Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Contaminant assessment of stranded and deceased cetaceans on the New South Wales coast of Australia with a focus on rare Ziphiidae species (#77)

Natalie L Palmer 1 , Amanda Reichelt-Brushett 1 , Duane March 2 , Jane Hall 3 , Karrie Rose 3
  1. Faculty of Science and Engineering, Southern Cross University, East Lismore , NSW, Australia
  2. Wildlife Solutions, Coffs Harbour, NSW, Australia
  3. Australian Registry of Wildlife Health, Taronga Conservation Society Australia , Mosman, NSW, Australia

Metal and organic pollutants are prominent marine contaminants that disperse into various environmental compartments, including the tissues of marine biota. Some contaminants biomagnify, leaving apex predators and long-lived cetaceans at risk of toxicity. Various tissues collected post-mortem from 18 cetaceans (16 Ziphiidae, one Megaptera novaeangliae, one Kogia breviceps) stranded on the New South Wales coast over the last 15 years were investigated for 15 metals/metalloids and 33 organic contaminants. Results are discussed in context with species, sex, age class, tissue type and post-mortem findings. Polychlorinated biphenyls (PCBs) and Dichlorodiphenyltrichloroethanes (DDTs) were commonly detected organic contaminants, <1mg/kg (in blubber and liver tissues). Mercury, cadmium and silver exceeded reported toxicity thresholds in several individuals. Liver tissue from one Mesoplodon layardii individual had the highest mercury concentration (363mg/kg). Mesoplodon grayi liver had the highest silver (19.7mg/kg), and the highest cadmium was in Ziphius cavirostris kidney (478mg/kg). This study provides some of the first recorded contaminant concentrations in stranded cetaceans on the New South Wales coast, and important baselines for cetacean species globally, including several rare Ziphiidae species.