Refining the use of warm water showers to remove sea lice from Atlantic Salmon and understanding the fish health implications of the technique

Description

Chemo-therapeutants and progressive animal husbandry practices are traditionally used in salmon farming to manage sea lice., With an increased report of sea lice treatment resistance and negative (and even lethal) effects to non-target organisms, there is an interest to find alternative management strategies. Current versions of warm water showers are very effective at removing mobile stages of sea lice from the skin of the salmon and preventing them from being reintroduced into the water column near the salmon cages. While this practice stops sea lice from re-infecting the fish, it also strips the protective mucus from the salmon skin, potentially compromising their immune defense and resulting in some unexplained mortality in the cages.

This project evaluated new sea lice warm water shower designs, assessed the implications of increased susceptibility to re-infections due to loss of mucus on the salmon, and developed a fish health index.

Creating a better commercial system to remove sea lice from salmon will lead to an increase in the condition of fish, resulting in healthier and larger fish that equate to a better product for industry and consumers. Concurrently reducing the use of chemical therapeutants also reduces the environmental impact of the salmon farming operations.

Findings

This research is helping to form the basis for the continued development of this technology and is seen as a valid tool for the control of sea lice in the future for the salmon aquaculture industry. Future research should explore long-term issues that may impact this technology.

Program name

Aquaculture Collaborative Research and Development Program (ACRDP)

Years

2016 - 2018

Principal investigator

Shawn Robinson
Research Scientist, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region
Email: Shawn.Robinson@dfo-mpo.gc.ca

Team member(s)

Duane Barker, Research Scientist, Huntsman Marine Science Centre

Steve Neil, Technician, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Craig G. Smith, Technician, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Collaborator(s)

Keng Pee Ang, Vice President, Research and Development, Feed and Nutrition, Kelly Cove Salmon Ltd.

Joel Halse, Aquaculture Engineer, Cooke Aquaculture Inc.