Process evaluation of urban river replenished with reclaimed water from a wastewater treatment plant based on the risk of algal bloom and comprehensive acute toxicity

Municipal wastewater reuse has an important role to play with scarce water resources and serious water pollution. However, the impact of reclaimed water on the aquatic ecology and organisms of the receiving water needs to be assessed. This study investigated one ecological restoration project of an urban river replenished with reclaimed water, and evaluated the risk of algal bloom and acute biological toxicity in the river. Results showed that the concentrations of permanganate index and ammonia nitrogen in the river could stably remain below the standard values, the concentrations of total phosphorus were high and most of the monitoring values were between 0.42 and 0.86 mg/L. The content of chlorophyll a was relatively lower, ranging from 0.06 to 0.10 mg/m3. The maximum value of Fv/Fm was 0.42, which was lower than the algal bloom prediction threshold of 0.63. Moreover, the results of luminescence inhibition rate on luminescent bacteria showed that the reclaimed water did not cause significant biological toxicity to the aquatic ecology. The study suggested that implementing urban reclaimed water reuse projects requires a series of ecological purification and restoration technologies in the receiving water, which can effectively guarantee the stability of water quality and the safety of water ecological environment.

Cloud-Native Coastal Turbid Zone Detection Using Multi-Temporal Sentinel-2 Data on Google Earth Engine

The lack of clarity in turbid coastal waters interferes with light attenuation and hinders remotely sensed studies in aquatic ecology such as benthic habitat mapping and bathymetry estimation. Although turbid water column corrections can be applied on regions with seasonal turbidity by performing multi-temporal analysis, different approaches are needed in regions where the water is constantly turbid or only exhibits subtle turbidity variations through time. This study aims to detect these turbid zones (TZs) in optically shallow coastal waters using multi-temporal Sentinel-2 surface reflectance datasets to improve the aforementioned studies. The herein framework can be paired with other aquatic ecology remote sensing studies to establish the clear water focus area and can also be used by decision makers to identify rehabilitation areas. We selected the coastlines of Guinea-Bissau, Tunisia, and west Madagascar as our case studies which feature wide-ranging turbidity intensities across tropical, subtropical, and Mediterranean waters and applied three different methods for the TZ detection: Otsu’s method for bimodal thresholding, linear spectral unmixing, and Random Forest (RF) machine learning method on Google Earth Engine as an end-to-end process. Based on our experiments, the RF method yields good results in all study regions with overall accuracies ranging between 88 and 96% and F1-scores between 0.87 and 0.96. TZ detection is highly site-specific due to the inter-class variability that is mainly affected by the nature of the suspended materials and the environmental characteristics of the site.

Green Room Circuit at Paulo VI Campus in Maranhao State University, Brazil

The implementation of the Environmental Management Advisory at Maranhão State University, in 2015, promoted environmental education actions as a continuous in the institution, and coordinated by the Environmental Management System of the advisory. The approval on the call for the creation of Green Rooms, by the Ministry of Environment, became this university qualified in 2018 to have a Green Room in its space, constituting a space for environmental interactions. Thus, the objective was to discuss the actions developed in 2018. Having a Circuit format, the Green Room of this academy (Green Room Circuit at Paulo VI Campus), in the year in question, four visits were made, with activities scheduled in the Fishery and Aquatic Ecology laboratories, Zoology laboratory, Botanical Collection (Rosa Mochel), Agroecological Trail and seedling workshops. Totalizing 109 participants, 33% were from the capital and 67% from the metropolitan region of Sao Luis and other municipalities of Maranhão state, northeast of Brazil. Therefore, the Green Room Circuit of Paulo VI Campus was faced as a potentializer and dynamizer, for the development of actions that contribute to a sustainable awareness among its participants.

Application of Compound-Specific Isotope Analysis in Environmental Forensic and Strategic Management Avenue for Pesticide Residues

Unintended pesticide pollution in soil, crops, and adjacent environments has caused several issues for both pesticide users and consumers. For users, pesticides utilized should provide higher yield and lower persistence while considering both the environment and agricultural products. Most people are concerned that agricultural products expose humans to pesticides accumulating in vegetation. Thus, many countries have guidelines for assessing and managing pesticide pollution, for farming in diverse environments, as all life forms in soil are untargeted to these pesticides. The stable isotope approach has been a useful technique to find the source of organic matter in studies relating to aquatic ecology and environmental sciences since the 1980s. In this study, we discuss commonly used analytical methods using liquid and gas chromatography coupled with isotopic ratio mass spectrometry, as well as the advanced compound-specific isotope analysis (CSIA). CSIA applications are discussed for tracing organic pollutants and understanding chemical reactions (mechanisms) in natural environments. It shows great applicability for the issues on unintended pesticide pollution in several environments with the progress history of isotope application in agricultural and environmental studies. We also suggest future study directions based on the forensic applications of stable isotope analysis to trace pesticides in the environment and crops.

The Future of a Cold Regions Deltaic Ecosystem Influenced by Multiple Hydrological Stressors

<p>The Peace-Athabasca Delta (PAD) in one of the largest (~6000 km<sup>2</sup>) freshwater deltaic ecosystem in the world.  This low relief, deltaic floodplain formed at the confluence of the Peace-Athabasca-Birch rivers the west end of Lake Athabasca in northwestern Canada.  Small changes in water level/depth have important implications for surface water connectivity and associated habitat quality The floodplains contain more than 1000 wetland-lake basins with varying degrees of connectivity to the main flow system.  Hydroperiod is influenced by occasional ice-jam and open-water inundations that recharge wetland basins.  This culturally important and biologically rich delta is a Ramsar Convention Wetland Site of International Importance, and is a key feature of the Wood Buffalo National Park (WBNP) that is listed as a UNESCO World Heritage Site.  The PAD ecosystem is influenced by contributing basin and local scale hydrological stressors from flow regulation (eg, hydroelectric dam, weirs), water and land use (eg, oil sands mining) and climate change.</p><p>Growing concern regarding increased cumulative effects on the delta led Indigenous Peoples petitioning UNESCO World Heritage Committee (WNC) to reassess the protection status of the park. The WBNP Action Plan was developed to address 17 UNESCO WHC recommendations to ensure maintenance of Outstanding Universal Value of the Park.  One key set of recommendations is to: 1) Conduct environmental flows assessments, to the highest international standard, in order to identify water flows needed to sustain the ecological functioning of the PAD under current and projected development and climate change; 2) Establish adequate baseline hydrological information for PAD assessments.</p><p>A significant scientific effort has been invested in the last four decades, particularly since 2010, in improving our understanding the relationship between streamflow, landscape controls and aquatic ecology in this cold-regions delta.  This information is key to assess historical and present states, learn from past development to inform planned development, and prepare for anticipated future hydro-ecological changes.  However, several key questions arise regarding what is the best approach to preparing for the future and managing such a complex system, what management options are possible within an environmental flow framework given known hydrological stressors, and what future ecosystem state does society want for the delta.  The goal of this presentation focused on the PAD is threefold:  i)  Provide an overview of major hydro-ecological research and water management;  ii)  Assess the potential applicability of riverine environmental flow frameworks to deltaic floodplain environments; and iii)  Explore the development of an environmental flow/water level framework and tools necessary to assess and manage changes to the aquatic ecology of this internationally important deltaic ecosystem.</p>

Unifying the sedaDNA scientific community

<p>Since the seminal paper in 1998 (Coolen and Overmann), sedimentary ancient DNA (sedaDNA) has become a powerful tool in paleoecology to reconstruct past changes in terrestrial and aquatic biodiversity. Still, sedaDNA is an emerging tool and there is a need for calibrations and validations to ensure the reliability of sedaDNA as a proxy to reconstruct past biota. One way to pursue this goal is by unifying the sedaDNA scientific community. Here, we present a few initiatives taken over the last years to transmit information, augment our knowledge about best practices and method standardisation related to sedaDNA analysis and strengthen collaborations between research groups. Also, we discuss tools and ideas that could be used to increase the visibility of sedaDNA research by the scientific community. Finally, we would like to use this opportunity to discuss with the audience about new strategies to unify experts from different research fields - including paleoecology, paleolimnology, paleoceanography, molecular ecology, aquatic ecology, terrestrial ecology, microbial ecology - around the use of sedaDNA.</p>

Identification of Individual Zebrafish (Danio rerio): A Refined Protocol for VIE Tagging Whilst Considering Animal Welfare and the Principles of the 3Rs

In aquatic ecology, studies have commonly employed a tagging technique known as visible implant elastomer (VIE). This method has not been widely adopted by the zebrafish research community and also lacks refinement with regard to animal welfare. The current paper introduces a new VIE tagging protocol, with the aim of improving existing tagging techniques by placing particular emphasis on the Three Rs. To improve animal welfare and fish survival, we added the use of an analgesic compound (lidocaine) through the marking procedure, followed by after-treatment with antiseptics (melaleuca, aloe vera, and PVP-I as active ingredients) to improve tissue regeneration and healing. The newly improved protocol has been quantitatively evaluated on different populations and age groups of zebrafish. This study will be useful to the scientific zebrafish community and to the wider field including biologist and aquarists, especially in consideration of animal welfare, where tagging techniques are considered as a potential noxious stimulus for fish.