Search results for "lakes"
showing 10 items of 178 documents
Elimination of cyanobacteria and microcystins in irrigation water—effects of hydrogen peroxide treatment
2020
AbstractCyanobacterial blooms pose a risk to wild and domestic animals as well as humans due to the toxins they may produce. Humans may be subjected to cyanobacterial toxins through many routes, e.g., by consuming contaminated drinking water, fish, and crop plants or through recreational activities. In earlier studies, cyanobacterial cells have been shown to accumulate on leafy plants after spray irrigation with cyanobacteria-containing water, and microcystin (MC) has been detected in the plant root system after irrigation with MC-containing water. This paper reports a series of experiments where lysis of cyanobacteria in abstracted lake water was induced by the use of hydrogen peroxide and…
New enveloped dsRNA phage from freshwater habitat.
2015
Cystoviridae is a family of bacteriophages with a tri-segmented dsRNA genome enclosed in a tri-layered virion structure. Here, we present a new putative member of the Cystoviridae family, bacteriophage ϕNN. ϕNN was isolated from a Finnish lake in contrast to the previously identified cystoviruses, which originate from various legume samples collected in the USA. The nucleotide sequence of the virus reveals a strong genetic similarity (~80 % for the L-segments, ~55 % for the M-segments and ~84 % for the S-segments) to Pseudomonas phage ϕ6, the type member of the virus family. However, the relationship between ϕNN and other cystoviruses is more distant. In general, proteins located in the int…
Top consumer abundance influences lake methane efflux
2015
Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This re…
Functional and genomic diversity of methylotrophic Rhodocyclaceae: description of Methyloversatilis discipulorum sp. nov.
2015
Three strains of methylotrophic Rhodocyclaceae (FAM1T, RZ18-153 and RZ94) isolated from Lake Washington sediment samples were characterized. Based on phylogenetic analysis of 16S rRNA gene sequences the strains should be assigned to the genus Methyloversatilis. Similarly to other members of the family, the strains show broad metabolic capabilities and are able to utilize a number of organic acids, alcohols and aromatic compounds in addition to methanol and methylamine. The main fatty acids were 16:1ω7c (49–59 %) and 16:0 (32–29 %). Genomes of all isolates were sequenced, assembled and annotated in collaboration with the DOE Joint Genome Institute (JGI). Genome comparison revealed that the s…
A fugacity model assessment of ibuprofen, diclofenac, carbamazepine, and their transformation product concentrations in an aquatic environment
2018
An updated version of FATEMOD, a multimedia fugacity model for environmental fate of organic chemicals, was set up to assess environmental behaviour of three pharmaceuticals in northern Lake Päijänne, Finland. Concentrations of ibuprofen, diclofenac, and carbamazepine were estimated at various depths at two sites: near a wastewater treatment plant and 3.5 km downstream the plant. When compared with environmental sampling data from corresponding depths and sites, the predicted concentrations, ranging from nanograms to hundreds of nanograms per litre, were found to be in good agreement. Weather data were utilised with the model to rationalise the effects of various environmental parameters on…
Climate change impact on SWAT simulated streamflow in western Kenya
2009
12 pages (3/4 p.); International audience; Weather and climate extremes such as droughts and floods have far reaching impacts in Kenya. They have had implications in a variety of sectors including agriculture, water resources, health, energy, and disaster management among others. Lake Victoria and its catchment support millions of people and any impact on its ability to support the livelihoods of the communities in this region is of major concern. Thus, the main objective of this study was to assess the potential future climatic changes on the Nzoia catchment in the Lake Victoria basin, and how they might affect streamflow. The Soil and Water Assessment Tool was used to investigate the impa…
A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
2018
Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The Europea…
Spatial community concordance of summer phytoplankton and profundal macroinvertebrates in boreal lakes
2014
Reliance of profundal benthic macroinvertebrate assemblages on epilimnetic algal production — a key element of pelagic–benthic coupling — is a well-recognized phenomenon in the literature but the details are still poorly understood. In particular, the importance of taxonomic composition of algal communities and associated qualitative aspects of the settling material to benthic invertebrates is poorly known. We addressed this issue by investigating concordance of summer phytoplankton and profundal macroinvertebrate community composition using data from 47 boreal lakes. We examined community variation and environmental correlates of phytoplankton and macroinvertebrates with nonmetric multidi…
The value of perfect and imperfect information in lake monitoring and management.
2020
Highlights • Knowledge on the value of monitoring can assist decision-making in lake management. • We calculate value of perfect information theoretically. • We estimate value of imperfect information with Monte Carlo type of approach. • Generally, monitoring is profitable to invest in if VOI exceeds the cost. • Additional monitoring is profitable even if the lake is in good condition a priori. Uncertainty in the information obtained through monitoring complicates decision making about aquatic ecosystems management actions. We suggest the value of information (VOI) to assess the profitability of paying for additional monitoring information, when taking into account the costs and benefits of…
Combined effects of eutrophication and warming on polyunsaturated fatty acids in complex phytoplankton communities:A mesocosm experiment
2022
Climate change and eutrophication are among the main stressors of shallow freshwater ecosystems, and their effects on phytoplankton community structure and primary production have been studied extensively. However, their combined effects on the algal production of polyunsaturated fatty acids (PUFA), specifically, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are currently unresolved. Moreover, the proximate reasons for changes in phytoplankton EPA and DHA concentrations are unclear, i.e., the relative importance of ecological (changes in the community composition) vs. ecophysiological (within taxa changes in EPA and DHA levels) factors. We investigated the responses of phytopla…