Publications related to Trophic state index

Combined Earth observations reveal the sequence of conditions leading to a large algal bloom in Lake Geneva

Damien Bouffard, Rafael Sebastian Reiss, Abolfazl Irani Rahaghi, Oscar Rodrigo Sepúlveda Steiner, Marco Toffolon, Frédéric Charles Soulignac

Freshwater algae exhibit complex dynamics, particularly in meso-oligotrophic lakes with sudden and dramatic increases in algal biomass following long periods of low background concentration. While the fundamental prerequisites for algal blooms, namely ligh ...

Springernature2024

Disentangling the effects of climate change and reoligotrophication on primary production in a large lake

Alfred Johny Wüest, Hugo Nicolás Ulloa Sánchez, Shubham Krishna, Emile Barbe

Climate change and reduction in nutrient loads have significant effects on primary production and phytoplankton growth dynamics. Since in the last few decades in many regions, nutrients in lakes were reduced simultaneously as the climate changed. Yet, it r ...

SPRINGER BASEL AG2023

Iron Reduction in Profundal Sediments of Ultraoligotrophic Lake Tahoe under Oxygen-Limited Conditions

Meret Aeppli

Increased periods of bottom water anoxia in deep temperate lakes due to decreasing frequency and depth of water column mixing in a warming climate may result in the reductive dissolution of iron minerals and increased flux of nutrients from the sediment in ...

2023

Colloidal transport and deposition through dense vegetation

David Andrew Barry, Li Chen, Congrong Yu

The effectiveness of submerged synthetic aquatic vegetation on removal of colloids from flowing water was investigated to explore retention of particulate nonpoint source pollutants in aquatic systems. In colloid transport experiments, the deposition rate ...

Elsevier2022

The Land-Water-Energy Nexus of Ruzizi River Dams (Lake Kivu Outflow, African Great Lakes Region): Status, Challenges, and Perspectives

Alfred Johny Wüest

Hydroelectric power (HP) represents the main source of electricity in Africa, including the Democratic Republic of Congo. The demand for new dam construction is high, and major projects are currently progressing through planning and implementation stages. ...

FRONTIERS MEDIA SA2022

Dynamics of wind-induced coastal upwelling and interbasin exchange in Lake Geneva during winter: Implications for deepwater renewal

Rafael Sebastian Reiss

Water quality in lakes is closely linked to hydrodynamics and often dominated by stratification, limiting the exchange between the epi- and hypolimnion. Thus, the vertical redistribution of biogeochemical tracers such as dissolved oxygen and nutrients by c ...

EPFL2021

Source apportionment of atmospheric P using the Positive Matrix Factorization (PMF) model

Athanasios Nenes, Kalliopi Violaki, Christos Panagiotopoulos

The PMF receptor model was applied to a combined dataset using specific markers such as phospholipids and sugars together with other metals (e.g. Al, Pb, V) and ions (e.g. K+, Ca2+, SO42-, NO3-) as tracers of main aerosol sources in order to characterize t ...

2020

Hypolimnetic oxygen depletion rates in deep lakes: Effects of trophic state and organic matter accumulation

Alfred Johny Wüest, Robert Vincent Schwefel, Beat Mueller

This study investigated the consumption of oxygen (O-2) in 11 European lakes ranging from 48 m to 372 m deep. In lakes less than similar to 100 m deep, the main pathways for O-2 consumption were organic matter (OM) mineralization at the sediment surface an ...

American Society of Limnology and Oceanography2020

Changing nutrient cycling in Lake Baikal, the world's oldest lake

Sebastiano Piccolroaz

Lake Baikal, lying in a rift zone in southeastern Siberia, is the world's oldest, deepest, and most voluminous lake that began to form over 30 million years ago. Cited as the "most outstanding example of a freshwater ecosystem" and designated a World Herit ...

National Academy of Sciences2020

Insights into the dynamics of the deep hypolimnion of Lake Geneva as revealed by long-term temperature, oxygen, and current measurements

Ulrich Lemmin

In order to identify or shed light on dominant long-term processes of the deep hypolimnion of Lake Geneva (309 m depth), time series of temperature and horizontal currents and profiles of temperature and oxygen, taken for over a decade in the deepest part ...

American Society of Limnology and Oceanography2020

Oxygen consumption in seasonally stratified lakes decreases only below a marginal phosphorus threshold

Alfred Johny Wüest, Robert Vincent Schwefel

Areal oxygen (O-2) consumption in deeper layers of stratified lakes and reservoirs depends on the amount of settling organic matter. As phosphorus (P) limits primary production in most lakes, protective and remediation efforts often seek to reduce P input. ...

Springer Nature2019

Atomistic Simulations of The Structure of Calcium Silicate Hydrates: Interlayer Positions, Water Content And A General Structural Brick Model

Aslam Kunhi Mohamed

Portland cement has been in use by human civilization for over a century. Yet, we do not fully understand its hydration reaction mechanisms due to the complexity of the system and its continued reaction over time making it hard to study it experimentally. ...

EPFL2018

Fast Potentiometric CO2 Sensor for High-Resolution in Situ Measurements in Fresh Water Systems

Nadezda Pankratova, Bernhard Wehrli

We present a new potentiometric sensor principle and a calibration protocol for in situ profiling of dissolved CO2 with high temporal and spatial resolution in fresh water lakes. The sensor system is based on the measurement of EMF between two solid-contac ...

AMER CHEMICAL SOC2018

An ecotoxicological view on neurotoxicity assessment

Wolfgang Schulz

The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts in ...

SPRINGEROPEN2018

Ecological strategies and metabolic trade-offs of complex environmental biofilms

Tom Ian Battin, Hannes Markus Peter

Microorganisms aggregated into matrix-enclosed biofilms dominate microbial life in most natural, engineered, and medical systems. Despite this, the ecological adaptations and metabolic trade-offs of the formation of complex biofilms are currently poorly un ...

Nature Publishing Group2017

Are flood-driven turbidity currents hot spots for priming effect in lakes?

Damien Bouffard

In deep stratified lakes, such as Lake Geneva, flood-driven turbidity currents are thought to contribute to the replenishment of deep oxygen by significant transport of river waters saturated with oxygen into the hypolimnion. The overarching aim of this st ...

Copernicus GmbH2016

Effects of climate change on deep-water oxygen and winter mixing in a deep lake (Lake Geneva)

Alfred Johny Wüest, Damien Bouffard, Robert Vincent Schwefel

Oxygen is the most important dissolved gas for lake ecosystems. Because low oxygen concentrations are an ongoing problem in many parts of the oceans and numerous lakes, oxygen depletion processes have been intensively studied over the last decades and were ...

2016

Effects of climate change on deepwater oxygen and winter mixing in a deep lake (Lake Geneva): Comparing observational findings and modeling

Alfred Johny Wüest, Damien Bouffard, Robert Vincent Schwefel, Adrien Gaudard

Low concentrations of dissolved oxygen remain a global concern regarding the ecological health of lakes and reservoirs. In addition to high nutrient loads, climate-induced changes in lake stratification and mixing represent additional anthropogenic menace ...

American Geophysical Union2016

Application of remote sensing for the optimization of in-situ sampling for monitoring of phytoplankton abundance in a large lake

Alfred Johny Wüest, Damien Bouffard, Isabel Blanca Sophie Kiefer

Directives and legislations worldwide aim at representatively and continuously monitoring the ecological status of surface waters. In many countries, chlorophyll-a concentrations (CHL) are used as an indicator of phytoplankton abundance and the trophic lev ...

Elsevier2015

Accelerated Water Quality Improvement during Oligotrophication in Peri-Alpine Lakes

Alfred Johny Wüest, Beat Mueller

Monitoring of four eutrophic Swiss lakes undergoing oligotrophication during more than 25 years (i.e., gradually decreasing nutrient loading, productivity, and associated symptoms of eutrophication) revealed that phosphorus (P) net sedimentation rates (the ...

Amer Chemical Soc2014