Sturgeon: Canada’s Diversified Freshwater Aquaculture Industry Phase 2

Final Report

Target Marine Hatcheries Ltd

AIMAP 2011-P05

Executive Summary

Twelve years of Target Marine's investing in and developing white sturgeon culture has successfully grown sturgeon from egg to over 100 kg in size and has resulted in essential expertise required to increase the diversification of the Canadian freshwater aquaculture industry. The large size and nature of the animals required an investment in developing and implementing improved innovative fish handling techniques.

The project has successfully resulted in the development and implementation of a safe and efficient holding and handling method for moving large animals within the Target Marine facilities. The methods and equipment were implemented and evaluated during the sorting of maturing female fish destined for caviar production. The handling equipment will be fundamental for sorting different stages of production fish and handling broodstock into the future. It will also be used for harvesting the caviar fish. The equipment aids in carrying out some of the actions detailed in the Freshwater Sector of the National Aquaculture Strategic Action Plan Initiative 2011 - 2015 (NASAPI). Under the highest environmental performance and traceability, Canada can become a new competitor in the global farmed caviar trade, while easing the pressure on endangered wild stocks.

Introduction

Target Marine's development of a successful white sturgeon aquaculture industry in Canada has passed through various stages of research, development, and early commercialization. It has become clear that the fish will continue to exceed sizes not initially anticipated a decade earlier. Culturing fish at 11 years of age and exceeding 100 kg in weight and 2 m in length has resulted in handling challenges. This project has refined and implemented a safe and efficient handling method for working with these large animals.

There are two main goals to work towards which align with the NASAPI: 1) Develop techniques to advance maturation, 2) Develop finishing diets and environmental parameters to optimize flesh and caviar quality. Activities required to reach these goals involve the fish being individually handled. In some cased these fish must be sorted, transferred into a stretcher, moved out of the tank, or transferred into separate containment. Specialized handling equipment was developed to accomplish these goals. At the onset of sturgeon culture at Target Marine it was projected that the fish would grow to 30 kg in size, as has been experienced in other countries. New handling techniques from this project now enable safe and efficient handling of fish exceeding 100 kg.

The objective of this project was the implementation of a safe and efficient handling method for large sturgeon during sorting, staging, spawning, and harvesting. This project will help to advance an industry that can position Canada as one of the world leaders in sustainable caviar supply, while helping to take pressure off endangered wild stocks.

Methods

Design

When designing the methods to handle large sturgeon, many aspects of the sturgeon biology and behaviour had to be taken into account as well as existing culture systems. The initial designs had the fish being captured and removed from the tank by handlers outside the tank, as is done with most species. Since the skilled handlers were able to keep the fish calm while capturing them in the tank, the method was changed to have handlers in the tank with the fish in order to minimize stress on the animals. The current and future anticipated size of the animals limited many existing designs of moving fish. All pieces of equipment were specified to hold the weight of the largest anticipated fish plus a certain amount of water retained in the stretcher. Heights of the tanks and clearance above the tanks were also important factors in the design of the system. Methods of handling were designed differently between indoor and outdoor handling due the limited clearance and access indoors. Another difference considered was the rough terrain outdoors versus the concrete floors indoors.

Testing

The system was tested for ease of use, efficiency of use, safety of use, and weight carrying capacity at all steps. Ease of use compared this method with previous methods including stain on the handler. Efficiency of use compared the number of fish that could be handled over a certain period of time compared to previous methods. Safety of use looked at all steps ensuring that they were safe for the handlers, technicians, and the fish. Weight carrying capacity was also tested at each step.

Evaluating

The results of the tests were evaluated for each step. Where there were potential improvements identified, that step went back to the design phase for redesign, application of modifications, retesting, and re-evaluation.

Results of Project Activities

Design handling method

Each step of large sturgeon handling was evaluated and considered for the designs. Considerations included maximum anticipated weight and length of individual fish, access to all tanks on site, clearances, moving distances required and minimizing stress on the fish. Concepts from Vancouver Island University and University of California Davis were implemented into the design. The different components of the system included specialized stretchers and carts, as well as a means of removing the fish from the tanks and moving them to different areas of the site. Another consideration of the system was that it should be able to be fabricated, purchased and implemented for the sorting of caviar fish in the winter. The initial design was successfully completed in July 2011.

Purchase equipment

The designs of the specialized pieces of equipment were taken to Canadian fabricators. The designs and materials were refined with their input and the items were purchased. A less expensive winch and scale were sourced that would still meet our requirements. The loader was purchased from a Canadian supplier. This activity was successfully completed in time for the sorting of the caviar fish.

Test the method

Fish were housed in 90 and 120 m3 tanks. The equipment and handling method was tested during sorting of the maturing female sturgeon. Fish were initially captured in a stretcher and became calm after a certain period of time. A biopsy was taken and the stage of development evaluated. Fish were then tagged for long term identification and tracking purposes. Stretchers containing the fish were then attached with straps to a pulley and removed from the tank while being weighed at the same time. Data was recorded on the stage of development, weight and other parameters. The stretcher was then placed in a cart to move out of the culture building. The stretcher was then picked up by the loader and taken to the appropriate tank where the fish was slid into the water. The entire method worked as planned with minimal stress on the fish.

The method was designed and built to handle and move large maturing production fish as well as both mature male and female fish during a spawning event. Although the method has not yet been tested during a spawning event, all steps of the spawning event have been considered and the system will work for this purpose. The next spawning event will happen in the summer of 2012.

Evaluate method

The methodology was evaluated for sorting and relocating maturing females. On the first step, the new stretchers simplified the capture of fish and significantly decreased physical strain on the handler. Fish calmed in a reasonable amount of time and reduced overall stress on the animal. This phase decreased the physical labour requirement by one person. To remove the fish from the tank with the new method significantly reduced the physical labour required by technicians. Fish were easily moved out of the tank with minimal stress on the animal. The automation allowed technicians to more closely observe, monitor the fish, and record necessary data. The carts made for easy and quick maneuvering between tanks and through the building. The fish remained calm and were sufficiently contained. The loader significantly reduced the time the fish was in transport and opened up access to outdoor tanks that previously required significant labour and stress on the animal. Some modifications were made throughout the process to the winch, stretchers and carts to improve the efficiency and safety of use.

Conclusion

The project was completed on time and very close to budget. The project has met its goals and objectives. Many of the techniques and projects carried out on the sturgeon rely in some part on sorting, moving, transporting or otherwise handling the fish. At the onset of sturgeon culture at Target Marine it was projected that the fish would grow to 30 kg in size, as has been experienced in other countries. With fish now exceeding 100 kg, new techniques for handling the fish were required. To carry out the various projects which further sturgeon culture practices, equipment and machinery was required to ensure safe and efficient handling.

The method of handling the fish was developed to be safe for both the handler and the fish. It minimizes stress on the fish and allows for an efficient means of moving the animals. The method involves sorting the fish in the tank initially. This step involves the handlers to be in the tank with the fish. The sorting is done by hand and each fish is individually placed into a stretcher. The fish are then weighed in the stretcher and removed from the tank. The stretcher keeps in a specific amount of water to minimize stress on the fish. The stretcher is then loaded onto a specially designed cart which enables the movement of the fish to the outside of the building or other short distances. The fish can also be loaded from the stretcher into a transport tank which can then be transported by loader to another production or holding tank where the fish will be released. The transport tank can also be loaded onto a trailer for longer transport distances.