Atlantic Salmon accounts for more than half of aquaculture production and export in Atlantic Canada – and it is only anticipated to keep growing. However, the densely stocked nature of most salmon aquaculture farms, and their proximity to one another, present the risk of sea lice outbreaks.
Dr. Lara Schmittmann, a postdoctoral researcher at the GEOMAR Helmholtz Centre for Ocean Research Kiel, is using biophysical ocean simulations to understand how diseases, like sea lice, travel and spread with water currents.
Hosted by Dr. Stefanie Colombo and supported by Ocean Frontier Institute’s (OFI) Visiting Fellowship program, Lara recently completed a research visit to Dalhousie University.
During her visit, she collaborated with industry experts at Dalhousie and the University of Prince Edward Island to combine methods and better understand how to mitigate the risk of sea lice for farmed and wild salmon in the Canadian Atlantic Coast.
Sea lice: an industry burden
Sea lice are tiny parasitic crustaceans that can infect various species of fish. The copepod Lepeophtheirus salmonis infects salmonids specifically.
“They attach themselves to the skin of fish to feed on their tissues, which leads to skin lesions and secondary infections that stress and compromise the health of the salmon,” explains Lara.
“Since most salmon are cultured close to the coast in clustered areas, these effects can be carried to neighbouring farms by water currents, spread to wild populations and pose economic losses for the industry,” she says.
Some countries such as Norway and Scotland are moving salmon farms offshore with one reason being to minimize these risks.
“There is debate about whether a similar approach could be beneficial in Atlantic Canada; however, it would be important to assess the implications prior.”
Working in a virtual ocean
Using a biophysical simulation model developed at GEOMAR, Lara is integrating information on sea lice with information about currents and environmental variables such as temperature and salinity to simulate how far and how quickly sea lice can travel. “It is like a virtual ocean in the computer,” she says.
The work is ongoing, and her hope is that this tool can predict where outbreak risk is most likely, improve aquaculture measures, and inform suitable sites for offshore salmon aquaculture in Atlantic Canada.
Ocean simulations as a conservation tool
Lara is also using the same methods to identify suitable restoration sites that enhance growth success and reduce disease risk for the endangered European Oyster in Europe.
“There is a network across Europe that works very well with different stakeholders and governance to coordinate different efforts and exchange methods to effectively and efficiently restore oyster populations.”
“Trying to inform restoration or aquaculture is not purely science, and I hope transdisciplinary approaches can have an impact,”
says Lara.
