Endocrine Disruption in marine mammals: relationships between contaminant exposure and reproductive physiology in the common harbour porpoise

Endocrine disrupting chemicals (EDCs) can cause developmental abnormalities resulting in altered morphometrics of reproductive organs. Marine mammals are good indicators of environmental change as they are often at the top of their food chain. Testicular weight has been shown to be negatively correlated with exposure to polychlorinated biphenyl’s (PCBs) in the harbour porpoise and in humans there is a negative association between PCB exposure and sperm quality. The ano-genital distance (AGD) is a measurement from the anus to the genital slit and has been known to shorten when pre-natal exposure to EDCs such as phthalates. The aim of this study is to gain a greater understanding into the effects of endocrine disrupting chemicals (EDCs) on reproductive functions in the common harbour porpoise. Using 30 years of stranding data this study will develop the methodology to compare the AGD to pollutant burden using historic photo archives.  In addition, this study will use archived testicular tissues to compare spermatophore development to contaminant burden and reproductive morphometrics. This project will: 1) Determine the variability in sexually dimorphic characters in harbour porpoise using photo archives 2) Determine relationships between sexually dimorphic indices and environmental contamination 3) Develop an index for determining spermatozoa quality in harbour porpoises 4) Determine the relationship between spermatozoa quality and environmental contamination