|BEN-HORIN, TAL - University Of Rhode Island|
|BURGE, COLLEEN - University Of Maryland|
|BUSHEK, DAVID - Rutgers University|
|GRONER, MAYA - Us Geological Survey (USGS)|
|HUEY, LAUREN - Virginia Institute Of Marine Science|
|BIDEGAIN, GORKA - University Of Basque Country|
|CARNEGIE, RYAN - Virginia Institute Of Marine Science|
Submitted to: Aquaculture Environment Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2018
Publication Date: 12/13/2018
Citation: Ben-Horin, T., Burge, C., Bushek, D., Groner, M., Proestou, D.A., Huey, L., Bidegain, G., Carnegie, R. 2018. Disease at the interface of aquaculture and wild oyster reefs. Aquaculture Environment Interactions. 10:557-567. https://doi.org/10.3354/aei00290.
Interpretive Summary: The effects of cultured and restored eastern oyster populations on the transmission of disease to nearby wild populations and vice versa are unknown. This study used an epidemiological modeling approach based on empirical data to assess whether cultured and wild populations in close proximity to one another interact with respect to disease prevalence and intensity. Results suggest that aquaculture stocking densities do not directly affect disease prevalence in nearby wild populations, but husbandry practices do. Maintenance of cultured oysters beyond the normal two-year grow-out period when disease prevalence and intensity are peak can have a negative impact on nearby wild populations. Furthermore, cultured oysters selected for disease tolerance that are not harvested in time pose an even greater risk to wild populations. These model predictions can be incorporated into shellfish husbandry and management practices.
Technical Abstract: The spread of disease from open-water fish and shellfish farms to sympatric fish and shellfish in the wild is a significant and contentious threat to coastal marine ecosystems. From empirical data, we quantified the transmission and pathology of the protozoan parasite Perkinsus marinus in populations of eastern oysters. We then investigated the dynamics of disease at the interface of cultured and wild populations using a coupled epidemiological model that captured the indirect interaction that occurs through shared parasitism of sympatric populations. The density of oysters in culture, which is commonly thought to lead to the spread of disease from farms to nearby wild populations had only indirect and mostly neutral effects on parasite transmission. Instead, we found that disease transmission responded directly to the rate of aquaculture harvests. Oyster aquaculture can theoretically reduce disease in conspecific wild populations by diluting encounters with disease-causing parasites, so long as they are harvested before infections peak in the cultured population. Selective breeding for increase tolerance to disease, as opposed to resistance to parasitic infection, leads to a counterintuitive increase in disease among sympatric wild oysters when planted oysters are harvested slowly or not at all. Evidence-based management informed by rigorous epidemiological investigations that test and predict interactions between fish and shellfish farms and wild populations may reduce conflict between stakeholder groups such as the aquaculture industry, environmentalists and resource management agencies.