Canadian Aquaculture R&D Review 2017

Finfish: Freshwater

Ontario’s Contributions to a Bi-National Initiative to Restore Bloater (Coregonus hoyi), an Extirpated Species, to Lake Ontario

Historically, Lake Ontario was home to four species of Deepwater Ciscoes (Coregonus spp.), a group of species related to Lake Whitefish. Collectively, these species formed the cornerstone of the deep water prey-fish community. Unfortunately, all four species were extirpated from the lake in the last century.

In 2010, the Ontario Ministry of Natural Resources and Forestry (MNRF) and the New York State Department of Environmental Conservation developed a draft plan to restore Deepwater Ciscoes to Lake Ontario which, if successful, would increase the availability of prey to native predators like Lake Trout and Atlantic Salmon. Initial efforts were to focus on Bloater (C. hoyi).

In winter 2011 and 2012, MNRF received its first fertilized gametes collected from wild populations in Lake Michigan. Given the challenge of collecting gametes at this time of year, a decision was made to set aside some surviving fish from each year class to begin developing brood stocks. Initial culture efforts were aimed simply at learning how to keep the fish alive. Our Lake Whitefish culture protocol was used as a starting point. While initial survival rates were very low, a variety of diet and temperature trials conducted over the next four years resulted in significant improvements in performance.

Six year classes of brood stock have now been established. While both sexes have shown signs of maturation, the timing and degree of maturation has been variable. Hormone induction and cryopreservation studies are now underway in collaboration with the University of Windsor. This research aims to restore a self-sustaining Bloater population within 25 years.

Date: JAN. 2011–JAN. 2020

Funded by: Ontario Ministry of Natural Resources and Forestry (MNRF)

Co-funded by: Canada-Ontario Agreement; Great Lake Fish and Wildlife Restoration Act

Project Lead: Kevin Loftus (MNRF)

Project Team: Tim Drew, Ryan Zheng, Jennifer Smith, Jake Ruegg, Matt Brailey, Brian Rosborough, Chris Wilson (MNRF)

Collaborators: NYSDEC; USFWS; USGS; Great Lakes Fishery Commission; U Guelph; U Windsor

Contact: ryan.w.zheng@ontario.ca

Bloater (Coregonus hoyi) yearling. Photo: MNRF

Female Bloater (Coregonus hoyi) brood fish. Photo: U Windsor

Development of Walleye (Sander vitreus) Intensive Culture Techniques to Enable Increased Production to Meet Demands

This research aims to increase the ability to produce Walleye for stocking into public waters to support provincial fisheries management objectives and to improve the ability to produce Walleye fingerlings to support the commercial aquaculture industry.

Walleye (Sander vitreus) is one of the most sought after recreational species in Ontario but some populations are in decline. The Ontario Ministry of Natural Resources and Forestry (MNRF) stocks Walleye at different life stages to enhance fishing opportunities and to restore degraded populations. Unfortunately, the MNRF is not able to meet the current demand for Walleye by stocking using traditional extensive (i.e., pond) culture methods. To address this gap, the MNRF is developing expertise in the intensive (i.e., indoor) culture of Walleye. They are building upon techniques pioneered in flow through systems by Summerfelt and colleagues in the 1990s and advanced by others in Iowa, Wisconsin and elsewhere. The ability to reliably grow Walleye intensively from hatch to the autumn fingerling stage would increase the options available to MNRF to meet stocking targets and would also provide benefits to the commercial aquaculture sector.

Two MNRF Fish Culture Stations (FCSs) are involved in this effort: Blue Jay Creek FCS with a Recirculating Aquaculture System (RAS); and White Lake FCS with a flow through system. Rearing trials have focused on finding a readily available, high quality, early rearing diet, and on investigating the effects of tank size on growth and survival. To date, there has been significant progress. We are now able to achieve survival rates in our flow through system comparable to those achieved by our U.S. colleagues, and similar performance is within sight in our RAS system. Success depends upon careful control of key parameters including turbidity, temperature, light, diet, and feeding regime.

Date: APR. 2013–OCT. 2018

Funded by: Canada-Ontario Agreement

Co-funded by: Ontario Ministry of Natural Resources and Forestry (MNRF)

Project Lead: Kevin Loftus (MNRF)

Project Team: Ryan Zheng, Jennifer Smith, Tim Drew, Paul Methner, Kyle Reynolds, Steffi Krause, Chris Wilson (MNRF)

Collaborators: Alan Johnson (DNR); Greg Fischer (U Wisconsin at Stevens Point)

Contact: ryan.w.zheng@ontario.ca

Walleye rearing room at the Blue Jay Creek Fish Culture Station. Photo: MNRF

Proprietary Infection Model for Saprolegnia Research Via in Vitro and in Vivo Systems

Infections by the Oomycete “water mould” (Saprolegnia sp.) are problematic at most freshwater fish hatcheries of the world. At some hatcheries, egg losses associated with Saprolegnia can vary between 10-50%. Infections on eggs can be manually removed via “egg picking”; however, it is quite laborious, can only be performed on eyed-eggs, and is not 100% efficient. The most commonly used approved therapeutant at hatcheries is formalin (Parasite-S™), but there are concerns about its safety for the fish and the user. Consequently, there is an urgent need to develop an alternative, safe treatment.

The Huntsman Marine Science Centre (HMSC) has developed a proprietary Saprolegnia infection model that can be used for in vitro or in vivo research. The model begins with Saprolegnia culture isolation and purification and has the option of infection via zoospores or hyphae. Moreover, the infection model allows control over rate of infection with specific control points on timing and temperature and has the added benefit of being maintained through in vitro or in vivo systems. Infections can be created and maintained on any life-stage of freshwater fish. The model has many applications: 1) new therapeutant development and testing; 2) regulatory approval data collection; 3) genomic profiling; 4) taxonomic assessment; and 5) investigative biology. In 2016, HMSC used the infection model with clients with great success to test efficacy, develop suggested use labels, re-infection rates following treatment, etc. One of the greatest advantages of the model is control over the infection process.

This model will be quite useful for research aimed at development of novel, alternative, and safe treatments against Saprolegnia infections at hatcheries.

Date: FEB. 2016–ONGOING

Funded by: New Brunswick Innovation Foundation (NBIF)

Co-Funded by: National Research Council–Industrial Research Assistance Program (NRC–IRAP); Atlantic Canada Opportunities Agency (ACOA)

Project Lead: Duane Barker (HMSC)

Project Team: Anne McCarthy, Esther Keddie (HMSC)

Contact: Duane.Barker@huntsmanmarine.ca

Website: http://www.huntsmanmarine.ca/

(a) Pure culture infection of Saprolegnia on SDA media. (b) SDA media plate of Saprolegnia-exposed eggs corresponding to scores of 0 (uninfected), 1 (infected), and 2 (heavy infection). (c) Saprolegnia-infected eggs in 24 micro-well, tissue culture plates for therapeutant testing. Photo: Duane Barker, Anne McCarthy (HMSC)

Reducing the Problem of Early Sexual Maturation in Arctic Charr

Early sexual maturation among diploid Arctic Charr and other farmed salmonids remains a serious problem, reducing meat quality and revenue. Photoperiod, temperature, and food availability exert a strong influence on somatic growth and the decision to commence sexual maturation, but how they interact is unclear. Fraser River Arctic Charr is a good “model salmonid” for study as both sexes suffer a high rate (>70%) of early sexual maturation in culture (10°C groundwater), a trait that has limited its commercialization in Canada. Preventing sexual maturation would greatly increase commercial viability of farming diploid Arctic Charr.

Reducing the incidence of maturity to less than 20% has been consistently achieved in three year classes by rearing fish under 24 h light (LL) from October to February. The timing of both the start-date and end-date of LL has been shown to be critically important. Reduction of the maturation rate was independent of somatic growth. This leads us to question the conventional model that the physiological trigger to mature is dependent on defined threshold levels of growth and/or body size. Nevertheless, further reductions in the maturity rate, to 0% in some cases, were achieved by combining LL with reducing somatic growth in winter, by either food deprivation or rearing at 5°C rather than 10°C. Compensatory growth following the return to full ration in April indicates winter growth suppression is practical. We propose that a two-step gating mechanism controls the growth-independent and growth-dependent factors dictating the physiological decision to mature.

Date: SEP. 2013–MAR. 2018

Funded by: Atlantic Canada Opportunities Agency–Atlantic Innovation Fund (ACOA–AIF)

Project Lead: Jim Duston (Dalhousie U)

Project Team: Qi Liu (Dalhousie U)

Collaborators: Tony Manning (NB–Research and Productivity Council); Rodrigue Yossa (Coastal Zones Research Institute)

Contact: jduston@dal.ca

Top: Marketable silvery immature fish; bottom: unmarketable highly coloured mature fish. Photo: Paul MacIsaac (Dalhousie U)

Development of Predictive Modeling Tools to Assist with Freshwater Aquaculture Site Decisions

Governmental agencies charged with the responsibility of licensing and regulating the aquaculture industry are in need of objective tools to assist in their decision-making processes. The development of such tools would also benefit industry, as currently, the primary factor limiting the expansion of the freshwater industry is access to new sites. The lack of tools to estimate ecological consequences of new sites has resulted in a very precautionary atmosphere, a complex and expensive application process, and ultimately, limited development of the industry.

The primary environmental concerns with cage aquaculture are related to benthic impacts and exceedance of the assimilative capacity of an ecosystem for nutrient inputs. Cage aquaculture has the potential to have far-ranging impacts on the lake ecosystem. Increased nutrient inputs can affect overall ecosystem productivity and excessive nutrient inputs can lead to eutrophication, which may include such undesirable consequences as the development of nuisance algal blooms, oxygen deficiency, and loss of biodiversity. The deposition of solid wastes under farms contributes to increased sediment oxygen demand, as well as the potential to significantly alter the quality of benthic habitat and the composition of benthic communities beneath and surrounding farms.

Date: MAY 2012–MAR. 2016

Funded by: DFO–Aquaculture Collaborative Research and Development Program (DFO–ACRDP)

Co-Funded by: Wild West Steelhead

Project Lead: Cheryl Podemski (DFO)

Collaborators: Rory Ylioja (Wild West Steelhead)

Contact: Cheryl.Podemski@dfo-mpo.gc.ca

Website: www.dfo-mpo.gc.ca/aquaculture/rp-pr/acrdp-pcrda/projects-projets/CA-08-02-003-eng.html

Collecting sediment trap samples for suspended particle analyses. Photo: Kristy Hugill (DFO)

Collecting sediment cores for benthic invertebrate and chemistry analyses. Photo: Megan Otu (DFO)

Impacts of Stocking Density on the Welfare and Production Performance of Arctic Charr (Salvelinus alpinus)

This project aims to observe the effects of stocking density on Arctic Charr with respect to welfare. Currently, aquaculturally-reared salmonids are primarily stocked at high densities in order to stimulate schooling, reduce potential conspecific aggressive behaviour, and ultimately increase the production quantity of market quality product. However, with such high stocking densities, stress, and other factors, which can be attributed to high stocking densities, may result in increased instances of infection and other detriments to production performance. To date, little research has been done examining the effects of stocking density on the welfare of farmed fishes. As such, this project will analyze genetic, biochemical/proteomic, and physiological parameters pertaining to welfare among 5 treatment densities: 20, 40, 80, 120 and 160 kg•m-3 (low to excessive, respectively).

The goal of this project is to improve the welfare of farm-reared fishes (specifically that of Arctic Charr). Improving the welfare of farmed fishes may subsequently result in increased growth rates/improved production performance, thus increasing the quality of marketable product as well as quantity of farm sales.

Date: NOV. 2016–DEC. 2017

Funded by: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Project Leader: Richard Moccia (U Guelph)

Project Team: Andrew Sevier (U Guelph)

Collaborators: Alma Aquaculture Research Station (U Guelph)

Contact: rmoccia@uoguelph.ca

Website: www.aps.uoguelph.ca/aquacentre/

Arctic Charr reared at 20 kg per cubic meter. Photo: Michael Burke (U Guelph)

Arctic Charr reared at 160 kg per cubic meter. Photo: Michael Burke (U Guelph)

Improving the Growth, Health, and Survival of Tilapia in a Greenhouse-Enclosed Intensive Recirculating Aquaculture System

Warm-water tilapia (Oreochromis niloticus) is becoming an important commercial freshwater fish in North America. Viva Aquaculture and Seafood Distribution Ltd. (Viva) in collaboration with The University of British Columbia (UBC) has engaged in sustainable tilapia aquaculture production to supply the strong market demand in British Columbia. To overcome technological uncertainties which cannot be removed using standard practice, the general project objective is to produce healthy tilapia in sustainable, environment-friendly, and in a less expensive way within a land-based facility without affecting the surrounding environment by generating “zero waste”. Based on biological principles, the research team has developed a sustainable land-based tilapia aquaculture system in a Canadian climate. Beneficial nitrifying bacteria were used to convert toxic nitrogenous wastes into non-harmful compounds, which are absorbed by selected aquatic vascular plants and microalgae. Innovative bio-engineering design to recirculate clean water and conserve heat to maintain suitable condition for tilapia culture was employed. A “zero waste” system is being developed to make fish production more sustainable, profitable, and environment-friendly. Our research has yielded initial results that show encouraging outcomes during the first year of project implementation. It is expected that employing these new innovations will lead to lower production cost, increased economic benefits, and improved fish quality; all of which will lead to an environmentally sustainable production of live tilapia.

Culturing tilapia in a land-based, enclosed intensive recirculating system using innovative bioengineering design, beneficial microbes, algae, and vascular aquatic plants will lessen environmental impact, lower production cost, provide economic opportunities, and produce a healthy and diversified source of seafood for Canadian consumers.

Date: FEB. 2015–DEC. 2018

Funded by: Viva Aquaculture and Seafood Distribution Ltd. (“Viva”)

Co-Funded by: Hero Invincible Bio Aqua Farm

Project Lead: Jesse Ronquillo (UBC; Viva)

Project Team: Chang Lin Ye, Kai Chen (Viva)

Collaborators: David Kitts (UBC)

Contact: jesse.ronquillo@ubc.ca

Website: www.vivaseafood.com

Aquaponics system for intensive tilapia culture. Photo: Jesse Ronquillo (UBC)

Aquaponics system for intensive tilapia culture. Photo: Jesse Ronquillo (UBC)

Aquaponics system for intensive tilapia culture. Video: Jesse Ronquillo (UBC)

The Development of Fast Growing, Late Maturing, and Salinity Tolerant Strains of Arctic Charr

The genetic improvement of Canadian strains of Arctic Charr to reduce the undesirable characteristics of poor growth, early maturation, and inability to tolerate seawater (and stress in general) would greatly facilitate development of the industry. Our goal is to integrate genomic methodologies into selective breeding programs to develop better performing strains in a lower number of generations than by conventional breeding methods alone. We will first develop genomic resources for Arctic Charr: 1) discover genetic markers [single nucleotide polymorphisms (SNPs)] from the Fraser, Nauyuk, and Tree River strains; 2) find out where the SNPs are located relative to each other in the genome through genetic linkage mapping; and 3) develop a high resolution genotyping tool (array). We will then use those resources to find SNPs that are located in or near genes that control the economically important traits under study. Adult fish with these SNPs could then be bred to produce better quality offspring to serve as parents for the next generation. Rearing trials with families from the Fraser and Nauyuk strains have been conducted at the Coastal Zones Research Institute (New Brunswick) and the Alma Aquaculture Research Station (Ontario). We have tracked the phenotypic performance of individuals (growth, age of maturation, and salinity tolerance) and will genotype each of those fish for up to 90 thousand SNPs. Tracking the inheritance of these markers will also allow us to expand our current SNP based linkage map of the Arctic Charr genome.

The combination of detailed genotype and phenotype data will enable the identification of regions of the Arctic Charr genome associated with traits of economic interest. This information can facilitate marker assisted selection of Canadian aquaculture Arctic Charr, increasing the industry’s productivity and worldwide competitiveness.

Date: MAR. 2012–DEC. 2018

Funded by: Atlantic Canada Innovation Fund (ACOA)

Co-Funded by: Natural Sciences and Engineering Research Council (NSERC)–Discovery Program

Project Lead: Moira Ferguson (U Guelph)

Project Team: Cameron Nugent, Anne Easton, Roy Danzmann (U Guelph)

Collaborators: Michael Burke (Alma Aquaculture Research Station); Claude Pelletier (CZRI); Ben Koop (UVic); William Davidson (SFU)

Contact: mmfergus@uoguelph.ca

Cameron Nugent and Oliver Franklin collecting Fraser strain Arctic Charr for measurement. Photo: Anne Easton (U Guelph)

A sexually mature three year old female Arctic Charr. Photo: Anne Easton (U Guelph)

Change in Rainbow Trout Phosphorus Absorption: Physiological Adaptations to a Phosphorus Deficiency

The proposed project challenges the hypothesis that the only source of phosphorus (P) available to freshwater fish is their food. The assumption is that they are incapable of absorbing significant quantities of P from their environment is supported by the relatively low (< 0.1 ppm of P in the water) concentration of this element in the natural environment of freshwater fish. However, preliminary observations in a recirculated system, in which P concentrations were about 1 ppm, found that physiological mechanisms appear to enable trout to absorb ambient P. Phosphorus deficient Rainbow Trout therefore appears to develop the ability to absorb external P to maintain homeostasis by introducing sodium phosphate (NaPi) cotransporters into gill tissue.

To test these hypothesis, we propose to: 1) produce P-deficient fish through a prolonged dietary deficiency in phosphorus; 2) monitor the change in P status in scales and carcasses and the overexpression of sodium phosphate (NaPi) cotransporters in the tissue of trout (gills, pyloric caecum, proximal and distal intestine); 3) confirm the capacity of deficient trout to absorb ambient P through phosphorus absorption tests in tanks; 4) demonstrate the ability of deficient trout to absorb P specifically through the gills via the McKim and Goeden holding device (1982); and 5) confirm P absorption by monitoring P concentrations in the blood (aortic cannula) and urine (urinary catheter).

This project will contribute to significantly advancing knowledge on phenotypic plasticity in fish and on the impact of nutritional deficiency, and will help to identify new homeostasis strategies.

Date: JAN. 2013–MAR. 2018

Funded by: Natural Sciences and Engineering Research Council of Canada (NSERC)

Project Lead: Grant Vandenberg (U Laval)

Project Team: Waly Ndiay, Marie-Hélène Deschamps, Émilie Proulx (U Laval)

Contact: Grant.Vandenberg@fsaa.ulaval.ca

Website: http://www.vrrc.ulaval.ca/fileadmin/ulaval_ca/Images/recherche/bd/chercheur/fiche/424160.html

Phosphorus-deficient Rainbow Trout in holding to measure specific absorption through the gills. Photo: Émilie Proulx (U Laval)

Aquastats: Ontario Aquaculture Statistics Program

In 2015, we estimate that Ontario fish farms produced 4,510 tonnes of Rainbow Trout, primarily for human consumption. Lake-based cage production of Rainbow Trout in the North Channel & Eastern Georgian Bay area accounted for 92% of the total production. Our records suggest that approximately 66 facilities culture one or more of tilapia, Arctic Charr, Brook Trout, bass, Walleye, and other species, with an estimated total production of 380 tonnes in 2015.

The total farm-gate value of the 4,510 tonnes of Rainbow Trout produced is estimated to be $23.2 million, with an average price of $5.13/kg. The sale of tilapia, Arctic Charr, Brook Trout, bass, and other fish species is estimated to be an additional $2.2 million. More than 80 facilities are involved with pond stocking, typically Rainbow Trout, Brook Trout, and bass, conservatively estimated to be $1.5 million annually.

The Ontario aquaculture industry is estimated to have generated a total of 195 person-years of direct, on-farm employment (137 person-years of full-time and 58 person years of part-time employment). Indirect employment is conservatively estimated at 150 person-years.

The total annual contribution that aquaculture makes to the Ontario economy is estimated to be $80 million, with additional economic value realised via the recreational and aquaria trade.

This project maintains a 27-year data collection series on Ontario aquaculture.

Date: JAN. 2016–MAY 2016

Funded by: Ontario Ministry of Natural Resources and Forestry (MNRF)

Co-Funded by: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Project Lead: Richard Moccia (U Guelph)

Project Team: David Bevan (U Guelph)

Collaborators: Sarah Desjardins, Mary Duda (Ontario Ministry of Natural Resources and Forestry)

Contact: rmoccia@uoguelph.ca

Website: www.aps.uoguelph.ca/aquacentre/

Ontario trout production 1988-2015.

Overview on the Improvement of the Fraser Strain of Arctic Charr (Salvelinus alpinus) at the Coastal Zones Research Institute

The growers and scientists of the Atlantic region have identified the major challenges faced by the Arctic Charr (Salvelinus alpinus) aquaculture industry: early maturation, poor egg quality and supply, and inconsistency of fillet pigmentation. To solve these issues, the Coastal Zones Research Institute (CZRI) implemented a breeding program whose objectives are: 1) to develop a fast-growing Arctic Charr that is commercially profitable in Canada and abroad; and 2) to develop and provide certified high quality eggs to the industry. In collaboration with its industrial and scientific partners, CZRI has rigorously performed selected breeding in order to improve the growth potential of each generation of the Fraser strain of Arctic Charr, while minimizing inbreeding and reducing the occurrence of early maturation. A seventh generation with 41 families was obtained in the autumn of 2015 and 2016, with a weight gain potential which has increased by 121% compared with the first generation. Overall, the team at CZRI overcame important challenges over the last decade and is progressing toward the production of one of the most promising strains of Arctic Charr for aquaculture.

The overall objective is to provide a commercial and competitive Arctic Charr to the Canadian industry and abroad.

Date: APR. 2013–MAR. 2019

Funded by: Department of Agriculture, Aquaculture and Fisheries of New Brunswick (DAAF)

Co-funded by: Atlantic Canada Opportunities Agency (ACOA); Coastal Zones Research Institute (CZRI)

Project Lead: Claude Pelletier (U Moncton)

Project Team: Caroline Roussel, Claude Landry, Luc Desjardins, Maurice Boudreau, Rodrigue Yossa (CZRI); Michel Desjardins (DAAF)

Collaborators: Christophe Herbinger, Philippe Fullsack (Dalhousie U)

Contact: Claude.S.Pelletier@umoncton.ca

Website: http://www.irzc.umcs.ca/flash_content/anglais/nousjoindre.html

Arctic Charr (Salvelinus alpinus) mature broodstock. Photo: CZRI

Evaluating Four Commercially Available Rainbow Trout Diets on the Growth and Feed Conversion of Ontario Domestic Rainbow Trout (Oncorhynchus mykiss)

In aquaculture, feed can account for approximately 40-60% of a Rainbow Trout farm’s operating costs depending upon the type and size of the farm and the feeding husbandry practices followed. Since the introduction of high-pressure moist extrusion technologies in the 1980s, modern dry and durable high-energy salmon and trout diets have been available to Ontario Rainbow Trout farmers. Choice of manufacturer is dictated by the cost, availability, and performance of the fish. While unit cost and availability of the feed are easily determined by the farmer, the performance of the fish fed any particular brand of feed is more difficult to ascertain. Feed evaluations are usually offered by the manufacturer or by fish farmers. There are obvious problems with either of these sources. Manufacturers promote their feed with a bias and seldom provide the relevant data to support their claims. Evaluations of fish feeds from fish farmers tend to be largely anecdotal. Furthermore, the effects of environmental conditions (water temperature, dissolved oxygen, fish densities, etc.), fish genetics, and culture methodologies can have greater influences on the growth and mortality of fish than does nutrition. As these effects are seldom accounted for and vary greatly from farm to farm and year to year, data collected by farmers are generally considered ineffective in determining which brand of feed to use.

The purpose of this study is to grow Rainbow Trout (Oncorhynchus mykiss) from 450 g to market size of 1,200 g using four different commercially available grower feeds.

This trial will indicate which feeds result in superior growth rates and feed conversion so that the aquaculturalist can make an informed decision in selecting a feed manufacturer and/or brand of feed. A significant reduction in feed costs can be achieved if fish growth, feed conversion, and cost/unit feed can be reliably evaluated.

Date: MAR. 2016–AUG. 2016

Funded by: Aqua-Cage Fisheries Inc.

Co-Funded by: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Project Lead: Richard Moccia (U Guelph)

Project Team: Alma Aquaculture Research Station (U Guelph)

Collaborators: Martin Mills Inc.; Skretting Canada; Aqua-Cage Fisheries Ltd.

Contact: rmoccia@uoguelph.ca

Website: www.aps.uoguelph.ca/aquacentre/

Sampling Rainbow Trout for growth trial. Photo: David Bevan (U Guelph)

Evaluation of Four Commercial Starter Feeds for Rainbow Trout (Oncorhyncus mykiss) Held Under Typical Commercial Hatchery Conditions

The rapid proliferation of aquaculture over the past two decades has seen the growth of fish feed manufacturers on the global, national, and local levels. Choice of feed manufacturer is dictated by the cost, availability, and performance of the fish. While unit cost and availability is easily determined by the aquaculturalist, the performance of the fish fed any particular brand of feed is more difficult to ascertain. Feed evaluations are usually presented by the manufacturer or by fish farmers. There are obvious problems with either of these sources. Manufacturers promote their feed with a bias and seldom provide data that supports their claims. Evaluations of fish feeds from fish farmers tend to be largely anecdotal. Furthermore, the effects of environmental conditions (water temperature, dissolved oxygen, fish densities, etc.), fish genetics, and culture methodologies can have greater influences on the growth and mortality of fish than does nutrition. As these effects are seldom accounted for and vary greatly from farm to farm and year to year, data collected by farmers are generally considered ineffective in determining which brand of feed to use.

The purpose of this study was to grow Rainbow Trout (Oncorhynchus mykiss) fry from first feeding to 35 g using starter feeds purchased from four different feed manufacturers. The objective was to determine which feeds best promoted growth and survivability.

There were no significant differences in either growth or mortalities when using starter feeds purchased from four different feed manufacturers. This suggests that the nutritional and energy requirements for Rainbow Trout starter feeds were meet, or exceeded, by all four manufacturers.

Date: DEC. 2014–JUL. 2015

Funded by: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Project Lead: Richard Moccia (U Guelph)

Project Team: Michael Burke (U Guelph)

Collaborators: Alma Aquaculture Research Station (U Guelph)

Contact: rmoccia@uoguelph.ca

Website: www.aps.uoguelph.ca/aquacentre/

Starter feeds for rainbow trout. Photo: David Bevan (U Guelph)

The Effects of Light Emitting Diodes on the Growth and Feeding Behaviour of Rainbow Trout (Oncorhyncus mykiss)

There is considerable economic pressure for hatcheries to switch from incandescent lighting to light emitting diodes, as these bulbs last longer and greatly reduce operating expenses. Current LEDs being marketed to the aquaculture industry produce a significantly different light spectrum than incandescent, with more short wavelength (blue-shifted) light and less long wavelength (red and infrared shifted) light.

In an aquaculture setting, Rainbow Trout are visual feeders, relying entirely on seeing the pellets to feed efficiently. Little is known on how the shift from incandescent to LEDs will affect feeding behaviour and growth of these commercially important salmonids. Feeding behaviour and growth rates will ultimately affect the bottom line of any hatchery or aquaculture facility; therefore, optimizing these under new lighting conditions is key.

Three decades of aquaculture research has been carried out at the Alma Aquaculture Research Station (AARS), a large portion of which has been done indoors using incandescent lighting. As the AARS is preparing to switch to LEDs to reduce energy costs, it is important to determine how these new lights will affect Rainbow Trout growth, and how this will change how previous studies are interpreted.

Date: AUG. 2016–DEC. 2016

Funded by: Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Project Lead: Richard Moccia (U Guelph)

Project Team: Wes Chase (U Guelph)

Collaborators: Alma Aquaculture Research Station (U Guelph)

Contact: rmoccia@uoguelph.ca

Website: www.aps.uoguelph.ca/aquacentre/

Spectrum emitted by traditional incandescent bulbs. Displays various intensity levels at different locations within AARS photoperiod lab.

Spectrum emitted by the AquaShift MLA-BL bulbs. Displays various intensity levels at different locations within AARS photoperiod lab.

Modulation of the Metabolism and Digestive Capacity of the Arctic Charr (Salvelinus alpinus) Through Dietary Restriction

This project seeks to improve zootechnics for the development of a competitive Arctic Charr culture industry. Reducing or alternating the frequency of feeding can induce a mechanism that fish use to counter the effects of dietary restriction: compensatory growth. Salmonids can actually increase their conversion efficacy and remarkably, regain their body mass following a dietary restriction.

To assess the effects of various feeding methods on the productivity of commercial Arctic Charr culture, the physiological parameters that dictate growth performances, such as digestive capacity, will be examined. Dietary restriction modulates the fish’s physiology in various ways based on the severity of restriction and feeding frequency. The goal of the project is to identify the most effective and sustainable feeding sequence that will ensure optimal physiological health and growth capacity. To achieve this, we will monitor digestive capacity after restriction and refeeding, and measure the digestibility parameters (e.g., trypsin activity and certain energy metabolism enzymes in the pyloric ceca).

Reducing the amount of food to reach a given growth level and optimizing food conversion helps reducing costs and reduce organic waste (e.g., phosphorus) in the environment. The current challenge is to increase the competitiveness of the aquaculture industry while maintaining good growth performances. Dietary restriction and refeeding trials have been conducted in partnership with Aquaculture Gaspésie Inc.

The goal of this project is to optimize zootechnics of the Arctic Charr, which is a strategic species in Canada for the development of consumer products.

Date: SEP. 2014–APR. 2017

Funded by: Atlantic Canada Opportunities Agency (ACOA)

Co-Funded by: Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec (MAPAQ)

Project Leads: Nathalie Le François (Biodome de Montréal); Pierre Blier (UQAR)

Project Team: Mirelle Caouette Houle, Arianne Savoie (UQAR)

Collaborators: Francis Dupuis (Aquaculture Gaspésie Inc.); Moïse Cantin, Catherine Roy (Pisciculture des Monts De Bellechasse)

Contact: nle_francois@ville.montreal.qc.ca

Mirelle Caouette Houle, UQAR aquaculture tank room/Ismer, Pointe-au-Père (Rimouski). Photo: Vincent Roy (UQAR)

Feeding sequences.