5 research outputs found
A survey of the levels of pesticides in bees, their colonies and forage
Bees provide important and economically valuable pollination services to agriculture and other ecosystems. Recent global honeybee declines have been attributed to pesticides, which can ultimately affect the overall functioning and survival of a colony. Various routes of exposure include contaminated beeswax, pollen and nectar. This thesis presents work which examines the presence, accumulation and levels of pesticides found within a number of honeybee related matrices and bumblebee bodies, with four main aims to this study. Firstly, determine which pesticides are contained within beeswax from around the UK. Secondly, monitor which pesticides accumulate in beeswax over a two year period. Thirdly, measure residual neonicotinoid levels in oilseed rape (OSR) nectar and pollen samples. Finally, quantify the levels of thiamethoxam and metabolite clothianidin in bumblebees, following feeding trial exposure, as part of a collaborative study. Analysis was conducted using gas chromatography–mass spectrometry (GC-MS) and quadrupole time-of-flight liquid chromatography-mass spectrometry (Q-TOF LC/MS), utilising the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction method. Bumblebee samples were extracted using a refined in-house procedure. Results evidenced apiculturally applied chemical treatments to be most likely found in beeswax samples whilst tau-Fluvalinate was most persistent and likely to accumulate in the hive, including foundation wax not exposed to such treatment. Varied levels of neonicotinoids were identified in hand-collected OSR nectar samples; and there require a greater level of analysis, to further understand the implications of these results on UK bees. No quantifiable levels were detected in pollen. Bumblebee analysis determined possible levels of exposure to thiamethoxam during feeding. This thesis provides the first known attempt of identifying pesticide presence and accumulation within UK beeswax, in addition to the levels within UK OSR nectar and pollen. The findings may have wider implications on the beekeeping community. Also presented are various methodologies suitable for future research
Long-term Geophysical Monitoring of Simulated Clandestine Graves using Electrical and Ground Penetrating Radar Methods: 4–6 Years After Burial
This ongoing monitoring study provides forensic search teams with systematic geophysical data over simulated clandestine graves for comparison to active cases. Simulated “wrapped,”“naked,” and “control” burials were created. Multiple geophysical surveys were collected over 6 years, here showing data from 4 to 6 years after burial. Electrical resistivity (twin electrode and ERI), multifrequency GPR, grave and background soil water were collected. Resistivity surveys revealed that the naked burial had low-resistivity anomalies up to year four but then difficult to image, whereas the wrapped burial had consistent large high-resistivity anomalies. GPR 110- to 900-MHz frequency surveys showed that the wrapped burial could be detected throughout, but the naked burial was either not detectable or poorly resolved. 225-MHz frequency GPR data were optimal. Soil water analyses showed decreasing (years 4 to 5) to background (year 6) conductivity values. Results suggest both resistivity and GPR surveying if burial style unknown, with winter to spring surveys optimal and increasingly important as time increases
Wildlife crime: The application of forensic geoscience to assist with criminal investigations.
Wildlife crime is a growing problem in many rural areas. However, it can often be difficult to determine exactly what had happened and provide evidential Court material, especially where evidence is ephemeral. This paper presents a case study where a badger sett had been illegally filled and evidence was rapidly required to support a prosecution before it was either destroyed by the suspect/further badger activities or eroded by weather/time. A topographic surface survey was undertaken, quantifying the number and spatial position of sett entrances, as well as which had been filled by a slurry material. A ground penetrating radar survey was also undertaken to quantify how much tunnels were filled. Study results evidenced five sett tunnels were filled out of twelve observed. The slurry fill material was not being observed elsewhere on the surface. GPR survey data evidenced ∼1m-5m of slurry fill in tunnels. A subsequent report was forwarded to the CPS as evidential material. Study implications suggest the importance of rapid geoscience surveys to assist Police Forces to both gain scientific evidence for prosecutions and to deter future wildlife crime. [Abstract copyright: Copyright © 2018 Elsevier B.V. All rights reserved.
Detection and characterisation of Black Death burials by multi-proxy geophysical methods
The construction of the new Crossrail railway discovered 25 well preserved skeletons shallowly buried in Central London in 2013. Subsequent carbon dating and aDNA analysis confirmed the archaeological age and presence of the Yersinia pestis “Black Death” plague epidemic strain. Here we present the non-invasive multi-proxy geophysical survey of the adjacent Charterhouse Square, rapidly undertaken to detect any further burials and characterise the site. Historical records suggested the area was a burial ground for Black Death plague victims, before subsequent cemetery and urban land use. Following initial trial surveys, surveys imaged ∼200 isolated and similar-sized burials in the south-west of the site. There were also two contrasting burial orientations present at various depths which suggested a series of controlled phased burials. A well-defined eastern burial boundary, taking the form of a ditch and bank, was also discovered. Geophysical surveys also identified a subsequent complex site history with multiple-aged features. This study revises knowledge of Black Death aged-burials and provides important implications for successful geophysical burial detection with significant time- and space-limited site constraints
Geophysical Investigations of WW2 UK air-raid shelters
Just before WW2, the British government prepared for an aerial onslaught that was predicted to raze cities and cause mass casualties. By 1938, the Air Raid Precautions Act officially stated that population protection would be through dispersal, meaning evacuation and small-scale protection, local authority responsibility often devolving to householders. Archaeological records of remaining air-raid shelters are relatively rare and under threat. This paper reports on geophysical surveys on three sites in Stoke-on-Trent and London.
Results found three intact Stanton shelters in Stoke-on-Trent, located by GPR, electrical resistivity, magnetometry, gravity and electromagnetic methods. In London, partially demolished shelters and an intact, mass public shelter were both detected by EM and GPR methods, with subsequent intrusive investigations confirming results.
Study outcomes shows hitherto-neglected wartime shelters are in varied condition, with geophysical surveys able to detect, characterise and assess them, helping bring WWII British history into the wider scientific community and public domain