Reliability of social media data in monitoring the global pet trade in ants

The global pet trade is a major risk to biodiversity and humans and has become increasingly globalized, diversified, digitalized, and extremely difficult to control. With billions of internet users posting online daily, social media could be a powerful surveillance tool. But it is unknown how reliably social media can track the global pet trade. We tested whether Instagram data predicted the geographic distribution of pet stores and the taxonomic composition of traded species in the emerging pet trade in ants (Hymenoptera, Formicidae). We visited 138 online stores selling ants as pets worldwide and recorded the species traded. We scraped ∼38,000 Instagram posts from ∼6300 users referencing ants as pets and analyzed comments on post and geolocation (available for ∼1800 users). We tested whether the number of Instagram users predicted the number of ant sellers per country and whether the species referenced as pets on Instagram matched the species offered in online stores, with a particular focus on invasive species. The location of Instagram users referencing ants as pets predicted the location of ant sellers across the globe (R² = 0.87). Instagram data detected 439 of the 631 ant species traded in online stores (70%), including 59 of the 68 invasive species traded (87%). The number of Instagram users referencing a species was a good predictor of the number of sellers offering the species (R² = 0.77). Overall, Instagram data provided affordable and reliable data for monitoring the emerging pet trade in ants. Easier access to these data would facilitate monitoring of the global pet trade and help implement relevant regulations in a timely manner.     

Trait-mediated effects on flowers: artificial spiders deceive pollinators and decrease plant fitness

Although predators can affect foraging behaviors of floral visitors, rarely is it known if these top-down effects of predators may cascade to plant fitness through trait-mediated interactions. In this study we manipulated artificial crab spiders on flowers of Rubus rosifolius to test the effects of predation risk on flower-visiting insects and strength of trait-mediated indirect effects to plant fitness. In addition, we tested which predator traits (e.g., forelimbs, abdomen) are recognized and avoided by pollinators. Total visitation rate was higher for control flowers than for flowers with an artificial crab spider. In addition, flowers with a sphere (simulating a spider abdomen) were more frequently visited than those with forelimbs or the entire spider model. Furthermore, the presence of artificial spiders decreased individual seed set by 42% and fruit biomass by 50%. Our findings indicate that pollinators, mostly bees, recognize and avoid flowers with predation risk; forelimbs seem to be the predator trait recognized and avoided by hymenopterans. Additionally, predator avoidance by pollinators resulted in pollen limitation, thereby affecting some components of plant fitness (fruit biomass and seed number). Because most pollinator species that recognized predation risk visited many other plant species, trait-mediated indirect effects of spiders cascading down to plant fitness may be a common phenomenon in the Atlantic rainforest ecosystem.     

Sterol production and phytosterol bioconversion in two species of heterotrophic protists, Oxyrrhis marina and Gyrodinium dominans

The kinetics and efficiency of sterol production and bioconversion of phytosterols in two heterotrophic protists Oxyrrhis marina and Gyrodinium dominans were examined by feeding them two different algal species (Rhodomonas salina and Dunaliella tertiolecta) differing in sterol profiles. R. salina contains predominantly brassicasterol (?99%) and <2% cholesterol. The major sterols in D. tertiolecta are ergosterol (45–49%), 7-dehydroporiferasterol (29–31%) and fungisterol (21–26%). O. marina fed R. salina metabolized dietary brassicasterol to produce 22-dehydrocholesterol and cholesterol. O. marina fed D. tertiolecta metabolized dietary sterols to produce cholesterol, 22-dehydrocholesterol, brassicasterol and stigmasterol. G. dominans fed either R. salina or D. tertiolecta metabolized dietary sterols to make cholesterol, brassicasterol and a series of unknown sterols. When protists were fed R. salina, which contains cholesterol, the levels of cholesterol were increased to a magnitude of nearly 5- to 30-fold at the phytoplankton-heterotrophic protist interface, equivalent to a production of 172.5 ± 16.2 and 987.7 ± 377.7 ng cholesterol per mg R. salina carbon consumed by O. marina and G. dominans, respectively. When protists were fed D. tertiolecta, which contains no cholesterol, a net production of cholesterol by the protists ranged from 123.2 ± 30.6 to 871.8 ± 130.8 ng per mg algal C consumed. Cholesterol is not only the dominant sterol, but a critical precursor for many physiologically functional biochemicals in higher animal. As intermediates, these heterotrophic protists increase the amount of cholesterol at the phytoplankton–zooplankton interface available to higher trophic levels relative to zooplankton feeding on algae directly.     

Zooplankton community resilience after press-type anthropogenic stress in temporary ponds.

Temporary ponds are physically disturbed environments that fluctuate on seasonal and interannual scales. These ecosystems are also susceptible to anthropogenic perturbation such as contamination inputs. However, the interactive effects of natural disturbance and anthropogenic stress on ecosystem processes and community dynamics have hardly been assessed in these ecosystem types. We used a multiple before-after control-impact (MBACI) design to study zooplankton community recovery from low and high inputs of a fire retardant in artificially constructed ponds over three hydroperiods. The retardant caused a decline in species richness and an increase in rotifers during summer and winter months relative to controls and pretreatment dates, and the duration of these changes varied among retardant treatments. In nonmetric, multidimensional scaling analyses the increased rotifer densities were reflected in loops that showed recurring deviations from and (upon collapse) approaches to reference conditions, while the effects of the anthropogenic stressor persisted in the ponds. The amplitudes of fluctuation followed no regular patterns; it varied with retardant treatment level and was higher in the third hydroperiod compared to the second in one of the treatments. From a temporal perspective, this non-dampened pattern suggests a new cause-effect mechanism for disturbance ecology, which we refer to as a "protracted press disturbance, roller coaster response" relationship. This model emphasizes stochastic oscillations in community composition, punctuated by periods in which the community approaches reference conditions. From the applied viewpoint, this model suggests that the accurate detection of perturbation and the implementation of sound management and restoration strategies will require intensive sampling designs that span multiple hydroperiods in persistently degraded ponds.     

OHP02 gravity wave campaign in relation to optical turbulence

Herein we present a campaign dedicated to the detection and the characterization of Gravity Waves (GW) in the Earth’s atmosphere in relation to the generation of Optical Turbulence (OT). The observations took place in France from 17 to 24 July 2002 at the Haute Provence Observatory (OHP) and simultaneously at the Sirene Observatory, some 20 km apart. From both sites, several balloons were launched that measured the classical PTU-Wind profiles and additionally the structure constant of the temperature field vertical profiles. A Generalized Scidar (GS) technique was implemented at the 1.93 m-diameter OHP telescope, providing profiles every minute. From our observations, a significant amount of GW activity was observed at both sites, but without clear evidence of correlation between the two sites. It seems from our observations that a wide spectrum of GW is present at a given altitude and that this could result in a lack of correlation between observations made from two sites 20 km apart. Most GW are non-stationary with long horizontal wavelengths (λ ∼ 100–200 km), kilometric vertical wavelengths (λ ~ 0.5–2 km) and long intrinsic period (T ~ 2–15 h). They belong in the category of “hydrostatic rotating or non-rotating waves”. Layers of optical turbulence detected by balloons and the Scidar technique correlate well with regions of GW activity. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Analysis of potentially toxic metal constraints to apply sewage sludge in Portuguese agricultural soils

Environmental Science and Pollution Research - The application of sewage sludge (SS) in the soil can be a valuable way to increase its content of organic matter. However, the concentration of...