Aquatic Invasive Species are those that have been introduced and become established in a new freshwater or marine habitat outside of their natural or past distribution. These may include any species of bacteria, plants or animals and must have significant negative impacts on the receiving environment and associated economy, society or human health to be considered an invasive.

 

Huntsman Marine researchers recently provided the first observations of the invasive colonial tunicate known as ‘sea vomit’ (scientific name Didemnum vexillum) in the western Bay of Fundy Quoddy Region in the international peer-reviewed journal BioInvasions Records with co-authors from Fisheries and Oceans Canada.

 

“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,” explains Dr. Claire Goodwin, Huntsman Marine Research Scientist and co-author of the publication.

 

Sea vomit is thought to originate from Japan but has rapidly spread from there to marine ecosystems globally, including in New Zealand, Europe, and both Pacific and Atlantic coasts of North America. Its structure and chemical defences deter natural predators within these new habitats thereby ensuring its invasion success. This species has the potential to severely impact both local marine life and industries as it can smother seabed dwellers, such as scallops, and foul commercial structures like wharves and aquaculture equipment. It can be spread by vessel traffic, movement of marine equipment, such as aquaculture infrastructure, and activities that disturb the seabed, such as construction and bottom fishing.

 

Using a variety of environmental monitoring techniques provide multiple perspectives on the timeline for initial invasion and establishing a population within a local ecosystem. The research team described use of environmental DNA methods on more than 200 seawater samples, diver-based visual surveys at 41 sites, and seven drift transects with near-seafloor optical imagery (such as drop cameras and remotely operated vehicles) to document the presence and extent of sea vomit colonies in the Quoddy Region of the western Bay of Fundy during 2018-2022.