In the twelve months, from 31st May 2017 to the first week of June 2018, most of our adult native oysters have survived and they have shown a constant weight gain, as per the graph.
Of the 314 adults that went out, 252 are still alive after the 12 months. Approx a dozen went missing, and the rest have died, with the highest level of mortality in the Inner Harbour, and shallowest, sites.
The growth rate in shell dimensions was greatest in the first days of deployment, from end May 2017 to early July 2017, then slowed before again becoming more obvious post summer. For the last two months we’ve been seeing new translucent shell growth.