Lake Survey Research Articles

Identification of Hazardous Glacial Lakes in the Yarlung Zangbo River Basin Based on Lakes Changes Determined Using Google Earth Engine

Glaciers have melted rapidly in the Yarlung Zangbo River Basin due to recent climate change, which has accelerated the expansion of glacial lakes. We performed a systematic survey of glacial lakes in the Yarlung Zangbo River Basin using the Google Earth Engine platform. This allowed us to map the distribution and monitor the evolution of glacial lakes over seven time periods from 1990 to 2020, using more than 140 Landsat Thematic Mapper and Operational Land Imager images at a 30-m resolution. The results show that there were 2088 glacial lakes in 2020, with a total area of 245.87 km2, mainly distributed at elevations of 3,800–5,800 m above sea level. From 1990 to 2020, the Yarlung Zangbo River Basin glacial lakes expanded by approximately 1.81 km2·a−1. A total of 153 glacial lakes in the Yarlung Zangbo River Basin were assessed. The assessment shows that 153 glacial lakes were divided into very high, high, medium, low, and very low level. The number of glacial lakes in each level is 23, 22, 32, 32, and 44, respectively. The very high and high level glacial lakes were mainly found in the Yi’ong Zangbo River Basin, Parlung Zangbo River Basin, the western of the Yarlung Zangbo River Basin and Nianchu River Basin. These glacial lakes deserve further attention and monitoring.

Hydrogeology of alpine lakes in the Northern Calcareous Alps: a comparative study on the role of groundwater in Filblingsee and Eibensee

Abstract In the Northern Calcareous Alps (NCA) there are countless small lakes with small orographic catchments that are often located only slightly below the respective summit regions. On the one hand, the lakes are located in karstable aquifers and their existence is likely to be related to karstification. Then, they are expected to be directly connected to the karst water body. These lakes are classified as karst lakes. On the other hand, the alpine environment is also influenced by glacial processes and lakes might be related to glacial erosion and deposition. For these glacial lakes, the share of groundwater inflow and outflow is regarded as subordinate even within high permeable karst lithologies. Here we compare two alpine lakes of potentially different origin in the NCA in Salzburg with the aim to provide a basis for an aerial survey of the numerous small alpine lakes in the NCA region and their characterization using the guiding parameters elaborated here. We consider (a) the lake geometry, (b) potential inflow and outflow systems, and (c) physicochemical parameters and hydrochemistry of the Filblingsee and the Eibensee, both located in the Fuschlsee region. Filblingsee was initially considered as a typical karst lake and Eibensee as a moraine-dammed glacial lake. Some clear differences arise in lake geometry, which in the karst lake shows a nearly round surface and concentric depth profile, while the glacial lake is elongated in the direction of glacier flow and has the deepest areas just upstream of the moraine dam. Both lakes show very little to no surficial inflow. Inflow and outflow occur in groundwater in both cases but are not directly tied to a highly permeable karst system. The depth profiles of the field parameters of the two lakes differ only slightly and show a dominant groundwater inflow in mid-depth regions but no flow through at the lake bottom. Water chemistry in both lakes and their potential outflows correspond to the respective aquifer in terms of solution load. Filblingsee can be characterized as a hanging lake in a secondarily sealed doline, Eibensee lies in a glacially excavated depression sealed by glacial sediments. While the inflow and outflow conditions and the hydrochemistry of both lakes are very similar, the lake geometry is a clear distinguishing feature that can be attributed to the different genesis of the two lakes. This can therefore be used as a guiding parameter for the classification of the numerous small alpine lakes in the NCA.

Morphometry of Juodis and Lydekinis lakes

Bathymetric surveys of Juodis and Lydekinis Lakes (located in outskirts of Vilnius city, Lithuania) were carried out on April 28 and May 1, 2020, from a boat with attached Lowrance HDI SKIMMER XDCR transducer (200 kHz), Simrad GO5 chartplotter and Lowrance Point-1 GPS/Glonass receiver. Average distance between profiles was ~10 m and depth measurement accuracy up to 2–5 cm. Accuracy of water surface elevation measurement using GNSS receiver Topcon Hiper SR up to 1–2 cm. Later, detailed (0.5x0.5 m) digital lake bottom models (DEM) were developed, bathymetric plans of the lakes were created, the main morphometric features were calculated, the boundaries and area of the lake catchments were defined, and the physical-geographical characteristics of the lakes were described based on field observations and various data. Juodis and Lydekinis are small shallow lakes of glaciokarst origin, located in Tapeliai glacial tunnel valley. Juodis Lake is considerably elongated while shape of Lydekinis Lake is close to the circle. According to survey data, the surface area of Juodis Lake is 9.2 ha, water surface elevation 135.8 m a.s.l., maximum depth 3.7 m, mean depth 1.2 m, volume 114.9 thousands m3, catchment area 344 ha. The surface area of Lydekinis Lake is 1.7 ha, water surface elevation 138.2 m a.s.l., maximum depth 4.9 m, mean depth 2.2 m, volume 36.3 thousands m3, catchment area 71 ha. During the observation period (from June of 2018 to April of 2022), the annual amplitude of water level fluctuations in Juodis Lake reached up to 0.16 m. Water level fluctuations in Lydekinis lake were very large due to the reconstruction of the dam and the installation of new culverts. Currently, the water level in Lydekinis Lake is significantly raised, most of the lake shore and the surrounding wetland are flooded. Keywords: Juodis, Lydekinis, glaciokarst, lake, bathymetric chart, morphometry, Lithuania

Использование геоинформационных технологий в изучении картометрических и морфометрических характеристик озер Северного Казахстана

The study is devoted to determining the possibilities of using geoinformation systems and technologies for organizing and implementing geoecological monitoring surveys of lakes in the territory of one of the largest lake regions within Kazakhstan—the North Kazakhstan region. The important task of creating a unified electronic catalog of lakes in the study area and placing it in free open access was practically solved. The studied quantitative and qualitative composition of topographic, cartometric, morphometric, hydrological, hydrochemical, hydrobiological, geoecological and other data on the lakes of the region made it possible to use in the catalog a number of cartometric and morphometric indicators common for all areal water bodies. For each of these indicators, a fixed set of values was determined containing information about various aspects of their state. In the procedure for describing and characterizing lakes, such parameters as their length, width, average and maximum depths, features of the bottom topography and its profiles, the length of the coastline and envelope, the degree of indentation of the coastline, the area of the reservoir and catchment area, the volume water mass, the degree of overgrowth of higher emersed vegetation, and others. Based on the analysis of the database of lakes created in Microsoft Excel application and desktop GIS digital mapping software product MapInfo Professional, a series of geoinformation and cartographic materials was prepared, in particular, maps that allow you to quickly obtain the necessary cartometric and morphometric indicators and geoecological characteristics of large lakes in the study region. Thus, by using the potential of graphical visualization of information from a specialized regional GIS in the MapInfo software shell, the possibilities of graphical representation of traditional statistical data of qualitative and quantitative cartometric and morphometric characteristics of lakes are clearly illustrated. The results of the work carried out, the obtained geoinformation and cartographic materials and significant amounts of information accumulated in databases of specialized regional GIS make it possible to organize and carry out a complex of full-scale monitoring studies of lakes for a large set of indicators, which is not only relevant and allows you to track the current state, but also to identify the dynamics of lake ecosystems within the territory of the region.

Eutrophication‐driven eco‐evolutionary dynamics indicated by differences in stoichiometric traits among populations of Daphnia pulicaria

Abstract Microevolution can have consequences at higher levels of ecological organization. Although divergence among populations can be rapid and driven by anthropogenic changes to the environment, the ecological relevance of evolution induced by human activities remains poorly understood. A frequent way in which human activities drive microevolution is the increase in supply of nutrients such as phosphorus (P) that are required for fitness‐relevant traits such as growth and reproduction. Because higher P concentrations decrease P‐use efficiency and feeding rate in heterotrophic consumers such as Daphnia, we hypothesized that such adjustments should alter consumer–resource dynamics. We examined how cultural eutrophication in temperate lakes causes trait variation in the grazer Daphnia pulicaria. We tested for variation in Daphnia traits and genetic variation in the metabolic enzyme phosphoglucose isomerase (Pgi) which are each known to respond to eutrophication. We then examined the impact of this variation on consumer–resource dynamics using a combination of experiments and a multi‐lake survey. We found that Daphnia from hypereutrophic lakes responded to experimental hypereutrophic conditions with increased growth rates and fecundity when raised on P‐fertilized seston, but had reduced performance on P‐poor seston relative to eutrophic source Daphnia. These results suggest that Daphnia may face a trade‐off in performance at low versus excess P that may be mediated in part by genetic variation at the Pgi locus. The variation observed in laboratory growth experiments scaled up to Daphnia populations in both mesocosm experiments and among lakes. In both the mesocosm experiment and in the lake survey, Daphnia from hypereutrophic source lakes reached high biomass while phytoplankton biomass also remained high. Given the prevalence and rapid eutrophication of freshwater ecosystems worldwide, these results indicate that considering the potential effects of evolutionary change in ecosystem models could be useful in forecasting the effects of anthropogenic environmental change on pivotal ecosystem services.

Morphology and zoogeography of the burrower-like gammarid Gammarus koshovi (Bazikalova, 1946) (Crustacea, Amphipoda, Gammaridae) – An overlooked and poorly known species in the Siberian fauna

A comprehensive survey of several lakes in the Tuva Republic of Russia yielded, besides the ubiquitous Gammarus lacustris, the discovery of a small freshwater, lacustrine amphipod not previously recorded in this area. A comparative study of the Tore-Khol Lake gammarid population, probably conspecific with Gammarus koshovi (Bazikalova, 1946) originating from Khubsugul Lake, was conducted. The species, G. koshovi, is characterized by a specific habitus: a small-sized compact body, all limbs shortened, carpi of pereopods (PIII and PIV) reduced, coxal plates broad, and pereopod dactyli sturdy. It has been suggested that juveniles of the euryoecious G. lacustris or other large species could be confused with the relatively small G. koshovi. Consequently, we decided to present the distribution of gammarid species throughout south Siberia and Mongolia, referring to the sequences of works primarily by Soviet authors, which may be hard to access by international readers. We discuss affinity with related groups, distribution, and ecology of G. koshovi to better understand their evolution. Additionally, the zoobenthic species diversity of widely represented groups in the ecosystems of Tore-Khol Lake is briefly reviewed. An identification key for the Siberian Gammarus with 10 species is provided.

THE “ONE HEALTH” APPROACH AS A POSSIBLE MODE OF ECOLOGICAL RISK ASSESSMENT (EXAMPLE OF CYANOTOXINS)

Cyanobacteria are a big group of photosynthetic prokaryotic organisms inhabiting fresh and sea waters and damp soils. Cyanobacteria produce secondary metabolites – cyanotoxins, which are potentially dangerous for humans and animals if present in drinking water, and pose real danger for waterfowl, fish, and zooplankton. Therefore, cyanobacteria are often considered as pathogenic organisms albeit they are unable to develop in animals’ organisms. As reported by the UNESCO international hydrological program CYANONET, cyanobacteria and cyanotoxins were found in surface waters in 65 countries. To study the occurrence of cyanobacteria and cyanotoxins in European lakes, two international cooperation programs were implemented, namely CYANOCOST in 2012–2016 and EMLS (European Multi Lake Survey) in 2015. Cyanotoxins are divided into groups according to their action on human organisms (hepatotoxins, neurotoxins, dermatoxins, and cytotoxins). Lately, the health impacts of harmful cyanobacteria have been more frequently detected and reported. However, reports of human and animal illnesses or death associated with harmful cyanobacteria tend to be investigated separately. One Health is an approach that recognizes that the health of people is closely connected to the health of animals and our shared environment. This review illustrates how the investigation of cyanotoxin-associated animal illnesses and death can be used to reduce the risks of human exposure to harmful cyanobacteria. The One Health approach is an environmental risk management method that requires the integration of efforts of different specialists.

Evaluation of the Composition of Ichthyofauna in Lakes Free from Commercial Use in a Tightly Protected Area of the Wolin National Park (Poland)

The ichthyological biodiversity of Polish lakes is poorly understood, even in lakes not used for fishing and those under strict protection. With this in mind, the aim of this study was to conduct a comprehensive ichthyological survey of several lakes in the Wolin National Park (Poland). The study was conducted in Domysławskie and Gardno lakes and the anthropogenic Stara Kredownia reservoir. Each fishing exercise was conducted using benthic nets over a 12 h period. The fish caught were measured and weighed, and the species identified. Shannon-Wiener (H) and Simpson biodiversity indices were determined. The catch comprised a total of 4580 fish (of which 4391 were caught in Domysławskie Lake) belonging to 15 species, with a combined weight of 98,165 g. In general, the most prevalent species were non-predatory fish: roach (Rutilus rutilus), freshwater bream (Abramis brama), white bream (Blicca bioerkna), bleak (Alburnus alburnus), and rudd (Scardinius erythrophthalmus). Individually, perch (Perca fluviatilis) and roach (Rutilus rutilus) were the most abundant species. Ichthyofauna diversity varied greatly between the studied water bodies, with 15 species found in Domysławskie Lake and only 6 species in Gardno Lake. In Stara Kredownia Reservoir, no fish were caught, but amphibians were observed, such as great crested newts (Triturus cristatus) and common newts (Lissotriton vulgaris). Based on the results obtained, Lake Domysławskie had a higher species ichthyofauna diversity than the other ‘tench and pike’ lakes. Gardno Lake had a much lower biodiversity.

Changes in acidity, DOC, and water clarity of Adirondack lakes over a 30-year span

Lake surveys conducted in 1987–88 and 2018–19 show changes in the chemical and optical properties of Adirondack lakes recovering from acidification. Among chronically acidified lakes (1980s pH < 5.5, ANC < 0 µeq L−1), increases in pH and reductions in monomeric Al were accompanied by significant increases in light attenuation, DOC, and CDOM. DOC-specific dissolved color (CDOM:DOC) doubled over the 30-year span, and is the likely factor accounting for loss of water clarity in Adirondack lakes during recovery from acidification. Monitoring data (1994–2002) from a subset of these lakes show that reductions in light attenuation were accompanied by stronger thermal stratification and greater hypolimnetic oxygen depletion. Lakes most affected by acidification experienced greater loss of water clarity during recovery relative to moderately acidified lakes. These findings are consistent with the hypothesis that lake acidification resulted in a reduction in light attenuation by CDOM resulting in greater water clarity in acidified lakes, and that this process has been reversed following regional declines in sulfate deposition.

David W. Schindler—Icon and Iconoclast

David W. Schindler—Icon and Iconoclast

Recreationist willingness to pay for aquatic invasive species management.

We estimated willingness to pay for local aquatic invasive species lake management in the form of a daily lake access fee by conducting summer lake surveys in Minnesota, USA. Similar pairs of lakes with differing infestations of zebra mussels, Dreissena polymorpha, and starry stonewort, Nitellopsis obtuse, were used as study sites to infer how being at an infested lake vs. being at an uninfested lake and different local species would impact responses. We also examined recreationists’ visit motivation, and aquatic invasive species perceived risk, knowledge, and awareness of problem. We estimated mean willingness to pay about nine to ten dollars per day, which did not differ significantly by lake. Additionally, perceived risk, awareness of problem, and visit motivation were significant in predicting willingness to pay, which could have important ramifications for aquatic invasive species management.

Quantification of the covariation of lake microbiomes and environmental variables using a machine learning-based framework.

It is known that microorganisms are essential for the functioning of ecosystems, but the extent to which microorganisms respond to different environmental variables in their natural habitats is not clear. In the current study, we present a methodological framework to quantify the covariation of the microbial community of a habitat and environmental variables of this habitat. It is built on theoretical considerations of systems ecology, makes use of state-of-the-art machine learning techniques and can be used to identify bioindicators. We apply the framework to a data set containing operational taxonomic units (OTUs) as well as more than twenty physicochemical and geographic variables measured in a large-scale survey of European lakes. While a large part of variation (up to 61%) in many environmental variables can be explained by microbial community composition, some variables do not show significant covariation with the microbial lake community. Moreover, we have identified OTUs that act as "multitask" bioindicators, i.e., that are indicative for multiple environmental variables, and thus could be candidates for lake water monitoring schemes. Our results represent, for the first time, a quantification of the covariation of the lake microbiome and a wide array of environmental variables for lake ecosystems. Building on the results and methodology presented here, it will be possible to identify microbial taxa and processes that are essential for functioning and stability of lake ecosystems.

The identification of watermilfoil, discovery of hybrid watermilfoil, and their implications for aquatic plant management in the Clark Fork River, Western MT, USA

Eurasian watermilfoil (Myriophyllum spicatum) is an invasive submersed macrophyte that has infested many waters in North America since its introduction. Eurasian watermilfoil has the ability to alter the structure and function of the ecosystems that it invades. Eurasian watermilfoil was first surveyed in the Clark Fork River, MT in 2008, alongside the native northern watermilfoil (Myriophyllum sibiricum). Three reservoirs (Cabinet Gorge, Noxon Rapids and Thompson Falls) on the lower Clark Fork River had entire lake surveys conducted using the point intercept method. Morphological data from these surveys showed that only Eurasian watermilfoil and northern watermilfoil were present during the time of the surveys in 2008. The results of the morphological identification were supported by molecular identification at three different laboratories. In 2015, a genetic survey of watermilfoil species was conducted on the Noxon Rapids Reservoir and found that hybrid watermilfoil (Myriophyllum spicatum × sibiricum) was present. This hybridization event poses a number of issues for aquatic plant management. Hybrid watermilfoil is much more difficult to identify morphologically than its parent types. The hybrid is also more invasive and may be differentially susceptible to some herbicides than the parental type Eurasian watermilfoil.

Testing the Waters: Tzeltal Maya Rituals, Reconnaissance, and Survey of Lakes in the Lacanhá Basin, Chiapas, Mexico

Ritual practices associated with bodies of water are well known and have been the focus of several research projects in Maya regions of Mexico. In the Northern Lowlands, for example, cenotes were and are important natural and cultural resources for prehispanic as well as for modern peoples. Based on our underwater archaeological research, we have found that ritual activities were present in other Maya regions, such as the Lacanha River basin. The recovery of ceramic sherds in the lagoons in the area of Nueva Palestina, Ocosingo, Chiapas, and ethnographic studies here suggest a continuation of the ancient to modern ritual practices associated with bodies of water. This new interdisciplinary work also allows us to know more about the ancient inhabitants of the Lacanha River basin where few systematic archaeological studies have been conducted.

Assessing Subaquatic Mass Movement Hazards: an Integrated Observational and Hydrodynamic Modelling Approach

High-resolution lake and reservoir bathymetric surveys can pinpoint locations that may experience underwater landslides (subaquatic sedimentary mass movements). These can pose a risk to underwater and shoreline infrastructure. This paper outlines an approach for using spatial variation in sedimentary patterns to identify areas susceptible to subaquatic mass movements in lakes and reservoirs. This study focusses on Lake Biel (Switzerland), which has experienced a protracted history of upstream alteration of river flow. Altered flow patterns increase risk of unstable sedimentary features and subaquatic mass movements. Data from sediment traps and cores, Acoustic Doppler Current Profilers and results from a 3D hydrodynamic model gave a consistent picture of spatial and temporal variation in weather-related sedimentation. Erosion caused by short-term rain events contributes the largest proportion of sediments to the lake. Strong rain events combine with typical wind patterns to drive lake circulation. The net effect results in preferential sedimentation onto a steeply sloping shelf prone to subaquatic slides. The integrated approach outlined here incorporates short- and long-term sediment dynamics to provide a systematic assessment of lake sedimentation and potential mass movement hazards. This research represents a first step in developing a risk-evaluation tool for aquatic hazard evaluation.

Muskrat distributions in a changing Arctic delta are explained by patch composition and configuration

Climate change is altering Canada’s western Arctic, including hydrology in the heterogeneous environment of the Mackenzie Delta, and these changes are impacting biotic communities. Muskrats are culturally important semi-aquatic rodents whose populations may respond to changing water levels in this region. We investigated the importance of patch configuration and patch composition — two properties affected by climate change — on muskrat presence and distribution in the Mackenzie Delta, using remote sensing and field-based surveys of lakes with and without muskrats. We tested multiple hypotheses about predictors of muskrat and forage biomass presence using a model-selection approach. We found that configuration and patch composition explained muskrat distribution in the Mackenzie Delta, with composition being of greater importance. Muskrats were more likely to occur in lakes with longer perimeters, higher amounts of forage biomass, and sediment characteristics that supported macrophyte growth. The latter two conditions are related to spring flooding regimes, which will likely be altered by climate change. This may result in a decrease in muskrat habitat in the Mackenzie Delta. Our research indicates that both patch composition and configuration are important for understanding species distributions in heterogeneous environments.

Origin of modern dolomite in surface lake sediments on the central and western Tibetan Plateau

Modern dolomite was found in the sediments of 20 lakes on the central and western Tibetan Plateau during lake surveys, in August to November of 2012–2015. We analyzed the mineralogy of authigenic carbonates and the chemical composition of lake water to investigate the environmental factors affecting dolomite formation and to determine the mechanisms of dolomite formation. X-ray diffraction analysis suggested that the dolomite content ranged from 3% to 10%, with a mean of 5%, and that the majority of the dolomite in the surface lake sediments was Ca-dolomite. Dolomite formed in a wide range of salinity environments. There was a positive linear relationship between salinity and Mg/Ca ratio, whereas the pH and sulfate (SO42−) concentration are not significantly correlated with Mg/Ca ratio. High Mg/Ca ratio, high salinity, high sulfate concentration, and high pH are important environmental factors in favor of dolomite precipitation. Evaporation and microbial activity are potential mechanisms for dolomite formation in the central and western Tibetan Plateau. The positive relationship between δ18O and δ13C indicates that the dolomite formed in lakes has a long residence time and undergoes continuous evaporation. The crystal morphologies of dolomite were scattered euhedral grains with diameters of 2–10 μm, as well as sub-spherical and spherical grains (<2 μm) which were present either as dispersed crystals or were aggregated into dolomite clusters. Dolomite crystals were identical both in shape and size to those of microbial dolomite previously discovered in modern lake environments and culture experiments. The dolomite precipitation temperature range calculated using the low-temperature microbial equation was close to the measured temperature, further indicating that microbial activity may be involved in dolomite formation. This study provides natural locations with different water salinities and other environmental factors for dolomite precipitation, which has important significance for studying the mechanism of dolomite formation.

Reduction of taxonomic bias in diatom species data.

Inconsistency in taxonomic identification and analyst bias impede the effective use of diatom data in regional and national stream and lake surveys. In this study, we evaluated the effect of existing protocols and a revised protocol on the precision of diatom species counts. The revised protocol adjusts five elements of sample preparation, taxon identification and enumeration, and quality control (QC) samples. We used six independent datasets to assess the effect of the adjustments on analytical outcomes. The first dataset was produced by five analysts from three laboratories following a standard protocol (Charles et al. 2002). The remaining datasets were produced by 2-3 analysts in 1-3 laboratories following a revised protocol. The revised protocol included the following modifications: 1) use of Battarbee settling chambers to prepare coverslips, 2) development of coordinated pre-count voucher floras based on morphological operational taxonomic units (mOTUs), 3) random assignment of samples to analysts, 4) post-count identification and documentation of taxa, and 5) increased QC samples. The revised protocol reduced taxonomic bias, as measured by reduction in analyst signal, and improved similarity among QC samples. Reduced taxonomic bias improves the performance of biological assessments, facilitates transparency across studies, and refines estimates of diatom species distributions.

Constraining dissolved organic matter sources and temporal variability in a model sub-Arctic lake

Circumpolar lakes comprise ~ 1.4 million km2 of arctic and subarctic landscapes and are vulnerable to change in vegetation, permafrost distribution, and hydrological conditions in response to climate warming. However, the composition and cycling of dissolved organic matter (DOM) is poorly understood for these lakes because most are remote and unstudied. The goal of this study was to assess timescale and source controls on DOM composition in Canvasback Lake, a shallow, sub-Arctic lake in interior Alaska with similar hydrologic and geomorphic characteristics to about a quarter of circumpolar lake ecosystems. Lake dissolved organic carbon (DOC) concentration varied by as much as 16% from the mean (3.34 mg L−1 change) through diel cycles in spring 2016 to fall 2017 and was accompanied by minor changes in DOM composition. At the seasonal scale, DOC concentration increased from spring through fall to very high concentrations under ice in winter. Decreases in both condensed aromatic and polyphenolic compound classes and lignin carbon-normalized yield, plus increased relative abundance of aliphatic compounds, suggests that DOM composition shifts from a pulse of allochthonous DOM in the spring to more autochthonous under-ice. These changes highlight the seasonally-dynamic nature of DOM in circumpolar lakes that are poorly captured by single-visit lake surveys and underscores the need to measure DOM properties and fate consistently across multiple timescales (i.e. seasonally) to better constrain the role of DOM in lake processes. To further assess DOM sources, a suite of endmember leachates were compared to bulk lake DOM, indicating solely allochthonous inputs are not well reflected in lake DOM, highlighting the role of degradation processes or mixing with autochthonous sources. Thus, Canvasback Lake appears less well connected to terrestrial inputs compared to past studies of northern high-latitude lakes and does not behave as previous boreal lake models suggest.

Toxic Algal Blooms Are Worsening with Climate Change

Researchers use remote sensing technology to carry out a global survey of large freshwater lakes.