Orla McKibbin1, Adriana Vergés1,2, Melanie Bishop3,2, Katherine Dafforn3,2, Mariana Mayer Pinto1,2
1University of New South Wales, Australia - 2Sydney Institute of Marine Science, Australia - 3Macquarie University, Australia
Marine infrastructure often hosts different and reduced biodiversity compared to natural habitats. This difference has led to the introduction of eco-engineering solutions, which combine ecological principles with engineering designs, attempting to increase biodiversity of marine ecosystems on infrastructure. Many eco-engineering projects have found increased biodiversity on the eco-engineered structures compared to control infrastructure after at least one year, however the mechanisms by which these increases occur are not well understood. Here we sampled intertidal marine assemblages on natural rocky shores, control seawalls and eco-engineered habitat panels regularly from two-weeks post installation until one-year post installation to assess if early recruitment of organisms lead to increased diversity after one year. We found that after one year, the eco-engineered structures had similar species richness to natural rocky shores and control seawalls, but this pattern was generally not apparent until the 12-month sample, indicating that other mechanisms such as competition and predation may influence mature assemblages more than initial settlement. When comparing different designs of eco-engineered panels, we found that complex panels recruited faster than the flat control panels, and that panels with water retaining features had significantly higher species richness than the other designs, from as early as two months post installation. We found differences in abundances of key functional groups between habitats, habitat forming algae and oysters were less abundant on eco-engineered seawalls compared to natural habitats and, in some cases, unmodified seawalls. In an age of rapid marine development, these differences need to be considered to ensure the maintenance of critical marine ecosystem functions and services into the future.
Biography
Orla McKibbin is a PhD student at the University of New South Wales, her research investigates the impacts of marine infrastructure on ecosystem functioning. She works in various marine ecosystems, including seagrass meadows, coastal seawalls and rocky shores. Orla is interested in applied ecology, to achieve solutions to improve ecosystem health in marine environments.