Adopt a Lake: Successfully Tracking Harmful Cyanobacterial Blooms in Canadian Surface Waters Through Citizen Science

The proliferation of harmful waterborne cyanobacterial algal blooms, some of which can produce potent toxins, poses severe risks to environmental and human health. Academic and governmental monitoring efforts may be constrained by budget, time, and staff, and thus miss otherwise significant pollution events. Here, we report on the implementation of a citizen science project to track harmful cyanobacterial blooms in lakes and waterways across Canada. Through both crowdsourcing and crowdfunding, the Adopt a Lake (Adopt a Lake 2022) campaign aimed to document the potential presence of cyanobacteria and toxins with the assistance of participants, thus improving public awareness of the issue of water quality preservation. Using social media, participants were encouraged to participate in the initiative by collecting samples during a bloom from a nearby pond or by making a financial contribution to support the initiative. Adopt a Lake benefitted from the analytical platform of Algal Blooms Treatment, Risk Assessment, Predictions, and Prevention (ATRAPP), a research project focused on the prediction and management of harmful cyanobacterial blooms. The presence of cyanotoxins, which can confirm whether a lake has a toxic bloom, was determined through high-resolution mass spectrometry analyses. This paper presents an overview of the implementation of the Adopt a Lake initiative, the campaign’s status, and the lessons learned, and it argues the importance of continual monitoring of cyanobacterial blooms

PRESENT DAY DEFORMATION IN THE EAST VIETNAM SEA AND SURROUNDING REGIONS

This paper presents velocities of present-day tectonic movement and strain rate in the East Vietnam Sea (South China Sea) and surroundings determined from GPS campaigns between 2007 and 2010. We determine absolute velocities of GPS stations in the ITRF05 frame. The result indicates that GPS stations in the North of East Vietnam Sea move eastwards with the slip rate of 30 - 39 mm/yr, southwards at the velocities of 8 - 11 mm/yr. Song Tu Tay offshore moves eastwards at the rate of ~24 mm/yr and southwards at ~9 mm/yr. GPS stations in the South of East Vietnam Sea move to the east at the rate of ~22 mm/yr and to the south at the velocities of 7 - 11 mm/yr. The effect of relative movement shows that the Western Margin Fault Zone activates as left lateral fault zone at the slip rate less than 4 mm/year.In Western plateau, the first result from 2012 - 2013 GPS measurement shows that the velocities to the east vary from 21.5 mm/yr to 24.7 mm/year. The velocities to the south vary from 10.5 mm/yr to 14.6 mm/year. GPS solutions determined from our campaigns are combined with data from various authors and international projects to determine the strain rate in the East Vietnam Sea. Principal strain rate changes from 15 nanostrain/yr to 9 nanostrain/yr in the East Vietnam Sea. Principal strain rate and maximum shear strain rate along the Red River Fault Zone are in order of 10 nanostrain/year. East Vietnam Sea is considered to belong to the Sunda block

Presence of less monitored bioactive cyanotoxins (anabaenopeptins, saxitoxins, and BMAA isomers) in surface waters

The proliferation of harmful cyanobacterial algal blooms is of concern due to the associated release of toxins affecting ecosystems and human health. Among a range of cyanobacterial toxins, the hepatotoxic microcystins are the most documented and have been associated with numerous poisoning episodes. Other bioactive cyanopeptides, such as anabaenopeptins or cyanopeptolins, are rarely monitored in surface water and drinking water. Nonproteinogenic neurotoxic cyanotoxins such as saxitoxins (and analogues) and β-methylamino-l-alanine (BMAA) (and isomers) can also be produced, but there are many analytical challenges in their measurement. Here, we set out to document the occurrence of saxitoxin, neosaxitoxin, and their decarbamoyl analogues, BMAA and isomers (AEG, BAMA, DAB), and anabaenopeptins -A and -B in bloom-impacted surface waters. A large set of lake samples were collected from North America and Western Europe countries and submitted to three specific high-resolution mass spectrometry methods, with limits of detection in the range of 0.7-20 ng/L. The initiative provides much-needed data on the occurrence of infrequently monitored cyanotoxins beyond microcystins

Autonomous online measurement of Β-D-glucuronidase activity in surface water: is it suitable for rapid E. coli monitoring?

Microbiological water quality is traditionally assessed using culture-based enumeration of faecal indicator bacteria such as Escherichia coli. Despite their relative ease of use, these methods require a minimal 18-24 h-incubation step before the results are obtained. This study aimed to assess the suitability of an autonomous online fluorescence-based technology measuring β-glucuronidase (GLUC) activity for rapid near-real time monitoring of E. coli in water. The analytical precision was determined and compared to an automated microbial detection system, two culture-based assays and quantitative real-time PCR (qPCR). Using replicate measurements of grab samples containing E. coli concentrations between 50 and 2330 CFU.100 mL−1, the autonomous GLUC activity measurement technology displayed an average coefficient of variation (CV) of less than 5% that was 4–8-fold lower than other methods tested. Comparable precision was observed during online in situ monitoring of GLUC activity at a drinking water intake using three independent instruments. GLUC activity measurements were not affected by sewage or sediments at concentrations likely to be encountered during long-term monitoring. Furthermore, significant (p < 0.05) correlations were obtained between GLUC activity and the other assays including defined substrate technology (r = 0.77), membrane filtration (r = 0.73), qPCR (r = 0.55) and the automated microbial detection system (r = 0.50). This study is the first to thoroughly compare the analytical performance of rapid automated detection technologies to established culture and molecular-based methods. Results show that further research is required to correlate GLUC activity to the presence of viable E. coli as measured in terms of CFU.100 mL−1. This would allow the use of autonomous online GLUC activity measurements for rapid E. coli monitoring in water supplies used for drinking water production and recreation.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Automated high frequency monitoring of β-D-glucuronidase activity in a drinking water supply: analytical validation and comparison with E. coli quantification methods

info:eu-repo/semantics/publishe

Occurrence and fate of antibiotics in the Seine River in various hydrological conditions

International audienceOccurrence and fate of 17 antibiotics were investigated in the aqueous phase of river water under different hydrological conditions at 5 sampling locations in the Seine River inner estuary. The target analytes belonged to 4 groups: quinolones, sulfonamides, nitro-imidazoles and diaminopyrimidines. This six-month survey (from January to June 2006) showed that different compounds were occurring at individual concentrations reaching 544 ng L(-)(1) (sulfamethoxazole). All 17 compounds were detected at least once in the survey. Sulfamethoxazole was detected in every sample, and showed the highest concentrations. Norfloxacin and flumequine were found to be the most ubiquitous quinolones, with detection frequencies of 33 and 75% respectively at the most contaminated site (Poses). Investigations concerning the origins of this contamination were made by means of a longitudinal profile along the Seine River between Paris and Poses. It showed large inputs of norfloxacin, ofloxacin, trimethoprim and sulfamethoxazole from wastewater treatment plants, with an increase in norfloxacin and sulfamethoxazole concentrations of 84% and 70% respectively, both reaching 155 ng L(-)(1) in the river, downstream from a wastewater outlet. The detected compounds showed different dissipation patterns and behaviours under different hydrological conditions. Higher inputs of norfloxacin were found in low flow conditions, which were rapidly attenuated along the stream. In contrast, sulfamethoxazole inputs were increasing in high flow conditions, and dissipation of this compound was found to be slow. Similar behaviour was observed for the synergist trimethoprim. Flumequine was also frequently detected and its input increased during flood events

Bacterial resistances to antibiotics and high frequency of resistance genes in effluent of shrimp farming facility (Long An, Viet Nam)

The emergence and the spreading of antibiotic resistant (AR) bacteria and antibiotic resistance genes (ARGs) are considered currently as a growing issue for human health. Shrimp farmers in Viet Nam have access to and make use of a wide variety of antibiotics and other chemicals to treat animals or prevent disease outbreak in their farms, but very little data are now available about the effects of these substances on bacterial communities. In this study, molecular analysis and microbiological cultures carried out in the effluent of an industrial shrimp farming facilities (Long An Province, Vietnam) showed the presence of very high numbers of ARGs among the bacterial communities, as well as a high ARGs diversity. PCR analysis showed the presence of nine ARGs (sul1, sul2, qnrA, ermB, tetA, aac (6)lb, dfrA1, dfr12, dfrA5) in bacterial isolates. Most of the strains possessed 4 to 7 different ARGs, conferring multidrug resistance capacity. Real time PCR analysis revealed the presence of high copy numbers of the sul2 gene in the effluent of the shrimp farm, ranging from 1,000 to 7,000 copies/ml, as well as up to 200,000 to 700,000 copies/g in the water and in the sludge respectively. These data indicated that antibiotic usage strongly promoted the emergence of multi-resistant bacteria that subsequently spread into the adjacent natural aquatic environment. These multidrug resistant bacteria could directly cause harmful effects, or serve as antibiotic genes reservoir, spreading the resistance genes to human and farming animal pathogens. This study is considered as a starting point for further projects aiming at monitoring antibiotic resistance issues and finding practical solutions, so as to propose long-term efficiency and sustainability to the aquaculture industry

The effect of environmental and therapeutic concentrations of antibiotics on nitrate reduction rates in river sediment

International audienceThe use of antibiotics in both human and veterinary medicine has led to increased presence of these compounds and antibiotic resistance in the environment. In this study, the effect of low, environmentally relevant (mg L-1) concentrations of vancomycin (VA), flumequine (FLU), and sulfamethoxazole (SMX) on nitrate reduction rates was studied in river sediments. Nitrate reduction rates were determined by supplying intact sediments for several weeks with both nitrate and antibiotics (ng L-1, mu g L-1, and mg L-1 concentrations), including a non-amended control. Furthermore the concentrations of the three investigated antibiotics were measured in the initial (natural) sediments and the sediments supplied with the antibiotics. The antibiotic concentrations in the sediments decreased (on average 62% for FLU and 93% for SMX) during the experiments, indicating loss of antibiotics due to sorption or (bio) degradation. Nitrate reduction rates were not affected by environmental concentrations of VA, FLU and SMX. FLU and SMX only partially inhibited nitrate reduction rates at high, therapeutic concentrations by 41 and 39% respectively. The three tested antibiotics significantly enhanced the production of nitrite, an intermediate in dissimilatory nitrate reduction. Nitrite production increased 1.9 and 1.4 fold for environmental VA concentrations (107 and 187 mu g L-1 respectively), application of 58 mg L-1 SMX resulted in a 7.5 fold increase and augmented 16 and 8.5 fold in the presence of respectively 13 mu g L-1 and 52 mg L-1 FLU. Even though inhibition of nitrate reduction rates was observed at therapeutic antibiotic concentrations, nitrate reduction proceeded under all experimental conditions, indicating the presence of resistance toward these antibiotics among the nitrate reducing bacteria. The accumulation of nitrite suggests that the nitrite reduction step was more affected than the overall nitrate reduction process. (C) 2013 Elsevier Ltd. All rights reserved

Occurrence of antibiotics in rural catchments

International audienc