CONFERENCES & EVENTS - AquaNet I
Abstracts

Animal Production Theme

Theme Leaders

Dr. Joseph Brown - Ocean Sciences Centre, Memorial University
Dr. Moira M. Ferguson - Department of Zoology, University of Guelph

AP 1: Stress in Fish: Diagnostics, Role in Disease, and Management


The relationship between the organismal and cellular stress responses in fish

N. Basu*¹, T. Nakano², D. Toa¹, E.G. Grau³, C.J. Kennedy⁴ and G.K. Iwama^1,5

¹Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 ²Marine Biochemistry Laboratory, Faculty of Agriculture, Tohoku University, Sendai 981-8555, Japan
³Hawaii Institute of Marine Biology, University of Hawaii, Kane'ohe, HI 96744, USA
⁴School of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6
⁵Institute for Marine Biosciences, National Research Council, Halifax, NS B3H 3Z1

Fish are constantly exposed to stress in captivity and in the wild. As a consequence, they have developed methods to cope with these stressors. At the organismal level, fish release stress hormones (i.e. cortisol) to mobilize energy stores, and at the cellular level they release various heat shock proteins (hsp) that have functions related to maintaining protein homeostasis. We found that elevated levels of cortisol significantly prevented or suppressed heat stress-induced increases of hsp70 in trout and tilapia tissues. Additionally, we found that toxicant exposure impaired the organismal and cellular responses to stress. In order to elucidate the mechanisms underlying our findings, we explored the association between the glucocorticosteroid receptor (GR) and various hsps following stress. Our findings demonstrate that the organismal and cellular stress responses are linked, and most likely regulated at the level of GR. Collectively, these findings demonstrate cross talk exists between the organismal and cellular stress responses. While cortisol and hsps are presently being utilized to quantify the stress and health status of fish, little information exists on their underlying physiology and regulation. The development of tools to assess and manage stress in fish is of utmost importance to the aquaculture industry, from an economic and health standpoint. Our findings provide vital data regarding future management of stress in fish.


Variation in the cellular hsp70 response among fishes from different thermal habitats

K. Nakano*¹, A. Takemura², S. Nakamura², Y. Nakano², S. Kudo³, Y. Tsuchiya⁴ and G.K. Iwama^1,5

¹Faculty of Agricultural Sciences and AquaNet, The University of British Columbia, Vancouver, BC V6T 1Z4
²Sesoko Station, Tropical Biosphere Research Center, The University of the Ryukyus, Okinawa 905-0227, Japan
³National Institute of Polar Research, Tokyo 173-8515, Japan
⁴Shimoda Marine Research Center, Tsukuba University, Shimoda 415-0025, Japan
⁵Institute for Marine Biosciences, National Research Council, Halifax, NS B3H 3Z1

The functional importance of 70-kDa heat shock protein (hsp70) in thermal tolerance of organisms is now widely accepted. However, the mechanism by which hsp70 provides species-specific thermal tolerance has not been fully examined yet. In this study, we explored the cellular hsp70 response in three fish species inhabiting different thermal environments. We examined levels of hsp70 and hsp70-mRNA in Trematomus bernacchii in the Antarctica, the tidepool sculpin, Oligocottus maculosus, in the temperate region, and in the five-banded damselfish, Abudefduf vaigiensis, in the subtropical ocean. The threshold temperature for the increased hsp70 level was well correlated with the thermal habitat of the species, indicating that the range of functional temperature for this protein may have been modified during the adaptation to inhabited environmental temperatures. The cellular hsp70 response was absent after heat shock in the Antarctic fish, although an increase in hsp70-mRNA level was observed, indicating that the translation of hsp70 in this species may have been lost or occurred at a very slow pace. These results suggested that the pattern of the cellular hsp70 response can be modified depending on the temperature range of the inhabited environment. They also cast an insight, beyond the well accepted conservativeness of hsp70, into the diversity of that protein.


AP 2: Shellfish Health: Development of Biochemical Indicators of Stress


Biochemical changes in juvenile sea scallops Placopecten magellanicus exposed to sub-lethal heat-shock

Nicole T. Brun*^1,2, Neil W. Ross², V. Monica Bricelj², Emmanuel E. Egbosimba² and Thomas H. MacRae<sup>1

1</sup>Department of Biology, Dalhousie University, Halifax, NS B3J 1Z1
²National Research Council, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1

As part of a project investigating the potential use of biochemical changes as stress indicators in shellfish, the expression of heat-shock proteins (HSP) in juvenile sea scallops Placopecten magellanicus (Gmelin) exposed and non-exposed to sub-lethal temperature stress was examined. Heat-shock proteins are highly conserved and have been shown to increase upon exposure to various stressors.

Scallops maintained at 10ºC were transferred directly to 22ºC for 3h, followed by a recovery period of 24h. Subsequently, scallop mantle and gill tissues were examined using SDS-PAGE followed by Western blotting analysis using antibodies against HSP-70. Results indicate that, while both scallop mantle and gill tissues expressed HSP-70, no significant differences in the amounts of HSP-70 were detected over time in either tissue. However, a 68 kDa gill tissue protein was recognized by HSP-70 antibody. Preliminary data from two-dimensional electrophoresis using mantle tissue from heat-shocked scallops revealed that, when compared to control samples, a number of proteins increased in intensity following heat-shock while others were down-regulated. These proteins will be analyzed by mass spectrometry to yield partial amino acid sequences that will be used to generate probes to screen scallop cDNA libraries, in order to identify scallop proteins whose expression is modulated on heat-shock.

Development of expressed sequence tags from different tissues of scallop

Tao Chen*¹, Emmanuel E. Egbosimba¹, Thomas H. MacRae², V. Monica Bricelj¹, Susan E. Douglas¹ and Neil W. Ross<sup>1

1</sup>National Research Council, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1
²Department of Biology, Dalhousie University, Halifax, NS B3H 4J1

The goal of our project is to evaluate sensitive biochemical indicators of stress in bivalves in order to provide information for improving husbandry or processing conditions. As a complement to the biochemical studies, we plan to obtain expressed sequence tags (ESTs) from different tissues of scallop to develop probes for genes of digestive enzymes and immunologically important proteins. With these probes, we plan to examine the ontogeny of digestive enzymes and other related proteins, as well as the changes in the expression of relevant genes in response to environmental conditions. We have constructed a scallop cDNA library from gonad (male) and intestine. The cDNA library titers were 9.7

Development of biochemical indicators of stress in shellfish and anti-microbial peptides from scallop

Emmanuel E. Egbosimba*¹, Nicole T. Brun¹, Joanne Harding², Cyr Couturier², Monica V. Bricelj¹ and Neil W. Ross¹

¹National Research Council, Institute of Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1
²Fisheries and Marine Institute of Memorial University of Newfoundland, St. John's, NF A1C 5R3

The developments in the technology for large scale shellfish production from the 1970's onward and attendant mass mortalities observed in spat production and adult stages of cultivation has necessitated the development of rapid methods of monitoring stress levels of shellfish that may result from environmental changes or disease. Traditionally, stress level monitoring have been approached from whole animal levels, using physiological parameters as reduced growth, inhibition of feeding and death. Measurement of such indexes were time consuming, multivariate, and non-specific and hence the need for introduction of faster more specific biochemical indicators. Our group has been investigating the development of biochemical stress indexes that include the monitoring of haemocyte lysosomal membrane integrity, heat shock protein and enzyme induction in tissues, and anti-microbial peptides levels in scallop tissues. Preliminary results on the anti-microbial peptide front has led to identification of an 7.5 kDa acid soluble polypeptide in the haemocytes of scallop with anti-microbial action against Aeromonas salmonicida. The level of the 7.5 kDa polypeptide was found to decrease following heat shock of scallop.

Physiological and biochemical indices of stress in mussels (Mytilus spp.) in relation to husbandry, harvesting and holding practices

Joanne Harding*¹, Cyr Couturier¹, G. Jay Parsons¹ and Neil W. Ross²

¹Fisheries and Marine Institute of Memorial University of Newfoundland, St. John's, NF A1C 5R3
²National Research Council, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1

Cultured bivalves are subjected to a variety of physical and environmental conditions during farming activities. Some conditions lead to stress and reduced performance or quality. The goal of this project is to evaluate a sensitive biochemical indicator of stress in bivalves in order to provide information for improving husbandry or processing conditions. The objectives are to evaluate: 1) seasonal changes in the stress of mussels related to reproductive cycle, 2) mussel stress responses to rapid environmental changes under controlled conditions and 3) the influence of handling, processing, and post harvest storage practices on mussel stress. The neutral red assay measures retention time of the neutral red dye in the hemocyte organelle, the lysosome, which is directly related to the stress of the hemocytes and can be correlated to the overall stress of the mussel. Mussels exposed to rapid thermal change exhibited signs of stress. Mussels held under wet storage (seasonal water temperature of 2-15

AP 3: Host-Pathogen Interactions: The Aeromonas salmonicida / Salmo salar Model System Applied to Non-salmonid Finfish

Immunoglobulin structure and diversity in vaccinated haddock (Melanogrammus aeglefinus)

B.E. Bentley*^1,2, A. Dacanay², L.L. Brown² and S.C. Johnson_²

¹Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
²Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

The specific humoral (antibody) immune response of gadids, such as haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua), appears to differ from that of other fish. Vaccination studies in haddock and cod have failed to elicit specific antibody responses as measured by ELISA or agglutination studies, although vaccination of cod apparently gave protection from disease. We are investigating the effects of vaccination of haddock on: immunoglobulin (Ig) quaternary structure and Ig diversity. The overall structure of haddock Ig is similar to that of salmonids; comprising of 85 kDa heavy chains and 25 kDa light chains. Preliminary data from non-reducing, denaturing agarose/acrylamide electrophoresis and analytical FPLC suggest that haddock Ig has a similar quaternary structure to salmon Ig. However, with respect to levels of disulphide cross-linking, haddock Ig appears to exist in its highest crosslinked form as a trimer whereas salmonid Ig exists as a tetramer.

Haddock plasma from four vaccine groups (commercial vaccine against Vibrio anguillarum and Aeromonas salmonicida; TNP-KLH conjugate and adjuvant; saline and adjuvant; and non-injected control) was analyzed by two-dimensional electrophoresis to investigate immunoglobulin diversity between vaccine groups. Preliminary data suggest differences in immunoglobulin diversity between individuals; however, more analysis is required to determine if the changes in diversity are attributed to vaccination or polymorphism between individuals.

Development of phage-display monoclonal antibodies to Atlantic halibut (Hippoglossus hippoglossus) and haddock (Melanogrammus aeglefinus) immunoglobulin

L.J. Windecker^1,2, A. Dacanay*¹, R.O. Ebanks¹ and L.L. Brown¹

¹Institute for Marine Biosciences, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1
²Malaspina University College, Biology Department, 900 Fifth Street, Nanaimo, BC V9R 5S5

Diversification of the aquaculture industry is creating an immediate requirement for fish health management strategies to encompass a growing range of species. Development of such strategies requires a basic understanding of the immunology of the animal. There are limited reagents, such as monoclonal antibodies, with which to study the immune systems of fish and none are commercially available for Atlantic halibut (Hippoglossus hippoglossus) or haddock (Melanogrammus aeglefinus). One of the reasons for this is the technical difficulty, and the high costs (both operational and time-related) associated with the generation of conventional monoclonal antibodies. Using the emerging phage display technology we have generated monoclonal antibodies to both haddock and Atlantic halibut immunoglobulin (Ig) in fewer than five weeks. Phage monoclonal antibodies (PhMAb) specific to Atlantic halibut and haddock immunoglobulin but not murine IgM, were isolated from the Griffin.1 phagemid library. PhMAb specificity was demonstrated by antibody capture ELISA assays. Mass spectrometric analysis of immunoglobulin tryptic digests was used to determine the epitope recognized by the PhMAb. Once fully characterized, the monoclonal antibodies developed in this study will allow future immunological analyses to be rapidly carried out with a greater degree of confidence than is presently possible. This will lead to an improved understanding of the immune system of these species and the eventual development of new health management strategies for them.

The efficacy of vaccination of haddock (Melanogrammus aeglefinus) against infection with the bacterial pathogen Vibrio angullarium

D.T. Gillett*^1,2, B.E. Bentley^1,2, M. Greenwell², L.L. Brown² and S.C. Johnson²

¹Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
²Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

Vibriosis has been reported as a cause of mortality in net-pen reared haddock (Melanogrammus aeglefinus) in the Bay of Fundy. The purpose of this study was to determine whether vaccination would protect haddock against vibriosis. A preliminary challenge involved immersing unvaccinated juvenile haddock for 15 minutes in 0, 103, 104, 105 or CFU ml-1 of Vibrio anguillarum (Strain V3 (PV)). Over an eight-week period, mortalities ranged from 20 to 50% in all groups, including controls. Triplicate groups of 20 juvenile haddock were vaccinated with either a commercial vaccine (against V. anguillarum and Aeromonas salmonicida), heat-killed V. anguillarum in Freunds Incomplete Adjuvant, adjuvant (adjuvant control) or PBS (control). Fish were challenged at 8 weeks post-immunization with 107 CFU ml-1of V. anguillarum via bath challenge. There were low cumulative mortalities (1.5 to 5%) in all groups over a 5-week period post-challenge and no difference in mortalities between groups. Kidney swabs from surviving fish revealed a high prevalence of Vibrio spp. (50 to 75%) in all groups. The lack of morbidity after challenge suggests that this strain of Vibrio may not be pathogenic to haddock when administered by bath challenge. It is possible that the lack of morbidity was due to acquired immunity brought about by previous exposure to this bacterium at an earlier developmental stage. It is also possible that the low morbidity may be due to innate immune responses. It has been suggested for cod that innate is more important than acquired immunity in their response to infectious diseases and it may be that haddock are like cod in this respect.

Characterization and expression of the recombination activating genes (RAG1 and RAG2) of Atlantic halibut (Hippoglossus hippoglossus)

D.T. Gillett*^1,2, J.A. Osborne², S.A. Sperker², L.L. Brown² and S.C. Johnson²

¹Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
²Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

Recombinase activation genes (RAG) are responsible for the initiation of the rearrangement of the V, D and J regions of immunoglobulin and T cell receptors. Two genes RAG1 and RAG2 have been identified from a variety of animals including the rainbow trout, zebra fish, Japanese pufferfish and bull shark. These genes are known to be expressed together in maturing B and T lymphocytes and can be used to determine the timing and location of pre B and pre T lymphocytes throughout development. Degenerate primers for RAG1 and RAG2 were designed based on published sequences. Using these primers we were able to amplify a 1.5 kb fragment of RAG1 gene from halibut (Hippoglossus hippoglossus) DNA. However, we have been unable to amplify RAG2. Sequencing the RAG1 product revealed high similarities (>80% nucleotide identity) to RAG1 genes from a wide evolutionary range of fish species, especially rainbow trout, Japanese puffer, turbot and the North American paddlefish. We are presently using this gene product to probe a halibut cDNA library to obtain the full-length cDNA sequence. Primers designed from this sequence are being used in RT-PCR to investigate the tissue distribution of RAG1 expression in juvenile halibut and the timing of RAG1 expression during ontogeny. We will use this product as a probe for in situ hybridization studies to localize sites of B and T cell maturation in larval halibut.

Investigations of the immune system of Atlantic halibut (Hippoglossus hippoglossus) using expressed sequence tags (ESTs)

K.C. Park*¹, J.A. Osborne¹, S. Tsoi¹, L.L. Brown¹ and S.C. Johnson¹

¹Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

In our laboratory we are using immunological and molecular techniques to investigate the response of Atlantic halibut to vaccination and pathogen exposure. Partial cDNA sequencing of clones from a cDNA library allows identification of clones that represent expressed genes. These partial sequences are called expressed sequence tags ("ESTs") and they are rapid and effective approach for gene identification. Atlantic halibut were immunized with a commercial injectable vaccine against Vibrio anguillarum and Aeromonas salmonicida. At 2, 7, 14 days post-vaccination, liver, spleen, and kidney tissues of the fish were collected. A combined mRNA pool from these tissues was used for constructing a cDNA library with a titer of 2 x 107 pfu/ul. Two hundred clones were randomly selected to determine insert size. Most of clones (75 %) had the insert size between 600 bp to 1.0 kb and the other 25% had insert size between 1 kb and 2 kb. Five hundred additional clones were randomly selected and are currently being sequenced. To date we have found structural, transport, transcriptional and translational factors, and receptor related genes, as well as genes involved in immune function. We plan to compare this cDNA library against a normalized and full-length library from the same tissues.

Constitutive gene expression in kidney and spleen of Atlantic halibut (Hippoglossus hippoglossus) and haddock (Melanogrammus aeglefinus)

S.A. Sperker*¹, J.A. Osborne¹, L.L. Brown¹ and S.C. Johnson¹

¹Institute for Marine Biosciences, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1

Our laboratory is investigating the ontogeny of the immune systems in haddock and Atlantic halibut and their immune responses to vaccination and pathogen exposure. We are presently developing for these species, a series of probes for a variety of genes known to be important in the immune responses of salmonids. To achieve this we are using reverse transcription-polymerase chain reaction (RT-PCR) and primers from several sources including rainbow trout-specific primers. Using RT-PCR we have demonstrated constitutive expression of two cytokines: transforming growth factor (TGF-ß) in the kidney and spleen of both species and interleukin 1- ß (I- ß) in the kidney and spleen of halibut. The enzyme cyclo-oxygenase (COX-2) that is involved with eicosinoid production is constitutively expressed in haddock and halibut kidney and haddock spleen. Constitutive expression of class II major histocompatibility complex (MHC-II) is present in the kidney and spleen of both species. All of these products have been cloned and sequenced. Using these RT-PCR protocols and probes developed from these clones it is our goal to examine the expression of these genes through development in both haddock and Atlantic halibut, as well as in primary cell cultures exposed to components of Aeromonas salmonicida cell walls.

AP 5: Production of Disease Resistant Transgenic Salmonids Expressing Major Histocompatibility Complex (MHC) Genes at all Temperatures

Temperature dependent expression of Class II major histocompatibility receptors in salmonids

K. Fujiki*¹, B. Cot¹ and B. Dixon¹

¹Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1

Major histocompatibility (MH) receptors initiate immune responses in all vertebrates. Class I MH receptors present peptides from intracellular pathogens, while their Class II counterparts present peptides derived from extracellular pathogens. Common carp (Cyprinus carpio) stop cell surface expression of Class I MH receptors by turning off the gene encoding the small subunit, beta-2-microglobulin, at low temperatures. Low temperature suppression of the response to extracellular pathogens has also been demonstrated in channel catfish (Ictalurus punctatus). Salmonid fishes also become more prone to bacterial diseases at low temperatures. In order to investigate if this is due to a down-regulation of MH receptors, we are producing polyclonal antisera to salmonid MH Class II a and b chains and performing reverse transcriptase-PCR experiments using rainbow trout, (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). To date we have isolated full-length clones of the rainbow trout MH a chain and are characterizing potential full-length b chain clones. We are also currently examining the temperature dependent expression of these genes in RTS-11, a rainbow trout macrophage-like cell line. If salmonids do down-regulate their MH genes at low temperature, we hope to counteract this effect with immunostimulants or by constructing a transgenic fish expressing these genes constitutively.

Temperature and expression of Class I major histocompatibility receptors in Rainbow trout, (Oncorhynchus mykiss)

S. Kales*¹, K. Fujiki¹ and B. Dixon¹

¹Department of Biology, University of Waterloo, ON N2L 3G1

Several investigations into the kinetics of Class I major histocompatibility (MH) assembly using mammalian cell lines suggest that cell-surface display and hence, a proper cellular immune response, require the association of all three molecular components, (heavy chain, beta-2-microglobulin and peptide antigen). A recent study, employing polyclonal antibodies, demonstrates a temperature-dependent regulation of cell-surface expression of Class I MH receptors in the common carp, (Cyprinus carpio) through the severe reduction in beta-2-microglobulin gene transcription at low temperatures. Studies on channel catfish (Ictalurus punctatus) also show a similar effect upon antigen presentation of the humoral response, which typically involves Class II MH receptors. Such results may provide one mechanism for the implied link between low temperature and fish immunosuppression. Current work is underway to develop polyclonal antibodies to recombinant Class I MH receptors in rainbow trout. These antibodies will be employed to investigate temperature-related cell-surface MH Class I expression in trout through antibody-dependent assays. Concurrent reverse transcriptase PCR experiments are also being used to investigate Class I transcript expression at various temperatures. This data will be used to circumvent low-temperature immunosuppression, perhaps through the development of a transgenic animal that incorporates a constitutive gene promoter, thereby improving disease resistance in fish stocks.

MH Class I regulation in the teleosts Salmo salar, Oncorhynchus mykiss and Cyprinus carpio

J.A. Parks*¹, B. Dixon¹ and P.M. Schulte²

¹Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1
²Department of Zoology, University of British Columbia, Vancouver, BC V6T 2Z4

Disease outbreaks are a significant problem for modern aquaculture facilities. Historically, there has been anecdotal evidence that the onset of some diseases is related to changing environmental temperatures. Disease onset at low temperatures may be related to immune suppression in teleost fish, possibly due to down regulation of the major histocompatibility genes (MH). The MH genes are a highly regulated part of the immune system in mammals. Although MH Class I genes have been identified in fish, little is known about their regulation. In order to gain insight into the regulation of the MH genes in fish at low temperature, we are currently characterising the promoter regions of these genes. We have used an inverse PCR strategy to clone and sequence the 5' flanking region of MH Class I genes in the teleosts Salmo salar, Oncorhynchus mykiss and Cyprinus carpio, and are currently developing approaches to characterize their function at low temperatures.

AP 7: Nutritional Value and Clinical Role of Dietary Lipid in Fish

Growth performance and health effects of replacing supplemental anchovy oil in grower diets of Atlantic salmon (Salmo salar)

S. Balfry*¹, N. Richardson¹, S. Lall² and D. Higgs¹

¹West Vancouver Laboratory, Fisheries and Oceans, 4160 Marine Drive, West Vancouver, BC V7V 1N6
2Institute for Marine Biosciences, National Research Council of Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1

There is growing concern in the aquaculture industry about the future availability and price of marine fish oils (MFOs) for aquafeeds. When MFOs are replaced with other lipids, it is essential to supply the optimum level of energy as well as the correct balance of fatty acids to ensure high growth rate without compromising fish health. In this research project, we are studying the effect of partially replacing MFOs with vegetable oils and/or animal lipid. Growth performance, cardiovascular function, eicosanoid production (immunomodulatory lipid mediators), and immune response will be examined.

The feeding trial was performed at the West Vancouver Laboratory, using Atlantic salmon (mean weight 102.3 g). Supplemental anchovy oil was partially replaced with flaxseed oil, sunflower oil, and poultry fat or a blend of each vegetable oil with poultry fat. Eight dietary treatment groups (triplicate groups, n=40) were fed to satiation twice daily for 20 weeks. At the end of this period, various growth performance characteristics were determined from the feed appetite data, feed analysis, fish weights, and tissue samples. Fish health was evaluated from haematological measurements and immune function assays. Preliminary growth performance, haematology, and immunology data will be presented and discussed with respect to the different dietary treatments.

Identification of leucotrienes, hydroxy fatty acids and prostaglandins in haddock and halibut leucocytes

M.S. Izquierdo¹, W.M. Indrasena*^1,2, J.E. Milley² and S.P. Lall^1,2

¹Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
²National Research Council Canada, Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1

Enzymatic conversion of dietary arachidonic acid and eicosapentaenoic acid via lypoxygenase and cyclo-oxygenase pathways results in the formation of biologically active eicosanoids such as prostaglandins, hydroxy fatty acids, leucotrienes and lipoxins. These compounds have multiple physiological and immunological functions in fish. Although many eicosanoids and their metabolites have been found in various tissues of some fish, their presence in haddock and halibut has not been reported. The present work has been carried out to identify eicosanoids in haddock and halibut tissues in order to determine the role of dietary lipids and polyunsaturated fatty acids on the immune response of these fish.

Blood from the caudal vein of haddock and halibut was collected and the leucocytes were isolated using a Percoll gradient. Eicosanoids generated from leucocytes with calcium ionophore were extracted and purified. They were analyzed by high performance liquid chromatography with a UV detector, and identified by comparing the retention times of commercially available standards and then by mass spectrometry. LTB5 and LTB4 were found to be the most abundant eicosanoids generated by both haddock and halibut followed by prostaglandins and hydroxy fatty acids respectively. 11-HETE and 12-HETE were the most common hydroxy fatty acids in both fish. A higher amount of 15-HEPE was found in haddock than halibut whereas halibut had more 15-HETE than haddock. The levels of various eicosanoids determined in these fish will be presented.

AP 8: Optimization of Larval Feeding and Digestion in Atlantic Halibut, Atlantic Cod, Haddock and two small Flounder Species

Early weaning of Atlantic cod larvae (Gadus morhua)

Tarcisio Alves*¹ and Joseph A. Brown¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

Culturing marine fish larvae requires extensive use of live food to produce healthy larvae but the weaning process from live feed to formulated pellets is crucial as it occurs during metamorphosis and is a time of increased mortality. In this study, weaning experiments were conducted with Atlantic cod (Gadus morhua) larvae in an attempt to decrease the timing of weaning while maintaining good growth and survival. Rotifers enriched with Algamac were used from 3 days post hatch (dph) until 25dph. When larvae reached about 8.5mm they were assigned to one of four treatments (3 replicates) in 30 l experimental tanks using Artemia (enriched with Selco or krill protein) for 3, 5, or 10 days and a no Artemia treatment. In the treatment with no Artemia, enriched Rotifers were used for an additional 7 days. Dry feed, ranging from 200 to 300

The development of digestive ability in larvae of haddock (Melanogrammus aeglefinus)

J.C. Perez Casanova*^1,3, H.M. Murray^2,3, N.W. Ross³, S. Douglas³ and S.C. Johnson³

¹Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
²Aquanet, Memorial University of Newfoundland, St. John's, NF A1C 5S7
³Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

The development a nutritionally complete formulated diet for larval haddock would simplify haddock production. Information on the digestive capabilities of larvae is important for the development of such diets. We are using biochemical techniques to determine digestive enzyme activities in whole body extracts. To date we have examined pepsin and trypsin activity from hatch through 45 days post-hatch (DPH). At hatch there are high levels of activity for both of these enzymes. Trypsin activity declined from 4 to 8 DPH, then increased again at 25 DPH. Pepsin activity peaked at 2 DPH then declined until 10 DPH. Pepsin activity increased again starting at 25 DPH. With exception of pepsin activity from 0 to 25 DPH these results compare well with those obtained using RT-PCR and in-situ hybridization techniques (see Murray et al. AquaNet Poster). Using in-situ hybridization techniques pepsin activity has been identified starting at 25 DPH, when the cardiac stomach apparently becomes functional. Earlier pepsin activity in the biochemical samples is likely due to a lack of specificity of the pepsin assay resulting in the measurement of other proteases that function at low pH. We have examined total protease activity from 8-45 DPH. Total protease activity increased through 15 DPH and then declined through 35 DPH. Lipase and alkaline phosphatase activity has been determined through 45 DPH. Activity of both of these enzymes showed increased activity after 30 DPH. We are presently developing primers and probes to confirm the results for our lipase activity using molecular and in-situ techniques.

The development of digestive ability in larvae of haddock (Melanogrammus aeglefinus) and Atlantic cod (Gadus morhua)

H.M. Murray*^1,3, J.C. Perez Casanova^2,3, N.W. Ross³, S.E. Douglas³ and S.C. Johnson³

¹AquaNet, Memorial University of Newfoundland, St. John's, NF A1C 5S7
²Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
³Institute for Marine Biosciences, National Research Council Canada, Halifax, NS B3H 3Z1

The development of a nutritionally complete formulated diet for fish larvae is important for optimum growth and survival. Information on the digestive capabilities of larvae is crucial for the design and development of such diets. In our laboratory we are examining the expression and activity of digestive enzymes in haddock and Atlantic cod larvae from hatch to 45 days post-hatch (dph), using biochemical and molecular techniques. Biochemical assays of larval whole-body homogenates of both species revealed both trypsin and pepsin activity at hatch which increased through development. Our RT-PCR and in situ hybridization studies supported the biochemical results for trypsin but not pepsin. Trypsinogen gene expression was detectable in newly hatched larvae of both species, where it was localized specifically in the hepatopancreas. Later, it became associated with more diffuse pancreatic tissue. Pepsinogen gene expression in both species was detectable by in situ hybridization at 30 dph and was localized within the gastric glands. This observation corresponded well to the histological appearance of the gastric glands in both species. The discrepancy between the biochemical and molecular studies with respect to the appearance of pepsin activity is likely due to the lack of specificity of the biochemical assay for pepsin, which results in the measurement of other proteases that work under acidic conditions. This discrepancy highlights the importance of using both biochemical and molecular techniques in parallel when studying the digestive capacity of animals.

Cannibalism in juvenile Atlantic cod (Gadus morhua)

K.M. Smith*¹ and J.A. Brown¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 1N2

Cannibalism has been reported in an increasing number of fish species, many of which are important for aquaculture. Cannibalism in Atlantic cod has been demonstrated to have a significant impact on juvenile production. Previously it has been found that size variation, food type and density influence the rate and extent of cannibalism. We set up experiments to expand on previous studies examining the effects of size variation, food type and density on the incidence of cannibalism in juvenile Atlantic cod. Cannibalistic behaviour was examined, focusing on the modes of prey capture and ingestion. Protocols for mitigating cannibalism by the adjustment of favorable conditions will be presented.

Digestive capability with diet type in Atlantic cod larvae

K. O'Brien-MacDonald*¹ and J.A. Brown¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

A major bottleneck in the mass production of cod (Gadus morhua) is the high mortality associated with the larval period, where starvation is a major factor. This is generally assumed to be due to problems related to feeding, digestion, nutrition, bacterial loading, or some combination of these factors. Foraging models predict success for fish based on contact with appropriate food at critical points in the life cycle. One examination of this is the hypothesis, which suggests that the degree of overlap between larval fish and their prey affects larval growth, survival, and recruitment (Cushing, 1990). Potentially important, yet neglected, components of prey selection are the nutritional quality of the food, and the ontogenetic shifts in food preference displayed by the larvae. Recent experiments have shown that the importance of food to the growth and survival of cod varies through ontogeny, with older larvae being more vulnerable to mismatches with food than young larvae (Gotceitas et al., 1996). However, comprehensive information on young fish is rare because of the difficulty with culturing and experimenting on the small delicate larvae. We propose to investigate the survival, growth, foraging behaviour, functional development of feeding, and onset of digestive enzyme activity in cod larvae in response to exposure to different enrichment formulations and prey types.

Optimisation of nutrition in winter flounder larvae (Pleuronectes americanus)

R. Vaillancourt*¹, C. Audet¹ and J.A. Brown²

¹Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, Rimouski, QC G5L 3A1
²Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

A major bottleneck in the mass production of winter flounder is the high mortality associated with the larval period. In order to find innovative solutions to address this problem, we proposed to investigate the development of winter flounder larvae fed different diets and prey types using ecological, biological, and biochemical variables. In 2001, we had three research goals: 1. To investigate the influence of different enrichment formulations for Brachionus plicatilis mass production on the functional feeding of winter flounder larvae, including histoenzymatic and molecular studies (with NRC-IMB); 2. To isolate and culture an indigenous zooplanctonic prey (Synchaeta sp.) naturally adapted to cold water which could offer better nutritional quality to winter flounder larvae at first feeding; 3. To establish conditions for Synchaeta mass production. Next year, we plan to compare first feeding with Synchaeta and Brachionus to determine if Synchaeta inclusion into larval diets will improve larval growth and hardiness and study how this could be achieved in terms of larval biology. Experiments related to objectives 2001-1 and 2001-2 are now completed and preliminary results will be presented. Objective 3 is in progress and will be completed in November so only the experimental approach will be presented.

AP 10: Aquaculture Broodstock and Seed Production: Production of the Next Generation of Genetic Markers

Gene mapping in Arctic charr, rainbow trout and Atlantic salmon

Karim Gharbi*¹, Rachael A. Woram¹, Moira M. Ferguson¹, William S. Davidson² and Roy G. Danzmann¹

¹Department of Zoology, University of Guelph, Guelph, ON N1G 2W1
²Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6

Genetic maps provide the basis for further investigations into genome biology, including analysis of transmission genetics, dissection of quantitative traits and study of chromosomal evolution. Potential benefits for aquaculture species include the production of commercial strains with optimal performance characteristics through marker-assisted selection. In a collaborative effort with other groups in North America, Europe (SALMAP) and Japan, we have embarked upon mapping the genome of various salmonid species with special emphasis on rainbow trout, Atlantic salmon and Arctic charr. Primary linkage maps have been constructed in each species using outbred pedigrees and anonymous DNA markers. Although our initial efforts focused on simple sequence repeats (SSRs), the recent addition of amplified fragment length polymorphism (AFLP) markers resulted in a significant increase in map density (over 500 markers in rainbow trout and Atlantic salmon and 250 in Artic charr). The current maps are based on sex-specific analysis of linkage data to account for the dramatic differences in gene transmission between male and female in salmonid species. While the male maps only contain information on the linear arrangement of genetic markers, we are using half-tetrad analysis to localize centromeres onto the female maps, thus relating the structure of linkage groups to the physical morphology of chromosomes. Although incomplete, the resulting maps have been successfully utilized to assess sex-specific differences in recombination rates, identify quantitative trait loci (QTL) and reveal chromosome divergence between species. Genes with known function (type I markers) are progressively incorporated into the framework maps as expressed sequence tags (ESTs) are accumulated from the EU-funded SALGENE project. Research supported by NSERC (Genomics and Strategic Grant Program) and AquaNet



Genomic organization of Hox genes in Rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar)

H.K. Moghadam*¹, M.M. Ferguson¹ and R.G. Danzmann¹

¹Department of Zoology, University of Guelph, Guelph, ON N1G 2W1

Hox genes specify the fate of cells in the anterior-posterior axis of animal embryos. They display striking evolutionary conservation of structure and expression. Invertebrates have a single Hox cluster whereas tetrapods possess four, suggesting a cluster duplication which facilitated the evolution of vertebrate body plans. Zebrafish and Medaka possess at least seven clusters, indicating a further duplication in the ancestor of teleosts. Salmonids experienced an additional polyploidization event, which suggests that sixteen Hox clusters may exist in salmonids.

Our research aims at mapping Hox genes within their linkage groups, in Rainbow trout (four backcross families) and Atlantic salmon (two outcross families). Gene specific primers were designed by aligning orthologous genes from various species and identifying the consensus blocks. Hox genes will be mapped by screening PCR products for SNP, using restriction enzymes, heteroduplex analysis or SSCP. To date, seven genes from clusters A and B have been amplified and partially sequenced. They show the highest homology with those of Medaka.

Identification and localization of the Hox genes will help us to refine the current linkage map and provide insights into the homeologous linkage groups in salmonids. It will also help to assess the degree of synteny among Hox gene clusters in the vertebrates.

The Structure, Sequence and Evolution of Salmonid Genes

Amit K. Goel*¹, Colin McGowan¹, Roy G. Danzman², Moira M. Ferguson² and William S. Davidson¹

¹Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6
²Department of Zoology, University of Guelph, Guelph, ON N1G 1V4

Because of their vast demand and aquaculture potential Salmonid fish species (salmon, trout and char), are of great economic importance. They are also of scientific interest, having evolved from a common tetraploid ancestor as a result of a gene duplication event that took place about 25- 100 million years ago. A broader understanding of salmonid evolution might be achieved by comparing differences in the evolutionary rates of the coding and non-coding regions of genes. Comparison of introns in a single gene/ several genes of related species (such as Atlantic salmon and rainbow trout) may be helpful in understanding the short-term dynamics of intron evolution and gene organization.

Until recently, most studies have focused on the coding regions of genomes. Few data are available regarding nucleotide substitution in introns that might throw light on molecular evolution in salmonids. Few studies have compared the rates of nucleotide substitution for introns and exons in many genes in a pair of closely related species. Such studies will require the sequencing of large numbers of introns and exons. To accomplish this, PCR primers can be designed to complement the highly conserved coding regions (exons), which flank the more variable introns regions. Being primed in conserved coding regions these primers can be applied to a range of species including higher vertebrates. Our goal is to develop molecular primers, using sequences for genes of known protein functions that have already been entered into the Genbank database, which can be used universally on salmonids and other fish species.

To date, in Atlantic salmon (Salmo salar) and Rainbow trout (Oncorhynchus mykiss), more than 30 different introns have been successfully amplified from 15 different genes. Comparisons for 13 introns from 6 genes, in two species are presented here.

The development of conserved genetic markers for genes of known function in salmonid fish species

Colin McGowan*¹, Evelyn A. Davidson¹, Roy G. Danzman², Moira M. Ferguson² and William S. Davidson¹

¹Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC
²Department of Zoology, University of Guelph, Guelph, ON

Fish represent the most primitive class of vertebrates, and have served as simple models for the investigation of genetic disorders, vertebrate development and genome structure. Salmonid species (salmon, trout and char) are of economic importance as part of the growing worldwide aquaculture industry. They are also of scientific interest having evolved from a common tetraploid ancestor, the result of a gene duplication event 25 - 100 million years ago. They are believed to be undergoing a process of diploidization, as homeologous chromosomes diverge from one another. Chromosomal rearrangements, such as centric fusions and pericentric inversions, have resulted in highly divergent karyotypes. A broader understanding of this evolutionary process will be achieved through comparative genome mapping within this group of fish.

Making comparisons between the linkage maps of different species will require conserved, non-ambiguous genetic markers that are associated with genes of known function. Such markers will permit the identification of linkage conservation between the genomes of salmonid species as well as the genomes of other fish species and higher vertebrates. Our goal is to develop genetic markers using sequences for genes of known protein function that have been entered into the Genbank data base. The approach we have taken is to identify conserved regions in the exons of genes by aligning a salmonid sequence with homologous sequence from several other species. Universal primer pairs are designed to anneal in these conserved regions and amplify putative introns using PCR. Once the PCR product has been confirmed as the target sequence, polymorphisms, which can be used in linkage studies, are detected using SSCP or heteroduplex analysis. In some cases, microsatellite DNA discovered within the intron can be used as a polymorphic marker.

To date, 24 different introns have been successfully amplified from 11 different genes. Many of the genes we are looking at may have some influence over quantitative traits, such as growth (growth hormone) or disease resistance (lysozyme), which are of economic importance to the aquaculture industry. Markers for some of these genes may provide important quantitative trait loci which can be used in selective breeding programs in addition to comparative mapping projects.

Supported by an NSERC strategic grant and AquaNet.

AP 11: Production of Single-Sex (All-female) Populations of Fish for Aquaculture

Effects of rearing temperature and the role of aromatase in sexual differentiation in Atlantic halibut (Hippoglossus hippoglossus)

V. Eborall*^1,2, T.J. Benfey¹, D.J. Martin-Robichaud² and M.E. Reith³

¹Department of Biology, University of New Brunswick, Fredericton, NB E3B 6E1
²DFO Biological Station, 531 Brandy Cove Road, St. Andrews, NB E5B 2L9
³NRC - Institute of Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1

As with many species of fish, the females and males of Atlantic halibut (Hippoglossus hippoglossus) mature at different sizes. A potential problem for the farmed production of this species is males reaching sexual maturity, with a consequent slowing of growth, before reaching market size. The production of all female broods of halibut is therefore desirable. It is now well established that sex determination in some fish species depends, in addition to genetics, on external factors, including temperature. This is likely due to interaction between temperature and the expression of aromatase, a steroidogenic enzyme responsible for the conversion of androgens to oestrogens. It is thought that the oestradiol-17ß produced by the action of aromatase is essential for ovarian development. It is therefore proposed to rear juvenile halibut at different temperatures and examine aromatase activity in the brain and developing gonads and relate this to sex ratios. To further investigate the role of aromatase in sexual differentiation, experiments will be done where fish will be treated with known aromatase inhibitors and sex ratios examined. In addition to providing basic information on sexual differentiation, this research is aimed at developing effective methods for the production of all female halibut populations for aquaculture.


Sex control in sturgeon

S. Flynn*¹, T. Benfey¹, M. Matsuoka², M. Reith² and D. Martin Robichaud³

¹Department of Biology, University of New Brunswick, Bag Service 45111, Fredericton, NB E3B 6E1
²NRC - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1
³Fisheries and Oceans Canada, 531 Brandy Cove Road, St Andrews, NB E5B 2L9

The sex ratio of sturgeon is 1:1 but male and female fish can not be distinguished externally. Sturgeon growers attempting to produce high value caviar expend considerable resources raising less valuable males. The goal of this research is to better understand the sex determining mechanisms, the process of gonadal differentiation and develop methods for the production of all female populations. The initial focus is on the production of diploid gynogens. These are fish which inherit only maternal genes and are produced by inactivating the paternal genome and duplicating the maternal genome. To achieve this milt was exposed to different dosages of UV radiation to determine the maximum dosage that could be sustained without affecting the ability of the spermatozoa to penetrate the oocyte and activate development. Hydrostatic pressure treatment was used to retain the haploid second polar body, normally extruded from the oocyte after activation. Based on microsatellite analysis using loci developed for other sturgeon species, diploid gynogens have apparently been created in one stock of shortnose sturgeon, but duplicate experiments in a second stock have yeilded less promising results. Diploid gynogens will be reared to determine sex ratios using histology, and will possibly be incorporated into commercial breeding programs.


Characterization and expression of P450 aromatase and 11ß-hydroxylase in Atlantic halibut (Hippoglossus hippoglossus) during early development

M. Matsuoka*^1,2, J. Munholland², T. Benfey¹ and M. Reith²

¹Department of Biology, University of New Brunswick, NB
²National Research Council, Institute for Marine Biosciences, Halifax, NS

Atlantic halibut is a promising species for aquaculture in Atlantic Canada. Because females grow faster than males, it would be advantageous for industry to be able to select, or exclusively produce, females. Understanding the timing and mechanism of sex determination and/or sex differentiation will provide information essential to manipulating the sex. Two enzymes, P450 aromatase and 11ß-hydroxytestosterone (which is then converted to 11-ketoteststerone, the final product of androgen pathway, by 11ß-hydrosteroid dehydrogenase), also from testosterone. The main goals of this project are to measure levels of mRNA transcription of these two enzymes and the activity of P450 aromatase at various stages of sex differentiation, and to develop an understanding of the sex determination mechanism of Atlantic halibut at the molecular level. In this poster, we present partial sequence of P450 aromatase mRNA and preliminary results of P450 aromatase transcription level at stages of sex differentiation using RT-PCR. We will also describe our plans for the isolation of 11ß- hydroxylase cDNA and investigating its expression.

AP 13: Optimizing Metabolic Design for Growth of Fishes at Low Temperature

Investigations into the overwintering metabolic organization of the Atlantic cod (Gadus morhua) and the winter flounder (Pleuronectes americanus)

J.D. Bondy*¹, A. Rosenberger¹ and J.S. Ballantyne¹

¹The University of Guelph, Department of Zoology, Guelph, ON N1G 1V4

Cold water induced metabolic depression in fish is a significant economic concern to the Canadian aquaculture industry since fish exposed to cold water have a reduced growth rate. To establish the biochemical basis for this, we examined the overwintering metabolic organization of the Atlantic cod and winter flounder using measurements of enzyme activities, isolated liver mitochondria, and plasma metabolites. Wild caught winter flounder and reared Atlantic cod were kept either at a constant temperature of 10°C or at temperatures that fluctuated with the ambient north Atlantic sea water. The fish were then sampled after 4 months when the temperature difference between the two groups was the greatest (2°C vs 10°C). The liver mitochondrial proton leak revealed a slower leak for each species at lower temperature, however, no significant difference was found in the proton leak between the control and experimental fish. The mean total plasma nonesterified fatty acid (NEFA) concentrations were higher in both the experimental (1447.9±418.9) and control cod (1760.9±355.8) than either the control (667.4±118.2) or experimental (914.3±164.2) flounder groups. This indicates that the dormant state observed in the flounder could be characterised by a reduction in certain plasma metabolites.

Effects of seasonal temperature on carbohydrate metabolism of the cod (Gadus morhua) and the winter flounder (Pseudopleuronectes americanus)

H. Levesque*¹ and T.W. Moon¹

¹University of Ottawa, Ottawa, ON K1N 5N6

The partitioning of metabolic resources is critical to the maintenance of growth in fish at low temperatures. To better understand this process, we have studied carbohydrate metabolism in a winter active species, the cod, and an in-active species, the winter flounder.

Fish were captured on the Newfoundland coast and each species was divided into two groups. One group was held at a stable temperature (9°C) whereas the other group was subjected to the variations of the natural temperature (from 0.3°C to 9°C). Ten fish of each group were sampled every two months to characterize seasonal changes in carbohydrate metabolism.

The activities of gluconeogenic (PEPCK, GOT, GTP, GDH, MDH, ME) and glycolytic (LDH, PK) enzymes were higher in the liver and muscle of cod, compared with winter flounder. Preliminary analyses also show that the activity of these enzymes are lower in the muscle and liver of winter flounder sampled in May, before the temperature increases of spring, compared with the reference groups and other ambient fish groups. Concentrations of plasma glucose and lactate decrease and concentrations of liver glycogen increase with lower temperatures for cod.

These preliminary results allow a better understanding of the metabolic adaptations occurring over the winter in the muscle and the liver of cod and winter flounder.

AP 14: Improved Freeze and Stress Resistance with Glycerol

Seasonal production of glycerol as an antifreeze in Rainbow smelt (Osmerus mordax) is not regulated by maximal activity levels of liver transaminases, PEPCK or G3PDH

J.M. Lewis*¹, K.V. Ewart² and W.R. Driedzic¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7
²NRC - Institute for Marine Biosciences, Halifax, NS B3H 3Z1

Rainbow Smelt (Osmerus mordax) accumulate high levels of glycerol in their blood where it acts as an antifreeze. Our long-term objectives are to understand the regulation of this process, to induce glycerol production in aquacultured species in order to prevent deaths from superchill and further extend the industry. A seasonal study on the effect of temperature on glycerol production was carried out from October 2000 to May 2001. Animals were allowed to track ambient temperature or were maintained at 8-10^oC. Glycerol production begins when the water temperature decreases to 5-6^oC. The concentration of glycerol in the blood is dependant upon temperature, with levels reaching 250-350 mM in smelt held at -1^oC. In the spring, glycerol levels subsequently decrease in association with longer photoperiod, even in animals maintained at low temperatures. As glycerol is produced in the liver, primarily from amino acids, the activity of a number of key enzymes (aspartate aminotransferase, alanine aminotransferase, phosphoenolpyruvate carboxykinase and glycerol-3-phosphate dehydrogenase) was monitored. There was no difference in the activity of these enzymes between animals producing glycerol and those animals that do not. As such, glycerol production in Osmerus mordax is not regulated by the maximal enzyme activity at these particular loci.

AP 15: Transgenic Fish with Improved Freeze Resistance by Antifreeze Gene Transfer

Expression of the ocean pout antifreeze gene in transgenic Atlantic salmon

R.S. Hobbs*¹ and G.L. Fletcher¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

The development of freeze resistant salmon would extend the range of salmon sea-pen aquaculture in Atlantic Canada. Previous attempts at producing freeze resistant transgenic salmon by introducing the type I antifreeze protein (AFP) gene from winter flounder have yielded much optimism. The AFP activity in the resulting transgenic salmon, however, was too low to confer freeze resistance to the fish. One possible reason for this may be due to the lack of an enzyme in salmon necessary to cleave the proAFP form of the type I AFP to produce the fully active mature protein. As an alternative, the gene encoding a type III AFP from ocean pout is being examined for the production of freeze resistance in salmon. The ocean pout AFP lacks the pro-sequence and is therefore fully active post-translationally and is constantly expressed in a variety of tissues. The ocean pout AFP gene was previously introduced into Atlantic salmon and shown to be stably inherited. The level and tissue specific expression of the ocean pout AFP gene in transgenic Atlantic salmon will be examined and compared to the expression of the same gene in the ocean pout.

Transgenic fish with improved freeze resistance by antifreeze gene transfer

S.P. Walker¹, S.Y. Gauthier*2, L.A. Graham², P.L. Davies² and G.L. Fletcher<sup>1

1</sup>Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7
²Department of Biochemistry, Queen's University, Kingston, ON K7L 3N6

The overall aim of the project is the production of freeze-resistant strains of Atlantic salmon via antifreeze protein (AFP) gene transfer. This would extend the range of salmon sea pen aquaculture in Atlantic Canada. A liver specific winter flounder AFP gene has previously been introduced into salmon. Although the transgene was shown to be successfully expressed, the resulting AFP levels were low. Since these initial studies the expression of AFP genes in peripheral tissues such as skin and gills, in addition to production in the liver for excretion into the blood, have been shown to be important in conferring freeze resistance in fish. In order to improve the performance of transgenic salmon containing AFP genes several strategies will be used. These include: the use of alternative genes fish AFP genes; increasing expression levels by increasing the gene dosage; and targeting appropriate tissue distribution of AFP production. The recently characterized insect AFPs from beetles and spruce budworm are between 10 and 100 times more active than fish AFPs. The activity and clearance characteristics of the insect proteins will be evaluated in fish. The insect AFP genes will be isolated and characterized and used for gene transfer experiments in salmon. Supported by AquaNet.

AP 16: Production of Transgenic Tilapia for the Treatment of Diabetes: ES-cell Approach


The development of a tilapia (Oreochromis niloticus) embryonic stem cell line


S. Danielle MacNeil*¹, Xiaoli Lu², Bill Pohajdak³ and James R. Wright Jr.<sup>1,2

1</sup>Dalhousie University, Department of Pathology, Halifax, NS B3H 4H7
²IWK Health Centre, Department of Pathology, 5850 University Avenue, Halifax, NS B3J 3G9
³Dalhousie University, Department of Biology, Halifax, NS B3H 4J1

Embryonic stem (ES) cell lines can be used to generate targeted gene mutations and germ-line chimeras. In our lab we have produced transgenic tilapia expressing a humanized tilapia insulin gene. We plan to transplant pancreatic islets from homozygous transgenic tilapia donors into patients with type I diabetes mellitus. In this study, our goal is to develop tilapia ES cell lines which can be used to generate homologous recombinants for the humanized tilapia insulin gene.

A tilapia ES-like cell line was generated by isolating blastoderms from blastula stage embryos and culturing them on a salmon fibroblastic cell line. Tilapia ES-like cells exhibit morphological characteristics of mammalian ES cell lines. The cells are small, round and grow in dense clusters. To confirm pluripotency, the cells will be treated with various growth factors to induce differentiation. Tilapia ES-like cells will also be tested for endogenous alkaline phosphatase activity and karyotyped. Growth analysis will also be performed.

The development of a tilapia ES cell line could have a significant impact on the tilapia aquaculture industry. When our methodology is fully developed, it should be possible to use it as a template for the generation of targeted gene mutations in other commercially important species.


The development of a synthetic ligand to tilapia (Oreochromis niloticus) insulin

Jaime Snowdon*¹, Bill Pohajdak, PhD², Kent C. Dooley, PhD¹ and James R. Wright Jr., MD, PhD^1,3

¹Department of Pathology and Laboratory Medicine, IWK Health Centre, 5850 University Avenue, Halifax, NS B3H 1V7
²Department of Biology, Dalhousie University, Halifax, NS B3H 4J1
³Departments of Surgery and Biomedical Engineering, Dalhousie University, Halifax, NS B3H 4H7

Our laboratory transplants tilapia islets as a treatment for experimental diabetes and has generated transgenic tilapia expressing a "humanized" tilapia insulin gene for possible future clinical application. Our ultimate goal is to knockout the native tilapia insulin gene in our transgenic fish. To detect human insulin, we use a radioimmunoassay which does not cross-react with tilapia insulin. However, we need an assay that is specific for tilapia insulin. Our approach is to develop synthetic aptamers, which are nucleic acids that bind molecules with high affinity and specificity.

Method: A library of oligonucleotides, each with an internal 75 base pair random sequence, is being custom synthesized. The library will be amplified by polymerase chain reaction (PCR) and the double strands will be separated. A synthetic peptide corresponding to the predicted antigenic region of tilapia insulin will be adsorbed to nitrocellulose membrane and incubated with the single-stranded oligonucleotides. The unbound oligonucleotides will be washed and the bound oligonucleotides will be eluted and PCR-amplified. The selection process will be repeated with purified tilapia insulin. The final product will be labeled and used to detect the presence and quantity of tilapia insulin in our transgenic fish.

AP 17: Genetic and Environmental Factors Affecting Growth and Production of Mussels (Mytilus edulis and M. trossulus)

Genetic and environmental factors affecting growth and production of mussels (Mytilus edulis and M. trossulus)

Marcelo Miranda*¹, David Innes¹, Raymond Thompson² and Cyr Couturier³

¹Department of Biology, Memorial University of Newfoundland, St. John's, NF A1C 3X9
²Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7
³School of Fisheries, Marine Institute, Memorial University of Newfoundland, St. John's, NF

Blue mussels are important for aquaculture in Atlantic Canada, where it has only recently been discovered that two species (Mytilus edulis and M. trossulus) coexist. Studies on the distribution, ecology and performance of the two species have been hampered by difficulties in distinguishing them, since they are morphologically very similar. A major concern to the mussel industry is the relative performance of the two species at different sites. Despite the absence of sufficient experimental data, there is the perception that M. trossulus is less desirable for aquaculture. The present research uses a combination of reciprocal transplant experiments between different aquaculture sites and grow out of laboratory generated spat of known parentage to investigate the genetic (within and between species) and environmental (between aquaculture sites) factors affecting growth and survival. Preliminary results show that Mytilus trossulus and hybrids occur at a higher frequency in the smaller size classes and M. edulis dominates the larger size classes. This pattern suggests that M. trossulus in these areas may have a higher mortality rate or a shorter life span than M. edulis.

AP 18: Factors, Risks and Significance of Emergent Neoplasia Diseases in Cultured and Wild Soft-Shell Clams (Mya arenaria) in Atlantic Canada

Factors, risks and significance of emergent neoplasia diseases in cultured and wild soft-shell clams (Mya arenaria) in Atlantic Canada

Gregory S. MacCallum*¹, Sharon E. McGladdery², Jeffery T. Davidson¹, Garth Arsenault¹ and Michelle Maillet²

¹Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PEI, C1A 4P3
²Department of Fisheries and Oceans Canada, Gulf Fisheries Centre, 343 University Avenue, PO Box 5030, Moncton, NB E1C 9B6

In 1999, mortalities of soft-shell clams (Mya arenaria) caused by or associated with haemic neoplasia occurred at several sites around Prince Edward Island and in Richibucto, NB. Haemic neoplasia has been well documented in bivalves (clams, mussels and oysters) worldwide since the early 1970's. The causes of haemic neoplasia is/are unknown. They have been linked to infectious triggers (neoplastic cells per se or a viral vector), anthropogenic carcinogens (e.g. polychlorinated biphenyls) and changing natural conditions (e.g. abnormally high water temperatures). The most urgent question, from an environmental and clam production perspective, is whether the neoplasia is infective or non-infective.

The objectives of this study are to: i) examine the transmissibility of this disease; ii) determine the geographic and seasonal distribution of haemic neoplasia in soft-shell clams from PEI (including a study to relate disease prevalence to five PEI clam populations); iii) examine common environmental variables between affected and unaffected sites on PEI, NS, and NS (e.g. temperature, bottom-type, terrestrial run-off, human activities/input); iv) determine whether or not sediment exposure affects emergence of haemic neoplasia; and v) determine whether or not clams which have survived haemic neoplasia have developed a resistance to the disease which can be passed onto their offspring.

AP 19: Immunological Response in Atlantic Salmon, and the Identification of Molecular Markers Associated with an Efficient Immune System

Susceptibility and immunological response of Atlantic salmon (Salmo salar) to cryptobiosis

A. Chin*¹, P.T.K. Woo¹ and B. Glebe²

¹Department of Zoology, University of Guelph, Guelph, ON N1G 2W1
²Huntsman Marine Science Center, St. Andrews, NB

Three families (A, B, and C) of Atlantic salmon were assessed to determine their susceptibility to cryptobiosis, a disease caused by the blood hemoflagellate, Cryptobia salmositica. Each family was divided into three groups: (i)Vaccinated (innoculated with attenuated C. salmositica), (ii)Vaccinated and challenged with the pathogen 4 weeks later, and (iii)Unvaccinated and infected with the pathogen. Parasitaemias in fish peaked between 3 and 4 weeks post-innoculation with either vaccine or pathogen. The peak was significantly higher (p<0.05) in group (iii) than vaccinated groups (i and ii) in all three families. Vaccination protected all three families from high parasitaemias. Family B had a significantly lower peak than Families A and C. Family C had a significantly higher peak than Family B only in unvaccinated group (iii). This variation in parasitaemia, humoral response, and cell-mediated response (the latter two will be determined using ELISA and respiratory burst assay respectively) between families provide insight into their immune system. The data, along with those from other families, will be used to find molecular-markers associated with 'good' immune response. 'Good' responders will be used in breeding programs for the Atlantic Salmon Federation.

AP 20: Development of Winter Flounder and Other Flatfish for Land-based and Inter-Tidal Aquaculture

Development of cage systems for on-growing of winter flounder (Pseudopleuronectes americanus) juveniles for culture in inter-tidal impoundments

M. Kirkpatrick*¹ and M.K. Litvak¹

¹Department of Biology, University of New Brunswick, P.O. Box 5050, Saint John, NB E2L 4L5

Winter flounder is an ideal candidate for culture in the cooler waters of the Atlantic coast. It is extremely hardy; it is eurythermal, euryhaline and possesses anti-freeze proteins, which makes it tolerant of inshore environment conditions. However, we do not know what type of system we can grow these fish in from the perspectives of maximizing growth and survival and making it financially reasonable for the culturist. To that end we are testing a variety of cage systems in situ for the on-growing of winter flounder. We will be using a multi-factor repeated measures design to determine the effect of cage type (materials, shapes, and depths...) and density on growth and survival of winter flounder juveniles. The experiment will start at the end of this summer and continue through to next year. With a longer term experiment we will also be able to determine the "behaviour" of winter flounder under conditions that will be used by industry.



Effects of yolk-sac volume and lipid content manipulation on eggs and larvae of winter flounder (Pseudopleuronectes americanus)

D.A. Jardine*¹ and M.K. Litvak¹

¹Department of Biology and Centre for Coastal Studies and Aquaculture, University of New Brunswick, Saint John, NB E2L 4L5

Most species of fish lay eggs that contain a yolk-sac which provides the nutrients and energy required by developing embryos for growth and survival. Yolk-sac volume varies considerably within and among species of fish. The volume may also differ among eggs of the same female depending on her genetic strain, age, size, and time of spawning. Researchers believe that yolk-sac volume is related to offspring survival and performance. However, experimental results have been variable, mainly due to poorly controlled experiments. I will develop a procedure that directly alters the yolk-sac volume of eggs within a single spawn of one female. Using this methodology, it will be possible to determine how yolk-sac volume affects survival and performance, independent of age, size, time of spawning and genetic strain effects. The methodology will be applied to eggs of winter flounder (a possible new aquaculture species in Atlantic Canada). Winter flounder eggs also possess a lipid globule within their yolk-sac that is used for energy and growth. I will use the methods developed above to remove the lipid globule from winter flounder eggs and examine how this affects development, survival and performance characteristics. Finally, highly unsaturated fatty acids (HUFAs) are now known to be essential for development of marine fish embryos, as marine fish cannot synthesize their own HUFAs. I will alter the fatty acid profile of winter flounder eggs by injection of docosahexanoic acid (DHA) (22:6n-3) and thus examine how DHA affects development, survival, and performance characteristics within this species. This research will solve several of the current paradoxes associated with the early life history of marine fish. The results obtained from these experiments will also be used to develop more effective larvi-culture techniques for winter flounder and could also be applied to other species.

Developing semen cryopreservation protocol for winter flounder, Pleuronectes americanus

Rick M. Rideout*^1,2, Matthew K. Litvak¹ and Edward A. Trippel²

¹Department of Biology and Centre for Coastal Studies and Aquaculture, University of New Brunswick, Saint John, NB E2L 4L5
²Department of Fisheries and Oceans, Biological Station, St. Andrews, NB E5B 2L9

Various existing fish semen cryopreservation protocol are being tested on winter flounder to determine the most effective means of cryogenically storing semen. Cryopreservation trials existed of a factorial design with three cryoprotectant chemicals (dimethyl sulphoxide, propylene glycol, and glycerol) crossed with two sperm extender solutions (A: sucrose, KHCO3, reduced glutathione, B: NaCl, KCl, Na2HPO4·7H2O). Freezing technique is being assessed by frozen-thawed sperm motility and fertilization rate. Presently, spawning in female winter flounder can be delayed several weeks via temperature manipulation but males are less susceptible to temperature-induced spawning delays. The development of semen cryopreservation protocol would allow the year-round availability of male gametes and would reduce the need to maintain large numbers of male fish in captivity.

AP 21: An Evaluation of Current and New Diagnostic Tests for Infectious Salmon Anemia Virus

Results from a preliminary study of the prevalence of Infectious Salmon Anemia Virus in farmed Atlantic salmon in New Brunswick

C. McClure*¹, L. Hammell¹, I. Dohoo¹ and L. Hawkins²

1Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI C1A 4P3
²Maritime Veterinary Services, St. George, NB E5C 3A5

Infectious Salmon Anemia (ISA) virus has been causing disease in New Brunswick Atlantic salmon farms since 1996. Industry control programs dictate early slaughter of all fish in an ill cage to prevent the virus from spreading. Evaluation of the success of this control measure requires knowledge of the virus prevalence within the sick cage and in surrounding cages.

The objective of this study is to compare the viral prevalence in cages that are clinically ill with healthy cages from the same farm and from neighboring farms. This case-control study used six ISA positive cages, six on-site control cages (ISA negative cages from positive farms), and five off-site control cages (ISA negative cages from the neighboring negative farm). Using an RT-PCR diagnostic test, the prevalences for the case cages, on-site control cages, and off-site control cages are 0.29, 0.22, and 0.04 respectively. Prevalences of case and on-site controls were not significantly different from each other, but were both significantly different the off-site control (p<0.02).

Early harvest of clinically ill cages will remove one source of virus, but on-site cages also have an elevated level of ISA virus that can potentially spread to other sites. Ongoing research includes increased number of cages sampled for a more accurate estimation of ISA prevalence and an evaluation of the risk factors that contribute to ISA infection.


Evaluation of diagnostic screening tests for Infectious Salmon Anaemia (ISA)

Pascale Nérette*¹, Larry. Hammell¹, Ian R. Dohoo¹ and Carol A. McClure¹

¹Department of Health Management, Atlantic Veterinary College, 550 University Avenue, Charlottetown, PEI C1A 7J7

Infectious Salmon Anaemia (ISA) is a disease of significant economic importance first diagnosed in New Brunswick in 1996. Current regulatory controls involve detection of disease in an ISA surveillance program followed by depopulation of all confirmed positive cages.

Current screening tests used include virus isolation, reverse transcriptase polymerase chain reaction (RT-PCR) and indirect fluorescent antibody test (IFAT). However little is known about the operating characteristics (sensitivity and specificity) or reproducibility and repeatability of these tests when used in a surveillance program on fish that are not clinically ill.

The overall objective of this study is to determine the operating characteristics of current and recently developed diagnostic tests for ISA virus infection. Tests to be evaluated include virus isolation (on SHK and CHSE-214 cell lines), RT-PCR, IFAT and a recently developed antibody ELISA. Unfortunately no reliable "gold standard diagnostic test" is available so a statistical procedure that can estimate the sensitivity and specificity in the absence of a gold standard will be used. Tests will be carried out in multiple laboratories on samples derived from Atlantic salmon from three populations of fish expected to have high, moderate and zero prevalence of infection.

AP 22: Impacts of Sea Ducks on Mussel Aquaculture Operations in Prince Edward Island

Predation by diving ducks at mussel culture sites in P.E.I.: Quantification of effects and development of mitigative techniques.

M. Dionne*^1,2, J.-S. Lauzon*², D.J. Hamilton^1,2, M.A. Barbeau², A.W. Diamond¹ and G.J. Robertson³

¹Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, Bag Service 45111, Fredericton, NB E3B 6E1
²Department of Biology, University of New Brunswick, Bag Service 45111, Fredericton, NB E3B 6E1
³Canadian Wildlife Service, 6 Bruce Street, Mount Pearl, NF A1N 4T3

Blue mussel cultivation on Prince Edward Island contributes $35 to 40 million to the island economy and employs roughly 1500 people (1999 figures). However, in recent years predation by diving ducks (Greater Scaup and Long-Tailed Ducks) has become problematic for mussel growers, costing the industry $1-2 million annually. Using a series of manipulative experiments and behavioural observations, combined with stage-based matrix modeling of results, we will attempt to assess the extent of the problem and develop non-disruptive (for ducks) ways to mitigate it. Specifically, we will grow mussels using a variety of seeding densities, seeding sizes, and socking materials, and with ducks present versus excluded. Mussel growth and survival will be monitored regularly. Feeding behaviour of ducks and prey size preferences will be quantified using focal animal and scan sampling, underwater videography, sampling of duck stomach contents, and monitoring of marked mussels. Particular questions of interest include the extent to which birds feed at night, preferred prey sizes, whether ducks also shake mussels off the socks, and the response of mussels to different rearing conditions. Results will provide mussel farmers with strategies for dealing with the duck problem, and increase the likelihood that ducks and mussel farms can peacefully coexist on PEI.

AP 23: Supplemental Algal Feeding for Field-based Oyster Nursery Culture

no abstracts submitted

AP 24: Enhancement of Production in Broodstock and Postlarvae (spat) of Marine Bivalves

Lipid quality of a cold-water diatom, Thalassiosira borealis, a potential food for bivalve broodstock

N.B. Richoux*¹, R.A. Stead¹, C.C. Parrish¹ and R.J. Thompson¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

The need exists in the aquaculture of cold water bivalves for algal diets that can support the production of high quality larvae and spat by broodstock. The algae commonly used as broodstock feed are tropical strains that are often of low nutritional quality when produced in large quantities. The aim of this study is to find a cold-water algal species that will successfully and economically support high-quality broodstock production for aquaculture in Newfoundland.

The cold water diatom, Thalassiosira borealis, was isolated from Newfoundland waters and cultured at the Ocean Sciences Centre, St. John's, NF. Experiments are currently being conducted to determine the nutritional value (lipid classes and fatty acid composition) of this strain throughout its growth as a monoculture. The lipid profiles determined from these experiments will be compared with those of tropical algal species traditionally used in the aquaculture of bivalves. In addition, T. borealis is currently being fed to blue mussels (Mytilus edulis) to determine the potential of this diatom as a broodstock diet. Preliminary results of the lipid classes and fatty acid composition of neutral and polar lipids of whole body tissue of the mussels will be presented.

Contribution of bacterial fatty acids in xenic diatom cultures to mussel nutrition

Catherine J. Stevens*¹, Nicole B. Richoux¹, Elizabeth A. Hatfield¹, Robert A. Stead¹, Christopher C. Parrish¹ and Raymond J. Thompson¹

¹Ocean Sciences Centre, Memorial University, St. John's, NF A1C 5S7

Probiotics are live microorganisms, used as food supplements, which enhance growth and survival of cultured animals. These microbes work by controlling the outbreak of infection and disease and, possibly, by directly supplying essential nutrients or digestive enzymes not present in regular food. Studies showing the benefits of probiotics in shellfish aquaculture have typically used single strains of bacteria and not natural assemblages, yet aquaculture occurs in situ, where shellfish are exposed to a diverse array of food particles. Maximal yields of product depend on identifying which foods best enhance growth. In this project, we will determine the levels of bacterial fatty acids in a xenic culture of Thalassiosira borealis and trace the fate of these biomarkers in mussel tissues during a 20 week grazing experiment with animals from a mussel farm in Notre Dame Bay (Newfoundland). We predict that some fraction of the bacterial fatty acids will be assimilated by the mussels and will thus appear in their neutral lipid pool (storage), indicating that microbial cells play a role in nutrition. By comparing the nutritional value of xenic and axenic cultures, we hope to evaluate the potential importance of natural assemblages of bacteria to mussel nutrition.

A comparison of microalgal diets for enhanced production of Placopecten magellanicus postlarvae

Lisa M. Milke*¹, V. Monica Bricelj¹ and Chris Parrish²

¹Institute for Marine Biosciences, National Research Council, 1411 Oxford St, Halifax, NS B3H 3Z1
²Ocean Sciences Centre, Memorial University, St. John's, NF A1C 5S7

The sea scallop, Placopecten magellanicus, is a commercially important species in Atlantic Canada, yet little is known concerning stage-specific diets that optimize hatchery production, especially during vulnerable, post-settlement stages. To this end, P. magellanicus postlarvae (350-700µm) were exposed for 28 days to six microalgal diets (at a volume-equivalent concentration of 40 T-Iso cells µl-1) in 400 L mesocosms. Diets included three diatom species (Thalassiosira weissflogii, Chaetoceros gracilis, and a previously untested, local isolate of Fragilaria familica), and three flagellates [Pavlova lutheri, Pavlova sp. (CCMP 459) known to support excellent growth of sea scallop larvae, and Tetraselmis striata (PLAT-P), used successfully for oyster spat] in combinations that consider both algal size and essential fatty acid (EFA) composition. Sampling for growth, survival (from video imaging), ingestion rate of scallops, and biochemical composition (including EFAs) of algae and scallops were conducted at regular intervals. This experiment is designed to meet several objectives: identify high-performance diets for implementation in commercial hatcheries, compare the nutritional value of three diatom species, determine if postlarvae are capable of particle size-selectivity, and test the hypothesis that a 22:6n-3 (docosahexaenoic acid, DHA)-deficient diet cannot support spat growth. It will also provide a basis for subsequent, more targeted nutritional research.

Development of feeding organs and implications for food acquisition in the sea scallop Placopecten magellanicus

Anne Veniot*¹, V. Monica Bricelj¹ and Céline Barré¹

¹Institute for Marine Biosciences, National Research Council, 1411 Oxford St, Halifax, NS B3H 3Z1

Postlarval development of Placopecten magellanicus is often associated with unexplained high mortalities and suboptimal growth during culture. To assess potential ontogenetic constraints in food acquisition, the differentiation of gills and associated feeding organs was examined by scanning electron microscopy. Key developmental transitions were identified for spat 0.35 to 14 mm in shell height. Morphogenesis was size-, not age-related. The gills remained relatively undifferentiated at 1-2 mm, when hatchery-reared seed are usually transferred to the field by commercial growers. Reflection of inner demibranchs occurred at ~1 mm, a critical developmental stage which coincided with an increase in the rate of filament proliferation and rapid development of the outer demibranch. Both demibranchs were formed at ~2.8 mm, providing enhanced surface area for filtration. The onset of the heterorhabdic (two types of filaments) adult form of the gill occurred at 3.5-5.5 mm, and full gill plication at ~7 mm. A distinct mantle ciliated tract, present in postlarvae < 3.5 mm (absent in adults), likely plays a role in particle rejection when the labial palps are still relatively undifferentiated. Our results suggest that sea scallops are not equipped with fully-functional feeding organs until relatively late in development and that gill morphology may be a determining factor in postlarval feeding capacity.

Environmental Integrity Theme

Theme Leader

Dr. R. Scott McKinley - Biology Department, University of Waterloo

EI 1: Genetic and Ecological Interactions Between Farm and Wild Atlantic Salmon

no abstracts submitted

EI 2: Objective Risk Assessment of Interactions among Cultured and Wild Salmonids

AquaWorld 1: The Aquaculture Flight Simulator

Michael Baumann*¹

¹University of British Columbia, Vancouver, BC

Aquaculture is a complex adaptive system in which social, economic and regulatory decisions will have consequences at various spatial, temporal and organizational scales. Decision-makers are faced with choices among alternative actions in order to achieve predefined goals. However, the outcome of each action may be uncertain, unexpected or even unknown, and real-world trial-and-error learning is not a viable option in a global economy.

As a first step to better understand the dynamics of the social, economic and environmental interactions in aquaculture I have designed the simulation program AquaWorld 1. The program simulates the behaviour of key performance indicators (e.g. number of fish farms, 'environmental quality') in response to externally forced actions (e.g. government regulation, media reports) and internal rules of action, which are defined by functional relationships between variables.

The purpose of AquaWorld 1 is scientific as well as educational. In order to allow non-experts to explore the complexities of aquaculture mathematical formulations in the simulation have been replaced by graphical interfaces that enable the user to informally change model structure, functional relationships, parameter values and initial conditions. The program interface is thus reminiscent of a flight simulator, only this time the user is 'flying' a billion-dollar industry.

Certainly, AquaWorld 1 does not simulate the full complexity of the real-world system. However, it is a heuristic tool to assess and manage the risks and opportunities arising in this fast-growing branch of Canada's economy.

Competitive interactions between cultured and wild salmon juveniles

Camela A. Matheson*¹ and Michael C. Healey²

¹Zoology, University of British Columbia, Vancouver, BC V6T 1Z1
²Institute for Resources and Environment, University of British Columbia, Vancouver, BC V6T 1Z1

Our research to date has focused on competitive interactions between farmed salmon (Atlantic and coho) and wild coho salmon populations during the juvenile phase. Two approaches have been used in this research; 1) aquaria trials to investigate behaviour and relative competitive ability of individuals competing one on one for food, and; 2) artificial stream channel trials to investigate habitat choice, behaviour and relative growth rates in groups of fish competing for food. Preliminary results for aquarium trials involving simultaneous introduction of juvenile fish indicate that wild Salmon River coho were dominant to wild Hopedale Slough coho but not to farmed coho from Target Marine (originally Kitimat River stock). Both Salmon River and Hopedale Slough coho were dominant to farmed Atlantic salmon from Target Marine (Mowi strain). When Atlantic salmon were given 3.5 days prior residence in the aquaria, the instances in which Atlantic salmon dominated Salmon River coho increased. In artificial streams, both coho and Atlantic salmon grew more in the presence of the other species than when alone and coho grew significantly more than Atlantic salmon. Based on the apparent dominance relationships between the species, it appears that coho obtain additional food ration by out-competing Atlantic salmon. Atlantic salmon are apparently stimulated to feed more in the presence of coho competitors based on their observed tendency to move off the bottom and into the water column.

EI 4: Risk and Consequences of Infestation from Salmon Lice

Physiological impact of different levels of salmon lice infestation on the cardiac and swimming performance of Atlantic salmon

Glenn N. Wagner*¹, R. Scott McKinley¹, Pål A. Bjørn² and Bengt Finstad³

¹Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC V6T 1Z2
²Norwegian College of Fishery Science, Breivika, N-9037 Tromsø, Norway
³Norwegian Institute for Nature Research, Tungasletta 2, N-7005 Trondheim, Norway

The salmon louse, Lepeophtheirus salmonis, is known to contribute to salmonid mortality by causing immunosuppression and osmoregulatory disturbances. However, the effect of increased lice numbers on host cardiovascular parameters and swimming ability has yet to be examined. The purpose of this study was to determine if the cardiac or swimming performance of Atlantic salmon is affected by increased lice infestation. Fish were infected with high (0.127 ± 0.018 lice kg-1), medium (0.021 ± 0.003 lice kg-1) and low (0.015 ± 0.003 lice kg-1) levels of lice over a period of 2 hours. Once lice reached adult stages, the ventral aorta of each fish was fitted with a Doppler cuff in order to measure cardiac output, stroke volume and heart rate during swim testing. Preliminary results show critical swimming speeds of highly infected fish (2.10 ± 0.12 bl s-1) declined significantly (P < 0.10) compared to medium (2.46 ± 0.09 bl s-1) and low (2.43 ± 0.16 bl s-1) treatments and controls (2.64 ± 0.10 bl s-1). Due to the fact wild salmon located in areas of intensive aquaculture have higher lice infestation levels than those in pristine areas, an understanding of any corresponding physiological impact on this migratory species is of great importance.

Risk and consequences of infestation from salmon lice

Pål Arne Bjørn*¹, Bengt Finstad², Scott McKinley³, Helge Tveiten, Finn Økland, Eva Thorstad, Helge Johnsen, George Iwama^4,5 and Stewart Johnson⁵

¹Norwegian College of Fishery Science, Breivika, N-9037 Tromsø, Norway
²Norwegian Institute for Nature Research, Tungasletta 2, N-7005 Trondheim, Norway
³Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC V6T 1Z2
⁴Faculty of Agricultural Sciences, University of British Columbia, Vancouver, BC V6T 1Z4
⁵Institute for Marine Biosciences, National Research Council, Halifax, NS B3H 3Z1

• 
  Objective 1: To determine whether aquaculture facilities increase the level of susceptibility of migrating salmonids to sea lice infestations.
  
  
• Objective 2: To determine the effects of sea lice infestation on salmonid reproduction.
  

Salmon lice (Lepeophtheirus salmonis Krøyer) today represents an important economical loss factor in international salmon farming industry. Only in Norway, the direct and indirect losses due to salmon lice may reach 300 to 500 million NOK. The problem has increased during the last decade, and while no direct link has yet been established, increasing evidence imply that the problem has some connection with the rapidly growing salmon farming industry. Co-occurring with salmon lice problems among farmed salmon, salmon lice epidemics have also become an increasing problem for wild salmonids. In Norway, salmon lice has become a severe problem especially for sea trout and Arctic charr, but new results also indicate that Atlantic salmon smolts may suffer high risks of infestations.

In this project we will address the salmon lice problem further through field and laboratory studies. We will use telemetry to map the detailed movements of migratory Atlantic salmon post smolts through a Norwegian fjord model environment of intensively fish farming activity. Environmental conditions associated with migratory behaviour, proximity to aquaculture facilities and the risks of salmon lice infestation will be noted. We will capture both wild migratory post smolts of Atlantic salmon, sea trout and Arctic charr in sympatry in a Norwegian fjord system. The risks and consequences of the infestation will be addressed, and possible differences between the species will be studied. Furthermore, we will use data on the infestation level on wild adult and escaped-farmed salmon to address the hypothesis of escapee's being an important host for salmon lice in coastal waters. Finally, the effects of known numbers of salmon lice on the reproductive endocrinology, condition and seawater growth of the fish, as well as gonadal size, spawning time, fecundity, egg size, fertilisation rate, and developmental and hatching success, will be determined.

Preliminary results from all these projects will be presented and discussed.

EI 5: Environmental Requirements for Sustainable Shellfish Aquaculture Development

The role of zooplankton in sustainable mussel aquaculture

Joy Stacey*¹ and Don Deibel¹

¹Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7

Our project will investigate the impact of mussel farms on the endemic zooplankton community and the role of zooplankton in the nutrient cycles of the farms. This is part of a larger study of the environmental sustainability of shellfish aquaculture. Few studies have investigated the extent to which bivalve farms affect the nature of the plankton community in the water column or the role of zooplankton in the nutrient cycles of the farms. Studies of natural mussel beds suggest that high densities of bivalves can alter the local abundance of some phytoplankton and zooplankton size classes. This may be due, in part, to competition between zooplankton and mussels for particulate food. Knowledge of the abundance, biomass and species composition of the resident zooplankton population will help to determine the extent to which this competition affects mussel productivity and whether, therefore, it is an important determinant of carrying capacity. Our investigation will compare the zooplankton community at two mussel farms in Notre Dame Bay, Newfoundland, with their respective reference sites to determine the presence or absence of an impact of the farms on the zooplankton community. Measurements of zooplankton carbon, phosphorous and nitrogen content and ammonium excretion will be used to assess the importance of zooplankton in nitrogen cycling at the farms. A pilot study was conducted in June 2001 with commencement of full sampling and experiments in August 2001.

Numerical modeling in mussel aquaculture

R.C. Tian*¹, D. Deibel¹, M.R. Anderson², R.B. Rivkin¹, R. Thompson¹, J.E. Stacey¹ and D. Churchill¹

¹Ocean Science Centre, Memorial University of Newfoundland, St. John's, NF A1C 5S7
²Department of Fisheries and Oceans, St. John's, NF A1C 5X1

Determination of carrying capacity, i.e. the standing stock at which production levels are maximized without negatively affecting growth rate, represents one of the major challenges in mussel aquaculture. Carrying capacity is determined by functional characteristics of the farm ecosystem. Numerical models are particularly well suited to address this problem because they quantify and integrate all the relevant dynamical processes. Model complexity depends on the specific question and can vary from just one state variable (e.g. suspended particulate matter) to 10 categories of mussels, and from purely physical transport to integration of physical, chemical and biological processes. Several key processes for prediction of sustainable yield are however under-represented in previous models. These include (1) physical dynamics in the water column that is in most cases prescribed, or described by depth-integrated, 2-D box models, (2) physical and chemical processes at the sediment-water interface, (3) elemental fluxes mediated by the microbial food web, (4) husbandry such as raft configuration, rope length, seeding and harvest time and density, and (5) climate forcing and long-term environmental interactions. Due to these limitations, the long-term, sustainable carrying capacity of mussel farms has rarely been assessed. One of the main objectives of our project is the development of a climate-driven, prognostic ecosystem model for mussel aquaculture. We will use the climate-driven Princeton Ocean Model (POM) for physical dynamics and our published biological model for food web dynamics. Mussel parameterization will be based on population dynamics linked to stock density, weight, temperature, seeding and harvesting. The model will be constrained by on-site measurements at mussel farms on the Northeast coast of Newfoundland. Our objective is to develop an operational tool for sustainable carrying capacity assessment, to provide strategies for site choice, optimal husbandry and management.

EI 6: Development of in-situ Early Warning Systems for Harmful Algal Blooms and Phycotoxin Monitoring at Aquaculture Sites

In-situ optical sensors as a tool to assess seston depletion by cultured mussels

Diego Ibarra*¹, Allan Cembella², Cheryl Rafuse¹, Stephane Kirchhoff¹ and John J. Cullen¹

¹Department of Oceanography, Dalhousie University, Halifax, NS B3H 4J1
²National Research Council, Institute of Marine Biosciences, 1411 Oxford Street, Halifax, NS B3H 3Z1

Mussels can deplete seston in the water when they are reared at dense concentrations. Mussels in seston-depleted areas are susceptible to reduced growth, which translates into lower production and consequent economic losses. The objective of this study is to quantify the decrease in seston concentration due to cultured mussels in Ship Harbour (Nova Scotia), an estuarine fjord with significant tidal flux. Seston differences between two points along the main current axis of a farm were assessed using two TACCS (Tethered Attenuation Coefficient Chain Sensor) optical systems (Satlantic, Inc.). Solar irradiance penetration (at 490 nm) between 4 and 8 m (depth interval where the mussels are concentrated) was used to calculate the depth-resolved attenuation coefficient (Kd490), as an index of seston concentration in such stratum. Seston quantity and quality (organic and inorganic particulate matter and phytoplankton pigments) and optical properties of seston and water (light absorption by dissolved and particulate matter), were assessed twice a week at discrete depths to validate the interpretation of Kd490. Preliminary results show a sinusoidal variation in Kd490 that corresponds to the tidal periodicity. Kd490 was always higher at the up-stream site and the difference between the up-steam and down-stream sites was accentuated at low-current conditions (up to 75% during slack tide). This result is consistent with depletion of seston by cultured mussels. These passive optical sensing systems are a valuable tool for continuous monitoring of the optical properties associated with plankton blooms and seston quantity at aquaculture sites.

Rapid monitoring of toxic phytoplankton using the MIST AlertT for PSP and ASP toxins at aquaculture sites in Atlantic Canada

C. Rafuse*^1,2, M.A. Silva^1,2, J.F. Jellett¹ and A.D. Cembella³

¹Jellett Biotek Limited, 327 Prince Albert Road, Suite 5, Dartmouth, NS B2Y 1N7
²Department of Oceanography, Dalhousie University, Halifax, NS B3H 4J1
³Institute for Marine Biosciences, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1

Toxic algal blooms pose a recurrent risk to human health through the consumption of bivalve shellfish contaminated by potent biotoxins. To protect the economic viability of aquaculture and wild harvest fisheries in areas affected by seasonal blooms of toxic algae many countries, including Canada, have instituted plankton surveillance programs as a early warning of impending toxicity. Unfortunately, monitoring programs are based on time-consuming identification of key toxic species by microscopy, and do not usually consider toxicity. An improvement on existing plankton monitoring methods was investigated at aquaculture sites in Atlantic Canada using conventional microscopic identification and a modification of a rapid immunodiagnostic test for PSP and ASP toxins (MIST AlertT). Intensive sampling (twice weekly) of the water column at selected sites was conducted between May and August, 2001 and showed that although peaks of several Alexandrium and Pseudo-nitzschia species were found, no highly toxic blooms occurred. The most significant finding was that only ASP toxins were clearly detected using the MIST AlertT. Cell concentrations of Alexandrium species were never high enough (>ca. 100 cells per assay) to be detected by the assay for PSP toxins. The MIST AlertT is a rapid and reliable method to detect low toxin levels in plankton assemblages as determined by both laboratory and field experiments.

EI 7: Water-Sediment Interactions: The Processes and Effects of Sorption / Desorption of Additives to Aquacultural Systems on Sediment and Water Quality

Protocols to assess organic compounds - Sediment interactions under varying aquatic conditions

S. Norstrom*¹ and L. Lavkulich¹

¹Institute for Resources and Environment, The University of British Columbia, Vancouver, BC V6T 1Z3

Aquacultural systems utilize a variety of organic compounds, many of which are xenobiotics, in commercial production. These include feed additives, growth stimulants and antibiotic agents. As all systems, aquacultural systems are leaky and these compounds find their way into the water column and ultimately sorbed onto sediments. During this process organics react with mineral particles to form flocs, proto-sediments or "marine snow" which do not settle immediately and may be moved by ocean currents over great distances. In addition the question remains, are these organic compounds rendered benign during this floc formation process? There is a dearth of information on the formation of these proto-sediments, under varying water chemistry conditions their formation is poorly understood and the efficacy of the xenobiotics unknown. Before these questions can be answered, techniques need to be developed to understand the characteristics of these proto-sediments. Chemical, microbiological and election-microscopic protocols are in the process of being developed to address these important issues.

EI 8: Intelligent Monitoring Systems for Aquaculture

Development of an automated reasoning system by monitoring activity levels in rainbow trout

W.J. McFarlane*¹, H. Williams*², J. Wilson¹, C. White³, R.Gosine², R. Moccia⁴ and R.S. McKinley³

¹Waterloo Biotelemetry Institute, University of Waterloo, Waterloo, ON N2L 3G1
²C-CORE, Memorial University of Newfoundland, St. John's, NF A1B 3X5
³Department of Animal Science, University of British Columbia, Vancouver, BC V6T 1Z4
⁴Aquaculture Centre, Department of Animal and Poultry Sciences, University of Guelph, Guelph, ON N1G 2W1

This ongoing study attempts to exploit swimming behaviour of adult rainbow trout (0.8-1 kg) to predict the energetic needs and overall well being of fish reared under aquaculture conditions. Through the use of state-of-the-art electromyogram (EMG) transmitters implanted into lateral red muscle, we are analyzing patterns of EMG activity (representing muscle activation) in fish during three distinct states: 1) fasting, 2) satiation and 3) acute stress. Individual activity levels will allow us to determine pattern signatures that will predict the energetic status and needs of fish. This pattern analysis will be accomplished by examining 50-60 distinct features of the collected EMG data, including maximum signal, frequency analysis, shape parameters and time series, using techniques such as Fast Fourier Analysis (FFT), Wavelets and filters. From these features, signature patterns of activity defining each of the three states may be characterized. Ultimately, the development of an automated reasoning system, to control automatic feeders and monitor environmental parameters from the perspective of the fish, is anticipated. Initial validation trials illustrate that EMG signals correlate with red muscle activation, and EMG procedures have no effect on swimming performance. This study represents the first of its kind, involving a collaboration of fisheries science and engineering, to create an automated reasoning system that allows free ranging fish to directly communicate their physiological needs.

EI 9: Sea Lice Resistance to Chemotherapeutants: Diagnosis, Mechanisms, Dynamics and Control

no abstracts submitted

EI 10: Improving Amino Acid Utilization in Salmonid Fish: A Key Factor to Improving Feed Efficiency and Reducing Waste Outputs in Marine and Freshwater Salmonid Fish Culture

Essential amino acids requirements of fish: A matter of controversy

P. Encarnacao*¹ and D. Bureau¹

¹Fish Nutrition Research Laboratory, Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1H 2W1

A survey of the scientific literature shows that the mode of expression of amino acid requirements of fish is a topic of disagreement between fish nutritionists. Some consider that EAA requirements are better expressed as % diet (Kim et al., 1991; NRC, 1993). Others suggest that amino acid requirements should be expressed in relation to the energy content of the diet (e.g., g/MJ digestible energy (DE); Rodehutscord et al., 1997). Another view is that EAA requirements are more accurately expressed in relation to the total amount of protein of the diet (i.e. % protein or g/16 g N; Cowey and Cho, 1993; Mambrini and Guillaume, 1999).

These different modes of expression affect how the information on EAA requirements is used when formulating practical cost-effective feeds and can result in diametrically opposite interpretations. Individual EAA levels deemed adequate in the diet may be very different depending on the mode of expression adopted, the composition of the diet formulated, and the amino acids composition of the ingredients used. This controversial issue deserves more attention.

Our objective is the realization of integrative studies aiming at a better understanding of amino acid utilization and requirements by fish. A series of studies will be conducted to examine the effect of diet composition (amino acid balance and digestible energy level) on lysine (the first limiting EAA) utilization and requirements of rainbow trout (Oncorhynchus mykiss).



Patterns and costs of growth, protein and lipid depositions in salmonid fish

P.A. Azevedo*¹, S. Leeson¹, S. Birkett¹, H. Bayley², C.Y. Cho¹ and D.P. Bureau¹

¹Dept. of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1
²Dept. of Human Biology and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1

The efficiencies of protein and lipid deposition are affected by the dietary digestible protein (DP) and digestible energy (DE) ratio and the fish species' growth potential. Four salmonid species (rainbow trout, Atlantic salmon, lake trout, and chinook salmon) of different sizes were fed four isoenergetic diets (DE = 20 MJ/kg) with DP/DE ratios of 18, 20, 22 and 24 g/MJ to satiation for several weeks. Growth within species (4.39 and 4.26 g/d for large size Atlantic salmon and rainbow trout and 1.17 and 1.15 for small size Atlantic salmon and Lake trout) was not affected by diet, suggesting that all the diets were nutritionally adequate. Proximate analysis of dressed carcass will be conducted to determine patterns of protein and lipid deposition in all species at different sizes and determine how these patterns translate into live weight gain and marketable product yield. Cost of protein deposition, lipid deposition and maintenance will be estimated using both factorial and multivariate analysis of the carcass composition data from the feeding trials and DP and DE intakes. A mechanistic and dynamic fish growth model based on biological and biochemical principles will be developed. Modeled energetic costs of maintenance and growth will be compared with those obtained with the statistical analyses.

EI 11: Cultured Salmon: Their Swimming Performance, Energetics and Reproductive Success in Relation to Fish Introductions and Escapements

Field measurements of swimming performance and metabolic expenditure with hatchery-reared and transgenic coho salmon (Oncorhynchus kisutch) in comparison with wild sockeye salmon (O. nerka)

Chris G. Lee*¹, Anthony P. Farrell¹, Scott G. Hinch² and Michael Healey³

¹Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1Y6
²Department of Forest Sciences, University of British Columbia, Vancouver, BC V6T 1Z4
³Institute for Resources and Environment, University of British Columbia, Vancouver, BC V6T 1Z3

Metabolic rates (MO2), critical swimming speed (Ucrit), and metabolic recovery were examined using a 471.2 L portable swim tunnel. We have established that high caliber respirometry field studies can be conducted in the field with adult salmon as our field measurements were comparable to laboratory measurements, except when fish were very close to spawning out. It was also established that metabolic differences exist among stocks and species and that depending on maturation state, a sexual dichotomy in Ucrit exists. Ucrit values and corresponding metabolic rates were 2.1 bl/s (15.1 mg O2/kg/L/min) at 18.0 °C for Seton sockeye, 1.6 bl/s (10.8 mg O2/kg/L/min) at 13.8 °C for wild Harrison sockeye,1.7 bl/s (9.1 mg O2/kg/L/min) at 7.9 °C for Harrison hatchery-reared coho, and 1.3 bl/s (8.4 mg O2/kg/L/min) at 8.7 °C for transgenic coho. Transgenic coho were poorer and less efficient swimmings compared to hatchery-reared coho at the same temperature. The slower time-to-50% recovery in sockeye compared to coho may reflect a higher absolute performance. The sockeye stock that migrated further inland to spawn attained a greater Ucrit speed and maximum aerobic capacity relative to coastal sockeye. Further research is being conducted on temperature effects among stocks.

EI 12: A Multi-disciplinary Approach with the Integration of Three Trophic Levels (Fish / Shellfish / Seaweed) for the Development of Sustainable Aquaculture Systems

A multi-disciplinary approach with the integration of three trophic levels (fish/shellfish/seaweed) for the development of sustainable aquaculture systems

S. Bastarache*¹, T. Chopin¹, S. Robinson², T. Lander², B. MacDonald³, K. Haya², D. Sephton², J. Martin², F. Page² and I. Stewart⁴

¹University of New Brunswick, Centre for Coastal Studies and Aquaculture and Centre for Environmental and Molecular Algal Research, P.O. Box 5050, Saint John, N.B., E2L 4L5, Canada
²Department of Fisheries and Oceans, 531 Brandy Cove Road, St. Andrews, N.B., E5B 2L9, Canada
³University of New Brunswick, Centre for Coastal Studies and Aquaculture, P.O. Box 5050, Saint John, N.B., E2L 4L5, Canada
⁴Atlantic Silver Inc., 2 Salar Court, St. George, N.B., E5C 3N1, Canada

As present monospecific aquaculture operations in North America and other parts of the world are at environmental, economic and social crossroads, common sense suggests integrating different types of aquaculture to develop responsible practices, optimizing the efficiency of aquaculture systems and diversifying the industry, while maintaining the health of coastal waters through the understanding of their assimilative capacities. Nutrification of coastal waters is becoming a pressing issue worldwide, and the contribution of the organic and inorganic outputs of aquaculture to significant regional nutrient loading is becoming more widely recognized. To avoid pronounced shifts in coastal processes, a balanced ecosystem approach requires that fed aquaculture (finfish) be integrated with organic and inorganic extractive aquaculture (shellfish and seaweed). Such a bioremediative approach provides mutual benefits to co-cultured organisms, economic diversification by producing other value-added marine crops, increased profitability per cultivation unit, and cost-effective means for reaching effluent regulation compliance by reducing the internalization of the total environmental costs.

The present project is conducting research, at an industrial pilot scale, at a site in the Passamaquoddy Bay, Bay of Fundy, where salmons, mussels, and kelps are being grown together to develop an integrated aquaculture model and train students and professionals in this innovative approach to aquaculture. The productivity and role of each component (fish, shellfish and seaweed) is being analyzed so that the appropriate proportions of each of them can be defined in order to develop a sustainable system in which metabolic processes counter-balance each other within acceptable operational limits and according to food safety guidelines and regulations. The ultimate goal of this project is to transfer this model to other sites and make it a concept transferable to other aquaculture systems. The Canadian fish aquaculture industry is obviously here to stay in our "coastal scape": it has its place in the global seafood supply and demand, and in the economy of coastal communities. To help ensure its sustainability, it needs, however, to responsibly change its too often monotrophic practices by adopting polytrophic ones to find increasing environmental, economic and social acceptability, and become better integrated into a broader coastal management framework.

EI 13: Development of Cold-water Recirculation Systems

Use of ozone in aquaculture recirculation systems

K. Baltzer*¹ and G.A. Gagnon¹

¹Department of Civil Engineering, Dalhousie University, Halifax, NS B3J 2X4

The use of ozone for seawater has been limited due to concerns over the potential to form bromate during ozonation. This research investigates the potential for ozonation to control pathogens and water quality in saltwater recirculation systems while minimizing bromate formation. Through full-scale monitoring and bench-scale testing it is the goal of this project to develop a design framework for ozonation in a recirculation system.

Sample analysis is currently on-going at Scotian Halibut, a 200 ton/year Atlantic halibut farm. Scotian Halibut is currently the largest aquaculture recirculation facility in Canada and has recently installed a small ozone generator for improving color and inactivate pathogens during water treatment of their recycled water. The other processes in the water treatment facility consists of a swirl separator, drum filter, and biofilter.

At the bench-scale level, an ozone generator is used to prepare an aqueous stock solution of ozone that is applied to process water from the Scotian Halibut facility in Woods Harbour, NS. The stock solution is used to investigate bromate production as well as the effect of ozonation on parameters such as pH, dissolved oxygen, biochemical oxygen demand, total suspended solids, ammonia, color, and turbidity.

EI 14: Optimisation of Existing Faecal Trap to Reach 99% Settable Solid Removal in Highly Recirc Systems Through Hydraulic Modelisation

no abstracts submitted

Social and Economic Aspects Theme

Theme Leader

Dr. Ralph Matthews - Department of Anthropology and Sociology, The University of British Columbia

SE 2: The Industrial Economics of Aquaculture Industries

no abstracts submitted

SE 3: The Institutional and Social Structure of Aquaculture: A Comparative Study of Norway, Chile, the Faeroes and Japan

Global commodity chains and vertical integration in the Faroes

G. Hovgaard*¹

¹Center for Local and Regional Development, P.O. Box 159, FO-700 Klaksvík, Faroe Islands

This investigation deals with recent changes in the composition of the economic organization of Faroese aquaculture business. The last 10 years, changes at this level have been fundamental. Since the 1980s, many small units have been transformed into a few large companies. These fewer and larger companies share three main characteristics: 1) concentration or integration between the different parts of the aqua-cultural industry, i.e. hatcheries, grow-out sites and food-production; 2) the entrance of multinational operators, particularly Norwegians; and 3) increasing growth in both physical output and profitability. Through these changes, Faroese aquaculture has clearly become part of a "global commodity chain" in which vertical integration plays a major role. The main question therefore becomes, whether there is a contradiction between aquaculture as a successful profit-making business and as an opportunity for sustainable community development? Theoretically speaking, the general changes in global capitalism puts the relations of the local and the global into new perspectives, in which the role of local networks and tradition in the new structure is of particular interest. The study will be undertaken as an qualitative analysis of two of the more succesful operators on the Faroes.

Impact of aquaculture industry on rural community: Chiloé, Chile

L.G. Barrett¹ and L. Read*²

¹Department of Sociology and Criminology, Saint Mary's University, Halifax, NS B3H 3C3
²International Development Studies, Saint Mary's University, Halifax, NS B3H 3C3

Globalization and its characteristic growth of modern industry, often at the expense of traditional sources of income, has had a dramatic socio-economic impact on communities. This poster will illustrate some of the complexities of the specific example of the salmon aquaculture industry in Chiloé, southern Chile. The central research question is whether or not the economic growth experienced by the aquaculture industry has had a positive or negative socio-economic impact on the relatively underdeveloped archipelago of Chiloé. In terms of the importance of this question, the salmon industry has provided the first stable source of income for Chiloé, an area previously characterized by subsistence activities. Together with the fact that Chile is now the second largest exporter of farmed salmon in the world, Chiloé is a fascinating case.

Four specific issue areas are defined to address the central question, namely, labour conditions in the salmon industry, community organization, social and family demographics and cultural disintegration. Six communities form the basis of the project. Within each community focus groups have been conducted with salmon workers, technicians and supervisors, fishers, artisanal aquaculturists, and women's and indigenous groups to provide a wide representation of community and the impact of the salmon aquaculture industry.

SE 4: Law and Policy Project: Towards Principled Access, Allocations and Operations in Aquaculture

Role of dispute resolution processes in aquaculture siting conflicts

Josh Bryson*¹ and Moira McConnell²

¹Research Student, Faculty of Law, Dalhousie University, 6061 University Avenue, Halifax, NS B3H 4H9
²Professor of Law, Faculty of Law, Dalhousie University, 6061 University Avenue, Halifax, NS B3H 4H9

This research study is part of Dr. Moira McConnell's AquaNet Law and Policy project into siting processes in Canada and Norway, focusing on the causes of conflict and methods used to resolve them. The object of this study is to examine aquaculture-siting conflicts in Canada and the measures that have been employed, if any, to resolve them. The study focuses on the relevant legislative regime and policy and the secondary sources discussing conflict resolution theory and models.

Key Canadian aquaculture case studies will be studied in order to assess the effectiveness of the conflict resolution framework. Thus far, research has commenced with two controversial sites in Nova Scotia: Northwest Cove, Lunenburg and St. Ann's Bay, Cape Breton. Although opposed by some members of the public, the site at Northwest Cove has already been approved by the Nova Scotia government. Approval is still pending for the St. Ann's Bay site. If approved, it will be one of the largest blue mussel farms in North America (1186.08 acres).

Dr. McConnell expects to complete a draft report by the spring of 2003. Research materials and results from this project will be available on the AquaNet Law and Policy website.

Developing the AquaNet Law and Policy website

Gloria Chao*¹, David VanderZwaag² and Jennifer Adams³

¹Research Fellow, Faculty of Law, Dalhousie University, 6061 University Avenue, Halifax, NS B3H 4H9
²Professor of Law, Faculty of Law, Dalhousie University, 6061 University Avenue, Halifax, NS B3H 4H9
³Research Student, Sir James Dunn Law Library, Dalhousie University, 6061 University Avenue, Halifax, NS B3H 4H9

The purpose of the website is two-fold.

First, it will describe the parameters of the AquaNet Law and Policy Project, including a brief description of the subprojects undertaken by the Network Investigators. Secondly, the website is intended to be a resource for the Network Investigators as well as anyone interested in aquaculture law and policy. It will include a listing of domestic and international primary sources, secondary sources, and research tools, such as lexicons. As the various subprojects are completed, the website will incorporate the research materials and findings gathered by the Network Investigators into its database and provide updates on the research produced by the Law and Policy Network Investigators.

Instead of duplicating existing aquaculture information available in electronic form, this website will focus on indexing that information through a series of hyperlinks and on collaborating with key aquaculture law and policy depositories: the Office of the Commissioner for Aquaculture Development (for domestic law and policy) and the UN Food and Agriculture Organization's Fisheries Library (for international materials).

The website will be attached to the existing Dalhousie Law Library website and /or the Dalhousie MELP webpage.

SE 6: The Social Construction of Aquaculture: Risks and Benefits; Work and Community

The role of science in aquaculture: From entrepreneurial stimulus to political weapon

E. Paradis*¹

¹Department of Anthropology and Sociology, University of British Columbia, Vancouver, BC V6T 1Z1

Science has undoubtedly played an important role in the development of shellfish aquaculture in Canada. Today, as the industry strives to expand, and the controversy around it seems to grow, one may ask what is science's input in all this? How does it interact with the industry? How does it influence people's lives? In a society which has become increasingly critical of scientific knowledge, science has evolved beyond the cognitive realm: it now extends its influence deep into the socio-political sphere, attaining a status which gives it the power not only to shape public debates, but to directly affect society's health, lifestyle, and economy. By examining the context in which science has evolved, I hope to better understand the role it has come to play in the development of shellfish aquaculture. I will attempt to trace a map of the networks science has created around this industry, and to demonstrate how it has become a growing medium between diverse social groups: both through the formation of alliances, and through the appropriation by laypeople of the scientific discourse. Scientific knowledge is a complex institution which role should be well understood, so that it may be used in a constructive way.

First Nations perceptions of aquaculture: Risks and benefits

A. Poon*¹

¹Department of Anthropology and Sociology, University of British Columbia, Vancouver, BC V6T 1Z1

Aquaculture is a controversial issue in British Columbia. Industry and environmentalists are at odds due to the different perceptions of risk that they hold. Although there has been much literature published on the differences between expert and public perceptions of risk, little has been written about how First Nations perceive aquaculture in terms of its risks and benefits. Because the First Nations play an important role in the public discourse of west coast aquaculture, this poster attempts to fill in that gap by examining the varying views held by the First Nations regarding aquaculture and by investigating the nature of their involvement.

The power of frames: aquaculture in British Columbia

D. K. Schreiber*¹

¹Department of Resource Management and Environmental Studies, University of British Columbia, Vancouver BC V6T 1Z3

Aquaculture in British Columbia is a fiercely contested industry. Both the environmentalist movement and the industry counter-movement have emerged out of this controversy as carriers and transmitters of meaning about aquaculture. These movements are able to influence the ways in which people understand aquaculture through the help of "frames", or central organizing ideas that are presented to would-be supporters. I examine the ways in which both environmentalist and industry movements frame aquaculture in advertisements, brochures, and newspaper articles. How frames get produced and why they become successful depends to a large degree on the extent to which they resonate with pre-existing meanings. Through framing, values and beliefs about nature as either an extractable resource or as a fragile organism are amplified and extended, and the significance of aquaculture is "packaged" around salmon to ease communication. The frames of both industry supporters and opponents are powerful because they are aligned in various ways with the taken-for-granted knowledge people already have about nature, including seemingly "objective" truths about the importance of predictability and control. Frames for aquaculture can also rely on simulated landscapes and communities that are difficult to distinguish from reality.

SE 7: Property Rights for Sea Ranchers (Mariculturers)

no abstracts submitted

SE 8: First Nations Involvement in Aquaculture in British Columbia

no abstracts submitted