Development of diets and feeding strategies for the implementation of sea lice cleaner fish in salmon farms in BC

Description

This project was an integral component of a larger project to establish a commercial perch sea lice cleaner fish industry to support salmon aquaculture in British Columbia (BC). Rearing species of so called “cleaner-fish”, fish that have a natural behaviour to eat organisms (parasites) from fish surfaces, alongside salmon has been proposed as a method to reduce or eliminate sea lice incidence in salmon farms in BC. Pile Perch are very effective in cleaning sea lice from infected fish under laboratory conditions.

For this research to advance to the next stage, it was vital to determine the optimal diets to feed the perch for sustained growth, health and welfare both prior to and after deployment in the farms. This research will help inform industry decision-making as healthy and robust cleaner fish have been shown to be the most effective at cleaning sea lice. To ensure availability of sufficient numbers of cleaner fish, a multi-faceted breeding program is necessary, a key component of which is a practical feed that will provide the nutrients for health and growth of the animals.

The goal of this project was to develop a base feed and feeding system for maintaining Pile Perch as part of an integrated program to reduce impacts from parasitic copepods (sea lice) in salmon farms in British Columbia.

Findings

A moist diet was developed and tested with two age classes of Pile Perch, newly born and sub-adults, using raw krill as a control. The diets were suspended in the water column and the growth and survival of the Pile Perch were measured. While the fish readily consumed both diets and exhibited excellent survival, the growth of the fish fed the control diet was significantly higher than those fed the experimental diet.

Feed and feeding system, as developed, were sufficient for culturing perch, but further work is required to increase the growth rate of the fish. Although this study focused on smaller perch, this diet would likely be effective for larger fish. Further testing in actual net pen conditions is the next step toward reaching the overall goal of reducing or eliminating the incidence of sea lice in salmon net cages.

Program name

Aquaculture Collaborative Research and Development Program (ACRDP)

Years

2017 – 2019

Principal investigator

Ian Forster, Research Scientist, Fisheries and Oceans Canada, West Vancouver Laboratory, Pacific Region
Email: Ian.Forster@dfo-mpo.gc.ca

Team member(s)

Shannon Balfry, Associate Research Scientist, BC Centre for Aquatic Health Sciences

Sam Ferguson, Senior Research Technician, BC Centre for Aquatic Health Sciences

Collaborator(s)

Jeremy Dunn, Executive Director, BC Salmon Farmers Association