Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Multi-Ecosystem Restoration: Optimizing Reef Restorations to Recover Multiple Marine Habitats (#10)

Dominic McAfee 1 , Sean D Connell 1
  1. The University of Adelaide, Adelaide, SA, Australia

Healthy seascapes are characterized by many interacting species and intermingled habitats (e.g., seagrass, kelp, bivalves, sedimentary) that co-create ecological functions of socio-ecological value. These co-created functions not only build stability and resilience to environmental change but may also combine to synergize the recovery of degraded ecosystems. Yet, single-species approaches still dominate marine restoration practice. In South Australia, we are examining the benefits of a multi-ecosystem approach to marine restoration by utilising the opportunities created by large-scale reef construction. Boulder reefs constructed to restore oysters also provide opportunities to restore lost kelp forests (provision of hard substrate) and seagrass meadows (hydrodynamic buffering and sediment stabilization). Ecological synergies created by co-restoring these habitats were immediately evident. For example, transplanted kelp forests increased oyster recruitment to reef boulders by orders of magnitude, which produced mixed oyster-kelp habitat that can synergistically benefit kelp re-attachment (haptera growth) and oyster habitat formation. Furthermore, the oyster-kelp combination increased hydrodynamic buffering leeward of reefs where seagrass transplants (hessian bags) show early signs of recovery despite the high-energy environment where they have historically failed. We propose that restoration practice should prioritize a multi-ecosystem approach that not only stabilizes but accelerates ecosystem recovery.