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This study investigates people’s behavioral responses to air pollution information in China. We find that elevated air pollution levels are positively associated with higher online searches for anti-PM2.5 masks and air filters. A 10 µg/m3 increase in PM2.5 is associated with a 3.6–8.4% increase of mobile queries for anti-PM2.5 masks, and 1.1–4.7% for air filters. Using a regression discontinuity design, we find that a haze alert issued when PM2.5 concentration exceeds 250 µg/m3 would double online queries for anti-PM2.5 masks and air filters. Online searches are also positively correlated with online sales. One day of severe pollution would induce a cost of 0.2 million USD on online expenditure on anti-PM2.5 masks. Some suggestive evidence shows that people in richer and polluted cities tend to search more for anti-PM2.5 masks and air filters than those in poorer and cleaner cities.

Offshore windfarm developments are expanding, requiring assessment and mitigation of impacts on protected species. Typically, assessments of impacts on marine mammals have focused on pile-driving, as intense impulsive noise elicits adverse behavioral responses. However, other construction activities such as jacket and turbine installation also change acoustic habitats through increased vessel activity. To date, the contribution of construction-related vessel activity in shaping marine mammal behavioral responses at windfarm construction sites has been overlooked and no guidelines or mitigation measures have been implemented. We compared broad-scale spatio-temporal variation in harbor porpoise occurrence and foraging activity between baseline periods and different construction phases at two Scottish offshore windfarms. Following a Before-After Control-Impact design, arrays of echolocation click detectors (CPODs) were deployed in 25 km by 25 km impact and reference blocks throughout the 2017–2019 construction. Echolocation clicks and buzzes were used to investigate porpoise occurrence and foraging activity, respectively. In parallel, we characterized broadband noise levels using calibrated noise recorders (SoundTraps and SM2Ms) and vessel activities using AIS data integrated with engineering records. Following an impact gradient design, we then quantified the magnitude of porpoise responses in relation to changes in the acoustic environment and vessel activity. Compared to baseline, an 8–17% decline in porpoise occurrence was observed in the impact block during pile-driving and other construction activities. The probability of detecting porpoises and buzzing activity was positively related to the distance from vessel and construction activities, and negatively related to levels of vessel intensity and background noise. Porpoise displacement was observed at up to 12 km from pile-driving activities and up to 4 km from construction vessels. This evidence of broad-scale behavioral responses of harbor porpoises to these different construction activities highlights the importance of assessing and managing all vessel activities at offshore windfarm sites to minimize potential impacts of anthropogenic noise.

Malathion, an organophosphate pesticide widely used in agriculture, poses significant risks to aquatic ecosystems. This study investigated the sublethal effects of malathion on hepatic HSP70 and CYPIA gene expression in fingerling Persian sturgeon (Acipenser persicus). Fish were exposed to 0.05, 0.1, and 0.2 mg L-1 malathion (corresponding to sublethal fractions of the LC50) for 7 days. Liver samples were collected at 1, 2, 4, and 7 days post-exposure, and gene expression was quantified using real-time polymerase chain reaction (PCR). Behavioral responses and mortality were recorded. No mortality occurred in any group; however, fish exposed to 0.2 mg L-1 malathion exhibited reduced feeding, impaired swimming balance, and decreased activity, especially toward the end of exposure. HSP70 expression peaked on day 1 at the highest concentration (15.7-fold higher than the control) and then gradually declined. CYP1A expression showed a similar dose-dependent pattern, with the highest induction (19.29-fold) observed on day 4 in the 0.2 mg/L group. Heat map visualization confirmed temporal and dose-dependent expression dynamics. A significant positive correlation (r = 0.73, P<0.0001) between the expression levels of HSP70 and CYPIA suggested a coordinated stress response to malathion exposure. These results demonstrate malathion-induced modulation of oxidative stress and detoxification genes in Persian sturgeon, underscoring the utility of these molecular biomarkers for monitoring organophosphate pollution in aquatic species.

Efficient estimation of the population size from dependent dual-record system (DRS) remains a statistical challenge in the capture-recapture type experiment. Owing to the non-identifiability of the suitable time-behavioural response variation model (denoted as Mtb) under DRS, few methods are developed in the Bayesian paradigm based on informative priors. Our contribution in this article is to develop a new integrated likelihood function from model Mtb motivated by a novel approach developed by Severini (2007). A suitable weight function on the nuisance parameter is derived with the knowledge of the direction of behavioural dependency. A pseudo-likelihood function is constructed so that the resulting estimator possess some desirable properties including negligible prior (or weight) sensitiveness. Extensive simulations show the superior performance of our proposed method to that of the existing Bayesian methods. Moreover, the proposed estimator is easy to implement from the computational perspective. Applications to two real data sets are presented. L’estimation efficace de la taille d’une population à partir d’un système à enregistrement double (SED) dépendant demeure un défi statistique de taille pour les expériences de type capture-recapture. Peu de méthodes ont été développées dans un cadre bayésien avec des lois a priori informatives, surtout à cause de la non-identifiabilité du modèle pour la variation temporelle du comportement (dénoté Mtb) avec un SED. Les auteurs développent une nouvelle fonction de vraisemblance intégrée à partir du modèle Mtb motivée par une approche novatrice proposée par Severini (2007). Ils dérivent une fonction de pondération appropriée pour les paramètres de nuisance avec la connaissance de la direction de la variation temporelle du comportement. Ils construisent une fonction de pseudo vraisemblance conférant à l’estimateur obtenu des propriétés désirables, notamment une sensibilité négligeable à la loi a priori et à la pondération. De plus, l’estimateur proposé est facile à implémenter d’un point de vue numérique. Les auteurs présentent une vaste étude de simulation démontrant les performances supérieures offertes par la méthode proposée par rapport aux méthodes bayésiennes existantes. Ils en présentent également l’application à deux jeux de données réelles.

Many marine mammals rely on sound for foraging, maintaining group cohesion, navigation, finding mates, and avoiding predators. These behaviors are potentially disrupted by anthropogenic noise. Behavioral responses to sonar have been observed in a number of baleen whale species but relatively little is known about the responses of minke whales ( Balaenoptera acutorostrata ). Previous analyses demonstrated a spatial redistribution of localizations derived from passive acoustic detections in response to sonar activity, but the lack of a mechanism for associating localizations prevented discriminating between movement and cessation of calling as possible explanations for this redistribution. Here we extend previous analyses by including an association mechanism, allowing us to differentiate between movement responses and calling responses, and to provide direct evidence of horizontal avoidance responses by individual minke whales to sonar during U.S. Navy training activities. We fitted hidden Markov models to 627 tracks that were reconstructed from 3 years of minke whale ( B. acutorostrata ) vocalizations recorded before, during, and after naval training events at the U.S. Navy’s Pacific Missile Range Facility, Kauai, Hawaii. The fitted models were used to identify different movement behaviors and to investigate the effect of sonar activity on these behaviors. Movement was faster and more directed during sonar exposure than in baseline phases. The mean direction of movement differed during sonar exposure, and was consistent with movement away from sonar-producing ships. Animals were also more likely to cease calling during sonar. There was substantial individual variation in response. Our findings add large-sample support to previous demonstrations of horizontal avoidance responses by individual minke whales to sonar in controlled exposure experiments, and demonstrate the complex nature of behavioral responses to sonar activity: some, but not all, whales exhibited behavioral changes, which took the form of horizontal avoidance or ceasing to call.

The Population Consequences of Disturbance (PCoD) model is a conceptual framework used to assess the potential for population-level consequences following exposure of animals to a disturbance activity or stressor. This framework is a four-step process, progressing from changes in individual behavior and/or physiology, to changes in individual health, then vital rates, and finally to population-level effects. Despite its simplicity, there are few complete PCoD models available for any marine mammal species due to a lack of data available to parameterize many of the steps. Here, we present an application of the PCoD framework for migrating humpback whales exposed to a simulated commercial seismic survey scenario. We approached the framework in two ways; first, progressing sequentially forwards through the steps and basing our assessment on lactating females. This cohort was considered to be the most vulnerable in terms of energetic costs of disturbance, and most likely to influence any change in population growth due to future breeding success. Field measurements of behavioral responses of migrating humpback whales to seismic air guns from a previous study were used to parameterize an agent-based model (ABM). This ABM was used to estimate the probability of response, where a response was defined as a change in the migratory movement of female-calf pairs, and the duration of any resulting delay in migration. We then estimated the energetic consequences of any delay in migration for the lactating females and created population growth models with which to assess any population-level effects. The results of the forwards approach suggested a low potential for population consequences of seismic surveys on migrating humpbacks. Working backwards through the framework, we investigated “worst case” scenarios that could potentially lead to a population-level effect. Here, we started with increasing calf mortality and assumed that an exposure time greater than 48 h would increase mortality risk. We determined the most likely context in which this exposure would occur (resting area) and then tested this context within an ABM. This backwards approach illustrates how the PCoD model can be used to make management decisions regarding animal populations and exposure to anthropogenic stressors.

Mitigating cetacean entanglement in fishing gear is of global interest, and strategies include the use of acoustic deterrent devices to warn whales of fishing gear. For baleen whales, responses to these devices are poorly understood. This behavioural response study compared the behaviour of humpback whales (Megaptera novaeangliae) in their feeding grounds off Iceland prior to, during, and after exposure to a whale pinger (Future Oceans: 3 kHz, n = 9 exposures) and a seal scarer (Lofitech AS Ltd.: 10 to 20 kHz, n = 7 exposures) using boatbased focal follows. Linear mixed effects models and binary generalized linear mixed effects models were used to analyze the effect of the devices on breathing rate, dive time, swimming speed, swimming directness, and surface feeding. There was a significant increase in swimming speed and a significant decrease in observed surface feeding during whale pinger exposures. There were no significant behavioural changes that were consistent across individuals during seal scarer exposures. In addition to experimental exposure trials, a field trial of whale pingers on a capelin purse seine was conducted. During this trial, humpback whales were observed entering the net from the bottom while the whale pingers were attached at the top, but the encircled whales were able to locate an opening free of pingers and escape without damaging the net. All in all, the results suggest pingers can be a useful entanglement mitigation tool in humpback whale feeding grounds given that a reduction in feeding around nets likely reduces the risk of whales swimming through them. Furthermore, the use of pingers may also reduce net damage by guiding encircled whales to a pinger-free opening. However, given the observed behavioural changes that may lead to fitness consequences if exposure to pingers is frequent, whale pingers are most advisable for short-term use in conjunction with other entanglement mitigation measures.

This paper identifies and characterizes vulnerability to climatic change in the Ngöbe-Buglé Indigenous community of Playitas, Panama, using a “trajectories of change” approach. Playitas is a community composed of swidden forest farmers that is undergoing rapid rates of change as a result of demographic shifts, regional development, and climate change. Working in collaboration with a community organization, various methods were used to identify and characterize livelihoods, social-ecological dynamics, environmental change, and behavioral responses to change, with the aim of informing future planning in the community. Qualitative methods included semistructured interviews (n = 26), community workshops, and participant observation. Causal-loop diagrams based on field data and the perceptions of community members were created to model trajectories of change. The research reveals that change is driven by both internal and external factors and that the responses of community members create both reinforcing and balancing feedback loops that overall generate increased stress in agricultural systems, social structures, and environmental components. Although community members historically relied on social relationships, Indigenous knowledge, and remoteness as sources of resilience to external disturbances, climate change is acting as a “multiplier” of their existing vulnerabilities and is undermining their capacity to adapt to current and future climatic changes.

Despite efforts to aid recovery, Eastern North Pacific blue whales faces numerous anthropogenic threats. These include behavioral disturbances and noise interference with communication, but also direct physical harm—notably injury and mortality from ship strikes. Factors leading to ship strikes are poorly understood, with virtually nothing known about the cues available to blue whales from nearby vessels, behavioral responses during close encounters, or how these events may contribute to subsequent responses. At what distance and received levels (RLs) of noise whales respond to potential collisions is difficult to observe. A unique case study of a close passage between a commercial vessel and a blue whale off Southern California is presented here. This whale was being closely monitored as part of another experiment after two suction-cup archival tags providing acoustic, depth, kinematic, and location data were attached to the whale. The calibrated, high-resolution data provided an opportunity to examine the sensory information available to the whale and its response during the close encounter. Complementary data streams from the whale and ship enabled a precise calculation of the distance and acoustic cues recorded on the tag when the whale initiated a behavioral response and shortly after at the closest point of approach (CPA). Immediately before the CPA, the whale aborted its ascent and remained at a depth sufficient to avoid being struck for ~3 min until the ship passed. In this encounter, the whale may have responded to a combination of cues associated with the close proximity of the vessel to avoid a collision. Long-term photo-identification records indicate that this whale has a long sighting history in the region, with evidence of previous ship encounters. Therefore, experiential factors may have facilitated the avoidance of a collision. In some instances these factors may not be available, which may make some blue whales particularly susceptible to deadly collisions, rendering efforts for ship-strike reduction even more challenging. The fine-scale information made available by the integration of these methods and technologies demonstrates the capacity for detailed behavioral studies of blue whales and other highly mobile marine megafauna, which will contribute to more informed evaluation and mitigation strategies.

BackgroundPrevious studies have examined public psycho-behavioural responses in the early stages of the epidemic, little is known after mass vaccination has been implemented. This study aimed to investigate the public's behavioural (adoption of COVID-19 precautionary measures) and psychological (depression, anxiety and stress) responses to COVID-19 and their relationships after the launch of the territory-wide vaccination programme in Hong Kong.MethodsA cross-sectional survey study using anonymous online or face-to-face questionnaires was conducted between June 2021 and September 2021. A convenience sample of Hong Kong Chinese residents aged ⩾18 years were recruited online by referrals and from a university-run community vaccination centre.ResultsA total of 1893 valid questionnaires were received. The results showed that Hong Kong residents have high levels of adoption of precautionary measures and low levels of depression, anxiety and stress after the mass vaccination. Hierarchical regression analysis identified that in the fully adjusted model, the adoption of precautionary measures was a consistent protective factor (β ranged −1.51 to −1.67, p < 0.001) for depression, anxiety and stress amid the COVID-19 pandemic.ConclusionsThis study offers new information on the public's psycho-behavioural responses to the pandemic, as well as insights into public health planning after introducing the mass vaccination.