freshwater monitoring
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2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dean Leverett ◽  
Graham Merrington ◽  
Mark Crane ◽  
Jim Ryan ◽  
Iain Wilson

AbstractDiclofenac is a nonsteroidal anti-inflammatory human and veterinary medicine widely detected in European surface waters, especially downstream from Wastewater Treatment Plants (WWTPs). Veterinary uses of diclofenac in Europe are greatly restricted, so wastewater is the key exposure route for wildlife. Proposed Environmental Quality Standards (EQS) which include an assessment of toxicity to aquatic organisms are under consideration by the European Commission (EC) to support the aims of the Water Framework Directive (WFD). The EC approach favours the use of a deterministic (single test value and an assessment factor) approach to the derivation of a direct toxicity EQS for diclofenac, resulting in an EQS of 0.040 µg L−1 based on a single mesocosm study. In this paper, we discuss potential issues with this approach with respect to the EC’s own guidance on EQS derivation and derive an evidence-driven alternative EQS of 0.126 µg L−1 using a probabilistic (species sensitivity distribution) approach that accounts for all of the reliable and relevant data and is in accordance with the guidance. Europe-wide freshwater monitoring data for diclofenac are used in an indicative compliance assessment using the EC and the alternative evidence-driven EQS. The implications of using only some data to derive an EQS that does not adhere to the guidance, compared to a guidance-compliant approach that uses all the data available are also discussed.


2021 ◽  
Author(s):  
Dean Leverett ◽  
Graham Merrington ◽  
Mark Crane ◽  
Jim Ryan ◽  
Iain Wilson

Abstract Diclofenac is a nonsteroidal anti-inflammatory human and veterinary medicine widely detected in European surface waters, especially downstream from Wastewater Treatment Plants. Veterinary uses of diclofenac in Europe are greatly restricted, so wastewater is the key exposure route for wildlife. Proposed Environmental Quality Standards (EQS) which include an assessment of toxicity to aquatic organisms are under consideration by the European Commission (EC) to support the aims of the Water Framework Directive (WFD). The EC approach favours the use of a deterministic (single test value and an assessment factor) approach to the derivation of a direct toxicity EQS for diclofenac, resulting in an EQS of 0.040 µg L− 1 based on a single mesocosm study. In this paper, we discuss potential issues with this approach with respect to the EC’s own guidance on EQS derivation and derive an evidence-driven alternative EQS of 0.126 µg L− 1 using a probabilistic (Species Sensitivity Distribution) approach that accounts for all of the reliable and relevant data and is in accordance with the guidance. Europe-wide freshwater monitoring data for diclofenac are used in an indicative compliance assessment using the EC and the alternative evidence-driven EQS. The implications of using only some data to derive an EQS that does not adhere to the guidance, compared to a guidance compliant approach that uses all the data available is also discussed.


2021 ◽  
Vol 62 (2) ◽  
pp. 427-463
Author(s):  
Thomas Kaltenbach ◽  
Nathalie Mary ◽  
Jean-Luc Gattolliat

Material collected in 1974 during the Austrian Hydrobiological Mission of F. Starmühlner to the Comoros and during recent years by one of the authors (NM) in the course of an ongoing freshwater monitoring program in Mayotte is the basis of this first larger study of the mayfly family Baetidae in the Comoros Archipelago (Comoros, Mayotte). We identified eight different species using morphological characters, four species on both the Comoros and Mayotte, three species on the Comoros only and one species on Mayotte only. Two species, Dabulamanzia mayottensis sp. nov. and Nigrobaetis richardi sp. nov., are new to science; they are described and illustrated based on their nymphs. The nymph of Afroptilum bicorne (Ulmer, 1909) is described for the first time and its assignment to this species is discussed. The description of the previously endemic Malagasy species Potamocloeon (Aquaediva) freitagae (Gattolliat, 2001), is complemented based on the additional material from the Comoros and re-examination of the type material. A key to the nymphs of all species of Baetidae in the Comoros and Mayotte is provided and the biogeography of the family in this region is discussed.


Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 100
Author(s):  
Lisa M. Labine ◽  
Myrna J. Simpson

Halogenated acetic acids (HAAs) are amongst the most frequently detected disinfection by-products in aquatic environments. Despite this, little is known about their toxicity, especially at the molecular level. The model organism Daphnia magna, which is an indicator species for freshwater ecosystems, was exposed to sub-lethal concentrations of dichloroacetic acid (DCAA), trichloroacetic acid (TCAA) and dibromoacetic acid (DBAA) for 48 h. Polar metabolites extracted from Daphnia were analyzed using liquid chromatography hyphened to a triple quadrupole mass spectrometer (LC-MS/MS). Multivariate analyses identified shifts in the metabolic profile with exposure and pathway analysis was used to identify which metabolites and associated pathways were disrupted. Exposure to all three HAAs led to significant downregulation in the nucleosides: adenosine, guanosine and inosine. Pathway analyses identified perturbations in the citric acid cycle and the purine metabolism pathways. Interestingly, chlorinated and brominated acetic acids demonstrated similar modes of action after sub-lethal acute exposure, suggesting that HAAs cause a contaminant class-based response which is independent of the type or number of halogens. As such, the identified metabolites that responded to acute HAA exposure may serve as suitable bioindicators for freshwater monitoring programs.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Lara Urban ◽  
Andre Holzer ◽  
J Jotautas Baronas ◽  
Michael B Hall ◽  
Philipp Braeuninger-Weimer ◽  
...  

While traditional microbiological freshwater tests focus on the detection of specific bacterial indicator species, including pathogens, direct tracing of all aquatic DNA through metagenomics poses a profound alternative. Yet, in situ metagenomic water surveys face substantial challenges in cost and logistics. Here, we present a simple, fast, cost-effective and remotely accessible freshwater diagnostics workflow centred around the portable nanopore sequencing technology. Using defined compositions and spatiotemporal microbiota from surface water of an example river in Cambridge (UK), we provide optimised experimental and bioinformatics guidelines, including a benchmark with twelve taxonomic classification tools for nanopore sequences. We find that nanopore metagenomics can depict the hydrological core microbiome and fine temporal gradients in line with complementary physicochemical measurements. In a public health context, these data feature relevant sewage signals and pathogen maps at species level resolution. We anticipate that this framework will gather momentum for new environmental monitoring initiatives using portable devices.


Author(s):  
Kelly Fernandes ◽  
Felipe Augusto Dörr ◽  
Ernani Pinto

Guanitoxin (GNT) is a natural organophosphate produced by some species of freshwater cyanobacteria, which inhibits the active site of acetylcholinesterase, preventing the hydrolysis of cholinesterases and consequently causing serious disturbances in the neuromuscular system. Despite having a chemical structure like synthetic organophosphates, there is still no analytical standard available for environmental and freshwater monitoring. Therefore, this study investigated the stability of GNT under different storage conditions, pH, and temperature. The toxin is produced by the cyanobacterium Sphaerospermopsis torques-reginae and monitored by liquid chromatography coupled to mass spectrometry (LC-MS) and LC-MS/MS for the identification and verification of its stability. The main degradation product formed is the hydroxy-amino-guanidinic derivative of the toxin. The results also indicate that GNT is stable in acidic medium (pH = 3.0), but can gradually degrade at room temperature (> 23 ºC) over a period of 96 h. Lyophilized biomass of S. torques-reginae containing GNT remained stable when stored in a refrigerator below 4 ºC. In addition, the extraction yield is higher when prepared from fresh S. torques-reginae cells than from lyophilized material. Thus, the results shown here contribute with valuable information for studies that aim at the isolation, identification, and monitoring of GNT in samples of raw water and cyanobacterial blooms.


2020 ◽  
Vol 192 (9) ◽  
Author(s):  
Elaine Ho ◽  
Andrew J. Trant ◽  
Michelle A. Gray ◽  
Simon C. Courtenay

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1611
Author(s):  
José Maria Santos ◽  
Maria Teresa Ferreira

Freshwater ecosystems have been severely damaged worldwide by a multitude of human pressures, such as pollution, nutrient enrichment, damming or overexploitation, and this has been more intense over the past five decades. It is therefore important that the impacts of such stressors can be effectively detected, monitored and assessed in order to provide adequate legislative tools and to protect and restore freshwater ecosystems. The use of aquatic biota to detect, measure and track changes in the environment is often known as freshwater biomonitoring and is based on the premise that the presence or absence of biotic assemblages at a given site reflects its degree of environmental quality. For over a century, since the early pollution-oriented indicators, freshwater monitoring has been developing and testing progressively more complex indicator systems, and increasing the plethora of pressures addressed, using different biological groups, such as benthic macroinvertebrates, macrophytes, fish, phytoplankton and phytobenthos. There is an increasing demand for precision and accuracy in bioassessment. In this Special Issue, five high-quality papers were selected and are briefly presented herein, that cover a wide range of issues and spatial contexts relevant to freshwater biomonitoring.


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