Bodies in sequestered and non-sequestered aquatic environments: a comparative taphonomic study using decompositional scoring system.

The study of decomposition by using accumulated degree days (ADDs) has been suggested not only in terrestrial decay but also for water-related deaths. Previous studies have demonstrated that the accumulation of thermal energy as a function of the post-mortem submersion interval (PMSI) can be derived from a descriptive decompositional scoring system (DSS). In order to verify how useful can the total aquatic decomposition score (TADS) for ADD prediction be, a comparative taphonomic study has been performed between two series of bodies: 16 corpses found floating in shallower waters with a presumptive PMSI from 3 to 118 days and exposed to water temperatures (Tw) between 10.5 and 20.3 °C approximately equating from a minimum of 46 to 1.392 ADD; 52 bodies, all victims of a single shipwreck, found in sequestered environments and subjected to constant Tw of 4 °C for 210 days approximately equating to 840 ADD. The two series of bodies have revealed different stages of decay and a large DSS variability. In most of bodies, freshly formed adipocere was able to delay the appearance of later decompositional stages explaining why most of the bodies were in relatively good condition. Although promising, the accuracy of the TADS model can be affected by adipocere and animal activity. The TADS model suffers of the same limitations for ADD calculations as they can give a false perception of accuracy due to the complexity of integrating all changing factors affecting human decay in sequestered and non-sequestered marine environments (currents, animal activity, water temperatures, depth of submersion).