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Microbial impacts on shellfish aquaculture in relationship to ocean acidification



Ocean acidification (characterized by high dissolved carbon dioxide (pCO2) levels) can affect shellfish fertilization rates, hatching success, larval development, shell deformation, seed production and survival. However, it is not clear whether high pCO2 levels alone are responsible for poor performance in some west coast shellfish operations. While hatcheries have successfully controlled levels of pCO2 for larval and nursery production through the use of buffering systems, there have continued to be high variations in batch to batch survival. This suggests that other uncontrolled aspects of the seawater composition during high pCO2 events may be at play, most notably bacterial compositions. This project will use next generation DNA sequencing technologies to assess bacterial communities associated with seawater coming into two shellfish hatcheries in the Pacific Northwest. The overall goal is to determine whether the bacterial compositions within incoming water, buffered water, and that associated with larval and juvenile culture are influenced by pCO2 concentration and to identify whether shifts in bacterial compositions occur between seed batches with good and poor survival.

The knowledge obtained through this research will be useful in the development of a mitigation strategy to reduce the impact of ocean acidification on the shellfish industry on Canada's West Coast. Additionally, the identification of factors that contribute to farmed shellfish mortality may lead to the development of monitoring tools. This would ultimately assist the industry in enhancing environmental sustainability and economic viability of shellfish aquaculture.

This project supports the optimal fish health objective of the Aquaculture Collaborative Research and Development Program (ACRDP), and pertains to the 2014-15 national ACRDP priority of maintaining healthy populations by being proactive in the development of approaches to manage health issues that may arise for cultured shellfish species.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)


2014 - 2015



Principal Investigator(s)

Kristi Miller

Collaborative Partner(s)

Island Scallops Ltd.

Fanny Bay Oysters Ltd.

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