Applying biogeochemistry to identify the geographic origins of insects - a model using prostephanus truncatus

"The application of geochemical screening for tracking insects and other organisms is poorly understood. We explored multi-elemental profiles of an insect pest and its food from different locations in order to identify intrinsic markers of geographic origin. ICP-AES screening was completed for soil, maize grains and Prostephanus truncatus of different geographic origin, with insects collected in the field or reared on maize under controlled conditions. Background level geochemical data are presented with concentrations of Cu, S and Sr in maize, and Al, Ba, Ca, Fe, S, Si, Sr, Ti and Zn in insects differing according to their origin, or that of their food. Cu, Fe and Zn determinations of insects were 20, 6.5 and 11.5 times the concentrations of the maize they were reared on. A Linear Discriminant Analysis (LDA) based on Al, Fe, Sr and Zn successfully assigned 78% of laboratory-reared P. truncatus and 94% of field-caught insects to their origin (68% and 75% respectively after jacknifing). There was excellent discrimination between insects reared on maize from Guanajuato and Nuevo Léon, and Guanajuato and Michoacán, good separation between Sonora and Nuevo Léon but overlap for Sonora, Guanajuato and Michoacán, and Michoacán and Nuevo Léon. The same LDA for field-caught insects gave complete separation between Michoacán and Sonora, but some overlap between Michoacán and Nuevo Léon. This robust ICP-AES technique successfully identified a combination of elements able to classify insects according to their origin. The model was restricted to elements showing a normal distribution but non-parametric tests suggest other elements may act as intrinsic markers. This shows the potential of atomic spectroscopy for remotely tracing insects and other biological materials, with applications including providing provenance data for species routinely captured for surveillance and to track natural enemies and wildlife.

Multi-hazards coastal vulnerability assessment of Goa, India, using geospatial techniques

The state of Goa in West India has a 105km long coastline with beaches and cultural heritage sites of significant importance to tourism. The increasing incidence of tropical cyclones in the Arabian Sea in recent decades and the devastating impacts of the December 2004 tsunami in India stressed the importance of assessing the vulnerability of coastal areas to flooding and inundation, notably in view of climate change induced sea-level rising (SLR). This study aims to develop a Coastal Vulnerability Index (CVI) for the state of Goa and to use this index to examine the vulnerability of the different administrative units of the state, known as talukas. This is accomplished by using seven physical and geologic risk variables characterising the vulnerability of the coast, including historical shoreline change, rate of relative sea-level change, coastal regional elevation, coastal slope, mean tidal range, significant wave height, and geomorphology using conventional and remotely sensed data, in addition to two socio-economic parameters: population and tourist density data. Using a composite CVI based on those relative risk variables, each of the seven coastal talukas was categorised according to its vulnerability. The resulting vulnerability map depicts the talukas that are the most and least vulnerable to erosion, flooding and inundation of coastal lands, and that the inclusion of socio-economic parameters influences the overall assessment of vulnerability. This study provides information aimed at increasing awareness amongst decision-makers to deal with disaster mitigation and coastal zone management, and is a first step towards prioritising areas for climate change adaptation in view of the projected SLR and increased storminess

Bacterial Diversity in House Dust: Characterization of a Core Indoor Microbiome

Our indoor microbiome consists of a wide range of microbial taxa. Whilst many of these microbes are benign, some are beneficial, some harmful, yet our knowledge of the spatial heterogeneity of bacterial assemblages in our residential environment remains limited. To investigate the existence of a common core house dust bacterial microbiome we selected household vacuum dusts, collected through a citizen science approach, from homes across two bioclimatic regions (UK, Oceanic/Maritime and Greece, Mediterranean). Following the extraction of DNA from each dust sample, we targeted the bacterial 16S rRNA gene using Illumina NextSeq sequencing. PERMANOVA analysis of the microbial communities at family level grouped samples within their distinct bioclimatic region and SIMPER analysis at genus level identified the statistically significant taxa responsible for driving diversity between these groups. A “common to all” core house dust microbiome consisted of Acinetobacter, Massalia, Rubellimicrobium, Sphingomonas and Staphylococcus; genera typically associated with human occupancy and common environmental sources. Additionally, a “unique location specific” microbiome was identified, reflective of the bioclimatic region. The Greek dusts indicated a lower average diversity than the UK house dusts, with a high abundance of Rhizobiaceae in the Greek samples. Our study highlights citizen science as a powerful approach to access the indoor residential environment, at scale, and establishes the existence of a “core” house dust microbiome independent of bioclimatic region

Editorial: The society for environmental geochemistry and health (SEGH): 50 years and beyond

When the SEGH international board released a short editorial paper back in 2019, we described an aim to increase the membership offering, whilst improving the diversity of input regionally, by scientific discipline and to ensure greater and more regular contact across the regions from 2020 onwards. Wider aspirations described in 2019 (Watts et al. 2019) are discussed within this short communication at the end of 2021 to evaluate progress made. In particular, how the SEGH community adapted to the unprecedented circumstances that have challenged each and every one of us throughout the COVID-19 pandemic since early 2020 and are likely to influence our activities for the foreseeable future