Despite the presence of OA in seagrass epiphyte samples throughout the year, OA was not detected in dugong or turtle tissue samples from animals thought to have been feeding in the region where P. lima were observed. There may be several explanations for this. Firstly, it is possible that while P. lima was ingested, the OA was not absorbed and assimilated during digestion. In addition, we estimated that the likely average exposure to OA in a dugong or a turtle consuming H. ovalis from any of the sites we assessed was 2440 and 120 ng/day respectively. Based on this estimated intake, and assuming 100% uptake through digestion with no metabolic breakdown or excretion and uniform distribution through tissue, the expected concentration in tissue after a 12 month average accumulated exposure would be 2226 ng/kg(dugong) or 73 ng/ kg(turtle). These estimates are well below the detection limit (10,000 ng/kg(tissue)) available using HPLC/MS/MS. Also, as the animals that were available for analysis were all stranded