Standard Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Lessons learned from small habitat enhancements adjacent to the Sydney Opera House to enhance fish biodiversity (#84)

Giglia A Beretta 1 , Emma Bombonato 2 , Alex Goad 3 , David J Booth 1
  1. Fish Ecology Lab, University of Technology, Sydney
  2. Sydney Opera House, TAFE NSW, Sydney, NSW, Australia
  3. Reef Design Lab, Melbourne

Natural edge habitats around urban harbours are mostly replaced by featureless walls and docks, to the detriment of suitable habitat for estuarine fishes.  We surveyed nearshore fish assemblages along the southern shoreline of Sydney Harbour for 18 months prior to the establishment of eight small artificial habitats (each consisting of 3 small “reef pods”) along the eastern edge of the Sydney Opera House (in 2019), where hard rocky reef structure is sparse.  Reef pods and harbour reference sites were surveyed (visual in-situ surveys and from stationary GoPro cameras) at 6-8 week intervals for twelve months prior to installation and then in 6-12months intervals.  We found 25 species of fishes utilising these nearshore habitats, with species richness differing seasonally.  The reef pods attracted 9 fish species not observed at that or other sites previously, including 4 endangered Whites seahorses in 2022 and a juvenile in 2023.  Overall, we showed that small artificial habitat enhancements can benefit the nearshore fish communities in urbanised estuaries.  The project was well supported by SOH and had wide media publicity and education links.  We will summariese benefits and obstacles in the light of the new Project Retsore restoration project in Sydney Harbour.