawes, Ian; Mackey, Tyler; Jungblut, Anne D (December 2023, Arctic, Antarctic, and Alpine Research)

   The McMurdo Dry Valleys are a cold and arid environment with low biomass relative to most ice- free environments. The ice-covered lakes in the valleys, however, provide a refuge for diverse microbial communities where liquid water persists year-round. Within these lakes, benthic micro- bial assemblages form ornate structures in the absence of burrowing and grazing organisms. In Lake Vanda, the microbial communities create pinnacles with features including tip, web, and ridge ornaments and brown, green, purple, and beige pigmented zones. Bacterial 16S rRNA gene composition differed between lake depths for all sampled features. Within each depth, community composition correlated with the relative distance into the pinnacle and there were also some significant differences between assemblages in certain zones. The bacterial community composi- tion in the zones may reflect how they respond to environmental changes as the mat is buried, altering the internal light environment and affecting 16S rRNA gene assemblages across niches from the surface to the interior. 

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5. Unpiloted Aerial Vehicle Retrieval of Snow Depth Over Freshwater Lake Ice Using Structure From Motion

   https://doi.org/10.3389/frsen.2021.675846  

   Gunn, Grant E.; Jones, Benjamin M.; Rangel, Rodrigo C. (July 2021, Frontiers in Remote Sensing)

   null (Ed.)

   The presence and thickness of snow overlying lake ice affects both the timing of melt and ice-free conditions, can contribute to overall ice thickness through its insulative capacity, and fosters the development of variable ice types. The use of UAVs to retrieve snow depths with high spatial resolution is necessary for the next generation of ultra-fine hydrological models, as the direct contribution of water from snow on lake ice is unknown. Such information is critical to the understanding of the physical processes of snow redistribution and capture in catchments on small lakes in the Arctic, which has been historically estimated from its relationship to terrestrial snowpack properties. In this study, we use a quad-copter UAV and SfM principles to retrieve and map snow depth at the winter maximum at high resolution over a the freshwater West Twin Lake on the Arctic Coastal Plain of northern Alaska. The accuracy of the snow depth retrievals is assessed using in-situ observations ( n = 1,044), applying corrections to account for the freeboard of floating ice. The average snow depth from in-situ observations was used calculate a correction factor based on the freeboard of the ice to retrieve snow depth from UAV acquisitions (RMSE = 0.06 and 0.07 m for two transects on the lake. The retrieved snow depth map exhibits drift structures that have height deviations with a root mean square (RMS) of 0.08 m (correlation length = 13.8 m) for a transect on the west side of the lake, and an RMS of 0.07 m (correlation length = 18.7 m) on the east. Snow drifts present on the lake also correspond to previous investigations regarding the variability of snow on lakes, with a periodicity (separation) of 20 and 16 m for the west and east side of the lake, respectively. This study represents the first retrieval of snow depth on a frozen lake surface from a UAV using photogrammetry, and promotes the potential for high-resolution snow depth retrieval on small ponds and lakes that comprise a significant portion of landcover in Arctic environments. 

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