Production & Efficiency Increase from Technology Transfer of New Zealand Double – Back Longline Oyster Grow-Out System

Taylor Shellfish Farms Canada ULC

Table of contents

• Executive Summary
• Introduction
• Technological Advancement
• Project Video
• Deliverables (Results)
• Conclusion

Executive Summary

Taylor Shellfish Farms Canada ULC has completed a technology transfer project that demonstrates a unique double-back longline farm design. Unique flotation drum designs and moulds from New Zealand make this system superior to previous designs and Taylor Shellfish Farms intends to commercialize the technology in Canada. This efficient system, primarily used for Mussel sock culture, was developed in Japan, Chile and New Zealand. Until now it has not been applied at all in North America.   

A specialized production machine was imported from New Zealand and then the unique flotation drums required for the system were produced. By October 2011, the farmsite was seeded with 10,000 oyster tubes, with hundreds more being added every day. With this double-back long line system, production within the existing tenure footprint has been doubled. The visual appearance of floats on the water has also been reduced dramatically.

Taylor Shellfish Farms Canada ULC has received numerous enquiries from other growers in the area about converting their own farms to this system, and Taylor Shellfish is working with them on delivery schedules. This project has clearly improved the economic and environmental sustainability of shellfish farming in Canada. 

Introduction

Currently, TSFC operates 12 fully active shellfish farm tenures in the Okeover Inlet / Desolation Sound farming region of British Columbia. This entire infrastructure incorporates a few deepwater rafts, but is mainly built as single-back long-lines.  While these single-back longline systems are typical of grow-out in BC, new farm layout design (double-back longlines) has been deemed able to accommodate a higher density of product within the same farm footprint, without negatively affecting biological carrying capacity.

This project involved the importation of new technologies and practices that will greatly improve Oyster tube grow-out production systems – in both output and efficiency. The project was planned in two phases. Phase I involves the importation of a specialized double-back longline flotation drum rotational mould from Innovative Design and Construction (INDAC) Ltd of Blenheim, New Zealand. The mould is designed and manufactured in New Zealand where its product, the INDAC flotation drum, is commercially available. The reason that the mould itself is being imported is that it would be much less expensive to do it this way than it would to build the mould here. The mould is considered to be a proprietary piece of INDAC’s operations. It is much simpler and more inexpensive to simply purchase and import the mould, and set-up a buoy manufacturing process at the existing Fanny Bay Oysters plant facility in Baynes Sound.

Phase II involves the conversion of a five hectare (5 Ha) single-back longline farm tenure, located at Church Point in Waddington Channel (West Redonda Island), to double-backs as a commercial scale prototype project farm. The existing (current) arrangement involves single-back longlines spaced parallel ten (10) metres apart. On each longline, seeded Oyster tubes are hung and spaced a half (1/2) metre apart. In converting the system to double-back longlines, each longline will be duplicated, and separated one meter 1/2 apart by the INDAC flotation drums.  Drums will be spaced 50 metres apart with small black floats providing line buoyancy every two metres between the flotation drums.

Technological Advancement

While rotational moulding technology is not new, the mould design for the specific INDAC flotation drums necessary to build double-back longline systems is an innovation that has only now (as a result of this project) been commercialized in Canada. The specific flotation buoys that it produces are specialized and proven equipment, crucial to the construction of the double-back system. 

The primary benefit of this project will be the near doubling of production within the existing tenure footprint. However, the double-back long line system is also much less demanding for maintenance than that of raft culture systems, and the Oyster tube culture method is much more efficient and environment-friendly for producing shucked meats than string culture. In addition, the double-back longline system can endure much higher energy (wind & wave) sites than raft culture. By ‘twinning’ the longlines, husbandry and harvesting operations become much more efficient because farm crews will be able to work from both sides of the work-vessel platform, instead of just the one. This doubles the crew’s productivity on board the vessel, allows for another hand on board, and contributes to stability and symmetry of the platform.

Project Video

A two-minute video was created to show the technology in a short interview with Fanny Bay Oysters General Manager, Brian Yip. This video can be viewed at the following URL: http://youtu.be/aVYI3SShN4U

Deliverables (Results)

• This report confirms the production of mould machine and flotation buoy has been completed as per design and delivered and installed on site.
• Production of hoist and ancillary equipment has been completed and installed on site.
• Production facility is operational at Fanny Bay oyster Union Bay
• Production of buoys has been consistent operating 5 days per week manufacturing average of 25 buoys per day.
• Prototype farm site has been seeded with 10,000 oyster tubes as of October 2011 with hundreds added on every day.
• The growth rate has been consistent but productivity has been increased by a factor of two.
• In the same production area, we are able to double our production and the time it takes to hang the tubes has been reduced by one third.

Conclusion

In conclusion the double- back long lines system has demonstrated and addressed the AIMAP’s sustainability goal by farming with less impact on the environment (doubling our output without increasing the farm size). The farm is socially responsible because of less visual impact of floats on the farm. We can now grow oysters more economically by reducing the flotation required for the same volume of production.