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Join the excitement with URG, Southern Cross University, and iNaturalist as we host thrilling Sea Slug Census events! Held for 2 weekends every November at both Port Stephens and Sydney, these events encourage divers to capture images of various sea slug species and upload on iNaturalist to conduct the census.

Did you know there are over 2,000 known sea slugs, with many more yet to be discovered? Sea slugs are remarkable climate change indicators due to their visibility, short lifespans, and easy identification. By participating, you contribute to scientific understanding of species distribution, climate change impacts, and potentially discovering new species. Dive into discovery with us!

Participate through scuba diving, snorkeling, or exploring rock pools.


  • Certified scuba divers are welcome, or you can participate as a snorkeler or rock pool explorer.

  • Bring an underwater camera (or waterproof camera for snorkelers).

  • Join individually or as part of a dive team.


  • Dive/snorkel site scope: Sydney, with a geographic range from Port Hacking to Pittwater, including Bare Island as the main census site.

  • Capture one photo of each sea slug species within the census timeframe and dive site scope—no need to identify them, just snap their photos!

  • Crop the photos to highlight the sea slug clearly.

  • Upload your results to iNaturalist. If you are facing challenges joining iNaturalist for the Census then let us know, and we'll ensure your observations are included.

  • Embark on this underwater adventure with us and make a splash in marine research!

How to participate in the Sea Slug Census

Sydney Sea Slug Census Events




The 2024 Sydney Sea Slug Census will be arranged in November 2024 over the weekends of 9-17 November. The Port Stephens Sea Slug Census will likely be scheduled for November 2024 too.

Sea Slug Census 2023.jpg

2023 - Total species found: 68 

BEST NUDI SPOTTERS - Sebastien Landat, Charlotte Elliot, Reka Tunde and Honam Law who provided 416 observations between them. Honam Law alone spotted 36 different species!

BEST PHOTO - To be announced in Feb 2024!

2022 Best Photo.JPG

2022 - Total species found: 23 

BEST NUDI SPOTTERS - Nyrie4wombie, Harry Rosenthal and Natalie-anna and Mike Jones who provided 34 observations and 16 species between them. 


2020 - Total species found: 53 

BEST NUDI SPOTTERS - Salvatore Gambacurta, Adad Were, Steven Coutt and Felipe Malbec with 40 species. 

BEST PHOTO – Team Party Boy's image of Janolus sp. Syd6

Download Sydney SSC 2020 result


2019 - Total species found: 25 

BEST NUDI SPOTTERS - Wilson Leung, Tom Chun, Frank Bai, Steven Kong, Agnes Chan & Kathy Law with 15 species. 

BEST PHOTO – Minh Tran's image of the common but undescribed Elysia sp

Download Sydney SSC 2019 result


2018 - Total species found: 61 (14 of these had not been found in the last 3 censuses)

BEST NUDI SPOTTERS - Dan Vaughan and Sandra Gendera with 38 species. 

BEST PHOTO – Wilson Leung and Kathy Law’s image of Nembrotha purpureolineata

Download Sydney SSC 2018 result


2017 - Total species found: 70 (23 of these had not been found in the last 2 censuses)

BEST NUDI SPOTTERS - Deb Aston, Ted Aston and Kim Dinh. 

BEST PHOTO – Ron Walsh’s image of mating Ceratosoma amoenum

Download Sydney SSC 2017 result


2016 - Total species found: 53

BEST NUDI SPOTTERS - Tom & Nicola Davis with 18 species. 

BEST PHOTO – Duncan Heuer’s image of Miamira magnifica

Download Sydney SSC 2016 result


2015 - Total species found: 43

BEST NUDI SPOTTERS - Will Owyong & Cath Shorthouse, John Turnbull & Yolana Kailichova – both with 18 species. 

BEST PHOTO – Ian Shaw’s image of Goniobranchus tasmaniensis

Download Sydney SSC 2015 result

Register now to participate in Sydney's Sea Slug Census Nov 2024

My planned Sydney Sea Slug Census activities (you can choose more than one):
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