Innovations in Atlantic Halibut Broodstock Conditioning and Holding

Final Report
Scotian Halibut Ltd
AIMAP 2012-M01

Scotian Halibut Limited (SHL) produces Atlantic halibut juveniles for the North American and European markets and houses large numbers of broodstock in order to supply gametes for juvenile production. SHL is in the process of shifting its reliance from wild broodstock to cultured stock for gamete (egg and milt) production. However, cultured females are typically unreliable producers of eggs in their first years of spawning but yet require an environment that lets them go through their reproductive cycles with minimum stress. The current method of enabling them to safely undergo reproductive development significantly slows their growth. 

The objective of this project was to use innovative broodstock management techniques in order to continue to maximize the growth of these sexually mature fish and shorten the time it takes for them to become effective contributors to commercial production. This required the availability of improved broodstock conditioning/holding systems. These were to be made available within two separate tank systems in order to have enough tank capacity to hold the stocks grown for integration into the broodstock program which have previously shown signs of reproductive development, such as release of gametes or swelling of ovaries. The first system was a retrofit of a large on-growing system (Module G) intended for holding the youngest stocks of sexually mature fish, and the second was a new two tank system, intended for the oldest stocks of sexually mature fish. Both systems are located at the SHL facility in Woods Harbour, NS.

Design of both systems was completed by June 2012. The retrofit of Module G, a 1152 m3 capacity PVC coated concrete form tank system, began in July 2012. The planned retrofit included the installation of water treatment equipment tailored to meet the special needs of larger halibut including improved solids removal, gas management, and temperature control. Fish were moved into that system by October 2012. Additional system improvements occurred which allowed more fish to be held in the system until a biomass of 5 tons was reached in March 2013. The halibut have adapted to the system and are feeding well, at a rate of 0.14 to 0.2% body weight (BW) per day. Monthly mortality rates are lower than the year previous. The system is maintaining water quality parameters that are better than those used for commercial grow out of halibut but additional improvements are desired in order to implement the desired broodstock management regime, in particular in terms of carbon dioxide level and temperature. Additional water treatment installations are still ongoing and their completion is expected to bring the system into compliance with the regime.

Removal of existing equipment and preparation of the area required for the new two tank system was initiated in December 2012. Installation of two new 9 m diameter fiberglass tanks began in the spring of 2013. There were numerous interruptions to the installation, but it was completed in October 2013. Work will continue on this system to produce a broodstock holding system that will allow the largest fish grown for broodstock to grow at a maximum rate while promoting their adaptation to an eventual integration into actively spawning broodstock tanks. This water system is planned to include the tailored solids removal, gas management, and temperature control of the Module G retrofit, as well as photoperiod control.

Scotian Halibut Limited was unable to complete the system installations by the time of this report writing due to several challenges including financing of the capital items, conflicts with a third party leasing space at the site, weather, and difficulty acquiring Canadian Standards Association (CSA) approval for imported equipment. 

We anticipate that the systems will be completed in 2014. The immediate effect of their completion will be to provide an ideal environment for halibut as they approach sexual maturity. This will accelerate growth of cultured F1 and F2 stocks being held for halibut broodstock, while reducing stress and mortality in order to decrease the age at which they produce reliable and significant quantities of gametes.

Introduction

Scotian Halibut Limited (SHL) officially commenced operations in 1998. High numbers of wild Atlantic halibut were collected locally in the early years of the company, allowing the hatchery to be commissioned in 2000. By applying proprietary broodstock management techniques, SHL was able to successfully create three temporally distinct spawning populations from wild fish in half the time reported to be required in the literature. This allowed the hatchery to become functional year round and therefore maximize use of its infrastructure early on.

SHL pressed to stay at the forefront of halibut broodstock technology by becoming involved in a broodstock development 2002 project funded by the DFO Aquaculture Collaborative Research & Development Program (ACRDP). Recognizing the advantages of such a program, SHL pursued this work further in 2004, with research support from Genome Canada and a loan, from the Atlantic Canada Opportunities Agency (ACOA) - Atlantic Innovation Fund (AIF). This broodstock program continues today and is recognized internationally. 

As part of the continuation of its stock improvement program, SHL needs to shift its gamete production reliance from wild fish to its cultured broodstock. This has been problematic for other companies because of the unreliability of egg supply by the smaller cultured fish. SHL has experienced similar difficulties and has had to extend its reliance on wild fish for juvenile production as a result. SHL hopes to overcome this problem via in-house established cryopreservation techniques and a unique broodstock conditioning strategy recently developed. 

This project will allow the application of this innovative conditioning strategy which allows the fish to grow at their maximum rate, even after sexual maturation. This stock conditioning strategy was being successfully applied, at a small scale at the Clarks Harbour facility where suitable tank space and water quality were available. However space at this site is limited and SHL wanted to apply its strategy on a commercial level at its Woods Harbour facility. Such an application required installation of additional equipment in Woods Harbour in order to succeed. 

SHL currently provides juveniles to local (Canadian) growers as well as international clients, relying solely on egg production from the company's broodstock that are held in Clarks Harbour, in the same building where the broodstock conditioning is occurring on a small scale. Holding both active spawning broodstock, and those fish next to enter the actively spawning population in the same location has been identified as being a risk to the continual supply of juveniles to the nascent halibut producers of Canada. The system installations allowed by this project ensure the holding of sexually mature, pre-spawning stocks at a site other than Clarks Harbour and could effectively serve as a back-up broodstock . 

The broodstock conditioning/holding system will encourage the production of improved progeny in less time since it will allow more rapid availability of domesticated halibut stock for aquaculture which will increase the competitiveness of SHL as well as that of its Canadian clients on the global marketplace. It will also promote the stability of the Atlantic halibut aquaculture industry by providing a back-up site for broodstock holding.

Project Overview

The technical gap addressed by this project is the need for acceleration of growth of cultured F1 and F2 stocks being held for halibut broodstock, while reducing stress and mortality, in order to decrease the age at which they produce reliable and significant quantities of gametes. When this project is completed, it will meet this need through the installation of an innovative broodstock conditioning/holding system that allows sexually mature fish to go through normal reproductive development but still promotes maximum growth rates for fish at this stage in their life cycle.

The management regime required to promote the broodstock growth was previously determined in-house. Its primary goal was to ensure the maintenance of optimum water quality targets including a temperature regime that would favour growth of the fish while accommodating reproduction. Water and system requirements were determined based on the estimated feeding rates and with target water quality parameters being CO2 (carbon dioxide) < 4 mg/L, O2 (oxygen) >100%, and TAN (total ammonia nitrogen) < 0.35 mg/L. Fish densities were also to be kept at a minimum (<12kg/m2).

Two distinct systems were envisioned to fulfill the project requirements. The first was an existing halibut grow-out system that would be modified to meet the needs of the youngest of the maturing broodstock fish with a management regime that would support growth for most of the year. Module G, the largest (volume) grow-out system at the Woods Harbour broodstock site, was chosen. This is an independent nine tank recirculating system that had not been in use for several years since the site was converted from a juvenile grow out to a broodstock grow out. The second was a purpose built two tank system that could be photo-thermally manipulated to meet the needs of the largest halibut in the stream of broodstock development. 

To accomplish the goals of the project, it was set up with two main activities: 1) system construction, and 2) fish entry and growth, with each activity conducted for both the Module G system retrofit and the new two tank system.

System Construction

Module G System Retrofit

Objective

The objective of this activity was to install holding systems for the youngest cohorts of sexually mature fish currently in the broodstock program. The populations of fish for this system would be just entering or have recently entered sexual maturity so that a high emphasis would be placed on promoting growth. Feeding rates would therefore be high relative to older fish that are more advanced in their sexual development, so that the system would be required to maintain water quality under conditions of high waste production and oxygen consumption.

Design

The make-up water and recirculation flows, as well as the oxygen supplementation requirements were established using bioenergetic modeling as per the specifications of the biological team. 

The design was finalized by the staff engineers June 2012. This Module G system retrofit consisted of re-building a water recirculation system for nine 8m diameter PVC form concrete tanks, supplied with UV treated make up seawater. The retrofit included specific improvements engineered for broodstock holding that included:

a) Improved Solids Treatment:
Fecal matter and excess feed material from large halibut are distinct from that derived from halibut grown for market. Waste produced by halibut grown for broodstock, consists of larger particles that are prone to breakage within a water re-use system which makes them harder to remove. The target of the retrofit was to remove solids in a way that took advantage of their large size. The first step was to create a gentle outlet flow that prevented particles from being broken down before primary treatment. Previously, and in other grow out modules, tank effluent was subjected to falling over four feet and splashing into a treatment tank breaking up the particles into more and finer particles. For this retrofit, primary treatment was elevated so that this falling of water was eliminated. Clarifiers were designed to passively remove large particles to minimize breakage, and small particles were given the opportunity to settle out. The clarifiers were expected to remove all settleable (heavy) solids, assuming that the remaining particles could be removed via foam fractionation. Foam fractionators were included downstream of the clarifiers to treat these finer solids.

b) Removal of Gametes
The fish to be grown within this system have the potential to produce gametes on an annual basis as they mature. The eggs and milt tend to be oily and sticky and can be difficult to remove from system water. Foam fractionation with ozone was included in the design to remove gametes and would have the added benefit of improving water clarity overall by removing fine solids and color. Foam fractionation within Module G was also engineered to have high energy efficiency. The SKIM design chosen floats inside the water treatment reservoir thereby avoiding an additional pump loop.

c) Gas Management
Recent research indicates that CO2 cannot be instantaneously treated by passive degassing. As some CO2 is removed, other forms of carbon react to find a new equilibrium point. In this process, more CO2 is formed. It is thought that there is typically only 20% of the carbon available as CO2 at any given time. It is estimated that the reforming process may take 2-3 minutes. Previously, and in other modules, CO2 removal occurred at one point in the recirculation loop –at the biofilter outlet. Within the Module G retrofit new CO2 degassers were added immediately downstream of the clarifiers. The CO2 removal at the biofilter outlet was maintained; and the foam fractionation step was considered to be an additional CO2 treatment point resulting in a three tiered treatment. 

d) Temperature Control:
The optimal temperature for halibut growth is 8-12°C. The purpose of this redesigned module was to grow future broodstock to the largest size possible at maturity as quickly as possible. To incorporate temperature control, a heating and cooling system exclusive to Module G was designed. It consisted of a heat recovery system and reversible heat pumps. The heat recovery system was designed to bring new water to within 2°C of the 10°C target temperature when the module is at 10°C. The heat pumps were sized to cool 200 US gpm of new water from 12°C to 10°C. The heat pumps were reversible – meaning that they could also heat the new water as well as cool it. In both cases, the effluent water would flow from the heat exchanger to the heat pumps where it would serve as a heat source or sink. Previously, and in other modules, heat recovery and heating systems could only treat the entire farm. It was not possible to only heat any one specific tank or module and there was no capacity for cooling. 

Installation

Prior to the project, this tank system did not have any water conditioning or water pumping or delivery equipment associated with it, only the tanks were in place. The initial phase of the installation consisted of ensuring the integrity of the tanks and plumbing. This was done by inspection by SHL`s on-staff engineer in June 2012.

Installation of equipment support and decking for the water treatment area soon occurred (July 2012), followed by the clarifiers, plumbing, and gas stripping equipment. Ample additional decking was required to support the clarifiers that were elevated to reduce breakage of solid waste particles as explained previously in the System Design section for the Module G retrofit. Water was turned on to the system and it was partially filled in August 2012. The system was operated on flow through at this time.

Two (2) tons of halibut were transferred to the system in October 2012 and the clarifiers were tested for their solids removal efficiency by our engineering team. Their operation was optimized by a slight modification which improved solids removal by 33%.

Additional pump installation followed to allow water recirculation to increase the biomass capacity of the system. The addition of 3 tons of fish occurred in March 2013 for a total of 5 tons. This last addition of the fish caused a noticeable darkening of the water. The installation of the `SKIM` foam fractionators with ozone injection in the water treatment sump for Module G is expected to remove this dark colour.

The foam fractionators with ozone injection and the temperature control system have not been installed in the Module G System Retrofit as of this report date. Their addition is expected in 2014. Refer to the Challenges section for details on the equipment installation delays.

Two Tank System

Objective

The objective of this activity was to install holding systems for the largest sexually mature fish currently in the broodstock program that are not being used for commercial production. The populations of fish for this system would be close to entry into the active spawning tanks size-wise and regularly show reproductive development, such as annual release of eggs or milt. Conditions in this system would try to balance maximizing growth with ensuring comfortable spawning conditions. Feeding rates would therefore be low relative to younger/smaller fish. It would also be necessary that these tanks be separable from other parts of the facility and from each other in terms of water temperature and photoperiod so that advancing or delaying of the spawning cycle could occur on an individual tank basis.

Design

Similar to the retro-fitted Module G system, the make-up water and recirculation flows, as well as the oxygen supplementation requirements were established using bioenergetic modeling as per the specifications of the biological team. The design was finalized by staff engineers in June 2012. This system consisted of two 9 m diameter, 2 m deep (159 m3) fiberglass tanks with independent water delivery and re-use water treatment systems supplied with UV treated make-up seawater. These tank systems included equipment with similar solids treatment components (clarifiers), and similar gamete removal components (foam fractionators) as described for the Module G retrofit; although in this case a different free-standing style of foam fractionator (distributed by RK2 Systems) was chosen since we were able to design gravity flow through them and avoid the typical secondary pump loop associated with this design. In addition the following was considered:

a) Gas Management
The multiple tiered CO2 control explained under the Module G System Retrofit Design section was applied within the two tank system design but implemented in a different way. In this case, the foam fractionation was considered the first CO2 treatment. The outlet of the foam fractionators would feed into a CO2 degasser for the second treatment and a passive vacuum degasser would be considered a third CO2 treatment point immediately prior to the tank inlet. 

Oxygen supply security was increased within the two tank design as a reflection of the high value of the fish to be held within this system. In addition to oxygen saturators, oxygen can be added directly to the tank via diffusers on an automatic delivery system controlled by a Programmable Logic Controller (PLC) panel with constant oxygen level monitoring if oxygen levels fall below 80% saturation at any time.

b) Temperature Control
The purpose of these tanks was to foster an environment for spawning broodstock to be integrated into the actively spawning broodstock populations used for commercial production while maximizing growth. To incorporate temperature control a heating and cooling system exclusive to each tank was designed. It consisted of a heat recovery system and reversible heat pumps. The heat recovery system was designed to bring new water to within 2°C of the tank temperature. The heat pumps were sized to cool 50 US gpm of new water from 6°C to 4°C with an ambient water temperature of 16°C.

The process flow for the water treatment is fundamentally the same as for the Module G system retrofit except that each tank within the two tank system has its own treatment system and there is no biofilter. The segregation of treatment systems will ensure that as fish reach the larger sizes, we can modify their environment to better adapt them to a prescribed spawning schedule. That is, we will be able to photo-thermally manipulate them to spawn at a specific time of year. There is no biofilter since feeding rates of these larger fish will be lower than those of the halibut in the Module G retrofit. The two tank installation was to occur in an area to be stripped of all existing equipment so that it was a relatively “green field” to start.

Installation

Prior to the project, the area intended for the two tank system was occupied by tanks and fish that were being contract grown for an outside company. All equipment that could be stripped without affecting these tanks was first removed. Approval to move the contract grown fish later followed (November 2012) and all remaining equipment could be taken out (initiated December, 2012). This required the removal of an outside wall of the building.

Installation of the sand base and base plumbing for the fiberglass tanks followed; but the first sand base for the new two tank system had to be reconstructed since the strength of the material surrounding the base was deemed insufficient. The tank bases were completed in early March 2013. The sumps for the tanks were inserted and tank construction continued in a step-wise fashion as fiberglass components were completed and weather allowed. Construction of the tanks was finished October 26, 2013.

As of the date of submission of this report, the clarifiers and sumps for waste water and heat recovery water collection are in place but are still to be connected. Other water system components yet to be installed include plumbing for water delivery to the tanks, plumbing and pumps for water recirculation, two foam fractionators with ozone injection and the temperature control system. Their addition is expected through 2014 with fish entry in 2015. Refer to the Challenges section for details on the equipment installation delays.

Fish Entry and Growth

Module G System Retrofit

Objective

The objective of this activity was to grow sexually mature halibut under optimum rearing conditions and collect relevant data to determine the growth improvements induced by this system.

Results

The first halibut (2 tons) entered the retrofitted tank system October 2012. As more water treatment came on line, more fish were added. A total of 5 tons of fish were resident in this system by March 2013. The broodstock currently held in Module G range in size from 2300 g to 3900 g. 

The halibut adapted to the system well, behaving normally, and showing no signs of stress. Various outcomes were monitored to determine the success of the new water system including fish health, growth, feeding rate, and water quality.

Fish Health:
There were no mortalities associated with the fish entry. The mean monthly mortality rate of all tanks is 0.29%. This is higher than the targeted 0.1% per month but well below previous years' experience of 1% monthly mortality or higher. Halibut from this module were sampled for disease testing in September and no environmentally induced health problems were evident in the findings released to date.

Growth:
Fish appear to be growing although we cannot quantify this as only one weight sample has been taken since the halibut entered the retrofitted system. Fish condition factor has not been assessed as excessive fish handling during summer and fall months (times of highest temperatures) is avoided to protect the health of the fish. 

Feed Rate:
The halibut are being fed dry feed at a rate of 0.14 to 0.20% BW per day. This is typical for fish this size. We had anticipated a feeding rate of 40% wet feed on a monthly basis which would convert to 0.27% dry feed on a daily basis. Average monthly feeding rates will increase when the moderated temperature regime is in place. 

Water Quality:
Oxygen has been maintained above 97% in all tanks with one exception where an emergency situation occurred and oxygen dropped to 52% and 71% in two of the tanks for a brief period. This did not cause any noticeable harm to the halibut stocks.

Average tank CO2 level has risen in the last month from 4.6 ppm to 7.4 ppm which is above our targeted 4 ppm but well below normal grow out operating parameters (10 to 15 ppm or higher). Addition of the foam fractionator and temperature control will reduce CO2 levels. The pH is at 7.05, within our targeted goal and ammonia levels are negligible.

The lack of the heat pump installation is significantly affecting the ability to control the temperature and maintain it within the desired range. The water quality within the Module G retrofit, as described above, is acceptable for grow out fish, according to the experience of the personnel of Scotian Halibut Limited, but lowered CO2 and improved temperature regimes will have to be achieved before the full benefits of the system will be achieved. Installation of the heat pump and heat exchanger are necessary to improve temperature control. 

Two Tank System

The objective of this activity was similar to that of the Module G System Retrofit but because the system is not yet completed, no fish entry has occurred.

1) Challenges

Various challenges were encountered resulting in delays to equipment installation, so that at this time, neither the modifications to an existing nine tank recirculation system nor the new two tank construction have been completed to their fullest extent. In particular, with respect to the nine tank system retrofit, not all of the waste control and temperature modulating equipment has been installed. The system has been modified to the extent that it can hold, and support five tons of broodstock, which it is currently doing; but the additional water treatment components that will ensure an optimum environment for these fish in order to allow an accelerated time to maturity have not. In summary, this system still requires the installation of the foam fractionators, heat recovery exchanger, and heat pumps. With respect to the two tank system installation, only the installation of the fiberglass tanks has been completed. Plumbing for water delivery to these tanks, plumbing and pumps for water recirculation, and water treatment equipment have not been installed. As a result, there are no fish in this second system at this time.

Specific challenges that impacted the completion of this project included:

a) Cash flow
For both systems, cash flow to complete the installations was the greatest hurdle encountered and continues to date. This was unexpected and related to production set-backs at the hatchery in 2012/2013 caused by subtle water quality issues which have since been rectified. This made any expense beyond critical operating requirements impossible for an extended period of time. The restricted cash flow resulted in delayed equipment delivery (i.e. ozone generator, pumps, monitors, heat pumps), and a delayed provision of services including a protracted fiberglass tank installation.

b) Site use by third party
Prior to the project's start, the area used for the two tank installation was populated by tanks containing fish being held for a third party under contract. Approval to move these fish out of that area took several months and delayed preparing the area for the fiberglass tank installation. 

c) Weather
The fiberglass tank installation could not be started during the summer of 2012 for the above-noted reasons which pushed the possibility for tank installation beyond the warm months. Because the area of the installation is unheated, work could not resume until the spring of 2013. And even after it became warm enough to start work on the fiberglass tanks, it was delayed several times due to high air humidity (i.e. fog) typical of that coastal environment.

d) Electrical
Within the Module G retrofit, the foam fractionator technology (“SKIMS”) that were imported from France had electrical panels and motors that were not CSA approved. These could not be installed until they were modified with CSA approved equipment or until the current equipment had passed a CSA assessment. The panels were assessed by a CSA inspector on October 28, 2013, but failed the inspection. Reasons cited for the failure fell into the following categories:

• Motors have inadequate or incorrect certifications
• Labelling inadequate or missing
• Wiring used does not meet the Canadian Electrical Code (CEC) or CSA standards
• Electrical controls do not meet CEC or CSA standards (components not provided)
• Enclosures and junction boxes do not meet CEC or CSA standards.
• Improper bonding (grounding) of equipment and enclosures.

At this time, SHL is in discussion with EMYG Environmental, the suppliers of the SKIMs, to have a CSA approved control panel for the SKIMs units supplied.   This appears to be the most expedient and cost effective option.  In order to accommodate the needs of the fish in the system, the foam fractionation needs to be in place by May 2014.

2) Conclusions

This project enabled Scotian Halibut Limited to renovate an existing grow out system so that it can be used for broodstock conditioning; and a new two tank broodstock conditioning system is in the process of being installed. Key results are yet to come. Additional system installation and fish and system performance data collection will continue.

SHL will complete both systems and support their operation in order to assess the ability of the systems to improve the growth of halibut being held for use as broodstock. We anticipate that the systems will be finished in 2014. The immediate effect of their completion will be to provide an ideal environment for halibut as they approach sexual maturity. This will accelerate growth of cultured F1 and F2 stocks being held for halibut broodstock, while reducing stress and mortality in order to decrease the age at which they produce reliable and significant quantities of gametes. 

3) Communications

Scotian Halibut Limited intends to report on this broodstock development activity at the annual Sea Farmers conference in Halifax in January 2014. In addition, upon commissioning of the new two tank system and fish entry, a press release in Hatchery International is anticipated to publicize Scotian Halibut Limited's improved broodstock management regime. Visits by Scotian Halibut's juvenile buyers are expected to occur within the upcoming months to promote the improved broodstock management capacity. 

4) Fish Entry and Growth

Module G System Retrofit

Objective

The objective of this activity was to grow sexually mature halibut under optimum rearing conditions and collect relevant data to determine the growth improvements induced by this system.

Results

The first halibut (2 tons) entered the retrofitted tank system October, 2012. As more water treatment came on line, more fish were added. A total of 5 tons of fish were resident in this system by March 2013. The broodstock currently held in Module G range in size from 2300 g to 3900 g (Table 2). 

The halibut adapted to the system well, behaving normally, and showing no signs of stress. Various outcomes were monitored to determine the success of the new water system including fish health, growth, feeding rate, and water quality.

Fish Health:
There were no mortalities associated with the fish entry. The mean monthly mortality rate of all tanks is 0.29%. This is higher than the targeted 0.1% per month but well below previous years' experience of 1% monthly mortality or higher. Halibut from this module were sampled for disease testing in September and no environmentally induced health problems were evident in the findings released to date.

Growth:
Fish appear to be growing although we cannot quantify this as only one weight sample has been taken since the halibut entered the retrofitted system. Fish condition factor has not been assessed as excessive fish handling during summer and fall months (times of highest temperatures) is avoided to protect the health of the fish. 

Feed Rate:
The halibut are being fed dry feed at a rate of 0.14 to 0.20% BW per day. This is typical for fish this size. We had anticipated a feeding rate of 40% wet feed on a monthly basis which would convert to 0.27% dry feed on a daily basis. Average monthly feeding rates will increase when the moderated temperature regime is in place. 

Water Quality:
Oxygen has been maintained above 97% in all tanks with one exception where an emergency situation occurred and oxygen dropped to 52% and 71% in two of the tanks for a brief period. This did not cause any noticeable harm to the halibut stocks.

Average tank CO2 level has risen in the last month from 4.6 ppm to 7.4 ppm which is above our targeted 4 ppm but well below normal grow out operating parameters (10 to 15 ppm or higher). Addition of the foam fractionator and temperature control will reduce CO2 levels. 

pH is at 7.05, within our targeted goal and ammonia levels are negligible.

The lack of the heat pump installation is significantly affecting the ability to control the temperature and maintain it within the desired range (Figure 17).

The water quality within the Module G retrofit, as described above, is acceptable for grow out fish, according to the experience of the personnel of Scotian Halibut Limited, but lowered CO2 and improved temperature regimes will have to be achieved before the full benefits of the system will be achieved. Installation of the heat pump and heat exchanger are necessary to improve temperature control. 

Two Tank System

The objective of this activity was similar to that of the Module G System Retrofit but because the system is not yet completed, no fish entry has occurred.

5) Challenges

Various challenges were encountered resulting in delays to equipment installation, so that at this time, neither the modifications to an existing nine tank recirculation system nor the new two tank construction have been completed to their fullest extent. In particular, with respect to the nine tank system retrofit, not all of the waste control and temperature modulating equipment has been installed. The system has been modified to the extent that it can hold, and support five tons of broodstock, which it is currently doing; but the additional water treatment components that will ensure an optimum environment for these fish in order to allow an accelerated time to maturity have not. In summary, this system still requires the installation of the foam fractionators, heat recovery exchanger, and heat pumps. With respect to the two tank system installation, only the installation of the fiberglass tanks has been completed. Plumbing for water delivery to these tanks, plumbing and pumps for water recirculation, and water treatment equipment have not been installed. As a result, there are no fish in this second system at this time.

Specific challenges that impacted the completion of this project included:

e) Cash flow
For both systems, cash flow to complete the installations was the greatest hurdle encountered and continues to date. This was unexpected and related to production set-backs at the hatchery in 2012/2013 caused by subtle water quality issues which have since been rectified. This made any expense beyond critical operating requirements impossible for an extended period of time. The restricted cash flow resulted in delayed equipment delivery (i.e. ozone generator, pumps, monitors, heat pumps), and a delayed provision of services including a protracted fiberglass tank installation.

f) Site use by third party
Prior to the project's start, the area used for the two tank installation was populated by tanks containing fish being held for a third party under contract. Approval to move these fish out of that area took several months and delayed preparing the area for the fiberglass tank installation. 

g) Weather
The fiberglass tank installation could not be started during the summer of 2012 for the above-noted reasons which pushed the possibility for tank installation beyond the warm months. Because the area of the installation is unheated, work could not resume until the spring of 2013. And even after it became warm enough to start work on the fiberglass tanks, it was delayed several times due to high air humidity (i.e. fog) typical of that coastal environment.

h) Electrical
Within the Module G retrofit, the foam fractionator technology (“SKIMS”) that were imported from France had electrical panels and motors that were not CSA approved. These could not be installed until they were modified with CSA approved equipment or until the current equipment had passed a CSA assessment. The panels were assessed by a CSA inspector on October 28, 2013, but failed the inspection. Reasons cited for the failure fell into the following categories:

• Motors have inadequate or incorrect certifications (require CSA/UL)
• Labelling inadequate or missing
• Wiring used does not meet CEC or CSA standards
• Electrical controls do not meet CEC or CSA standards (components not provided)
• Enclosures and junction boxes do not meet CEC or CSA standards.
• Improper bonding (grounding) of equipment and enclosures.

At this time, SHL is in discussion with EMYG Environmental, the suppliers of the SKIMs, to have a CSA approved control panel for the SKIMs units supplied.   This appears to be the most expedient and cost effective option.  In order to accommodate the needs of the fish in the system, the foam fractionation needs to be in place by May of 2014.

6) Conclusions

This project enabled Scotian Halibut Limited to renovate an existing grow out system so that it can be used for broodstock conditioning; and a new two tank broodstock conditioning system is in the process of being installed. Key results are yet to come. Additional system installation and fish and system performance data collection will continue .

SHL will complete both systems and support their operation in order to assess the ability of the systems to improve the growth of halibut being held for use as broodstock. We anticipate that the systems will be finished in 2014. The immediate effect of their completion will be to provide an ideal environment for halibut as they approach sexual maturity. This will accelerate growth of cultured F1 and F2 stocks being held for halibut broodstock, while reducing stress and mortality in order to decrease the age at which they produce reliable and significant quantities of gametes.

7) Communications

Scotian Halibut Limited intends to report on this broodstock development activity at the annual Sea Farmers conference in Halifax in January 2014. In addition, upon commissioning of the new two tank system and fish entry, a press release in Hatchery International is anticipated to publicize Scotian Halibut Limited's improved broodstock management regime.

Visits by Scotian Halibut's juvenile buyers are expected to occur within the upcoming months to promote the improved broodstock management capacity. 

8) Acknowledgements

Scotian Halibut Limited is grateful to the Aquaculture Innovation and Market Access Program (AIMAP) for their financial support of this project. Scotian Halibut Limited also received financial support from ACOA through their AIF program and is anticipated to receive assistance from the NS Department of Economic and Rural Development through their CII program.