Abstract Detail

Phycological Section

Wu, Shelly [1], Hood, Craig [1], Pinckney, James [2], Wee, James [1].

Assessing Periphyton Accumulation on Hair Submerged in Aquatic Environments to Determine the Postmortem Submersion Interval (PMSI).

In forensic science, no reliable method exists for determining the postmortem submersion interval (PMSI), the time a human corpse has been submersed in natural waters. Previous studies emphasized microbial growth and decomposition of pig carcasses as a model. No study has investigated periphyton accumulation on human hair for determining the PMSI. Standardized natural and synthetic hair tufts were submerged in a freshwater and estuarine water site for five weeks. Periphyton growth was assessed with three methods: 1) Cryo-Scanning Electron Microscopy was used to observe periphyton community development qualitatively, (2) SPOT Software with optical microscopy was used to calculate periphyton community surface area along individual hair samples, and (3) Chlorophyll a biomass was determined on hair-tuft samples with High Performance Liquid Chromatography. Both microscopy methods illustrated progressive community development over time, but the natural hair indicated scavenging activity or sloughing starting the third week of submergence. 1-way ANOVA of the chlorophyll a data showed that growth was not significantly different on most of the hair treatments over time except on the natural hair from the brackish site, when the first and second week were different (P = 0.026). Similarly, the surface area data illustrated that growth on the synthetic hair and natural hair from the brackish site was significantly different between the first and second week (P = 0.002 and P = 0.004 respectively). The surface area data for all the hair treatments were significant, but the trends were not consistent with each other. A follow up experiment will be conducted to refine the methodology. Funding: Louisiana Board of Regents' Supervised Undergraduate Research Experience (SURE) Grant, Loyola University New Orleans SGA Richard Frank Grant, and Loyola University New Orleans Mullahy Biology Endowed Fund.

Broader Impacts:

1 - Loyola University New Orleans, Biology
2 - University of South Carolina, Biology

Keywords:
Postmortem Submersion Interval (PMSI)
Periphyton
Hair.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PPC007
Abstract ID:940
Candidate for Awards:None