EcoNetwork Port Stephens Marine Studies group: pilot dolphin study 2025-26
By Iain Watt
November 2026
Iain Watt is a Marine Scientist, President of EcoNetwork Port Stephens, instigator of the Port Stephens Eco Destination forum, a member of Port Stephens Council’s Environment Advisory Group (EAG) and Port Stephens Great Lakes Marine Parks Advisory Committee.
Since the launch of the EcoNetwork Port Stephens Marine Studies Group in late 2025, the primary focus has been on initiating a comprehensive dolphin survey within the Port Stephens estuary.
The study was set up in response to growing concerns our local Indo-Pacific bottlenose dolphin population is in decline. We don’t know why but given how important these dolphins are to local tourism, and the ecology of the Bay, it’s a concern.
On top of that, more than 70 turtle deaths have been reported in the estuary over the past year, and the cause also remains unknown. Clearly something is up with the estuary.
To address this, it was decided to assess the status of the dolphin population by undertaking a full census of the population and to include turtles in the survey protocol.
“Dolphins and turtles can act as ecological canaries in the coalmine.“
Photo Lisa Skelton
The last study was undertaken by the Macquarie University in the late 1990s and early 2000s, 26 years ago! Our study will replicate as near as possible that study to ensure results are comparable.
Achievements to date have included
- Several discussions with the GMs of Imagine and Moonshadow TTQ about their concerns regarding the apparent decline in dolphin numbers; a briefing session with their interested skippers and crew, and preliminary data collection trials during actual dolphin watching trips
- The development of a mobile phone app to facilitate the recording and storage of sighting information. This has been trialed extensively and is currently in its final development stages and will be released to the public in December
- The app has undergone an extensive trial period involving crew members from the dolphin watching vessels and observations from a private vessel. The charter vessels target known areas for sightings while the private vessel ranges through areas not visited by the charter vessels
- Partnerships developed with ORRCA, Imagine Cruises, Moonshadow TQ Cruises, the Irukandji Shark and Ray Centre and the Worimi Green Team
- Receiving 12 environmental DNA kits with analysis – to be worked together with DPI for wider results
- Fin photos are being collected and archived for future analysis by ORRCA volunteers; and
- Securing archival fin photographs from Lisa Skelton and uploading them to Flukebook has been an important step towards developing an effective data handling and analysis process.
Results so far
Since the first use of the mobile app at the end of November 2025, over 300 discrete entries have been captured in the database, only a few of which can be considered spurious or duplicates. Up until 22 June 2026, the cumulative tally was 1189 dolphins recorded during 236 sightings (refer Fig 1 below).
The app at work and next steps
The app is easy to use and will be released to the public in due course.
More sightings will help pinpoint the hotspots where the dolphins are frequenting, which will allow the associated habitat to be identified and its ecological health monitored.
This will also help assess whether poor habitat condition explains why some dolphins have reportedly been moving out of the estuary and contribute to future management of these iconic species.
The app is also set up for recording turtle sightings, and the same criteria will be applied for monitoring the turtle population in the estuary.
Photo identification
Photos of the dorsal fins are collected to record and identify the individual animals. The dorsal fins have unique identifying marks referred to as “nicks” or “notches”, (cuts or missing pieces on the edge of the fin) along with scars, rake marks (tooth marks from other dolphins) pigmentation and overall fin shape and rigidity. The fins are described for photo identification as follows:
- Leading edge: the front edge, facing the direction of travel
- Trailing edge: the back edge. Most identifying marks are found here
- Tip (or apex): the top point of the fin, sometimes missing or curled
- Base: where the fin joins the body.
A clear side-on photo of the dorsal fin is called a fin profile or an ID shot, and a collection of these is a photo-ID catalogue.
