Tunicates fowling line, Murray River, PEI (DFO)

“Tunicates, or sea squirts, are small marine animals that spend most of their lives attached to an underwater substrate. They are named "tunicate" for their thick skin resembling a tunic. They feed by filtering seawater through their siphons” (DFO website).

Ecological & Economic Impacts of Tunicates

• May outcompete other organisms for food and space, thereby altering the natural commu.nity dynamics;
• Threaten aquaculture, fishing and other coastal and offshore activities;
• Increase the weight of the aquaculture cultivation gear, causing work to be more demanding;
• Increase the operating costs for shellfish producers and processors.

Local Concerns

Currently tunicates have not been found on the Miramichi. DFO’s tunicate monitoring program is relatively new starting in 2009, with 28 sites monitored throughout the Gulf Region coastlines of New Brunswick, Nova Scotia and Prince Edward Island. Two of these sites are located on the Miramichi estuary at wharves in Baie St. Anne and Neguac. The program expanded in 2010 with 34 sites being monitored, with a new site on the Miramichi at the Escuminac wharf with assistance from MREAC staff. In 2011, MREAC placed two more lines at the Chatham Wharf.

There are five tunicates that DFO are aware of being present in the Gulf Region: Clubbed, Golden Star, Pancake batter, Vase and Violet Tunicates. These tunicates have been spotted at monitoring sites around Prince Edward Island and some found in Nova Scotia. Tunicates were discovered in New Brunswick at two locations, the Violet Tunicates was found along the southeast coastline around Cape Tormentine and during the summer of 2010 the Golden Star Tunicate was found at Caraquet.

Map of Gulf Region with DFO's Tunicate Monitoring sites for 2010, with the exception of the new Escuminac site (DFO)

At these monitoring sites, two collector lines are placed in the water with three PVC plates spaced out along the lines. If tunicates are present in the water, they may attach themselves to these plates and grow. The collector lines are weighed down by a brick at the bottom and remain afloat with a buoy attached to the top. The lines are placed in wharves where there is a lot of boat traffic, the most common pathway for tunicate “hitchhikers”. These lines are deployed into the water late May or early June, plates are exchanged in August, and then finally retrieved in October. The plates are stored and sent to the DFO office in Moncton where they are processed in the lab to determine if tunicates are present, and if so, what species and what percentage of the plate is covered.

Illistration of collector line for AIS monitoring (DFO)
	Collector line in water at Escuminiac Wharf

Preventive Measures

General:

• Learn about these species and how to recognize them using the identification guides in this booklet (you can also download the PDF document);
• Do not move organisms from one area to another;
• Never release live bait, aquarium fish or plants into open water or sewer.

When taking your boat out of the water:

• Inspect and remove fouling plants and animals from boat, motor, anchor, trailer and equipment with freshwater or spray with pure vinegar (protect your eyes);
• Clean hull and dispose of removed material far from the water;
• Drain water from your motor, bilge and wells. If possible, let equipment dry completely;
• Use environment-friendly anti-fouling paint or products on your boat hull.

Shellfish harvesting:

• Clean shellfish where they were collected;
• Move as little water as possible with the shellfish;
• Spread any leftover water on the lawn;
• "De-sand" shellfish in the original water or in a bucket with water that will be thrown onto the lawn.

Diving and other water sports:

• Rinse equipment with fresh water after every trip;
• Let equipment dry completely.

(Excerpt taken from DFO website)

To find out more about tunicates in New Brunswick, check out DFO's Tunicates website or AIS research website.