A three-year study looking at the distribution and spread of the invasive colonial tunicate “sea vomit” in the Bay of Fundy is well underway.
“The project started last April, so has been going a year,” said Dr. Claire Goodwin, who is leading the project for the Huntsman Marine Science Centre in St. Andrews, New Brunswick.
Huntsman received $749,019 in funding from the Department of Fisheries and Oceans Aquatic Invasive Species Prevention Fund to conduct the study.
“Although scientists recorded sea vomit in the Bay of Fundy in 2013 and 2014, we thought it had died out. But recent SCUBA surveys by our dive team and DFO drop camera surveys in deeper water found extensive populations around Deer Island. This species could severely impact both local marine life and industries. We urgently need more information on its presence in the Bay of Fundy,” said Dr. Goodwin.
Huntsman is partnering with Coastal Action, Passamaquoddy Recognition Group, Fundy North Fishermen’s Association, Fisheries and Oceans Canada and the University of New Brunswick for the study.
The team is using a suite of techniques to establish the current distribution and invasion pathways of the harmful species, including SCUBA surveys, remotely operated vehicle (ROV) surveys, collection of specimens from fishers, monitoring using Environmental DNA (eDNA) and specialised genetic techniques to examine invasion pathways.
“The Deep Trekker ROV acquired for this project allows us to explore and survey deeper waters than we can target with SCUBA diving. We recently conducted a successful survey of Nova Scotia’s waters and unfortunately, found that sea vomit was common around the Tusket Islands. Using the ROV’s claw, we were able to collect samples for further analysis,” said Kelly Mackarous from Coastal Action.
“Using the ROV we were able to survey the tide swept waters of Letete Passage, fortunately we didn’t find sea vomit in this area as of yet,” added Alexa Meyer from the Passamaquoddy Recognition Group.
Collecting samples from fishers was started in January, said Dr. Goodwin. “This part was coordinated largely by Emily Blacklock, who is the science advisor for Fundy North Fishermen’s Association who are partnering on the project. Coastal Action, who are also partners in Nova Scotia, also worked with fishers to collect samples.”
Blacklock said the Fundy North Fishermen’s Association is excited to take part in the project and are thankful to have so many fishers willing to participate.
“Working with our fishers during their scallop season will allow for the distribution of sea vomit to be examined over a large area of the Bay of Fundy in a relatively short time period,” she said.
The team is also engaging citizen scientists in recording through Marine Invader Monitoring and Information Collaborative (MIMIC) surveys of shores and wharves and submission of records through the iNaturalist online platform. They will also conduct a series of marina and harbour surveys to look for other invasive species such as the violet tunicate and Asian shore crab.
“As fishers are collecting for us as part of their normal fishing activities, we are constrained by the timings of their licences. Those still fishing will continue to collect samples for us over summer. When we are timing scientific surveys for sea vomit and other ascidians, we usually aim for later summer or fall as this is when the colonies are likely to be largest,” said Dr. Goodwin.
Sea vomit can die back over winter when water is colder, said Dr. Goodwin. “However, we suspect this may not be happening anymore in the Bay of Fundy due to rising water temperatures.”
Sea vomit, known scientifically as Didemnum vexillum, is cream or pale yellow. It forms a rubbery crust over the seabed and manmade structures. It can smother native marine life and foul commercial structures such as wharves and aquaculture cages. It can spread via its larvae or by the transfer of whole or pieces of adult colonies on boat hulls or fishing gear for example.
Sightings of sea vomit and other invasive species can be submitted through iNaturalist, by email to fundyseavomit@gmail.com or via text 506-607-9148. Sightings should include name of recorder, date of records, location and an image. More information on invasive species can be found at https://www.huntsmanmarine.ca/marineinvasivespecies.
Dr. Goodwin said a report will be published at the end of the project in March 2027 that will provide information on the extent of sea vomit in the Bay of Fundy.
“We do also hope to work with fishers to develop manageable control strategies for sea vomit and other invasives.”
