PORT PHILLIP COMMON DOLPHIN PROJECT

The Port Phillip Common Dolphin Project aims to maintain a long-term understanding of Port Phillip’s community of common dolphins (Delphinus delphis) to inform wildlife and ecosystem reporting and management.

This community of dolphins is as remarkable as everywhere else in the world but Port Phillip; they live in the open ocean. They share the bay with approximately 120 bottlenose dolphins and five million people.

Our researchers first discovered a handful of common dolphins near Mornington in 2005.

The following figure provides a snapshot of the growth trend in the dolphin community. We use the measure of the number of individual dolphins identified each year and average this over five-year blocks to even out the variability from differences in methods and effort. The final figure of 58 is the average number of individuals for 2020, 2021 and 2022. This is likely to change as the data for 2023 and 2024 are added.

We now have over 150 animals in the Port Phillip Catalogue which includes all we have identified in the bay since 2005.

In 2023, we confirmed the birth of at least six calves of the third generation since they entered the bay 2005. Also, the movement of common dolphins from near Mornington in Port Phillip to Bass Strait waters near Wonthaggi.  So, this study extends beyond Port Phillip into Bass Strait.

As one of Port Phillip’s top-order predators, their success reflects the vitality of their environment. Our research data is contributed each year to the Port Phillip Environmental Management Plan reporting process.

While these dolphins present a wonderful success story, this is not the case for many ‘urban dolphin communities’ in Australia and elsewhere around the world. So there is no room for complacency.

We have concerns about injury and skin lesions on some dolphins, which reinforces the need for ongoing monitoring of these unique dolphins. The Dolphin Research Institute holds the only long-term knowledge of these unique dolphins and is committed to maintaining this to ensure their protection.

You can read more in the series of blog posts lower down the page.