Dr Joseph DiBattista, School of Environment and Science, Griffith University
Home to the billowing sails of the Opera House and the shimmering arches of the Harbour Bridge, Sydney is famed for its magnificent harbour – but what lies beneath the water’s surface? This information might be up to date for some of the more conspicuous and taxonomically resolved groups of resident animals, such as the fishes of Sydney Harbour (we are now up to 675 known fish species, with 10 more new records added since our scientific publication in Marine Pollution Bulletin in December 2022), but what about the inconspicuous and less resolved animals and plants? Moreover, there are large swaths of Sydney Harbour where we have little documented biodiversity data, even at some of the most frequented swimming beaches or adjacent to some of the most heavily populated suburbs.
The purpose of our Blue World and Australian Museum sponsored project, as part of the Valerie Taylor City East Prize, was to increase biological records at Parsley Bay, Camp Cove, and Shark Beach in southern Sydney Harbour. We are in the process of doing this by establishing a high-quality data set of common, rare, and/or threatened marine species and their associated habitat via underwater citizen science observations, mostly via snorkel and SCUBA diving. Participation in citizen science has exploded in Australia with increased access to technologies such as smartphones and underwater cameras, as well as slick and user-friendly web platforms like iNaturalist, and so the latter science social network serves as the basis for our Marine Biodiversity of Southern Sydney Harbour project. We encourage anyone and everyone to help us balance the books and be our “eyes in the water” by recording the amazing biodiversity that lives alongside us in southern Sydney Harbour; these data are intended for research and conservation purposes.
As a complement to the citizen science data, we continue to conduct monthly environmental DNA (eDNA) seawater sampling at Parsley Bay and Camp Cove with our research partner Dr Shaun Wilkinson in New Zealand, founder of Wilderlab, as well as highly active community members like Nicole McMahon. eDNA can be thought of as genetic “breadcrumbs” left behind in the environment that can identify every living thing, from microbes to mammals. After 13 months of sampling at these two locations, we have now detected 161 and 184 species of fish (with approximately 74% faunal overlap), respectively, with a number of cryptic species detections as well as detections of commercially important species. Using these DNA tools, we have also detected a number of marine animals for the first time in Sydney Harbour, and some of these species for the first time south of the Great Barrier Reef! We are also finding that combining the forces of citizen science and eDNA provides a richer and more robust source of biodiversity data than each method ever could in isolation.
One of the important marine species that we are recording as part of this project is the endangered White’s Seahorse (Hippocampus whitei), which is the focus of some of the upscaled restoration efforts being led by Project Restore based out of the Sydney Institute of Marine Science (SIMS). Moreover, with the help of our collaborator Dr David Harasti at NSW Department of Primary Industries, four seahorse hotels were installed in-kind by Sealife Aquarium on 23 March, 2023 in approximately 6 metres of water at Parsley Bay to support the recovery of this species in our very own Sydney Harbour. All the more reason to protect the diverse, inner harbour ecosystems, like Parsley Bay, that host these endangered sea creatures, from further construction and infrastructure developments.
The final aspect of our project has been setting up a “Marine Education and Research” activity space at Parsley Bay Cafe to create some visibility around the richness of biodiversity found in the ocean and forest reserve at this location, activate the space alongside the local community, and give the opportunity to exceptional and enthusiastic NSW marine biology researchers to share their research findings with us. These regular events are supported by the National Parks Association of NSW and Woollahra Council. So far, we have heard amazing presentations focused on citizen science, jellyfish, sea urchins, White’s seahorses, seashells, and larval fish. Please do join us at our next event on 9 March, 2024 at Parsley Bay Kiosk (9:00 AM – 10:30 AM AEDT), where we will hear from researchers working on re-establishing crayweed in NSW, the conservation of cownose rays, and more citizen science opportunities aimed at cataloguing marine biodiversity.
Dr Joseph DiBattista most recently served as NSW Senior Research Scientist and Curator in the Ichthyology Section at the Australian Museum (2018-2023), where he maintains Research Associate status and continues to coordinate legacy fish biodiversity and genomic initiatives. He is currently based at Griffith University on the Gold Coast as Senior Lecturer in the School of Environment and Science.