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Abstract

This dissertation aims to assess the influence of warm and cold-water temperatures on the rate of cadaveric decomposition in aquatic environments. Despite the relevance of understanding such decomposition, there is an absence of generalisable research to geographical regions across the UK. As a result, postmortem interval (PMI) estimations are lacking in accuracy. Although Aquatic Decomposition Scoring (ADS) systems have attempted to quantify this process, such as the one by Heaton, Lagden, Moffatt and Simmons (2010), decay differs latitudinally and longitudinally. Using field-based observations, two piglet cadavers were utilised in a summer study and two for a winter study. One piglet in each study was left above ground to decompose whilst the other was placed in a man-made pond.
The results demonstrated a decreased decay rate of the winter aquatic cadaver, which was still fresh after 102 days (779.5 ADD). Comparatively, the summer aquatic cadaver had reached active decay after 38 days (564.1 ADD). Analysis of the temperature data revealed the average water temperature during summer was 14.1^o C compared to 7.6^o C for winter. Cooler water temperatures demonstrably delayed autolysis and putrefaction, inhibiting the onset of bloat. Furthermore, the delayed bloat stage prevented insect access. In both studies, the terrestrial piglets reached dry skeletonisation, providing support for the differences between aquatic and terrestrial decomposition. The colonising insects of both summer cadavers were also identified, these being Calliphora vicina, Calliphora vomitoria, Lucilia illustris and Lucilia caesar. L. caesar was the most abundant, followed by C. vicina, C. vomitoria and L. illustris, this latter species found exclusively on the aquatic cadaver. The research demonstrates how temperature distorts the PMI, highlighting the need for such research.

Course: Criminology and Forensic Studies - BSc (Hons) - C2039F

Date Deposited: 2020-10-26

URI/permalink: https://library.port.ac.uk/dissert/dis13582.html