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Aquatic invasive species in Western NL


By Jaymie White Local Journalism Initiative Reporter

SOUTHWEST COAST — ACAP Humber Arm Inc. is a not-for-profit organization that serves the Bay of Islands and Humber Valley coastal regions across the western region of the province. They are led by a volunteer board of directors who represent stakeholders from a wide array of fields such as academia, government, first nations, industry, economic development, and the community. Their efforts are concentrated in marine and freshwater quality, marine species and aquatic invasive species, habitat protection and restoration, and knowledge mobilization. Last week, ACAP Humber Arm held an online question and answer session to share information about aquatic invasive species. Sheldon Peddle, Executive Director, said the session was held in relation to a discovery found in Burgeo of vase tunicate, one of a handful of aquatic invasive species found in provincial waters. According to the Government of Canada, vase tunicate are aquatic animals with a sac-like body protected by an outer body covering called a ‘tunic’. They occur either individually (solitary) or integrated into groups (colonial). Each individual animal feeds by filtering seawater through their bodies. “Since the vase tunicate is a filter feeding animal, it is a natural competitor for other filter feeders (including mussels and other commercial bivalves). Aquaculture farms in the Maritimes (particularly Nova Scotia and Prince Edward Island) have reported decreased size and condition of commercially raised mussels, increased harvesting costs due to tunicate removal, and water quality issues on fish farms. The vase tunicate is mostly composed of water, and in dense aggregations can carry substantial weight. This added weight may lead to increased maintenance cost to boaters, as well as decreased boat speed and maneuverability.” “This was a new documentation. Obviously, it raised the interest of folks in the community, especially some of the members of the fishing sector there in Burgeo. So we wanted to make sure we got factual information to folks as soon as we could,” said Peddle. “So we did have a research scientist with Fisheries and Oceans Canada join us for an online session and they gave a quick overview of vase tunicate, and then a little question and answer with any folks that were online.” There were numerous concerns surrounding the discovery. “When we speak of an invasive species — some folks don’t even know what we mean when we say invasive species — invasive species would be something that’s not native to our local waters, and typically, you would just call that an introduced species or an alien species, but invasive means it also has some sort of detrimental, negative impact as well,” explained Peddle. “In the case of vase tunicate, it’s not native to our waters. It was first discovered in the waters in Newfoundland around Placenta Bay as recently as 2012, so only about ten years ago would have been the first time it was documented, and it’s considered invasive because it has both ecological and economic impacts. It does colonize, reproduce, and spread really quickly, and in doing so, it will displace native species. It’ll take over their habitat. It will also attach itself to kelp and other sea vegetation, and it can sort of weigh those down or block sunlight from getting to that vegetation and photosynthesizing. So that would be the ecological impact. Economically, it is of a huge concern to the Aquaculture Industry Association. In addition to growing on vegetation, it will grow on hard surfaces and infrastructure. It likes dark spaces. So typically you’ll find it underneath floating wharves or fixed wharves, or if a boat has been stationary for a while. It’ll grow underneath, attached to the boat, again, weighing things down and blocking. So for aquaculture, it’s a big concern because it will grow on infrastructure related to aquaculture, and it will weigh it down, potentially even sink it. It is obviously for boaters as well, because it will attach to your boat, or if you have your own personal floating dock, it will attach to that.” There are also other aquatic invasive species in the area. “The aquatic invasive species most people will be most familiar with in Newfoundland Labrador is the European green crab, and again, it was first documented in Placenta Bay. That was first documented in 2007, and we first documented it ourselves in the Bay of Islands in 2012. That is now fairly widespread across the entire island,” said Peddle. “Most people have heard about green crab anyways, but we have been doing monitoring at a lot of places throughout the island portion of the province for a number of years, trying to get early detection being the key, trying to detect the presence of any new species as they move into a new area, and the way we’ve been doing this is very low tech, but it’s effective. We have been deploying AIS (Aquatic Invasive Species) settlement plates which are simple pieces of PVC plastic.” The plates are placed in an area and retrieved at a later date. “The pieces of PVC plastic are suspended on a midwater column and we’ll tie them to a floating dock or whatnot, so they rise and fall with the tides. There’s a weight on the bottom, so they’re constantly submerged, and we’ll deploy those in the spring or the summer, come back, retrieve them in the fall of the year,” said Peddle. “We’ll do a visual inspection ourselves to see what’s growing on it and if there are any invasive species growing on them. Then we’ll also, if we think there is something there, send them to the Fisheries and Oceans Canada’s lab in St. John’s for verification. We’ve been doing this for quite some time and this is what led to the discovery in Burgeo. When we were down there on November 12, and pulled the plates. It was hard to get them out of the water. There was so much weight.” Vase tunicate wasn’t the only species found when ACAP Humber Arm conducted its research. “The plates out in Burgeo, they all were completely covered in vase tunicate. Those only went out in August. We were late putting them out this year, so they were only out for less than 100 days, and they were absolutely, completely covered. So it shows how quickly these things spread and colonize as well,” said Peddle. “But these settlement plates will also indicate the presence of some other species, so there’s another one scientific name being Memorandapora. It grows on kelp and if you look at it really closely, it grows in little cells that look like coffins, and what it does is it makes the kelp or whatever vegetation it’s growing on very brittle. So then with the water currents, the kelp will actually break off and die. You can’t sway naturally, so it kills off just vast meadows of natural seagrasses. That has been documented several places around the island. We were looking for the coffin box, but discovered the vase tunicate.” The location of the discovery was easily accessible. “Where we found them was near the floating wharfs. That was a little bit of good news because it’s easy to take floating docks out of the water and clean them. It’s harder to clean your fixed docks,” said Peddle. “Unfortunately, it had already spread and all underneath the fixed docks, the pairings pilings and whatnot in Burgeo are covered, but interestingly as they were down there looking — and we have the underwater video of that — as they were there, looking for that, they discovered Memorandopore as well, so it’s a double whammy for the Burgeo region.” Total eradication would be nice, but it isn’t likely to happen. “Eradication is a lofty goal, but perhaps not realistic. These things spread so much that eradication, is it possible? We don’t know. Education and awareness in terms of containment is going to be big, so somewhere like Burgeo, now that you know vase tunicate is present, try and remove it, try and get rid of it,” said Peddle. “It may mean floating docks, people that normally don’t take their floating docks out may have to take their floating docks out once a year or whatnot to get them cleaned. We will be sending divers down to Burgeo now to remove things from the fixed structures as well, but it will now be working with harbour authorities and others. There may have to be guidelines put in place that, if you’re leaving an area that you know is infected or infested, to make sure your boat is properly clean before you go to an area where vase tunicate is not. That works both ways, so the harbour authority in Burgeo may need to put something up, telling people, before you leave Burgeo harbour, please inspect your boat, make sure this is removed. Other locations where vase tunicate is not present may also want to have signage put up telling people to please clean your boat before you berth in our area, designated cleaning areas, but really it is the education how to identify the species and then notify folks. So we can try to respond as much as we can. Again, eradication, perhaps not being realistic, but to contain it at least.” The plan is to return to Port aux Basques to do similar work and determine whether or not any invasive species have reached the waters there. “The AIS settlement plates that we spoke of, we did not have any of those in Port aux Basques, but we did have some out in Margaree this year, and the good news is we didn’t find anything,” said Peddle. “But given that we now know that some of these aquatic invasive species are present in Burgeo and they seem to be creeping west along the south coast, we’ll certainly be back next year with settlement plates all throughout this region to try and detect for the presence of the aquatic invasive species.” Anyone with more information or who wishes to report any concerns can contact ACAP Humber Arm via Meta, call the office at (709) 637-4222, or send an email to: info@acapumberarm.com.

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