shallow lake

Magmatism in the Quaternary Clear Lake volcanic field (CLVF), with its youngest eruption having only occurred c. 10 ka ago, is commonly invoked as the heat source for the world's largest commercial geothermal reservoir, The Geysers, in northern California. A shallow silicic magma reservoir in the upper-middle crust has been discovered for some time, but the location and mechanism of a potential deep mafic magma reservoir have remained elusive. Here, we present a seismic tomographic model that images the entire crustal column, clearly revealing a multilevel transcrustal magmatic system beneath the Geysers-Clear Lake area...

In shallow lakes, there are complex relationships between lake eutrophication and greenhouse gas emissions that deserve to be studied, which are important for solving lake eutrophication, slowing down climate warming, and reducing carbon emissions. In order to explore the relationship and mechanism between eutrophication and greenhouse gases (GHGs), the net GHGs emission flux and transformation of carbon, and nitrogen in 45 shallow freshwater lakes were investigated from May to September 2022. Eutrophication facilitated potential denitrification rate (Dt ) without increasing nitrous oxide (N2 O) production based on the significantly positive relationship between eutrophication and Dt ...

The nitrogen (N) removal characteristics in water columns and sediments of shallow lakes, influenced by various factors, may exhibit spatial variations in lakes with algal-macrophyte dominance. The N removal rates in water columns and sediments of Lake Taihu were investigated. Our findings indicated that the total N removal rates in Lake Taihu followed the order of algae-dominance > macrophyte-dominance > pelagic lake (without the presence of algae and macrophytes). Correlation analysis revealed that the key environmental factors affecting denitrification and anammox in sediments of algae/macrophyte-type lakes were nitrate nitrogen (NO3 - -N), nitrite nitrogen (NO2 - -N), ammonia nitrogen (NH4 + -N), and chlorophyll a (Chl-a)...

Shallow lakes are typically dominated by macrophytes, which have important functional roles regulating trophic conditions and creating biological habitat. Macrophytes have been shown to strongly influence water chemistry and shape microbial communities in shallow lakes. In Florida, many large, shallow lakes are dominated by alien invasive, submersed macrophytes, such as hydrilla (Hydrilla verticillata [L.F.] Royle) and are intensively managed to reduce infestations and contain the spread of these alien invasive macrophytes...

The influence of macrophytes on the optical environment of the littoral zone was assessed by studying the effect of monospecific Potamogeton perfoliatus on the quantitative and qualitative properties of light and the response of plants to this altered environment. P. perfoliatus was shown to alter the optical environment and consequently its own architecture: in high-density pondweed patches, 67 percent of incident light was absorbed in the top 10 cm, while spectral properties of light was significantly altered...

This research investigates the influence of water composition, the presence of seasonal algal mats, detrital inputs and the activity of microorganisms on the crystallization of aragonite in the sediments deposited in the hypersaline Laguna Honda wetland (S of Spain). The high alkaline and hypersaline waters (pH > 9.2 and C.E. > 70 mS/cm) of the wetland lake are rich in SO4 2- (>24,000 mg/l), Cl- (>21,000 mg/l), Na+ (>11,000 mg/l) Mg2+ (>8400 mg/l) and Ca2+ (>1000 mg/l), and are supersaturated for dolomite, calcite and aragonite...

Shallow urban lakes are naturally vulnerable to ecosystem degradation. Rapid urbanization in recent decades has led to a variety of aquatic problems such as eutrophication, algal blooms, and biodiversity loss, increasing the risk to lake-wide ecological sustainability. Instead of a simple binary assessment of ecological risk, holistic evaluation frameworks that consider multiple stressors and receptors can provide a more comprehensive assessment of overall ecological risk. In this study, we analyzed a combined dataset of government statistics, remote sensing images, and 1 year of field measurements to develop an index system for urban lake ecological risk assessment based on the pressure-state-response (PSR) framework...

Microplastic contamination is ubiquitous across the globe, even in remote locations. Still, the sources and pathways of microplastics to such locations are largely unknown. To investigate microplastic contamination in a semi-remote location, we measured microplastic concentrations in nine oligotrophic lakes within and around the International Institute for Sustainable Development-Experimental Lakes Area in northwestern Ontario, Canada. Our first objective was to establish ambient concentrations of microplastics in bottom sediments, surface water, and atmospheric deposition in semi-remote boreal lakes...

A variety of lakes located in the dry steppe area of southwestern Siberia are exposed to rapid climatic changes, including intra-century cycles with alternating dry and wet phases driven by solar activity. As a result, the salt lakes of that region experience significant fluctuations in water level and salinity, which have an essential impact on the indigenous microbial communities. But there are few microbiological studies that have analyzed this impact, despite its importance for understanding the functioning of regional water ecosystems...

Day and nighttime autumn fish abundance and biomass were studied in the pelagic and littoral zones of Lake Sauka in Latvia. Both pelagic methods (hydroacoustics and trawling) revealed significantly higher fish abundance and biomass during the day than at night, especially in deeper zones (below 3 m). Roach (Rutilus rutilus) and Eurasian perch (Perca fluviatilis) dominated the trawl catches during the day, while roach and ruffe dominated at night. Fish smaller than 14 cm strongly dominated in both the trawl catches and hydroacoustic observations...

The magnetic properties of lake sediments account for close relationships with heavy metal(loid)s (HMs), but little is known about their relationships with chemical fractions (CFs) of HMs. Establishing an effective workflow to predict HMs risk among various machine learning (ML) methods in conjunction with magnetic measurement remains challenging. This study evaluated the simulation efficiency of nine ML methods in predicting the risk assessment code (RAC) and ratio of the secondary and primary phases (RSP) of HMs with magnetic parameters in sediment cores of a shallow lake...

Anthropogenic eutrophication remains a critical global issue, significantly impacting surface water quality. Numerous regions have implemented beneficial management practices to combat agricultural nonpoint pollution, often evaluating efficacy at the field scale, but not downstream. In this study, we conducted an extensive, 11-year (2010-2020), all-season, weekly monitoring program in a small, shallow, hypereutrophic lake and main tributary located in a cold climate, northern temperate zone, within a predominantly agricultural-forested mesoscale watershed...

The Arctic is the fastest warming biome on the planet, and environmental changes are having striking effects on freshwater ecosystems that may impact the regional carbon cycle. The metabolic state of Arctic lakes is often considered net heterotrophic, due to an assumed supply of allochthonous organic matter that supports ecosystem respiration and carbon mineralization in excess of rates of primary production. However, lake metabolic patterns vary according to regional climatic characteristics, hydrological connectivity, organic matter sources and intrinsic lake properties, and the metabolism of most Arctic lakes is unknown...

BACKGROUND: The mechanosensory lateral line system is an important sensory modality in fishes, informing multiple behaviours related to survival including finding food and navigating in dark environments. Given its ecological importance, we may expect lateral line morphology to be under disruptive selection early in the ecological speciation process. Here we quantify the lateral line system morphology of two ecomorphs of the cichlid fish Astatotilapia calliptera in crater Lake Masoko that have diverged from common ancestry within the past 1,000 years...

N-cycling processes mediated by microorganisms are directly linked to the eutrophication of lakes and ecosystem health. Exploring the variation and influencing factors of N-cycling-related genes is of great significance for controlling the eutrophication of lakes. However, seasonal dynamics of genomic information encoding nitrogen (N) cycling in sediments of eutrophic lakes have not yet been clearly addressed. We collected sediments in the Baiyangdian (BYD) Lake in four seasons to explore the dynamic variation of N-cycling functional genes based on a shotgun metagenome sequencing approach and to reveal their key influencing factors...

Cyanobacterial bloom is a pressing issue affecting water supply security and ecosystem health. Phosphorus (P) released from cyanobacterial bloom during recession is one of the most important components involved in the lake P cycle. However, little is known about the consequences and mechanisms of the P cycle in overlying water and sediment due to the anthropogenic treatments of cyanobacterial blooms. In this study, treatment methods using hydrogen peroxide (H2 O2 ), polyaluminum chloride (PAC), and the feces of silver carp were investigated for their influence on the P cycle using microcosm experiments...

Prediction of the complex cyanobacteria-environment interactions is vital for understanding harmful bloom formation. Most previous studies on these interactions considered specific properties of cyanobacterial cells as representative for the entire population (e.g., growth rate, mortality, and photosynthetic capacity (Pmax)), and assumed that they remained spatiotemporally unchanged. Although, at the population level, the alteration of such traits can be driven by intraspecific competition, little is known about how traits and their plasticity change in response to environmental conditions and affect the bloom formation...

Seagrasses are marine flowering plants that inhabit shallow coastal and estuarine waters and serve vital ecological functions in marine ecosystems. However, seagrass ecosystems face the looming threat of degradation, necessitating effective monitoring. Remote-sensing technology offers significant advantages in terms of spatial coverage and temporal accessibility. Although some remote sensing approaches, such as water column correction, spectral index-based, and machine learning-based methods, have been proposed for seagrass detection, their performances are not always satisfactory...

Stratigraphic determination of the Anthropocene, the "Great Acceleration", requires more key globally synchronous stratigraphic markers which reflect the significant human impacts on Earth. Lacustrine sediment magnetic characteristics are of considerable importance in Anthropocene studies because they respond sensitively to environmental changes. There are many shallow lakes in the Songnen Plain (SNP) in northeast China, which are conducive to obtaining Anthropocene sedimentary records. This study explored magnetic materials in lacustrine sediment responses to environmental evolution impact by human activities on the SNP by measuring magnetic parameters in dated sediment cores from 5 shallow lakes in the SNP, northeast China...

Ecological water replenishment is a crucial and effective measure to improve the water quality and ecological function of lakes. However, the effects of ecological water replenishment on the pollution characteristics and ecological risks of trace elements and bacterial communities in lake surface water are still kept unclear. We investigated the pollution levels and potential ecological risks for trace elements, as well as variation of the bacterial community in surface water in the BYD lake before and after ecological water replenishment...