A field trial to determine the optimal treatment regime for Ciona intestinalis on mussel socks

摘要

The invasive tunicate species Ciona intestinalis (Linnaeus, 1767) has had an economic impact on the aquaculture of the blue mussel Mytilus edulis (Linnaeus, 1758) in Prince Edward Island (PEI). This tunicate fouls mussel socks suspended on long lines in the water and reduces both weight and numbers of mussels, decreasing overall productivity. This study determined the relative effects of high pressure water treatment schedules over a four month period on two sites in the Murray and Brudenell Rivers on PEI. Results indicated that initiating treatment early (July) in the season and treating another two or three times during the season had the greatest effect on reducing tunicate numbers and size and enabling greater mussel productivity. While the most effective treatment may ultimately be site-specific, the two sites in this study support the notion that beginning treatment when tunicates are small is one of the most significant parts of the treatment plan. Two or more treatments (approximately monthly) are then needed to effectively control C. intestinalis , and allow mussels to reach their full growth potential.