M ajor innovations in culture practices will be required if bivalve aquaculture is going to adapt to the challenges of changing ocean chemistry and ri sing temperatures due to climate change present. The shellfish industry must adapt to the reality that environmental conditions are going to be increasingly unpredictable, thus p ractices that increase growth rate and shorten the time to harvest will be beneficial. One such innovation would be the application of electric field potential to produce improve bivalve growth rate . The application of an e lectric field potential (aka ‘Biorock’ technology) is based on the discovery that the passage of a low voltage current through a conductive material drives the accretion of dissolved minerals to form limestone deposits. While the original goal of the technology was to construct mineral material from seawater, observations revealed that organisms that relied on carbonate ions to build their skeletons or shells recruited to these accreted structures and exhibited elevated growth rates. The most high-profile application of this technology has been in coral reef restoration in which steel rebar is used as a conducting substrate for mineral accretion and coral reef restoration. Similar potential benefits of electric field potential technology have been reported for shellfish, with published research showing that Pacific, Eastern, and Pearl oysters that were grown on charged structures showed elevated growth rates and improved survival as compared to oysters grown on control structures. One advantage of applied electric field potential technology is that it is inexpensive to deploy, since it requires low voltages (<12 volts) that are easily provisioned by low-cost renewable energy sources such as wind and solar, and low-cost metal cages or ropes. This allows the technology to be deployed in remote grow-out locations.
The shellfish industry is under already under strain because of ocean acidification (OA) which is associated with poor seed production, reduced growth rates, and thinner shells. Electric field-driven accretion of carbonates results in localized increases in aragonite. W e hypothesize that this localized carbonate increase may be advantageous to bivalves that require carbonate ions for shell development . Therefore, we hypothesize that electric field potential technology may serve to offset the effect of OA which may otherwise depresses calcification rates in shellfish. There is also considerable interest in the restoration of the west coast’s reefs of indigenous Olympia oysters, which are seen as playing a key role in defending coastal ecosystems from climate change and protecting the coast from sea level rise and wave-driven erosion. Electric field potential may prove to have utility in the restoration of this important natural resource.
To the best of our knowledge, electric field potential technology has never been deployed in a commercial aquaculture setting, and so it’s benefits to the industry remains unknown. Evidence that electric field potential technology improves shellfish resilience and growth will have considerable ramifications throughout the industry because this is a technology that can be easily deployed. We believe that innovative farming practices such as those proposed here could benefit the industry and spur further innovations. The type of work described in this abstract is also technical and therefore benefits from an academic-commercial partnership.