Freshwater Aquatic Ecosystems Research Articles

Herbul black henna (hair dye) causes cardiovascular defects in zebrafish (Danio rerio) embryo model.

Herbul black henna (hair dye) have been widely used as cosmetic agents to temporarily change the color of hair. Their use was tremendously increased in the past decade. Especially, hair dye containing paraphenylenediamine (PPD) is extensively used globally because of its abundance and low cost. PPD, one of the main chemicals in hair dye, is known as a toxin. Hair dye has various adverse effects, including negative impacts on human health, especially during pregnancy and on aquatic environment. Although a large amount of dyes has been released into the environment, studies on environmental toxicity of these substances are still poorly understood. Hence, the main objective of this study is to evaluate the potential cardiovascular toxicological effects of hair dye on zebrafish (Danio rerio) embryo as a model. After exposing zebrafish embryos to various concentrations (100, 200, 300, 400, 500, and 600μM), their cardiotoxicity and other teratogenic effects were examined for various exposure periods ranged from 24 to 96hpf. As a result, the tested embryos could not survive over intervals of 48h after 72 and 96hpf at higher concentrations (300, 400, 500, and 600μM), except the lower concentration cases (100 and 200μM) some embryos were survived, respectively. However, hair dye increases mortality and decreases yolk stalk length, heart rate and severely affects heart looping in zebrafish embryos. In addition, the dye was observed to induce cardiovascular defects in transgenic Tg (fli1a:EGFP) and Tg (flk1:EGFP) zebrafish embryos at environmentally realistic dye concentrations. However, further study using bioassays is fundamentally required to predict the toxicity of hair dyes, aside from providing the information on their safe levels for living organisms. Therefore, the present results would be vital for the ecological risk assessment of hair dye, particularly for freshwater aquatic ecosystem and human health.

Assessing the Performance of Methods for Monitoring Ice Phenology of the World’s Largest High Arctic Lake Using High-Density Time Series Analysis of Sentinel-1 Data

Lake ice is a dominant component of Canada’s landscape and can act as an indicator for how freshwater aquatic ecosystems are changing with warming climates. While lake ice monitoring through government networks has decreased in the last three decades, the increased availability of remote sensing images can help to provide consistent spatial and temporal coverage for areas with annual ice cover. Synthetic aperture radar (SAR) data are commonly used for lake ice monitoring, due to the acquisition of images in any condition (time of day or weather). Using Sentinel-1 A/B images, a high-density time series of SAR images was developed for Lake Hazen in Nunavut, Canada, from 2015–2018. These images were used to test two different methods of monitoring lake ice phenology: one method using the first difference between SAR images and another that applies the Otsu segmentation method. Ice phenology dates determined from the two methods were compared with visual interpretation of the Sentinel-1 images. Mean errors for the pixel comparison of the first difference method ranged 3–10 days for ice-on and ice-off, while average error values for the Otsu method ranged 2–10 days. Mean errors for comparisons of different sections of the lake ranged 0–15 days for the first difference method and 2–17 days for the Otsu method. This research demonstrates the value of temporally consistent image acquisition for improving the accuracy of lake ice monitoring.

Assessments of Bioaccumulation Factor (BAF) for heavy metals (Pb and Hg) in an aquatic insect Laccotrephesruber: A major faunal component for three contrasting freshwater aquatic ecosystems of West Bengal and Odisha

Although insects harbor almost all the terrestrial habitats but occur with negligible abundance in the aquatic environment mainly because of their tracheal mode of respiration. The present paper has attempted to find out the Bioaccumulation Factor (BAF) of a major aquatic insect species, Laccotrephesruber which inhabits in higher densities in three distantly located freshwater bodies having contrasting ecological factors overcoming even different environmental odds, especially the loads of two toxic heavy metals such as lead (Pb) and mercury (Hg).Collection and preservation of the aquatic insects alongwith estimation of different water quality parameters were made following standard methodologies (APHA, 2005). The heavy metals of the water, soil, selected aquatic plants and insect species were determined by Atomic Absorption Spectroscopy (AAS) from three selected study sites of [(1) a water impoundment – Rissia Dam in Odisha, (2) a large water body at Tamluk, West Bengal, and (3) a large pond at Haldia, West Bengal].In this study, above three study sites were selected in order to determine the concentrations and variation of two heavy metals (Pb and Hg) and their trend of accumulation in water, soil, aquatic plants and one aquatic insect species. After undertaking a yearlong (March’2019 – February’2020) field survey, Bioaccumulation Factors (BAF) of those heavy metals in an aquatic insect species, Laccotrephesruber and were deducted along with the recording ofdifferent pronounced ecological parameters (water quality – pH, temperature, conductivity and Total Dissolved Solids). It was seen that, lead (Pb) was found to be higher than mercury (Hg) in all the structural components (water, soil, vegetation and insect) of the three aquatic ecosystems including within the body of Laccotrephesruber of all (slight exception for soil of Rissia Dam). Besides, the concentrations of both the heavy metals were highest in the study site 3 (within industrial belt) followed by study site 2 (under the human activities) and study site 1 (in the natural undisturbed environment).From the BAFanalysis of Laccotrephesruber, it is seen that – (i) Hg is very bioaccumulative than Pb in Rissia Dam; (ii) Pb is moderately bioaccumulative than Hg in Tamluk; and (iii) Pb is very much bioaccumulative thanHg in Haldia.

Bacterial Diversity in Aquatic Ecosystems over the Central Himalayas, Nepal: Progress and Future Perspectives

Nepal hosts a large area of freshwater aquatic ecosystem including glacier associated system like glacier-fed streams and lakes as well as stream fed lowland lakes. Bacteriological studies are very important in aquatic ecosystems as bacteria are the major participants in biogeochemical cycles and food web structures. This study reviewed available literature in bacteriological studies of aquatic ecosystems in the Central Himalayas, Nepal and revealed that such studies are very limited. Thus, we conclude that future research works need to proceed through the latest molecular methods with high throughput technique using multiple environmental factors in the aquatic ecosystem.

The influence of biotic and abiotic factors on banded common loon (Gavia immer) reproductive success in a remote, mountainous region of the northeastern United States.

Habitat degradation resulting from anthropogenic activities can threaten wildlife populations. Even wildlife existing in seemingly pristine areas are at risk of airborne pollutants and urban development. The common loon (Gavia immer), a top-trophic level predator in freshwater aquatic ecosystems, has previously experienced detrimental changes in reproductive success as a result of anthropogenic activities. However, long-term studies and large sample sizes are necessary to ascertain the impacts of various anthropogenic activities on this long-lived species. Using a multi-year dataset, we investigated the effects of multiple biotic and abiotic factors on the probability of adult male and female common loon hatching and fledging success. From 1998-2017, we banded individual loons, collected blood samples to assess mercury (Hg) exposure of the birds, and monitored their reproductive success. Adult female loon hatching success was negatively associated with the amount of rainfall received in a given year while fledging success was positively associated with the amount of shoreline development. Adult male loon hatching success was positively associated with the amount of shoreline development and fledging success was negatively associated with the number of other loon pairs on a lake.

A Maastrichtian terrestrial palaeoenvironment close to the K/Pg boundary in the Golfo San Jorge basin, Patagonia, Argentina

In this paper, we present new palaeontological data regarding plant remains (palynomorphs, mesofossils, and leaves) from the uppermost part of the Lago Colhué Huapi Formation (Maastrichtian), at the headwaters of the Río Chico, Golfo San Jorge Basin. We also suggest a palaeoenvironmental reconstruction of these deposits, taking into account the information reported herein and previous palaeontological and sedimentological studies.Several spores of bryophytes, lycophytes, and monilophytes (ferns) as well as zygospores of Zygnemataceae form part of the freshwater aquatic ecosystem. The new species of Palmae affinity, Spinizonocolpites riochiquensis sp. nov. is described in this paper. Besides, we present the first record of leaf fragments with probable Palm-affinity in the Upper Cretaceous of Patagonia, which could reassert the presence of the Arecaceae in the basin.The palaeoflora recognized in the upper Lago Colhué Huapi Formation contributes to interpreting palaeoecological and palaeoclimatic conditions of a stratigraphic interval close to the Cretaceous/Paleogene extinction event, at the latitude of Patagonia.

Diffusive CO2 Flux Across the Water-air Interface of Reclaimed Shrimp Ponds in the Minjiang River Estuary Based on the TBL Model

Freshwater aquatic ecosystems are important sources of greenhouse gases, such as CO2. However, few studies have presented data on the greenhouse gas flux from coastal aquaculture ponds. Diffusion models are important tools for estimating the CO2 exchange flux across the water-air interface of aquatic ecosystems. Several different parameterized means were selected to estimate the CO2 gas exchange rate (kx) and CO2 diffusive flux across the water-air interface of shrimp ponds in the Minjiang River Estuary. The results indicated that:① the CO2 gas exchange rate and diffusive flux over the culture period all presented significant temporal variation. This variation showed a dynamic trend:October > September > November > July > August and November > July > August > September > October. ② Wind speed, kx, CO2 concentration, pH, DOC concentration, and Chl-a concentration were important factors affecting the temporal variation of CO2 diffusive flux. ③ There were differences in the estimated value of CO2 diffusive flux across the water-air interface of the culture ponds in the Minjiang River Estuary among different parameterized approaches (P<0.01). This indicates that the model method has some uncertainties in estimating the CO2 diffusive flux in culture ponds. Our results suggest that the models RC01 and CW03 are more suitable methods for estimating the CO2 diffusive flux at the water-air interface of estuarine reclaimed aquaculture ponds in the Minjiang River Estuary, after comprehensive analysis of the water environment and the different estimation results.

Design and Application of Silica Micro-Clusters for Microalgae Separation

Eutrophication has attracted social’s attention as it is a worldwide problem in freshwater aquatic ecosystem. Therefore, cultivation of microalgae in nutrient-rich medium can serve as wastewater treatment as they remove the pollutants from aquatic environment and the microalgal biomass can produce biofuels or other valuable bioproducts. Although microalgae harvesting by gravity sedimentation method is less expensive but it promotes slow sedimentation rate and increases the possibility of biomass deteriorates during harvesting process. In this research, the silica micro-clusters (SMCs) was being synthesized and surface functionalized by positively charged chitosan to improve the attachment with microalgal cells in order to promote rapid microalgae removal through sedimentation. The cell removal efficiency of Chlorella sp. can reach up to 99.41 ± 0.64 % by using 1 g/L of surface functionalized SMCs (SF-Si). Moreover, it also tended to promote high rate of cell sedimentation at 22.71 ± 3.02 cm/h which was about 162 times faster than self-sedimentation. This method of silica-aided-sedimentation (SAS) had proven effective to harvest the multi-species microalgal cells which collected from Tualang lake, Perak, and achieved cell separation efficiency up to 100% by 80 mg/L of SF-Si.

Short communication: Microfibre pollution hotspots in river sediments adjacent to South Africa’s coastline

River sediment samples collected in the lower reaches of catchments along South Africa’s coastline have microfibre levels ranging from 0 to 567 fibres/dm3. This range is similar to those of sandy beach sediments along the coast. Much higher microfibre levels are observed in KwaZulu-Natal and the Wild Coast region, compared to the Cape South Coast. There is a significant positive relationship between river sediment microfibre levels, and the percentage of households in the catchment area that do not have access to piped water. The implication is that rural communities that rely on rivers as their primary or only source of water, including for directly washing clothes in, may be significantly contributing to microfibre pollution of freshwater aquatic ecosystems. If microfibre pollution is found to have ecosystem or human health implications such as chemical toxicity or fibre-induced mesothelioma, this will be detrimental to river biota and these communities.

Linking Exposure and Kinetic Bioaccumulation Models for Metallic Engineered Nanomaterials in Freshwater Ecosystems

We developed a model (nanoBio) to simulate long-term kinetic bioaccumulation of metallic engineered nanomaterials (ENMs) across trophic levels within a freshwater aquatic ecosystem based on current understanding of environmental and biological fate. Seven species were chosen to understand exposure pathways, accumulation through trophic levels, and the potential for biomagnification. Uptake, elimination, and dissolution of the ENM are the only processes modeled, though different routes and rates are accounted for with each species. We explored the bioaccumulation of nCuO, nTiO2, and nZnO. nanoBio estimates the potential range in average body concentration across populations. Estimated bioconcentrations ranged from 1.7 × 10–8 pg nCuO g–1 for Selenastrum capricornutum to 27 μg nTiO2 g–1 for Oncorhynchus mykiss. The highest overall biomagnification was predicted for nTiO2 within the highest trophic level species. ENM dissolution decreases total biomagnification; however, the released metal ions may still caus...

Ice Wedge Degradation and Stabilization Impact Water Budgets and Nutrient Cycling in Arctic Trough Ponds

AbstractTrough ponds are ubiquitous features of Arctic landscapes and an important component of freshwater aquatic ecosystems. Permafrost thaw causes ground subsidence, creating depressions that gather water, creating ponds. Permafrost thaw also releases solutes and nutrients, which may fertilize these newly formed ponds. We measured water budget elements and chloride, ammonium, and dissolved organic nitrogen (DON) across a chronosequence of trough ponds representing different stages of ice wedge degradation and stabilization. We developed a coupled hydrologic and biogeochemical model to explore how ice wedge degradation affects hydrology and nutrient availability in trough ponds in the advanced degradation stages (DAs), which are characterized by deep troughs with warmer temperatures relative to the other stages. DAs experienced greater evaporation than the other stages, and subsurface inflows entered the DAs from a wide area. Chloride accumulated in the ponds with time since thaw, implying that subsurface fluxes are delivering solutes from the thawing permafrost. Ammonium accumulated at high rates in the initial degradation stage and was seasonally depleted over the summer in all degradation stages. Ammonium trends in the DAs were consistent with high concentration inflows and in‐pond assimilation at rates between 0.37 and 2.0 mg N m−2 day−1. Seasonal DON trends indicated that the accumulation of recalcitrant organic matter may eventually limit aquatic ecosystem production and foster pond infilling. These results provide direct evidence of nutrient release from thawing permafrost and the utilization of these nutrients by Arctic trough pond ecosystems and highlight infilling as a mechanism by which Arctic surface waters may be lost.

The impact of flooding on aquatic ecosystem services

Flooding is a major disturbance that impacts aquatic ecosystems and the ecosystem services that they provide. Predicted increases in global flood risk due to land use change and water cycle intensification will likely only increase the frequency and severity of these impacts. Extreme flooding events can cause loss of life and significant destruction to property and infrastructure, effects that are easily recognized and frequently reported in the media. However, flooding also has many other effects on people through freshwater aquatic ecosystem services, which often go unrecognized because they are less evident and can be difficult to evaluate. Here, we identify the effects that small magnitude frequently occurring floods (< 10-year recurrence interval) and extreme floods (> 100-year recurrence interval) have on ten aquatic ecosystem services through a systematic literature review. We focused on ecosystem services considered by the Millennium Ecosystem Assessment including: (1) supporting services (primary production, soil formation), (2) regulating services (water regulation, water quality, disease regulation, climate regulation), (3) provisioning services (drinking water, food supply), and (4) cultural services (aesthetic value, recreation and tourism). The literature search resulted in 117 studies and each of the ten ecosystem services was represented by an average of 12 ± 4 studies. Extreme floods resulted in losses in almost every ecosystem service considered in this study. However, small floods had neutral or positive effects on half of the ecosystem services we considered. For example, small floods led to increases in primary production, water regulation, and recreation and tourism. Decision-making that preserves small floods while reducing the impacts of extreme floods can increase ecosystem service provision and minimize losses.

Native crustacean species as a bioindicator of freshwater ecosystem pollution: A multivariate and integrative study of multi-biomarker response in active river monitoring

The aim of this study was to evaluate the ability of Palaemonetes argentinus to evidence the environmental degradation due to pollutants mixture in a freshwater aquatic ecosystem. For this purpose, an active monitoring (96 h exposure) was carried out in seven sites along the Ctalamochita River basin (Córdoba, Argentina), as a case of study.Our results evidenced sewage discharges impact in the water quality index, as well as metal pollution in water (Ag, Al, B, Pb, Hg) and sediments (Hg) with a potential effect on aquatic biota. The accumulation of total metals measured in exposed P. argentinus showed significant correlation with metals in water. Also, metallothioneins in cephalothorax showed significant changes along the basin, correlating with soluble concentrations of Cr, Zn, Cd, Hg, and V measured in shrimp tissues, which would be reflecting their bioavailability in the environment. In addition, the increase in antioxidant and detoxifying enzymes suggests the occurrence of oxidative stress in exposed shrimps. The integrative biomarker response index (IBR) pointed out the effect of metals on P. argentinus but also the occurrence of others pollutants.Finally, a high consensus was observed for water, sediments, and shrimps through the multivariate analysis (90%), indicating that P. argentinus can reflect changes in the abiotic matrixes. Moreover, studied sites were grouped according to their environmental quality.The use of active biomonitoring and the integration of biological responses through an IBR confirm that native biota could be a useful monitoring tool for bioavailable pollutants in aquatic ecosystems constituting a highly valuable approach.

Landscape-Scale Effects of Supra-Seasonal Drought on Semi-Aquatic Snake Assemblages

Climate change is predicted to alter the frequency and intensity of precipitation events, placing stress on freshwater aquatic ecosystems and their associated wildlife. Thus, understanding interspecific variation in drought sensitivity and the repeatability of those responses across heterogeneous landscapes is critical. Semi-aquatic snakes serve important roles within aquatic ecosystems and several species are threatened. Yet, little is known about the effects of drought on semi-aquatic snake populations or assemblages. We systematically trapped 20 isolated wetlands in South Carolina before (2006) and after (2013) a multi-year supra-seasonal drought to determine drought-induced shifts in occupancy and detection for five semi-aquatic snake species. Our results confirm that supra-seasonal drought differentially affects semi-aquatic snake species across landscape scales. Specifically, site occupancy decreased dramatically following drought for banded watersnakes (Nerodia fasciata) (0.95 to 0.69) and Florida green watersnakes (Nerodia floridana) (0.32 to 0.05), but was relatively unchanged for black swamp snakes (Seminatrix pygaea), mudsnakes (Farancia abacura) and glossy crayfish snakes (Regina rigida). Species lacking adaptations that make them resistant or resilient to drought may become locally extirpated if climate change projections are realized or landscapes are degraded or fragmented in ways that prevent drought recovery.

Binary effect of titanium dioxide nanoparticles (nTio2) and phosphorus on microalgae (Chlorella ‘Ellipsoides Gerneck, 1907)

The wide application of titanium dioxide nanoparticles and phosphorus in the manufacturing of many industrial products mainly used in agricultural sector has resulted in the release of considerable amounts of these compounds into freshwater aquatic ecosystem. These compounds may cause some unexpected effects to aquatic organisms. This study assessed the binary effects of Titanium nanoparticles (nTiO2) and Phosphorus on Chlorella ellipsoides. Toxicological assay test of the compounds nTiO2 (1.25 μM) alone and the combination of Titanium dioxide (1.25 μM) and Phosphorus (16, 32, 80, 160, 240 μM) was assessed, after 96 h exposures, for optical density (OD680), specific growth rate, chlorophyll levels and lipid peroxidation via Malondialdehyde (MDA) activity. Superoxide dismutase (SOD), peroxidase (POD) and glutathione-s-transferase (GST) activities were also measured. Two-way ANOVA showed a significant interaction (P < 0.05) between binary mixture. Co-exposure showed a decreased phosphorus bioconcentration in the microalgae with significant increase (P < 0.05) in chlorophyll a/b and total chlorophyll contents. A significant decrease (P < 0.05) in specific growth rate and optical density were recorded whereas, antioxidant enzymes (MDA, SOD, POD, GST) activities were significantly (P < 0.05) increased. These results showed that the addition of nTiO2 to Phosphorus affected the physiology of microalgae and should be of great concern for freshwater biodiversity.

In shallow water ecosytems the abiotic environment is more important than prey abundance for foraging terns

Shallow freshwater aquatic ecosystems are discrete feeding patches for fish eating birds. A unique feature of these ecosystems is that their physical conditions can change dramatically in a short period of time, particularly temperature, turbidity, and dissolved oxygen. Based on previous research we predicted that increasing turbidity will reduce the availability of fish to birds due to reduced visibility, while increasing temperature and decreasing dissolved oxygen will increase their availability through increases in activity and movement towards the more oxygenated surface areas, respectively. We also predicted that overall abundance of fish should increase feeding activity by terns. We measured these environmental variables, bird activity, and fish abundance from May to August from 2006 to 2008 in a marsh in southern Manitoba, Canada. Our results showed that only variation in dissolved oxygen levels affected feeding activity by terns. Since there was no relationship between bird and fish abundance either within or among years, these results suggest that it is the availability of prey (i.e. the upward movement of fish into the water column) and not their abundance per se that influences the number of avian predators present and hence the risk of predation to fish. These data demonstrate how the physical environment of aquatic ecosystems can impact terrestrial avian predators, and the link that exists between the physical environment and predator-prey interactions.

Swimming in a sea of drugs: Psychiatric drugs in the aquatic environment could have severe adverse effects on wildlife and ecosystems.

Tomas Brodin, a behavioral ecologist at Umea University, Sweden, was driving home from work 1 day in 2011 and listening to the radio. A chemist was being interviewed, talking about how he had discovered 20 different pharmaceuticals in the tissue of rainbow trout near a wastewater plant. Brodin, whose research focuses on animal personality, was immediately intrigued: Since pharmaceuticals change the personality of humans, could this affect wildlife too? “We had been joking about this possibility in the lab”, Brodin said. But now this joke seemed more real than he had expected. Brodin contacted the chemist from the radio show, Jerker Fick, who turned out to be working in the same building. Together with Jonatan Klaminder and Micael Jonsson, they began to collaborate on investigating the effect of psychiatric drugs in the environment on fish behavior. > … drugs that make people less fearful or less depressed could similarly act on neural circuits that process emotion and behavior in fish. A growing world population along with better medical care have drastically increased the consumption of pharmaceuticals during the past few decades. There are about 4,000 active pharmaceutical ingredients in use. In 2012, about 60% of US Americans took at least one prescription drug; 15% were taking more than 5. One in six adults in the USA reported taking a psychiatric drug in 2013. Many pharmaceuticals are not fully metabolized or broken down in the human body, but are excreted as active substances, which are only partially removed by most wastewater treatment plants. Various drugs therefore enter freshwater aquatic ecosystems where they may persist in their active form for decades [1]. Their concentrations may be low, but fish and other aquatic organisms are exposed to them persistently. ### Effects of psychiatric drugs on fish behavior There have been increasing concerns that residues of antibiotics could generate antibiotic resistance …

Can an aquatic macrophyte bioaccumulate glyphosate? Development of a new method of glyphosate extraction in Ludwigia peploides and watershed scale validation

Glyphosate is intensively used in agricultural fields and it is frequently detected in non-target wetland ecosystems. The floating hydrophyte Ludwigia peploides is widely distributed in American streams and it is an abundant species. Therefore, our objectives were (1) to establish and validate an extraction and quantification methodology for glyphosate in L. peploides and (2) to evaluate the role of this species as a potential glyphosate biomonitor in an agricultural watershed. We developed a new method of glyphosate extraction from leaves of L. peploides. The method recovery was 117± 20% and the matrix effect 20%. To validate the method using environmental samples, plants of L. peploides were collected in March 2016 from eight monitoring sites of El Crespo stream. Surface water and sediment samples were collected at the same time to measure glyphosate and to calculate bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs). Glyphosate was detected in 94.11% in leaves, the concentrations ranging between 4 and 108 μg/kg. Glyphosate was detected in surface water and sediments at 75% and 100% of the samples, at concentrations that varied between 0 and 1.7 μg/L and 5–10.50 μg/kg dry weight, respectively. The mean BCFs and BSAFs were 88.10 L/Kg and 7.61, respectively. These results indicate that L. peploides bioaccumulates glyphosate mainly bioavailable in the surface water. In this sense, L. peploides could be used as a biomonitor organism to evaluate glyphosate levels in freshwater aquatic ecosystems because, in addition to its capacity to bioconcentrate glyphosate, it is easy to sample and it has a restricted mobility.

Aquatic toxicity of several textile dye formulations: Acute and chronic assays with Daphnia magna and Raphidocelis subcapitata

Dyes are widely used in various sectors and can be released into the environment where they persist for a long time because of their high stability to light or temperature and their resistance to environmental degradation. Dyes are often poorly characterized and toxicological/ecotoxicological data are available only for a few. These features, coupled with their toxicity, make dyes a possible source of ecological concern, particularly for freshwater aquatic ecosystems. Therefore, new data may be very useful for their risk assessment. In the present study, we investigated the aquatic toxicity of 42 commercial dye formulations using the application of in silico tools and ecological bioassays. The in silico approach was used to assess the similarities among the dyes, highlighting that dyes from the same chemical class are generally similar. No correlation was found among dyes with the same color. Acute and long-term ecotoxicological assays with daphnids and algae were applied to evaluate the potential impact of these products, according to the OECD guidelines 201 and 202. The bioassays were able to identify structures with potential ecotoxicity: only 9 formulations showed toxicity lower than 100mg/L for daphnids while 30 dyes were toxic for algae. In our experimental conditions, algae were more sensitive to dye toxicity, particularly when the effects on cell number were considered.

Indicator-Driven Conservation Planning Across Terrestrial, Freshwater Aquatic, and Marine Ecosystems of the South Atlantic, USA

Abstract Systematic conservation planning, a widely used approach to identify priority lands and waters, uses efficient, defensible, and transparent methods aimed at conserving biodiversity and ecological systems. Limited financial resources and competing land uses can be major impediments to conservation; therefore, participation of diverse stakeholders in the planning process is advantageous to help address broad-scale threats and challenges of the 21st century. Although a broad extent is needed to identify core areas and corridors for fish and wildlife populations, a fine-scale resolution is needed to manage for multiple, interconnected ecosystems. Here, we developed a conservation plan using a systematic approach to promote landscape-level conservation within the extent of the South Atlantic Landscape Conservation Cooperative. Our objective was to identify the highest-ranked 30% of lands and waters within the South Atlantic deemed necessary to conserve ecological and cultural integrity for the 10 primary ecosystems of the southeastern United States. These environments varied from terrestrial, freshwater aquatic, and marine. The planning process was driven by indicators of ecosystem integrity at a 4-ha resolution. We used the program Zonation and 28 indicators to optimize the identification of lands and waters to meet the stated objective. A novel part of our study was the prioritization of multiple ecosystems, and we discuss the advantages and disadvantages of this approach. The evaluation of indicator representation within prioritizations was a useful method to show where improvements could be made; some indicators dictated hotspots, some had a limited extent and were well represented, and others had a limited effect. Overall, we demonstrate that a broad-scale (408,276 km2 of terrestrial and 411,239 km2 of marine environments) conservation plan can be realized at a fine-scale resolution, which will allow implementation of the regional plan at a local level relevant to decision making.