Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Regional-scale variation in sedimentation influences oyster recruitment at remnant Sydney rock oyster reefs (#43)

Rick Leong 1 , Ana Bugnot 1 2 3 , Wayne O'Connor 4 , Ezequiel Marzinelli 2 3 5 , Katie Erickson 1 2 , Alistair Poore 1 , Paul Gribben 1 3
  1. University of New South Wales, Kensington, NSW, Australia
  2. School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW, Australia
  3. Sydney Institute of Marine Science, Mosman, NSW, Australia
  4. Department of Primary Industries , Port Stephens, NSW, Australia
  5. Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore

There are currently major efforts to restore oyster reefs globally, and in Australia, for which  ~ 90 percent of oyster reefs have been lost. Recruitment – a process fundamental to population maintenance and restoration success – can vary at multiple spatial scales, but the scales which best predict recruitment patterns are poorly known. Here, we determined patterns of recruitment of the Sydney rock oyster (Saccostrea glomerata), across regional-,  landscape-, patch- and within-patch- scales at remnant reefs in three estuaries in New South Wales. Recruitment patterns varied most strongly at regional scales and appeared related to sedimentation patterns operating at the same scale. We then ran a recruitment experiment in six estuaries with high and low levels of sedimentation which showed that recruitment was highest in the low sediment estuaries. Our results suggest that differences in abiotic conditions (i.e., sedimentation) at regional scales have important implications for oyster recruitment and should be one of the first considerations when planning restoration projects for oysters.