Community-based marine restoration to generate social license and ecological knowledge for upscaling oyster reef restoration

Community-led restoration operates at the intersection of ecological
feasibility and social acceptability. In the marine realm, restoration is
challenging due to gaps in ecological knowledge on how and where to
restore lost ecosystems and limited public engagement that provides social
license for restoration. The restoration of lost oyster reefs provides a
prime example because these ecosystems have been degraded to functional
extinction on many coastlines, resulting in limited knowledge on their
restoration potential and generational amnesia among communities that
these ecosystems ever existed. To generate an evidence-based and social
license for future restoration work, we engaged high school students and
coastal residents in research on where to restore lost oyster reefs in
South Australia’s iconic Coffin Bay. Using a mixed methods approach, we
aimed to understand (1) the motivation of high school students to
participate in restoration research, (2) to quantify ecological responses
to habitat provision (oyster and biodiversity recruitment) to identify
appropriate restoration sites, and (3) assess the response of residents’
to the ecological outcomes, including their willingness to support future
restoration efforts. The high school students anticipated
personal benefits (e.g., new experiences, career development),
environmental benefits (e.g., nature connection), and benefited the local
community (e.g., recreational activities). Students received SCUBA diving
certification that enabled them to deploy 28 restoration units (shell
baskets) at 8 sites throughout Coffin Bay. This experiment was retrieved
after 3 months to reveal high-density recruitment of oysters and
biodiversity at all sites, key environmental indicators for identifying
suitable sites for restoration. Most residents engaged with the results
expressed surprise in the ecological outcomes (the density of native
oyster recruitment and associated diversity of marine life) and were very
supportive of more oyster restoration occurring (91% of respondents). This
study demonstrates that ecological feasibility and social licence are not
sequential hurdles to be overcome independently, but mutually reinforcing
processes that can be co-generated through community-based research. These
results show that when restoration is designed as a socio-ecological
learning system, rather than a technical intervention alone, it can unlock
local stewardship, political momentum, and generate restoration-ready
knowledge.