Adopting Innovative Technology to Develop Canada's White Sturgeon Aquaculture Industry
Final Report

Target Marine Hatcheries Ltd
AIMAP-2009-P39

Project Summary
Achieving the goal of developing Canada's white sturgeon aquaculture industry will result in white sturgeon caviar having one of the premier values of any agriculture product in Canada. Under the highest environmental performance and traceability, Canada will become a new competitor in the global farmed caviar trade while helping to take pressure off endangered wild stocks.  The objective of this project was to design and construct a retrofit for two existing outdoor reuse tanks using recirculation technology in order to provide fine control of the rearing environment while conserving water and energy.  This objective has been successfully accomplished.

Results of Project Activities
The retrofit system was designed and dimensioned together with an engineering company using expert consultation and expertise in white sturgeon culture and recirculation systems.  The partners in the project provided abundant expertise for the successful completion of the project. The project was completed on time and under budget.

The previously existing tanks which were to be retrofit with recirculation technology were running with approximately 50% of the water flow being pumped through a C02 stripping and oxygenation tower at the start of the project.  At that time these tanks contained Target Marine's first production group of land-based coho salmon which were successfully harvested from both tanks of this reuse system.  The tanks were subsequently cleaned and disinfected for the retrofit project.

The sturgeon slated to enter the new system were being reared in the adjacent system under the same reuse design as described above.  Fish were evaluated for behaviour and performance in the tanks on the previous water reuse system.  This previous system experienced water quality deterioration when operated above 50% reuse in certain conditions; thus, the retrofit was designed to allow for the next level of water conservation by filtering out solids and ammonia.

System design
This milestone was completed successfully.  The system was designed with in-house staff, a local engineering company and other expert consultation.  As described above, the existing system contained a side loop for half of the water flow from tank side boxes to be stripped of CO2 and have O2 added.  The new system design included a second side loop from the tank bottom discharge leading to an inlet box, drum filter, pump sump, mixed bed bioreactor, and then back to the two tanks via inlet wands.  Additionally, the ultraviolet filter was added to the previously existing side loop.

Initially, the design was to move the water from the new side loop back to the tanks with an air lift; however, this design was modified to include pumping into the biofilter to make the overall operation of the system more efficient.  The initial engineering for the project was modified to account for this.  The engineering was also modified after initial digging for placement of the filters when it was discovered that existing underground site works from 1986 were not in the exact location as anticipated.  This is not an uncommon problem at old hatcheries and the design was easily modified to accommodate this.  The engineering was therefore delayed, though successfully completed together with a local engineering company.

Equipment Purchase
This milestone was completed successfully.  Once the system was designed it was determined that there was ample expertise in-house to construct some of the system components, thus, the pump sump and tank screens were constructed and assembled in-house.  All of the other system components were ordered and delivered as per the final system design. Interestingly, many suppliers contacted Target Marine about supplying equipment after the DFO announcement of the successful projects was published, albeit too late for this project.  Delays were encountered on equipment delivery around the Christmas season, which was as expected.

System Installation
This milestone was completed successfully.  As the project time frame was condensed, it was determined that the most efficient way of installing the system was to carry it out in-house. Sufficient expertise existed on site; hence, most of the installation was done in-house.  This included all of the plumbing, most of the equipment installation and some of the electrical.  The entire system has been successfully installed as per the final design.

System Testing
This milestone was completed successfully.  Testing of each system component and the system operational performance as a whole was carried out.  The system operated as planned.  The project objective of significantly reducing required water usage compared to sibling tanks has been met.  Approximately 99% less water is used in this system than sibling flow through tanks operating on the site with sturgeon.  Approximately 98% less water is used than sibling reuse tanks which used to hold the sturgeon that are now in the new system.  The decreased water flow translates into a significant decrease in heating energy required to increase the temperature in the culture tanks, thus meeting another one of the project objectives.  This makes controlling the water temperature economically feasible.

Production Testing
This milestone was completed successfully.  Two year old white sturgeons were stocked into the system and short term fish performance was evaluated.  Although the system testing did not reveal any issues, an unexpected design issue arose once fish were in the system.  As a high volume of water is designed to move through the bottom tank drains to be filtered, the high current held some of the demersal fish against the screen.  A new design of screen was installed to prevent this and the fish and system are now performing well. Swimming behaviour has so far appeared normal, with increased swimming activity higher in the water column with increased water temperatures. Feeding rates and feeding behaviour are normal and are increasing as expected with the increasing water temperature.  Solids are efficiently removed from the system at high recirculation rates, thus solving the issues with suspended solids building in the water of the previous system.  Carbon dioxide was removed in the previous reuse system, though it is now more efficiently removed due to the air injected into the mixed bed bioreactor.  The removal of ammonia is currently efficient thus far, though the feeding rate and biomass in the system are currently low.  It will take approximately one year to reach the planned peak biomass at which time it is anticipated that the removal efficiency of all of these wastes will continue to be high. Fish will continue to be monitored for feeding rate, growth rate, behaviour, survival, and maturation in the months and years to come.

Project Support

This project benefited from the support of several organizations.  The white sturgeons that were stocked into the system existed due to the work carried out by Vancouver Island University.  The Freshwater Fisheries Society of BC contributed expertise on sturgeon broodstock as well as sturgeon health.  Dr. Joel Van Eenennaam from the University of California Davis was an integral player in helping to developing a system that would meet the maturational requirements of the fish.  The Pacific Organic Seafood Association has developed standards for organic aquaculture which were used when designing the recirculation system.  Unfortunately the executive director of the Sunshine Coast Community Futures retired from that organization, thus they were not able to contribute to the project as planned.

Overall Project Results
The project was completed on time and under budget.  The reduced project cost is mainly due to the work done in-house building and installing equipment and the materials that were purchased before the start date of the project. The project has met its goals and objectives.  Two existing outdoor reuse tanks were retrofit with green recirculation technologies resulting in a system that now enables control of the rearing environment, conserves water, and conserves heating energy. The operational functionality of the system has been successful.  The design of this system is repeatable on other existing reuse tanks. It is anticipated that the use of this technology could reduce the time to maturation and caviar production.  The ultimate success of this project will be determined with the age of maturation of the sturgeons that have entered the system.

AIMAP funding has enabled this project which will help to facilitate the production of white sturgeon caviar, thus contributing to the sought-after diversification of the Canadian freshwater aquaculture industry.  Canada is now one step closer to becoming a new competitor in the global farmed caviar trade while easing the pressure on endangered wild stocks.