Ecological consequences when organisms avoid a contaminated environment: A study evaluating the toxicity of fipronil.

The ability of aquatic organisms to sense the surrounding environment chemically and interpret these signals correctly is crucial to their survival and ecological niche. This study applied the Heterogenous Multi-Habitat Assay System - HeMHAS to evaluate the avoidance potential of Daphnia magna to detect fipronil-contaminated habitats in a connected landscape after a short (48 h), previous, forced exposure to an environmentally relevant concentration of the same insecticide. The swimming of daphnids was also analyzed by recording the total distance covered. D. magna preferred areas with less contamination, although the effect of fipronil on their swimming ability (a decrease) was observed for all the concentrations tested. The application of non-forced multi-compartment exposure methodologies is a recent trend and is ecologically relevant as it is based on how contamination can really produce changes in an organism's habitat selection. Finally, we consider the importance of more non-forced exposure approaches where Stress Ecology can be aggregated to improve systemic understanding of the risk that contaminants pose to aquatic ecosystems from a broader landscape perspective.

Zooplankton vulnerability to glyphosate exacerbated by global change.

Anthropogenic activities generate a severe footprint at a global scale. Intensive agriculture is a global change driver that affects aquatic systems due to the discharge of pollutants. This situation can be modified or aggravated by other aspects, such as the disturbance history and other global change factors. Following our study line, it is necessary to evaluate how the disturbance history combined with temperature changes can affect the functioning of aquatic systems. The objectives of this study were divided into two phases. The objectives of phase 1 were to induce vulnerability in Daphnia magna populations through a disturbance history based on sublethal glyphosate concentration exposure under different temperature conditions (20 °C and 25 °C). In phase 2, vulnerability was assessed through the exposure to subsequent stressors (starvation, increased salinity and paracetamol) combined with changes in temperature. During the glyphosate exposure period in phase 1, differences were observed in the D. magna populations with respect to temperature, with lower abundance at 25 °C than at 20 °C. However, no differences were observed in abundance regarding glyphosate treatment. The results obtained in phase 2 with the new stressors combined with temperature changes in both directions, revealed stronger effects in vulnerable populations than in control populations. In addition, the temperature changes modulated the effects in the starvation and increased salinity tests. Agrochemical sublethal concentrations induce vulnerability in D. magna populations and inflicted temperature changes can act as a modulating factor for this vulnerability, showing the complexity in assessing the responses under the multiple scenarios associated with global change.

Sublethal exposure to agrochemicals impairs zooplankton ability to face future global change challenges.

Intensive agriculture is characterized by the application of multiple stressors that damage aquatic systems. Currently, ecotoxicological evaluations are considered insufficient to understand the environmental risks of stressor mixtures and their consequences in ecosystems. In addition, future global change scenarios could alter the predicted effects of agrochemicals in aquatic systems based on single exposures, making it necessary to consider the history of environmental disturbances that may result in vulnerability to subsequent environmental changes. The objectives of this study were to induce disturbance histories by exposure to sublethal glyphosate concentrations in microcosms and to assess whether this disturbance results in vulnerable populations using Daphnia magna as the target species. Populations were considered vulnerable if their sensitivity to new stressors (inanition, temperature and salinity) was higher than that of undisturbed populations. To induce disturbance history, microcosm aquatic communities (two cladocerans and one microalgae) were exposed to two glyphosate sublethal concentrations (below the No Observed Effect Concentration, NOEC values for D. magna, 0.1 and 1 mg L-1) in microcosms under controlled conditions in a culture chamber for 48 days. After this period, no significant differences were observed with respect to the control microcosms in the selected parameters (cladoceran abundance, microalgae cell abundance, microalgae colony formation, pH and dissolved oxygen). To test vulnerability, our target D. magna populations, which were previously exposed to different glyphosate treatments, were subjected to inanition, elevated temperature and salinity. Our results showed that D. magna populations with disturbance history performed worse in all the scenarios compared to the populations from undisturbed conditions. These results underscore the need to study how environmental disturbance history influences population responses to new and future stressors. Moreover, our findings raise concern regarding the sublethal effects of pesticides on aquatic populations.

Ecotoxicological assessment of the effects of fluoxetine on Daphnia magna based on acute toxicity, multigenerational reproduction effects, and attraction-repellence responses.

Fluoxetine, a common pharmaceutical used as an antidepressant, is already considered potentially hazardous to biota due to its increasing use and detection in European, North American, and Asian rivers. We studied the effects of fluoxetine on Daphnia magna, as we hypothesized that fluoxetine might have harmful effects, short and long-term, at different levels: survival, behaviour, and reproduction (offspring production). We applied two different approaches: (i) a scenario at environmentally relevant concentrations (0.1-1.0 µg/L) and (ii) a scenario simulating a future worsening of contamination (1-800 µg/L) until the reach of lethal concentrations. In the former, we examined whether there are multigenerational effects on reproduction and on the avoidance/colonisation behaviour in previously exposed populations. In the latter, three responses were assessed: survival, avoidance behaviour and reproduction. We did not detect differences in the reproduction output of D. magna among the treatments over the three generations examined. Irrespective of the multigenerational treatment, D. magna colonised the environments with fluoxetine in a similar way. In the second scenario, we determined the lethal concentration for 50% of the population (96 h-LC50 = 365 µg/L), which, in spite of the toxic effect, was attractive to organisms during the avoidance tests (24 h); in fact, D. magna were attracted (no repellence) even to the highest concentrations of fluoxetine tested (800 µg/L). Lastly, in a 21-day chronic toxicity test the reproduction output of D. magna increased with higher concentrations of fluoxetine. This effect might be related to the fact that the organisms in the contaminated treatment began their first reproduction earlier, when compared to that in the control treatments. In conclusion, this study discusses an identified hazard for aquatic biota due to the fluoxetine attraction effect and a predictive assessment of the consequences expected if its indiscriminate use increases.

Effects of climate change in the elderly's health: a scoping review protocol.

INTRODUCTION: Climate change is a global problem that affects human health, especially the most vulnerable groups, including the elderly. However, no scope review includes the perspective of institutions specialised in climate change and health and whose reports are the basis for policies orientated on the environmental health. Therefore, this study aims to identify these effects on older people health. The results will allow health professionals to have valuable information enabling them to provide quality care in meeting the demand that this situation is producing. METHODS AND ANALYSIS: A scoping review of the relevant literature will be performed from 2008 to 2021. The Joanna Briggs Institute guidelines and the PRISMA-Scoping Review Extension checklist will be used. A peer-reviewed search will be conducted using the electronic databases Medline, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane, PsycINFO and Cuiden Plus between October and December 2021. Original quantitative studies and reports from official agencies on the effects of climate change on the elderly health in any health and geographical context will be included. Literature selection will be made by two reviewers. The table format used for data extraction will be reviewed by the review team and tested by two reviewers. ETHICS AND DISSEMINATION: This study does not require approval by an ethics committee to be conducted. This article will result in the mapping of the direct and indirect effects of climate change on the health of the elderly. The results will be published in scientific journals to be accessible to health professionals in the creation of care plans for the elderly at climate risk.

Environmental disturbance history undermines population responses to cope with anthropogenic and environmental stressors.

Since aquatic ecosystems receive runoff of most anthropogenic pollutants, risk assessment tools and protocols have been developed in order to protect them. However, most ecological risk assessments focus on the study of single species exposed to a single chemical, overlooking the environmental reality of multiple chemical exposures and stresses over generations. To advance in realistic predictions of population and community changes, the environmental disturbance history should be considered. The aim of this study was to evaluate how environmental disturbance history (continuous expected sublethal exposure to one chemical for several generations) determines populations' responses to another stressors. The experiments were performed with Daphnia magna as model organisms. To create a disturbance history, dimethoate was used as first stressor at two different concentrations: medium (0.089 mg·L-1) and high (0.89 mg·L-1). The population exposed to medium concentration ("vulnerable population") showed no differences from the control population in the selected parameters (body size and reproductive success). Our interest in the vulnerable population was to determine whether, after a first stressor, the detected non-effect hides a population impairment, which might undermine populations' responses to future stressors. After 4 generations under dimethoate exposure, the vulnerable D. magna population was exposed to a second chemical stressor (glyphosate) and an environmental stressor (food scarcity) as compared to control. The vulnerable population showed both less resistance to glyphosate and less resistance to starvation, corroborating the hypothesis that a disturbance history of continuous expected sublethal chemical exposures undermines populations' responses to further chemical and environmental stressors.

Not Only Toxic but Repellent: What Can Organisms' Responses Tell Us about Contamination and What Are the Ecological Consequences When They Flee from an Environment?

The ability of aquatic organisms to sense the surrounding environment chemically and interpret such signals correctly is crucial for their ecological niche and survival. Although it is an oversimplification of the ecological interactions, we could consider that a significant part of the decisions taken by organisms are, to some extent, chemically driven. Accordingly, chemical contamination might interfere in the way organisms behave and interact with the environment. Just as any environmental factor, contamination can make a habitat less attractive or even unsuitable to accommodate life, conditioning to some degree the decision of organisms to stay in, or move from, an ecosystem. If we consider that contamination is not always spatially homogeneous and that many organisms can avoid it, the ability of contaminants to repel organisms should also be of concern. Thus, in this critical review, we have discussed the dual role of contamination: toxicity (disruption of the physiological and behavioral homeostasis) vs. repellency (contamination-driven changes in spatial distribution/habitat selection). The discussion is centered on methodologies (forced exposure against non-forced multi-compartmented exposure systems) and conceptual improvements (individual stress due to the toxic effects caused by a continuous exposure against contamination-driven spatial distribution). Finally, we propose an approach in which Stress and Landscape Ecology could be integrated with each other to improve our understanding of the threat contaminants represent to aquatic ecosystems.

Flow Cytometry Assessment of Microalgae Physiological Alterations under CO2 Injection.

Growth rate (GR), esterase activity (EA), membrane potential (MP), and DNA content were measured by flow cytometry to test if this powerful tool could be included in risk assessment and monitoring programs. This study tests a battery of endpoints that were measured on Scenedesmus (Acutodesmus) obliquus as model species, under high levels of injected CO2 to be proposed as biomarkers of effect. New technologies such as carbon capture and storage (CCS) bring positive consequences on CO2 mitigation strategies but also could have negative consequences if a CO2 leakage occurs during injection. Under this scenario, pH might drop down to 4 pH units around the pipe where the leakage happens. The study focus on to ascertain if the endpoints fulfill the requirements such as sensitiveness, be timely and cost-effective, be easy to measure and interpret, and be nondestructive, valuable attributes in effective biomarkers. CO2 injected at high levels significantly affects the EA, the membrane polarization, as well as GRs. However the DNA content did not shown a clear response under this condition. In conclusion, the GR, the EA, and the MP analyzed by flow cytometry fulfilled the attributes mentioned above and are proposed as biomarkers of effect in CCS monitoring programs. © 2020 International Society for Advancement of Cytometry.

Going deeper into phosphorus adsorbents for lake restoration: Combined effects of magnetic particles, intraspecific competition and habitat heterogeneity pressure on Daphnia magna.

Aquatic population responses to chemical exposure may be exacerbated by intraspecific competition pressures, being also shaped by habitat heterogeneity. Magnetic particles (MPs) have been recently proposed as promising phosphorus (P) adsorbents for lake restoration. This study focuses on assessing the effects of MPs on the abundance of the crustacean Daphnia magna under different levels of both intraspecific competition pressure and habitat heterogeneity. The experimental design consisted of two experiments (in homogeneous and heterogeneous habitats) done in glass jars with four concentrations of MPs: controls of 0g MPsL-1, and treatments of 1, 1.5 and 2g MPsL-1. In addition, competition treatments were established by using different population densities, and hence, no competition (C), low (L) and high (H) competition pressures were simulated. The experiments lasted for 7 days, with a 4-day pre-exposure period, in which competition was all allowed to take place, and a 3-day post-exposure period. Twenty-four hours after adding MPs, the MPs were removed by applying a magnetic separation technique. The results showed that competition pressures occurred and significantly reduced population abundances during the pre-exposure period. During the post-exposure period, the combined effects of competition and MPs were detected in both homogeneous (Ho-) and heterogeneous (He-) habitat experiments, showing a significantly drastic reduction in abundances. In fact, the lethal concentration for 50% of the population (LC50 -24h) was 0 and 0.16g MPsL-1 in the Ho- and He-experiments respectively, indicating that the addition and especially the removal of MPs cause extreme mortality. These results indicated that even though competition plays a role in shaping populations, its influence was down-weighted by the stronger pressures of MPs. In addition, as no significant differences between homogeneous and heterogeneous habitats were found, we may state that the refuge offered was not protective enough to avoid the effects of MPs. In conclusion, the removal of the MPs causes drastic effects on D. magna abundances despite the concentration of MPs, competition or habitat structure. Finally, considering the validated high efficiency of MPs for P removal, and in the context of a future whole-lake application, it is essential to restrict the use of MPs to the moments when D. magna is absent in the study site. Further research on the effects of MP removal on other organisms is required before implementing the addition of MPs as a restoration tool.

Effects of experimental long-term CO2 exposure on Daphnia magna (Straus 1820): From physiological effects to ecological consequences.

The carbon capture and storage (CCS) technologies that were proposed to mitigate environmental problems arising from anthropogenic CO2 emissions, also have potential environmental risks. An eventual CCS leak might induce very low pH values in the aquatic system. Due to the lack of knowledge of long-term CO2 exposures with very low pH values, this study aims to know the effects and consequences of such a situation for zooplankton, using the Daphnia magna experimental model. A CO2 injection system was used to provide the experimental condition. A twenty-one days experiment with control and low pH treatment (pH = 7) replicates was carried out under light and temperature-controlled conditions. Survival, individual growth, RNA:DNA ratio, and neonates production were analysed during the aforementioned period. No differences on survival (except last day), individual growth and RNA:DNA ratio were observed between both control and low pH treatments. However, clear differences were detected in neonates production and, consequently, in population growth rates and secondary production. The observed differences could be related with an energy allocation strategy to ensure individual survival but would have ecological consequences affecting higher trophic levels.

Tweet if you want to be sustainable: a thematic analysis of a Twitter chat to discuss sustainability in nurse education.

AIM: To explore the concept of sustainability in nursing using social media as a vehicle for discussion on the topic. BACKGROUND: There is a need for an increased awareness among nurses of the issues that are crucial for the healthcare sector to prepare for climate change and contribute to sustainable development. However, topics about sustainability and climate change are not a requirement of nursing curricula in Europe; social media provides an opportunity to raise issues and promote discussion. DESIGN: A thematic analysis of a Twitter discussion. METHODS: A Twitter discussion session hosted by @WeNurses took place on 24 March 2015 over 1 hour. Data were gathered via this online discussion hosted on Twitter, a social media platform. Following the discussion a thematic analysis of the posted Tweets was conducted. FINDINGS: One hundred and nineteen people posted nine hundred and ninety six Tweets, a reach of 3,306,368. Tweets broadly followed the questions posted by the team. Several threads related to the sustainable use of healthcare resources and the need to reduce waste was evident. A Word Cloud of the Tweets highlighted prominent words in the discussion: sustainability, nursing/nurses, curriculum, important, waste, practice, resources, student, plastic, health, gloves. CONCLUSION: Social media is an effective way of engaging nurses and students in a discussion on challenging issues. Sustainability appears to be important for nurses, with a particular emphasis on resource use and the importance of sustainability topics in nurse education.

Effects of intra- and interspecific competition on the sensitivity of aquatic macroinvertebrates to carbendazim.

The Ecological Risk Assessment of pesticides and other potentially toxic chemicals is generally based on toxicity data obtained from single-species laboratory experiments. In the field, however, contaminant effects are ubiquitously co-occurring with ecological interactions such as species competition and predation, which might influence the sensitivity of the individuals exposed to toxicants. The present experimental study investigated how intra- and interspecific competition influence the response of sensitive aquatic organisms to a pesticide. For this, the effects of the fungicide carbendazim were assessed on the mortality and growth of the snail Bithynia tentaculata and the crustacean Gammarus pulex under different levels of intraspecific and interspecific competition for a food resource. Interspecific competition was created by adding individuals of Radix peregra and Asellus aquaticus, respectively. The interaction of competition and carbendazim exposure significantly influenced B. tentaculata growth, however, combined effects on survival and immobility were considered transient and were less easily demonstrated. Positive influence of competition on G. pulex survival was observed under low-medium carbendazim concentrations and under medium-high density pressures, being partly related to cannibalistic and predation compensatory mechanisms, enhanced under food limiting conditions. This study shows that intra- and interspecific competition pressure may influence the response of sensitive aquatic organisms in a more complex way (positive, non-significant and negative effects were observed) than just increasing the sensitivity of the studied species, as has generally been hypothesized.

Effects of ammonium nitrate on larval survival and growth of four Iberian amphibians.

The purpose of this study was to understand the differences in tolerance to ammonium nitrate in four Iberian amphibians. Results showed a negative effect on amphibian survival and larvae total length. Three different tolerance groups on amphibian survival were established. The two first groups showed a higher reduction, around 90% and between 70 and 80% after 96 h exposition at the maximum concentration tested (180 mg NH4NO3/L), while the third group showed no mortality in any concentration tested. In addition, a reduction in larvae total length was also detected for all four species, with Bufo bufo as the most sensitive species.