Decomposition in an artificial lentic environment: approaches to post-mortem interval estimation

While terrestrial decomposition has been extensively researched to produce reliable methods of estimating the post-mortem interval of remains, there is limited literature documenting aquatic decomposition. Consequently, the ability to reliably estimate the post-mortem submersion interval for remains in water bodies is poor, despite markedly varying insect succession between aquatic and terrestrial decomposition This study was conducted to compare decomposition on Sus domesticus carcases in terrestrial and artificial lentic environments, aiming to provide more detailed characterization of aquatic decomposition and document the role of terrestrial organisms in the accompanying insect succession. Three trials consisting of six stillborn piglets in lentic environments and three in terrestrial environments were observed daily over a period of 12 months. Decomposition stage and morphological changes between terrestrial and lentic piglets were noted. Insects were sampled from remains and reared to adulthood for identification. Lentic decomposition was prolonged relative to terrestrial decomposition, reflecting aquatic decomposition characteristics accompanied by terrestrial insect colonization. Diptera were more prevalent on terrestrial remains, and Coleoptera in the lentic environments, with few dipteran taxa common between environments. Results show the variability of decomposition stages, characteristics and insects between terrestrial and lentic remains, and are discussed with regard to implications for aquatic forensic casework.