Middle Holocene Oyster Shells and the Shifting Role of History in Ecological Restoration: How a Dynamic Past Informs Shellfish Ecosystem Reconstruction at an Australian Urban Estuary

Abstract

At Western Australia's Swan-Canning Estuary, extensive subfossil shellfish assemblages of Middle Holocene origin were largely destroyed through dredging for cement production in the first half of the twentieth century. This case-study of an extractive industry driving shellfish ecosystem decline builds on existing historical studies of commercial over-harvesting of oysters, and historical and paleo-ecological investigations of sustainable, long-term indigenous oyster harvests, presenting an important new perspective on global shellfish ecosystem decline and the enduring cultural value of shellfish resources by revealing processes of cross-cultural knowledge transfer, unfolding environmental understanding and extensive environmental change across Western Australia's post-European settlement history. We explore these histories in detail for the first time, before considering their relevance to a shellfish ecosystem reconstruction initiative currently underway at this major Australian urban estuary.