A reappraisal of the history and economics of the Pacific oyster in Britain.
The Pacific oyster (Crassostrea gigas) was introduced into British waters to support an industry suffering from the decline of the native oyster. Until recently significant conservation risk was thought to be negligible as British coastal waters were considered incompatible with the establishment of self sustaining populations. Those circumstances have changed. On warming southern coasts the Pacific oyster has naturalised and now occupies an intersection between two policy imperatives: one concerning the conservation of protected habitats, the other relating to livelihoods and the economics of coastal communities. This combined with inconsistencies of attitude and policy between immediate European Union neighbours has made the future management of the Pacific oyster contentious. In this context policy is influenced not just by scientific evidence but also by perceptions of the history and economics of the species in each member state. However whereas the conservation risk is increasingly well documented, the history and economics of the species are not. To balance the policy equation we reappraise the commercial history of the species in Britain and provide a first estimate of the full value to the British economy of British reared Pacific oysters, employing a novel approach to the economics of a single aquaculture species. The established view on the history of C. gigas in Britain has it introduced for aquaculture in 1965. Informed by formal taxonomic recognition of its synonymic relation with the Portuguese oyster, along with a search of primary sources, we provide a revised history with the first reliably documented introduction 75 years earlier, in 1890. The economic significance of the species, when conventionally reported as "value at first sale", is also underestimated. The full economic significance of a species is better represented by Gross Output and Gross Value Added through all stages of the value chain, but few if any estimates of these have been attempted for a single species. On the basis of an analysis of the 2011/12 market for British reared C. gigas from production to ultimate consumption, we estimate annual Gross Output to be over £13 million (more than five times the value at first sale), and GVA to be over £10 million. On the basis of the world market and comparisons with neighbouring state production, it is argued that British Pacific oyster production could be significantly increased once uncertainty over its management is resolved.