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Workshop: Atlantic Canadian tunicate workshop



During the late '90s two invasive species of tunicate were determined to be having a detrimental impact on numerous shellfish aquaculture sites in Nova Scotia (Ciona intestinalis) and Prince Edward Island (Styela clava). The tunicate populations have continued to increase in various areas and while research is on-going into the biology and possible treatment measures it was felt that industry should meet with individuals with experience dealing with various types of tunicate and fouling mitigation measures. The purpose of this workshop was to bring together mussel producers/processors, international tunicate experts, local researchers and interested government officials to discuss the current situation in Atlantic Canada and to develop potential management plans for those areas most heavily impacted and areas with minimal infestation. Speakers were brought in from the United States, New Zealand and the region, while growers from Nova Scotia, PEI gave a personal account of their experience at ground zero.

The following key points were raised in the panel discussion: eradication is not conceivable, management being the only alternative; Styela has no known predators in PEI, unlike Ciona in NS; to control tunicate costs growers/processors $0.115 per lb; techniques for spraying tunicate (acetic acid) applied in agriculture industry; management approach: juveniles are attracted to adults, placing tunicate collectors along side mussel lines might reduce fouling; experts have never seen such heavy infestations; fallowing has not proved viable management approach; proactive approach such as early detection/immediate removal is recommended; new technology in New Zealand to control Ciona on mussel crop by limiting its inoculation pressure was key to managing tunicates; short term (emergency) and long term (developmental mitigation efforts) funds should be available to the industry/researchers.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)


2003 - 2003



Principal Investigator(s)

Thomas Landry

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