Terms of Reference

National Workshop

Potential Technologies for Closed-containment Saltwater Salmon Aquaculture

January 29 – 31, 2008

Sidney, BC

Chair: Mike Chadwick

The purpose of the workshop is to develop and provide scientific advice on the status of salt water closed-containment technologies. Closed-containment is a barrier technology that attempts to restrict and control interactions between farmed fish and the external aquatic environment with the goal of minimizing impacts and creating greater control over factors beneficial to aquaculture production.

The documentation from this inclusive process will inform the Fisheries and Oceans Canada regarding possible investment of public funds in closed-containment technology development as it may be applied to commercial-scale salmon aquaculture. It will also serve to inform other interested parties on alternative rearing technologies.

The Department believes that current best practices have improved the environmental performance of salmon farming in Canada. In initiating this review, the Department recognizes the importance of continuous innovation and is taking steps to review technologies, approaches and systems that could provide further improvements to current practices.

Context

Closed-containment technology is being proposed as an alternative for salmon aquaculture because it is perceived that it may reduce escapes, control deposition/dispersal of solid and dissolved wastes, and reduce interaction with wild fish and marine mammals (Table 1).

Currently, there are no commercial-scale, closed-containment systems for salmon aquaculture in the marine environment. However, various components of closedcontainment technologies have been developed to try to address a number of specific concerns (Table 1). Even so, there is an inherent difficulty in evaluating these new technologies in an integrated fashion because no standards have been established and there is limited information on past performance of the technologies. In addition, it is critical that the performance of a closed-containment system is evaluated within a commercial production scale (~ 1,000 – 3,000 metric tonnes).

Specific Objectives of the Workshop:

1) To define the strengths and weaknesses of various system designs and technologies in the context of potential use for commercial-scale, closedcontainment rearing of salmon;

2) To identify performance parameters and criteria for design evaluation, biological and ecological performance, associated cost (capital and variable) and logistic support;

3) To document and assess current technologies that can be used for each unit process (component) and to evaluate how each technology affects the dynamics of the system;

4) To evaluate what unit processes are required to provide the water quality conditions to optimise fish growth and welfare, while minimizing impact to the external aquatic environment;

5) To provide technical background to aid in system integration and experimental design for future research and pilot projects;

6) To develop a “gap-analysis” that might be used to assess future closedcontainment research needs; and

7) Create dialogue with industry, ENGOs, governments, First Nations and academia.

To help meet the objectives of the workshop, six technical working papers will be prepared prior to the workshop: (See Annex for more details)

1) Review of past experiences.

This review would cover all technologies in a complete system that have been tried in the past and would evaluate both biological and ecological performance. Some of the information will be from land-based salt-water aquaculture or systems that use pumped sea water. There is not a lot of information. There are some operating salt water systems in Europe. E.g. pump ashore turbot farms in Spain as well as past pump ashore projects in Scotland, Norway, Iceland and Canada. Information from pilot projects utilising Future Sea technology would be included as would recirculation systems developed for salmonid production since many parts of this process work equally in freshwater and saltwater systems. Aquaria technology and systems developed for other fish species may be included where deemed relevant, but in general, the focus would be on systems developed for salmonid culture at commercial scale.

2) Conduct an engineering evaluation of the design and operation of closed-containment systems.

Focus would be a comparison of existing structures that would include, design, operation, structural integrity, construction, installation and other engineering considerations such as escape prevention, predator avoidance, mechanical performance, pump intakes, waste capture and biofouling. Ease of operation to allow for routine operation process such as fish handling, grading and harvesting would be included. Performance evaluation should consider downstream costs where applicable e.g. antifouling treatment.

3) Conduct a comparative analysis of the biological requirements for salmonid production at a range of densities in closed-containment systems.

The aspects to be considered would include feed quantity and quality, feed conversion, rearing densities, growth, water temperature, oxygen requirements. This analysis would provide insight to what might be reasonable upper densities for salmonid production as well as the most likely operating growth models. Describe the requirements for keeping fish alive and the densities that are required to be economically viable. Are there benefits to keeping fish in closed systems? Need to design systems that will be effective at commercially viable densities.

4) Conduct an engineering evaluation of the unit process technologies to maintain water quality for optimal fish growth and fish health. The following unit processes are gas management control systems, solid and soluble waste removal systems, disinfection systems, backup systems and culture tanks.

This review paper will be bounded by the conditions set in papers 2 and 3 above. Suspended solids and the far field effects of containment waste should also be discussed.

5) Assess and review the potential transmission of pathogens and parasites between closed-containment systems and the external environment.

The assessment would examine a broad range of strategies that could be used to mitigate the transmission include location of water intake, disinfection, therapeutant treatment vaccination and fish husbandry. Information on water remediation techniques exist for ballast water and the containment of invasive organisms and so some of this information may be pertinent

6) Using the results of the five papers above, conceptualize a series of integrated systems that could be considered in the development of a pilot project or model farm.

The analysis would decide what components or processes should be included and how the unit processes would function as an integrated system. It would examine a range of levels for mitigation of environmental impacts as well as a range of levels of commercial production capacity. Various cost estimates would be developed along with estimates of energy footprint.

Each working paper should take into consideration and examine as it related to their topic: the available technologies; the advantages and disadvantages of these technologies with regard to water quality and fish performance, the design and operation; the capital and operating costs as they relate to scale of application; and, the ability to integrate efficiently into a culture system.

Outputs of the Workshop

The documentation produced from this workshop will be: a Science Advisory Report that summarizes the main conclusions of the meeting; a Proceedings Document that summarizes the main points raised at the meeting and a critical evaluation of the working papers; and a series of Research Documents that will outline the provided scientific and technical details.