The Burrunan dolphin is one of three recognised species of Bottlenose dolphins which is approximately 2.5m in length and has a distinct tri-colouration pattern, from dark grey on the upper side of the body, a paler grey midline and cream underside. It has broad tail flukes, a prominent rounded head, falcate (or curved) dorsal fin, and a short stubby rostrum (nose). There are only two known resident populations in Victoria; one in Port Phillip Bay (approximately 120 individuals) and the other in the Gippsland Lakes (approximately 63 individuals). Burrunan dolphins are social animals and are most commonly seen in pods of 2-30 animals.
Photo: Marine Mammal Foundation
Key threats to the Burrunan dolphin are pollution (chemicals and heavy metals); litter and marine debris such as plastics; disturbance from vessels interrupting core biological activities such as foraging and resting; underwater noise disturbance; entanglement with fishing ropes, global climate change and environmental change impacting salinity and water quality. Fresh water skin disease has affected the population in the Gippsland Lakes, when weather conditions caused excessive influx of fresh water into the normally brackish-to-salty lake system. Complex environmental changes to the Gippsland Lakes, such as increased sedimentation, dramatic salinity declines, algal blooms, temperature changes and anoxic conditions may also contribute to the health decline of the dolphins. Increased incidence of these weather events could threaten the small population in the lakes. Other possible threats are low population sizes and low genetic diversity.
What's being done?
Efforts to save the species are being supported by a $49,940 grant through the Victorian Government’s Biodiversity On-Ground Action Icon Species Grants program, which funds targeted actions designed to protect and conserve Victoria’s threatened species.
This funding is going towards;
- Investigating the current health status of Burrunan dolphins in the Gippsland Lakes
- Collecting valuable baseline information on the possible causes of the Gippsland Lakes Burrunan dolphin mortality event
- Assessing current contaminants in the Gippsland Lakes and their possible effects on the Burrunan dolphin population
- Providing information to manage and mitigate against further impacts and mortality events.
Conserving Victoria's threatened species requires a collaborative approach. There are a number of organisations and groups working to protect the Burrunan dolphin, these include:
- Australian Marine Mammal Conservation Foundation
- East Gippsland Catchment Management Authority
- Port Phillip Bay Fund Targeted Actions 2020-2021 (PENDING)
Page last updated: 29/11/22