On the evening of June 12th, we received reports of a deceased dolphin calf near the Canning Bridge. We were devasted to learn that this was Djinda’s calf, who was born in April.
At 2 months old, it’s not possible to identify a dolphin using the traditional way (i.e. by the nicks and notches found on the dorsal fin). Instead, Dr Delphine Chabanne examined some markings and spots on the body of the dolphin, which she matched with images taken of the calf on her previous surveys. We decided to name the calf ‘Walken’ meaning Rainbow in Noongar 🌈. A necropsy was undertaken by colleagues at DPIRD and we now know that Walken had a severe lungworm infestation, which resulted in pneumonia, ultimately causing her death.You may be surprised to hear that dolphins, like most other mammals, can get parasites such as lungworm. Here are some Q+A’s we’ve put together for you:
1. What is lungworm?
Lungworms are a group of parasites that infect the lungs and airways of mammals. Lungworms are common in pinnipeds (seals) and cetaceans (dolphins + whales).
2. How do dolphins get it?
Usually by eating fish hosting lungworms. There is also a chance that it can be passed from mother-calf during pregnancy.
3. What are the symptoms of lungworm?
Generally, there are no symptoms but sometimes weight loss and lethargy can indicate infection
4. Are the other dolphins in the river at risk?
Parasites are naturally occurring in all environments and lungworm is common in dolphins. This does not necessarily mean the dolphins will become infected or die from an infection. Research suggests that lungworm is less common in adult dolphins, but in young calves, an infection can cause pneumonia when further compromised by high environmental changes (e.g., changes in weather conditions).
We cannot control natural factors such as these however, we can all help dolphins and the little calves in our Riverpark by picking up discarded fishing line, keeping your distance (100m), and reducing your speed on the water. RIP little Walken
A huge thank you to the team at DPIRD’s Diagnostics and Laboratory Services for conducting the necropsy
All photos by Dr Delphine Chabanne from Murdoch University