Scallop fishers scoop invasive sea vomit from Bay of Fundy in aid of science

Scallop fishers in the Bay of Fundy are keeping an eye out for a creamy-white species that grows on the seabed and could be described as gross.  

The invasive marine invertebrate is known as sea vomit, sea squirt and pancake-batter tunicate, and large patches of it were found near Deer Island in 2020 and 2022, according to the Huntsman Marine Science Centre in Saint Andrews.

The centre approached the Fundy North Fishermen's Association for help collecting samples of sea vomit for a three-year research project.

Emily Blacklock, the science director for the association, will be among 50 scallop fishers looking for sea vomit in their scallop catches, scraping off any they find and storing it in ethanol-filled vials.

"They can be scraping it off rocks or off scallops, putting it right in the jar and bringing it back to shore and then telling us where they found it, how much of it they found in the area, all the information on the tide and the depth and the weather to help us figure out when it was there and why," Blacklock said.

Scallop season began earlier this month and continues until fishers hit their quota.

Scallopers use large drags to scrape the seabed, scooping up other things along with scallops, said Blacklock, who is also a PhD student at the University of New Brunswick and a part-time lobster fisher.

Claire Goodwin, a research scientist at Huntsman, is leading the research project on sea vomit, which is native to Japan.

She said the invasive tunicate forms "a rubbery crust" on the ocean bed, disturbing the area's marine ecosystem.

"It can grow very, very quickly once it's introduced to a place," Goodwin said. "It doesn't have many native predators. There's nothing that will really eat it to keep the population down, and it forms very big mats over the surface of the seabed."

Goodwin said these patches smother marine life in the area by competing for space with other species that rely on the seabed or rocks for food and shelter. She said the rubbery crust blocks other organisms from accessing the seabed and suffocates the larvae trying to come out.  

She said if these patches are not controlled, they can spread for several metres, eventually covering an area's entire seabed, which can hurt industries such as the scallop fishery. 

Goodwin said sea vomit may have started growing in the area years ago but just wasn't known to fishermen.

These invasive species die during winters when water temperatures drop, but temperatures have not been dropping much in the Bay of Fundy over the last few years because of climate change, she said.