Barnacle colonization of shoes: Evaluation of a novel approach to estimate the time spent in water of human remains

Abstract

Estimating the time since death (minimum Post Mortem Interval, minPMI) is a necessary part of a forensic investigation. Besides considering the typical signs of death, minPMI can be estimated using the insects and other arthropods that colonize the remains (forensic entomology). In an aquatic environment, both insects and crustaceans may provide information regarding the time spent in water of the remains (minimum Floating Interval, minFI and minimum Post Mortem Submersion Interval, minPMSI), and this can also assist in determining the minPMI. Barnacles (Crustacea: Cirripedia) are common crustaceans that colonize solid substrates in marine environments and they can be found in association with organic and inorganic remains recovered from the sea. Barnacles colonize both floating and submerged remains and their growth rate is temperature dependent. Despite their potential to be indicative of the minFI and/or minPMSI, only a few case studies have considered it for this purpose, and scant research has been conducted in this field.

The ecology of Lepas-based biofouling communities on moored and drifting objects, with applications for marine forensic science

“…The use of biofoulers to more accurately estimate the origin and minimum duration at sea of forensically interesting objects such as corpses is emerging as an important field (Magni et al 2015), especially given that decomposition is generally poorly understood in marine environments (Pirtle et al 2019), and marine forensic studies are often forced to rely on hydrodynamic models to estimate the origins of both corpses (Mateus et al 2015) and other objects such as wrecked ships (Palmer et al 2014). A greater understanding of how differing flow regimes between moored and freefloating objects impact community succession, diversity, and growth of Lepas will help improve these estimates.…”

“…Although the value of biofoulers as a forensic tool has been acknowledged, current uses focus on individual species (Magni et al 2015); few studies consider community responses (Dickson et al 2011). The growth rates of invertebrates can be used to estimate parameters such as minimum time since death (Anderson 2009;Pirtle et al 2019), but these studies often rely on generalised growth data that may not reflect the geographic region of interest. Further, marine invertebrate growth rates depend on many factors, including temperature (Nishizaki and Carrington 2015), food availability and quality (Inatsuchi et al 2010;Lavajoo 2019), and competitive interactions (Guilhem et al 2020).…”

Evaluation of barnacle (Crustacea: Cirripedia) colonisation on different fabrics to support the estimation of the time spent in water by human remains

“…Furthermore, in several circumstances, the nature and variability of aquatic environments can be problematic when applying the currently established medico-legal and forensic entomological practices for minPMI estimation [1,8]. In recent years, efforts to provide a better estimation of minPMI, minPMSI and minFI in forensic aquatic-related cases have explored other avenues [13], such as the use of crustaceans (Arthropoda: Crustacea) [14]. Some areas of research consider the effects of motile crustaceans (e.g.…”

“…crabs, Crustacea: Decapoda) as colonisers and decomposers of remains, acting as insect-proxy in the ocean [9] or in freshwater [11,15]. Others have instead focused on the use of barnacles (Crustacea: Cirripedia: Sessilia and Pedunculata), common marine biofouling crustaceans, that colonise the remains settling on shoes, clothing or directly on teeth and bones [14,[16][17][18].…”

“…Despite the clear forensic potential, literature on barnacles at present is focused primarily on taxonomy, distribution, biochemistry (of their glue) and biofouling mechanisms [23,24]. The use of barnacles in forensic science to date accounts for a small number of case reports [16][17][18]25] and only one study based on the colonisation of barnacles on different types of shoes has been published [14]. In many cases, bodies enter the water fully clothed, therefore the present research considersfor the first time the colonisation of barnacles on fabrics commonly used in clothing.…”