Summary

The WA tropical rock oyster research and development project investigated the aquaculture potential of two native (or endemic) rock oyster species, Saccostrea A and Saccostrea echinata by growing (wild and hatchery-reared) spat at several intertidal and subtidal sites in the Pilbara and Kimberley regions of WA. Initial stages of this project involved retrofitting a research hatchery in Perth with the goal to produce oyster spat and developing farm sites in northern WA in preparation to receive and grow-out these spat to determine their suitability as aquaculture candidates in a northern WA context.

Whilst the project started well in late 2019 with farm site development, it is important to note that the project outcomes were significantly impacted by several factors including the onset of the COVID-19 pandemic and associated regional travel restrictions and isolation protocols in place throughout WA until mid-2022, the departure of key personnel and project lead scientist prior to project completion and ongoing water quality issues in the hatchery that limited the supply of spat for field trials. Despite this, both Saccostrea A and S.echinata were able to be grown in the Pilbara for 17 and 21 months respectively and showed promise as aquaculture products. This report summarizes the key findings of the field growout trials of oysters.

A crucial objective to develop a sustainable tropical rock oyster industry in northern WA is securing a reliable supply of spat for farmers. To address this, the viability of both collecting wild and hatchery rearing spat of the two target species was explored. It was determined that relying on wild spat collection alone is unlikely to be feasible for growth of a tropical rock oyster industry in the Pilbara or Kimberley with target species being either absent from wild collection devices or mixed with unsuitable species. Hatchery spat will most likely be required to complement wild collections or fully supply commercial farm operations.