Fighting vase tunicate in the Magdalen Islands

A new invasive species, detected in 2007 in the Cap-aux-Meules fishing harbour, is proliferating at an worrying rate. Vase tunicate (Ciona intestinalis) is an invasive tunicate from Northern Europe that is spread by ocean currents and human activities. This tunicate competes with bivalves such as blue mussels for food and space. By attaching itself to mariculture structures, it affects the survival and quality of farmed animals and reduces their productivity.

At Prince Edward Island, the introduction of vase tunicate had a dramatic effect on the mussel aquaculture industry. The tunicate attaches itself to submerged structures and increases their weight and resistance to ocean currents, which speeds equipment deterioration. By its presence, the tunicate also prevents mussel larvae from attaching themselves to mariculture structures. In the Magdalen Islands, where fishery and mariculture activities form a large part of the local economy, the presence of vase tunicate could have significantly adverse effects. Fortunately, it has not yet been observed at mariculture sites in the Islands.

To fight the propagation of this undesirable species, Fisheries and Oceans, the Magdalen Islands ZIP (Priority Intervention Zone) Committee and the Merinov centre in the Magdalen Islands have been working together closely since the summer of 2013.

Thanks to financial support from the Community Interaction Program, part of the St. Lawrence Action Plan, tunicate-infested floating docks are removed from the water, cleaned and treated with an environmentally friendly anti-fouling agent to prevent new tunicates from attaching themselves. In a further attempt at preventing the propagation of vase tunicate, an awareness campaign has been implemented to inform the public and visitors of this major issue. Regular visits are made to the various marinas in the Magdalen Islands to inform recreational boaters of the risks associated with this species and of the efforts being made in the fight against invasive species.

The best approach for protecting our ecosystems against this invasive species is to prevent its arrival and establishment in the first place and to do this, everybody's cooperation is essential.

What you can do

Consult the Aquatic Invasive Species Identification Booklet:

• learn how to recognize Vase Tunicate;
• follow the general guidelines and report your observations.

Aquatic invasive species are a major issue worldwide. An invasive species is defined as a non-native species that, transported out of its normal range, successfully settles in a new habitat, and that has significant ecological or economic impacts. Once introduced, invasive species reproduce rapidly and can grow to uncontrollable proportions in the absence of natural predators. Invasive species compete with native species for food and space or begin to prey on them. They therefore pose a threat to local biodiversity. Commercial shipping and pleasure boating are among the main vectors responsible for the introduction of these species.

Green crab, Japanese green algae and several tunicate species are currently the most worrisome invasive species in Quebec's maritime regions.

Nathalie Simard
Science

Jean-Philippe Marcoux
Magdalen Islands ZIP Committee

Madeleine Nadeau
Magdalen Islands Merinov Centre