PNNL

Abstract

Oysters perform critical roles in shorelines ecosystems helping to improve water quality, provide habitat for species, and prevent erosion; these ecosystem functions are present even when farmed. Oyster farming is often viewed as environmentally friendly, due to these environmental benefits, combined with the limited need for nutrient inputs. Still, fossil fuels play a large part in oyster farming practices, powering boats, tools, farming equipment, and facilities such as hatcheries. One procedure in particular – oyster tumbling – performed to control biofouling, produce a desirable shape and size, and sort oysters is often a source of emissions on farms, with few options for diesel alternatives at remote sites. As the oyster farming industry grows and as practices such as integrated multi-trophic aquaculture expand, decarbonization of the industry becomes more important. Oyster grow-out methods that integrate ‘ocean-powered’ tumbling or gear that is designed to use various ocean movements to tumble oysters address decarbonization problems by eliminating the need for fossil fuel-powered tumblers and tend to be less labor intensive for the farmer. A variety of ocean-powered gear is available and in operation by numerous farms across the United States, with new approaches and designs still being explored, making ocean-powered oyster tumbling accessible across different environments. Ocean movements may primarily come from tidal exchange, currents, wind waves or a combination. This paper compares methods of ocean-powered tumbling, explores the transition from standard fossil fuel-powered tumbling techniques to ocean-powered tumbling, and estimates the emission reductions of decarbonizing the oyster farming industry.