The diatoms test in veterinary medicine: A pilot study on cetaceans and sea turtles

Fishing activities are considered one of the most relevant threats for cetaceans and sea turtles conservation since these animals are sometimes found dead entangled in fishing gears. Currently, postmortem diagnosis is based mainly on the presence of nets and lines on the body and the related marks and injuries evident at gross examination. A more detailed and objective evidence is needed to clarify doubts cases and the diatoms technique, used in forensic human medicine, could support drowning diagnosis also in this field. Diatoms' investigation was implemented to be applied in marine vertebrate on 8 striped (Stenella coeruleoalba) and 1 bottlenose (Tursiops truncatus) dolphins and 5 sea turtles (Caretta caretta) stranded along the Italian coastlines with a likely cause of death hypothized on necropsies carried out by veterinary pathologists. Diatoms were microscopically searched in the bone marrow collected from long bones implementing protocols used in human medicine and their presence was observed in 4 cetaceans and 2 sea turtles. Despite a clear relation between diatoms' presence and amount and the likely cause of death was not proved due to the poor number of samples, the higher burden of diatoms was found in 3 animals deemed to be death for the interaction with human activity. Despite more studied are necessary to identify the possible relation between the cause of death and diatoms' findings, the present study implemented this technique to be adapted to marine animals, confirming its possible application also in veterinary forensic medicine.