Wastewater and marine bioindicators surveillance to anticipate COVID-19 prevalence and to explore SARS-CoV-2 diversity by next generation sequencing: One-year study.

This study presents the results of SARS-CoV-2 surveillance in sewage water of 11 municipalities and marine bioindicators in Galicia (NW of Spain) from May 2020 to May 2021. An integrated pipeline was developed including sampling, pre-treatment and biomarker quantification, RNA detection, SARS-CoV-2 sequencing, mechanistic mathematical modeling and forecasting. The viral load in the inlet stream to the wastewater treatment plants (WWTP) was used to detect new outbreaks of COVID-19, and the data of viral load in the wastewater in combination with data provided by the health system was used to predict the evolution of the pandemic in the municipalities under study within a time horizon of 7 days. Moreover, the study shows that the viral load was eliminated from the treated sewage water in the WWTP, mainly in the biological reactors and the disinfection system. As a result, we detected a minor impact of the virus in the marine environment through the analysis of seawater, marine sediments and, wild and aquacultured mussels in the final discharge point of the WWTP.

Sociability strongly affects the behavioural responses of wild guanacos to drones.

Drones are being increasingly used in research and recreation but without an adequate assessment of their potential impacts on wildlife. Particularly, the effect of sociability on behavioural responses to drone-associated disturbance remains largely unknown. Using an ungulate with complex social behaviour, we (1) assessed how social aggregation and offspring presence, along with flight plan characteristics, influence the probability of behavioural reaction and the flight distance of wild guanacos (Lama guanicoe) to the drone's approach, and (2) estimated reaction thresholds and flight heights that minimise disturbance. Sociability significantly affected behavioural responses. Large groups showed higher reaction probability and greater flight distances than smaller groups and solitary individuals, regardless of the presence of offspring. This suggests greater detection abilities in large groups, but we cannot rule out the influence of other features inherent to each social unit (e.g., territoriality) that might be working simultaneously. Low flight heights increased the probability of reaction, although the effect of drone speed was less clear. Reaction thresholds ranged from 154 m (solitary individuals) to 344 m (mixed groups), revealing that the responsiveness of this guanaco population to the drone is the most dramatic reported so far for a wild species.

An experimental approach to evaluate the potential of drones in terrestrial mammal research: a gregarious ungulate as a study model.

Research on the use of unmanned aircraft systems (UAS) in wildlife has made remarkable progress recently. Few studies to date have experimentally evaluated the effect of UAS on animals and have usually focused primarily on aquatic fauna. In terrestrial open arid ecosystems, with relatively good visibility to detect animals but little environmental noise, there should be a trade-off between flying the UAS at high height above ground level (AGL) to limit the disturbance of animals and flying low enough to maintain count precision. In addition, body size or social aggregation of species can also affect the ability to detect animals from the air and their response to the UAS approach. To address this gap, we used a gregarious ungulate, the guanaco (Lama guanicoe), as a study model. Based on three types of experimental flights, we demonstrated that (i) the likelihood of miscounting guanacos in images increases with UAS height, but only for offspring and (ii) higher height AGL and lower UAS speed reduce disturbance, except for large groups, which always reacted. Our results call into question mostly indirect and observational previous evidence that terrestrial mammals are more tolerant to UAS than other species and highlight the need for experimental and species-specific studies before using UAS methods.

Gills CYP1A of Oncorhynchus mykiss as a sensitive biomarker of crude oil pollution in freshwater environments.

The induction of CYP1A activity (EROD) and protein expression was compared in liver and gills of rainbow trout from a stream polluted with crude oil, and through laboratory exposures to 1% and 5% of water accommodated fraction of the crude oil (WAF) for 1 and 4 days. Gills EROD increased 1.6-2.7-fold in fish from the polluted stream and during experiments, while liver EROD was induced only by 1% WAF at day 1 (1.5-fold). Contrastingly, crude oil pollution strongly induced both liver and gills CYP1A protein expression in the field (14-36-fold) and in experiments (4-25-fold). This highlights that crude oil induced CYP1A activity markedly in gills but only slightly or not at all in the liver, suggesting that differences between organ EROD activities are related to the modulation of CYP1A enzyme activity but not to the regulation at transcriptional or translational levels.

Effects of Short-Distance Recreational Mushing on Oxytocin, Gastrin, and Creatinine Kinase in Sled Dogs.

A considerable increase in creatinine kinase (CK) activity and gastrin hormone due to exercise has been observed in sled dogs during endurance mushing races; however, there have been no studies on sled dogs during recreational mushing. Although oxytocin hormone is involved in social behaviors and empathy, it has not been studied in sled dogs. This study aimed to assess changes in plasma CK activity, and gastrin and oxytocin concentrations in adult sled dogs used in touristic mushing in North Patagonia, Argentina. Blood samples were collected before, during, and after the winter season of 2017. Creatinine kinase activity measurement was done using an enzymatic assay. Hormone analyses were performed using commercial Enzyme-Linked InmunoSorbent Assay kits. Results showed an expected two-fold increase in CK activity during the winter, with recovering basal values after winter (< 400 UI/L), low and stable levels of gastrin (9.4 ± 8.8 pg/mL), and a slight increase in oxytocin (23%) after mushing activities. No evidence indicated gastrin alterations or muscular damage from touristic mushing, but an oxytocin increase would indicate a stimulation of the brain reward system.