However, growers are often unable to attribute changes in shellfish survival or health to these environmental factors due to a lack of data and the resources and network required to acquire and interpret these data.
We find that growers are concerned about OA, among many other environmental stressors such as marine pathogens and water temperature. Through interviews conducted with West Coast shellfish farm owners and managers (‘growers’), we investigate perceptions of OA and environmental change and identify specific strategies for adaptation. As such, the social-ecological system exemplified by this industry serves as an opportunity to identify and address strategies for local adaptation. The shellfish aquaculture industry along the West Coast is particularly vulnerable to OA, given the negative effects of low pH on shellfish survival and growth. This can result in ecological and social consequences, making necessary the exploration and support for locally relevant strategies to adapt to OA and other environmental changes. West Coast experience a myriad of environmental stressors, including exposure to low pH waters exacerbated by ocean acidification (OA). Overall, our study demonstrates the consistent features of oyster bacterial communities across spatial and temporal scales and provides an ecologically meaningful baseline to track environmental change.Ĭoastal communities along the U.S. This core made up a disproportionately large contribution to sample abundance (34 ± 0.14 %), despite representing only 0.034% of diversity across the study, and have been associated with healthy oysters in other systems. Whilst the majority of bacteria-oyster associations were transient and highly variable, we observed clear patterns of stability in the form of a small core consisting of six persistent Amplicon Sequence Variants (ASVs). gigas harboured spatiotemporally variable bacterial community that were distinct from bacterioplankton in surrounding seawater. gigas, at two Irish oyster farms, unaffected by SMS, over the course of a year. Here, we characterised the associated bacterial community of C. Currently, a lack of understanding of natural spatiotemporal dynamics of the host-bacteria relationship limits our ability to develop microbial-based monitoring approaches. For the Pacific oyster, Crassostrea gigas, Summer Mortality Syndrome (SMS) is one of the biggest constraints to growth of the sector and is set to expand into temperate systems as ocean temperatures rise. gigas coincides with an increase in the abundance of putative bacterial pathogens in the oyster microbiome and highlights the negative consequences of marine heat waves on food production from aquaculture.Ī breakdown in host-bacteria relationships have been associated with the progression of a number of marine diseases and subsequent mortality events. Our findings indicate that heat stress-induced mortality of C. This pattern was confirmed by qPCR, which revealed heat stress increased the abundance of Vibrio harveyi and Vibrio fortis by 324-fold and 10-fold, respectively. 16S rRNA amplicon sequencing revealed a change in the oyster microbiome when the temperature was increased to 25 ☌, with a notable increase in the proportion of Vibrio sequences. Under the same temperature conditions and with the addition of antibiotics, the mortality rate was only 4.3%, strongly indicating a role for bacteria in temperature-induced mortality.
We rapidly raised the seawater temperature from 20 ☌ to 25 ☌ resulting in an oyster mortality rate of 77.4%.
The oyster harbours a diverse microbial community that may act as a source of opportunistic pathogens during temperature stress. Links between rising seawater temperature and disease have been documented for many aquaculture species, including the Pacific oyster Crassostrea gigas. Marine heat waves are predicted to become more frequent and intense due to anthropogenically induced climate change, which will impact global production of seafood.