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Basin Head’s unique Irish moss seeing growth thanks to restoration efforts

Moss has grown to 100 square metres, up from 2 square metres in 2012.

A group of researchers and conservationists in eastern P.E.I. is working to restore Basin Head’s unique Irish moss by planting as much as they can before the ice sets in for winter.

And they say after a few years of restoration efforts, the population of moss has grown.

Madelyn Stewart, project lead with the Souris and Area Branch of the P.E.I. Wildlife Federation, said the amount of Irish moss growing in the lagoon was only about two square metres in 2012.

Today, Stewart said the moss has grown to over 100 square metres.

“It’s definitely expanded and because of all our work … we’ve also seen other benefits to the estuary with the eel grass growing and more organisms coming into the arm,” said Stewart.

But Stewart said the work to completely restore the moss is far from over.

The Irish moss grows only in the waters at Basin Head in eastern P.E.I. It is unique both in its proportions, growing to the size of a dinner plate, and in its lifestyle. It doesn’t have a holdfast (attachment organ) to anchor itself to a rock or a shell. Instead, it tangles itself up in clumps of mussels.

Since 2015, Stewart said the team has been working hard to help the population of Irish moss grow by planting more of it throughout the lagoon.

Planting moss clumps

Stewart said in order to plant the Irish moss, the group first has to create what it calls clumps, which use mussels to create a place for the moss to cling to and use as a space to grow. She said the clumps are made by combining the mussels and moss in a sack and hanging it in the lagoon for a few days until the mussels begin to attach.

Once they do, the clumps are dropped in the water in three different planting beds along the lagoon where they are left to grow.

She said all the mussels that are introduced to the lagoon are first rinsed to remove any possible invasive species.

Since work to restore the moss in the area began in 2015, Stewart said, the group has planted over 13,000 moss and mussel clumps. She said normally crews begin planting in June and continue about twice a week until early November when the lagoon starts to freeze.

“It is only found in Basin Head so because it’s a unique species you kind of want to preserve the amount as much as you can, as well as preserve the amount of biodiversity of this area,” she said.

“The Irish moss provides so many beneficial relationships to other organisms within the estuary, so by protecting the Irish moss we’re able to really benefit the entire estuary.”

She said the project also involves removing green crabs from the lagoon, which are considered to be an invasive species. Stewart said the crabs feed on the mussels the moss needs in order to thrive, which has contributed to its disappearance over the years.

“This year alone through 50 days of fishing we’ve removed over 80,000 green crabs from the arm, which is very significant and will hopefully help keep the mussels safe and therefore the Irish moss with the mussels.”

‘We’re in it for the long haul’

Irene Novaczek, the senior scientist for the Basin Head marine protected area with the Department of Fisheries and Oceans, said when she started working in the area in 2014 the situation was “critical.”

“We had almost lost the population here,” she said.

But now, she said she is very encouraged by the growth she’s seeing.

“We have a very good success rate of getting the mussels successfully in the water, binding to the moss and planting them out,” she said.

Novaczek said when researchers revisit the clumps that have been planted, it’s not just the moss that appears to be thriving. She said the clumps are now also home to other marine life, like shrimp, small fish, worms and a safe space for mussel and oyster spat to grow.

“They’re just a really rich, three dimensional, complex, protective environment that shelters just a multitude of species.”

She said the goal now is to keep up restoration efforts with the hope that the moss reaches a point where it is able to sustain itself within the lagoon, but said it’s too soon to know when that could be. She said researchers will continue to monitor the area closely.

“We’re in it for the long haul,” Novaczek said.

She said planting will wrap up for the year soon, before the ice sets in and crews will be back out on the water to start planting again sometime next June.

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