Living seawalls in Sydney Harbour

SIMS scientists from UNSW together with NSW OEH, DPI and international collaborators are working on a project exploring “living seawalls” in Sydney Harbour.

The main goals of the project are to investigate 1) how adding complexity to seawalls might provide refuges for marine life from heat stress and 2) how “pre-seeding” seawalls with important habitat-forming species might enhance ecological structure and function such as productivity. To test these ideas, 3D-printed concrete tiles with different levels of complexity and seeded with key habitat forming species (the Sydney rock oyster, Saccostrea glomerata and the calcareous red algae Corallina officinalis ) were attached to seawalls around Sydney Harbour.

Over a period of twelve months they attracted significant marine life such as seaweeds, crabs and fish. Tiles were collected and taken to the aquarium facilities at SIMS, where half were subjected to an experimental “heatwave”. For 5 days, tiles were subjected to ambient seawater temperature (24oC at the time) or increased water temperatures (27oC). After the heat stress, we measured productivity and filtration rates (using the same procedure described above) and diversity of mobile and sessile organisms.

Findings of this project will provide important information to coastal managers and relevant stakeholders on how to build and manage marine urban infrastructure under a changing environment.

People involved in the project: From UNSW – Mariana Mayer-Pinto, Katherine Dafforn, Ana Bugnot, Shinjiro Ushiama, Alessandra Carbone and Emma Johnston. From OEH – Jaimie Potts, Peter Scanes. From SIMS: Beth Strain From DPI: Tim Glasby From University of Bologna: Laura Airoldi

A number of volunteers helped immensely during fieldwork. Special thanks to Giulia Fillipini, Sofia Seizig and Marc Uya.

mariana pinto experiement March 2017 Mariana_research tile