Ulva as an aquaculture crop and IMTA component species has received mixed results globally; success has been achieved in South Africa and Israel, whilst in Europe the results have been poor. This project aims to determine if Ulva lactuca is a suitable candidate as an inorganic extractive species component within marine IMTA systems in British Columbia. The inorganic extractive feasibility of U. lactuca was determined with combination of real time growth and nutrient uptake experiments, alongside a SWOT analysis and literature review to reveal the possible potentialities and pitfalls. U. lactuca was cultivated in 680 litre tanks in the effluent of Wolf Eels, Anarrhichthys ocellatus in a recirculation system at the Aquatics facility at the University of Victoria. Growth experiments of wild local U. lactuca strains attained summer growth of up to 17.43% specific daily growth rate, with winter growth of up to 4.26% specific daily growth rate. U. lactuca demonstrates a preference for Ammonia-N uptake over other forms of inorganic nitrogen and a reduced nutrient uptake capacity during dark periods. Nitrate uptake capacity up to 202µm N gDW-1 day-1 was exhibited. These figures display the excellent biological potential of local Ulva lactuca strains to act as an inorganic extractive. However currently, long term maintenance of the crop proved problematic with instability with growth rates and nutrient uptake capacity. Cultivation issues in combination with poor economic outlook will restrict the feasibility of this species to specific types of IMTA system. Beneficial steps towards the deployment of U. lactuca inorganic extractive components would include: (i) the identification of suitable sterile strains or employment of “germling” spore production, (ii) the use of a rotational, light weight, cage cultivation system, (iii) being farmed in combination with a dark period nutrient removal species, such as Chondrus crispus, (iv) being farmed in conjunction with in-situ algivorous species. / Graduate / 0792

Submitted by MARCELO HENRIQUE CORREA ASSUNÇÃO null (marcelohassuncao@yahoo.com.br) on 2017-06-20T02:54:52Z No. of bitstreams: 1 tese_marceloassuncao_final.pdf: 1226336 bytes, checksum: f3c615d93eada896ca7e57893d573911 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-06-21T13:27:50Z (GMT) No. of bitstreams: 1 assuncao_mhc_dr_jabo.pdf: 1226336 bytes, checksum: f3c615d93eada896ca7e57893d573911 (MD5) / Made available in DSpace on 2017-06-21T13:27:50Z (GMT). No. of bitstreams: 1 assuncao_mhc_dr_jabo.pdf: 1226336 bytes, checksum: f3c615d93eada896ca7e57893d573911 (MD5) Previous issue date: 2017-05-05 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste estudo foi investigar o fluxo de gases do efeito estufa (GEE) em viveiros de criação de organismos aquáticos. Nós testamos se o uso de sistemas multitróficos e multiespaciais (IMTA), povoados com lambari-do-rabo-amarelo (Astyanax lacustris) e camarão-da-amazônia (Macrobrachium amazonicum) numa região tropical, altera o fluxo de gases do efeito estufa em comparação com um sistema de monocultivo de A. lacustris. Nós desenvolvemos um experimento em viveiros de fundo natural com três tratamentos e quatro réplicas: monocultivo (Tetra), IMTA livre (Free IMTA) e IMTA tanque rede (Cage IMTA). O experimento durou 68 dias, entre os meses de novembro e janeiro de 2016. Nós mensuramos os fluxos de dióxido de carbono (CO2), metano (CH4) e óxido nitroso (N2O) por meio das metodologias difusiva e dissolvida. A média dos fluxos na metodologia difusiva foi de -8.93 mg.m-2.h-1 para o CO2, -0.88 mg.m-2.h-1 para o CH4 e 1.78 mg.m-2.h-1 para o N2O. A concentração de CO2 variou de 0.0481 a 0.6668 mg.L-1, CH4 de 0.0003 a 0.0053 mg.L-1 e N2O de 0.0789 a 0.1177 mg.L-1. Nossos resultados indicam variação ao longo do tempo, com maior fluxo de GEE no início do experimento, diminuição ao longo do período de cultivo e tendência de neutralidade com relação a emissão de GEE no final do período experimental. / CNPq: 147409/2013-6 / CNPq: 473199/2011-4 / CNPq: 306361/2014-0 / FAPESP: 2012/18593-5

Les systèmes intégrés d’aquaculture multi-trophique (IMTA) proposent de limiter les rejets dans l’environnement en associant la culture d’espèces de niveaux trophiques différents et le recyclage des déchets. Les détritivores sont un groupe trophique intéressant car ils permettent l’extraction de matière organique particulaire. Hediste (Nereis) diversicolor est un polychète qui connait un intérêt croissant du fait de sa capacité de bioturbation dans les sédiments et de sa haute valeur commerciale en tant qu’appât et nourriture potentielle pour animaux. L’objectif principal de cette thèse est d’évaluer le potentiel d’ H. diversicolor dans la bio-remédiation des rejets solides en système IMTA. Plus spécifiquement, l’étude a eu pour objectifs : i) de calibrer une nouvelle méthode de mesure des composés organiques des rejets (azote, carbone, phosphore, lipides), ii) d’évaluer l’activité métabolique (respiration) d’H. diversicolor nourries aux fèces de Dicentrarchus labrax en fonction de leur taille et de différentes températures, et iii) d’utiliser un modèle bioénergétique pour simuler croissance, respiration et excrétion d’H. diversicolor selon différents scenarios IMTA.Pour obtenir une caractérisation rapide des composés organiques, une méthode novatrice (NIRS) a été calibrée. Les composés des rejets ont varié entre 44-77% de matière organique, 2-5% d’azote organique total, 11-51% de carbone organique total, 9-26 de rapport carbone/azote, 1-3% phosphore total and 2-12% de lipides (% de matière sèche).Les taux métaboliques de H. diversicolor nourries aux fèces ont été estimés par consommations d’oxygène à différentes températures (11, 17, 22 and 27°C). Les effets de la température et de la taille du ver sur les consommations en oxygène ont été significatifs, mais ces niveaux de respiration (12.3 µmol g-1 de poids sec h-1 à 20°C) correspondaient probablement à un métabolisme basal dû aux conditions expérimentales (jeun et obscurité).Les simulations du modèle DEB H. diversicolor ont été comparées aux données expérimentales de taux de croissance, de respiration et d’excrétion, ce qui a permis de corroborer les prédictions du modèle. Le modèle DEB a permis de tester différents scenarios pour prédire les réponses métaboliques, la croissance, la maturité et la reproduction d’ H. diversicolor à différentes températures (5 à 25°C) et disponibilité alimentaire (f variant de 0.5 à 1, correspondant à la disponibilité des fèces). Le modèle DEB s’est avéré être un outil utile pour prédire les réponses physiologiques sous différentes conditions environnementales dans un contexte IMTA. / Integrated Multi-Trophic Aquaculture (IMTA) systems are based on the concept of limiting aquaculture discharges associating species of different trophic levels to reuse wastes. Deposit-feeders are one trophic group that has gained attention for the extraction of particulate organic matter. Hediste (Nereis) diversicolor is a polychaete species that has gained increasing interest for its bioremediation capacity through bioturbation activity in sediments, and high commercial value as fish bait and animal food sources. The main objective of this thesis was to evaluate the fish waste bioremediation capacity of polychaete H. diversicolor in IMTA context. More specifically, i) to predict organic compounds (nitrogen, carbon, phosphorus, lipids) in marine fish waste, ii) to evaluate the metabolic responses - respiration - of H. diversicolor fed with solid waste of seabass Dicentrarchus labrax at different temperatures and body size, and iii) to use a bioenergetic model (DEB) to simulate growth, oxygen consumption and excretion in different IMTA scenarios.To provide fast characterization of organic compounds we used an innovative method based on near infrared reflectance spectroscopy (NIRS). Chemical content of the waste measured by NIRS models after calibration, ranged from 44-77% organic matter, 2-5% total organic nitrogen, 11-51% total organic carbon, 9-26 carbon/nitrogen ratio, 1-3% total phosphorus and 2-12% lipids (% of dry matter).Fish waste fed H. diversicolor metabolic rates were evaluated through oxygen consumption at different temperatures (11, 17, 22 and 27°C). The effect of temperature and worm body size was significant on oxygen consumptions, however these respiration measures (12.3 µmol g-1 of dry weight h-1 at 20°C) may represent basal metabolic rate due to experimental conditions (starvation, darkness).DEB model of H. diversicolor was compared to experimental data on growth, respiration and excretion rates, which corroborated DEB model predictions. DEB was then applied to test different scenarios predicting metabolic responses, growth, maturity and reproduction of H. diversicolor at different temperatures (5 to 25°C) and food levels (f varying from 0 to 1, corresponding to fish waste loading). DEB revealed to be a useful tool in IMTA context, predicting physiological responses in different environmental conditions.

Earth’s population is expected to reach 9 billion by 2050. Ensuring food security for the growing world population is one of today’s society’s major challenges and responsibilities. Aquatic products have the potential to contribute significantly in the growing population’s dietary requirements. Since increasing the pressure on most natural fish stocks is now widely agreed not to be an option, the aquaculture sector needs to grow. The challenge is to increase aquaculture production without depleting natural resources or damaging the environment but also in a financially sustainable way. Integrated Multitrophic Aquaculture (IMTA) is one method of sustainable aquatic production. Integrating bioremediatory organisms that extract particulate organic matter or dissolved inorganic nutrients with monocultures of fed species has the potential of reducing the particulate and soluble waste loads from effluents, whilst producing a low-input protein source that may also increase the farm income. IMTA is a viable solution for mitigating the environmental impact of waste released from fish farms. The fish waste is exploited as a food source for lower trophic, extractive organisms giving an added value to the investment in feed. Studies up to now have shown that under experimental conditions as well as in small-scale commercial studies, various filter-feeding, deposit-feeding and grazing species can ingest fish waste particles. The aim now is to achieve IMTA optimization, where extractive organisms can ingest most of the finfish waste food and excretions. Any such design is likely to be complex incorporating a multidisciplinary approach, and therefore to date a reason why most studies have failed to prove the environmental and economic benefits of IMTA. Consequently, the aim of this study is to develop ways of selecting an ideal combination of species for a specific locality, manage the cultures in a way that ensures the maximum nutrient recycling feasible per unit of area; and ensure high growth rate of the extractive organisms while being financially beneficial. The approach taken was a combination of investigative literature reviews, computer modelling work and small-scale growth trials to determine the relative growth of extractive organisms fed fishfeed and waste, followed by the development of a systems-based model of interaction and growth efficiency for combinations of organisms within an IMTA system. This study starts by investigating, with small-scale laboratory experiments, the potential of two organic extractive species, the lugworm, Arenicola marina and the sea urchin, Psammechinus miliaris, as organic extractive components of IMTA systems. Their ability to consume and assimilate salmon faeces was evaluated as well as their remediation efficiency. This was done by comparing the carbon, nitrogen and phosphorus content of the pellet-faeces mixture to that of the sea urchin faeces and sea urchin gonad content. Their growth, gonadosomatic index (GSI) (for the sea urchins), tissue carbon, nitrogen and phosphorous content were compared between seaweed diets and a diet consisting of a mixture of salmon faeces and feed pellets. The results showed statistically significant gonad carbon content for the sea urchins fed with faeces. Similarly, statistically significant higher phosphorous content was found in the tissues of the lugworms fed with the mixture of salmon faeces and pellets than in the lugworms of the other two groups. The subsequent and main phase of this study was the development of a model for optimising IMTA performance. The modelling process included model development, run, optimization and risk assessment. The IMTA model developed consisted of Atlantic salmon Salmo salar, the sea urchin Paracentrotus lividus and the macroalgae Ulva sp. It simulates the growth as well as the uptake and release of nitrogen by these organisms under environmental conditions of a hypothetical site on the west coast of Scotland. The aim of the model was to maximize the potential of IMTA in terms of productivity and to reduce the amount of nutrients that are released in the environment, and thus to contribute towards a more sustainable and productive form of aquaculture. The IMTA model developed can be re-parameterised to simulate the growth and nutrient uptake of different species and the growth and nutrient uptake under different environmental conditions. This capacity of the model was used in order to do a comparative study of the nitrogen bioremediation potential of three different invertebrate species, cultivated as part of an IMTA. These species were the lugworm (Arenicola marina), the blue mussel (Mytilus edulis) and the purple sea urchin (Paracentrotus lividus). The results of this comparative study showed that weight for weight, M. edulis is more efficient in removing POM than P. lividus that is in turn better than A. marina with regard to the amount of nitrogen they can assimilate. But in terms of cultivation area required for the production of the same total biomass, P. lividus was better at removing POM followed by M. edulis and then by A. marina.

Ett stagnerat globalt fiske har lett till en snabb utökning av vattenbruket för att tillgodose den globala marknaden. Traditionellt vattenbruk har i västvärlden kännetecknats av monospecifika odlingar, ofta med mycket grav påverkan på sin omnejd. Ett återupptäckt alternativ till denna i längden ohållbara tappning av vattenbruk har därför växt fram. Integrerad multi-trofiskt vattenbruk (IMTA) är en teknik som, genom att odla organismer från flera trofiska nivåer tillsammans, kan minska utsläppen och öka produktiviteten hos en odling. En växande global befolkningen kommer dock leda till ökande konflikter mellan kustnära vattenbruk och intressenter såsom industrier, myndigheter och privatpersoner. Då vattenbruket fortsätter att växa skulle en lösning på dessa konflikter vara att rikta dess expansion mot det öppna havet. Frågan är då om IMTA vore effektivt utomskärs och hur det i så fall skulle kunna optimeras ur både produktions- och kostnadsperspektiv. Denna undersökning tyder på att en pelagial expansion skulle ge en positiv påverkan av de olika ekologiska, ekonomiska och infrastrukturella aspekter rörande utomskärs-IMTA. Dock kräver en sådan förflyttning omfattande förarbete i utvärdering av lämpliga lokaler. En analys av olika arter och dess egenskaper, monetära värde, tillika möjligheter att optimera systemet visar på att utomskärs IMTA är möjligt, men begränsas av ingenjörsmässiga faktorer. / The stagnated global fishing has led to a fast expansion of aquaculture to meet the increasing global demand for seafood. Traditionally aquaculture in the western world has been defined as large monospecific cultures, often with grave implications on its surrounding environment. An alternative to the conventional and unsustainable method has thus been rediscovered and developed. Integrated Multi-Trophic Aquaculture (IMTA) is a technique that, by cultivating organisms of different trophic levels together, can decrease effluents and increase the productivity of a farm. Furthermore, the growing global population will lead to increasing conflicts between coastal aquaculture and other stakeholders such as industries, governments, and private citizens. Since aquaculture continues to grow, a possible solution to such conflicts could be an offshore expansion of aquaculture. However, whether an IMTA system still would be effective in an offshore setting is unclear. This is also the case regarding the possibility to optimize an offshore IMTA system concerning productivity and investment costs.  The present article shows that a pelagic expansion of IMTA would positively affect the ecological, economical and infrastructural aspects regarding offshore IMTA compared to inshore IMTA. However, such a transposition would require comprehensive preparatory evaluations of suitable sites. An analysis of several species and their attributes, monetary value, and capability of optimizing the system indicates that offshore IMTA is possible but is limited by structural-engineering factors.

Aquaculture facilities involve mooring a large amount of artificial structures in offshore areas, which are colonised by a wide group of marine organisms, forming characteristic fouling communities. Many studies have focused on determining what sessile organisms are able to settle on nets, ropes and buoys, owing to the specific problems they cause and their economic cost to the aquaculture industry. Although sessile fouling communities are well-studied from the point of view of controlling this community on aquaculture facilities, little is known about the epifaunal mobile species inhabiting these artificial structures. This thesis addresses the study of crustacean amphipods, which have been scarcely studied regarding their species composition and relation to the habitats created by the sessile species and despite being detected in high abundances. After the general introduction, which sets the study framework, Chapter 1 is a preliminary study on the composition of fouling assemblages on aquaculture facilities in the Mediterranean Sea, comparing them with others such as those in harbours or offshore structures. Therein, it is shown that fouling communities are made up of mainly bivalves, algae, hydroids and bryozoans and amphipods usually represent more than 80 % of motile fauna associated with these organisms. Moreover, amphipod assemblages are characterised by seven frequent and dominant species: Elasmopus rapax, Jassa marmorata, Jassa slatteryi, Ericthonius punctatus, Stenothoe tergestina, Caprella equilibra and Caprella dilatata. A quantitative study of amphipod densities is carried out in Chapter 2, where mean amphipod densities observed in fish farm fouling amounted to 176,000 ind.m-2 and reached maxima up to 1,000,000 ind.m-2. There, the role of the macro- and microhabitat in supporting such amphipod communities is explored. The effect of the modification of marine currents on pelagic communities due to the introduction of coastal infrastructures is analysed in Chapter 3. Therein, it was detected a retention effect on planktonic amphipods near such facilities, noticeable in the increased abundance of hyperiids and migrating amphipods from different benthic and floating habitats. The influence of fouling amphipods on other habitats is analysed in Chapters 4 and 5, it is shown that fish-farm fouling acts as a source population of amphipods dispersing towards both defaunated sediments in soft-bottoms and surrounding floating habitats. Finally, in the last chapter, based on the possibility of using wild fauna already growing in fish farms, the applicability of amphipods as an accessory culture is tested in an offshore integrated multi-trophic aquaculture (IMTA) system with finfish as main fed species. Throughout this thesis it has been shown that fish-farming activities affect the amphipod assemblage in several ways such as the establishment of high population densities or the intimate connectivity between different subpopulations. As a result, a new potential commercial application arises from the possibility of using them as biofilters of aquaculture wastes, within an off-coast integrated multitrophic aquaculture system, promoting a more sustainable development of aquaculture in the marine environment. / Las estructuras artificiales que conforman las instalaciones de acuicultura en mar abierto suelen ser colonizadas por multitud de organismos marinos, que forman comunidades de fouling características en estas estructuras. Muchos estudios se han centrado en la descripción de los organismos sésiles que se desarrollan sobre cabos, redes y boyas de las instalaciones de acuicultura, debido a los problemas que generan para el cultivo y los costes adicionales que significan para la industria derivados de su necesaria eliminación. Sin embargo, aunque las comunidades de fouling sésiles han sido bien estudiadas desde el punto de vista de su control en las instalaciones de acuicultura, poco se sabe sobre la epifauna que habita estas estructuras artificiales. Esta tesis se centra en el estudio de los crustáceos anfípodos, los cuales aún no han sido estudiados en cuanto a la composición de especies y a su relación con los hábitats creados por los organismos sésiles, a pesar de haber sido detectados en grandes abundancias en las instalaciones de acuicultura. Después de una introducción general, que establece el marco de estudio, el capítulo uno es un estudio preliminar sobre las comunidades de fouling de las instalaciones de acuicultura en el Mediterráneo, comparándolas con las desarrolladas en otras estructuras artificiales como puertos o plataformas petrolíferas. En este capítulo, se demuestra que las comunidades de fouling están compuestas principalmente por bivalvos, algas, hidrozoos y briozoos y que más de un 80% de la fauna asociada a estos organismos son anfípodos. Además el poblamiento se caracteriza por la presencia de siete especies de anfípodos que son frecuentes y abundantes: Elasmopus rapax, Jassa marmorata, Jassa slatteryi, Ericthonius punctatus, Stenothoe tergestina, Caprella equilibra y Caprella dilatata. Un estudio cuantitativo de las densidades de estos anfípodos se lleva a cabo en el capítulo 2, donde se encuentra que la densidad media es de 176.000 ind.m-2, con máximos de más de 1.000.000 ind.m-2. Allí se explora también el papel de los macro y microhábitats en mantener dichas poblaciones de anfípodos. El efecto de la modificación de corrientes sobre las comunidades plantónicas debida a la instalación de las piscifactorías se analiza en el capítulo 3. En él, se detectó una retención de los anfípodos planctónicos cerca de las instalaciones, evidenciada por el incremento en las abundancias de hipéridos y de anfípodos migradores desde diferentes hábitats bentónicos flotantes. La influencia de las grandes densidades de anfípodos del fouling sobre otros hábitats se estudia en los capítulos 4 y 5, donde se observó que el fouling actúa como fuente de anfípodos migradores, exportando individuos que colonizan tanto sedimentos defaunados en el fondo marino como otros hábitats flotantes cercanos. Finalmente, en el último capítulo se analiza la posibilidad de aprovechar la producción natural y la conectividad observadas a través del cultivo de anfípodos como parte de un sistema de acuicultura multitrófica integrada (AMTI) en mar abierto con peces como especie principal. A lo largo de esta tesis, se demuestra que la acuicultura influencia las poblaciones de anfípodos marinos, tanto en el establecimiento de grandes densidades de población como en la conectividad entre las diferentes subpoblaciones. Como resultado, surge una nueva aplicación comercial de la posibilidad de usar los anfípodos del fouling como biofiltros, reciclando los residuos de la acuicultura dentro de un sistema de acuicultura multitrófica, garantizando así un desarrollo más sostenible de la acuicultura en el medio marino.

Orientador: Patricia Maria Contente Moraes-Valenti / Resumo: O experimento inicial teve como objetivo avaliar o desempenho produtivo do tambaqui, camarão-da-amazônia, e curimbatá em sistema integrado. Foram avaliados os parâmetros zootécnicos e limnológicos dos sistemas de cultivo com tambaqui e camarão-da-amazônia e com tambaqui, camarão-da-amazônia e curimbatá. Após o período de cultivo dos animais foram feitos plantios de hortaliças no sedimento dos viveiros que é rico em nutrientes resultantes do cultivo anterior. O objetivo do segundo experimento, foi determinar o desempenho produtivo das culturas de alface, almeirão, espinafre e rúcula em sistema de integração agricultura – aquicultura (IAA), visando a produção em pequena escala. Os resultados observados no primeiro experimento não mostraram diferença entre os tratamentos, mas indicaram que o cultivo de tambaqui, camarão-da-amazônia e curimbatá é tecnicamente viável para a fase inicial de engorda (recria). Assim, o cultivo com três espécies favorece a produtividade e melhor eficiência do sistema de cultivo. Já nos resultados do segundo experimento, a rúcula apresentou maior produtividade entre as hortaliças cultivadas, apresentando diferença significativa entre os tratamentos realizados. Assim, os dados de produtividade mostraram a possibilidade do cultivo de hortaliças em viveiros de aquicultura utilizando o sedimento como substrato. / Abstract: The initial experiment had as objective to evaluate the productive performance of tambaqui, Amazon river prawn, and curimbatá in an integrated system. The zootechnical and limnological parameters of the cultivation systems with tambaqui and Amazon river prawn and tambaqui, Amazon river prawn and curimbatá were evaluated. After the period of cultivation of the animals were planted of vegetables in the sediment of the nurseries that is rich in nutrient resulting from the previous cultivation. The objective of the second experiment was to determine the productive performance of lettuce, endive, spinach and arugula cultures in an agriculture - aquaculture integration system (IAA), aiming at small - scale production. The results observed in the first experiment showed no difference between the treatments, but indicated that the cultivation of tambaqui, Amazon river prawn and curimbatá is technically feasible for the initial fattening phase. Thus, the cultivation with three species favors the productivity and better efficiency of the cultivation system. In the results of the second experiment, to date, there were significant differences between treatments, with arugula being the most productive species. The productivity data showed the possibility of growing vegetables in aquaculture nurseries using the sediment as a substrate. / Mestre

To assess the spatial distribution of nutrient wastes around an open-water integrated fish/mollusk/kelp farm in-situ kelp bioassays were employed. Growth rates were measured over a four-month growing season and used as a proxy for relative nutrient concentrations. Seasonality and depth effects on growth rate were also assessed. Growth around the pens was 0.20 cm • day-1 higher than at the control, and reached a maximum of 1.4 cm • day-1. Optimal growth was achieved at 8 m. Growth at 8 m was significantly higher by 1.5 cm • day-1 compared to surface waters at 2 m. Early spring had the highest growth rates with a peak of 1.4 cm • day-1 recorded on June 21. This study re-iterates the fundamental benefits of IMTA and shows the potential of in-situ assay as an alternative to error-prone and costly water sampling to asses nutrient status in water. / Graduate

The goal of this thesis was to detail spatial and temporal organic particulate dynamics at an integrated multi-trophic aquaculture (IMTA) site on the west coast of Vancouver Island, Canada. To accomplish this goal, in-situ optical measurements of particulate scattering (bp), particulate backscattering (bbp) and the particulate backscattering ratio (bbp:bp) were collected in conjunction with discrete sampling for particulate organic carbon (POC) and chlorophyll a (chl a) concentrations. These measurements were performed over three seasons (autumn, winter and summer) at reference sites and at sites within and directly adjacent to the fish component of the IMTA system. Chapter 2 of this thesis focused on the examination of bio-optical relationships over various timescales (seasonally, daily and within-day) to describe temporal and vertical particulate variability and to assess the effectiveness of bio-optical methods for environmental monitoring. Autumn showed low bio-optical magnitudes with distinct lower cage increases possibly attributable to aquaculture derived wastes. In spring, sampling was performed over diatom bloom conditions, dominating the bio-optical measurements. During summer, an Emiliania Huxleyi bloom likely occurred, strongly enhancing bbp and bbp:bp magnitudes in the thermally stratified upper water column. Throughout these conditions, bp was predominantly influenced by chl a suggesting sensitivity to phytoplankton concentrations. While bbp was conditioned by chl a during the diatom bloom, it was also highly sensitive to the presence of inorganic and likely detrital materials. Finally, bbp:bp was sensitive to particulate compositions, showing low values (< 0.010) in diatom dominated waters and high values when refractive coccoliths were likely present. Notably, in autumn, bbp:bp was conditioned by detrital particles and along with bbp, showed post-feeding lower cage increases suggesting that these parameters could be useful candidates for particulate waste tracking during low ambient particle conditions. In chapter 3, the temporal, vertical and horizontal dispersion of the aquaculture derived particulate wastes are detailed. Autumn was the only period to show waste signals, likely due to their quick dilution into the particulate rich fields in spring/summer. During this period, post-feeding particulate waste increases were focused at the bottom of the cage with possible vertical sinking towards the seafloor. Minimal horizontal dispersion towards the scallop portion of the system was observed; however, more comprehensive sampling over differing hydrographic regimes is necessary to characterize waste dispersion. Based on our temporally limited autumn results, the most appropriate placement of uptake species for waste assimilation would be directly below the studied cage. Our results highlight the need for high spatial and temporal resolution methods for particulate monitoring within IMTA settings as discrete sampling may miss “patchy” waste dispersal streams. The bio-optical measurements performed during this study could fill this need as they can provide high resolution information on particulate concentrations and compositions not achievable solely through the use of discrete water sampling. With further research, optical instrumentation could be incorporated into IMTA systems allowing for the near real time and continuous collection of data on particulate dynamics. This knowledge could greatly aid in the design and implementation of systems optimized for waste removal by uptake species. / Graduate / 0792 / 0768 / 0752 / jdelbel@uvic.ca

Among efforts to develop sustainable approaches towards the intensive rearing of finfish within open marine waters, is the development of integrated aquaculture techniques. Integrated Multi-Trophic Aquaculture (IMTA), has been promoted as a way to reduce unwanted environmental impacts associated with the intensive production of marine finfish within net-pens. The principle aim of this concept, is the bioremediation of nutrient discharges from fish aquaculture. This is to be achieved by integrating fish cultivation with the growing of species from lower trophic levels, which use the nutrient discharges as a food source. Many studies have been performed that investigate the ability of various species of macroalgae to remove dissolved nutrient discharges, and the ability bivalves to remove solid-bound nutrients, presented as either fish faeces, or an enhanced production of phytoplankton that may be promoted by nutrients emitted by fish-farms. IMTA has also been suggested as a means to improve overall productivity per unit of feed applied to fish, through the conversion of nutrient emissions into additional biomass, such as the tissues of macroalgae or bivalves. Within the research community which focuses upon the environmental impacts of aquaculture, there is a growing awareness that sustainable solutions to aquaculture production cannot be realised through a focus restricted to the growing-phase, and to a limited set of environmental impacts which may this activity may produce. This is because changes to a specific production phase often promote changes at phases located elsewhere along a products value chain. Life-Cycle Assessment (LCA), is a method employed for modelling the environmental impacts that may potentially be generated across the value chain of a product. It is particularly useful for identifying instances of environmental impact shifting; a term used to describe situations where efforts to reduce the contribution of a specific production phase towards one or more environmental impacts, has the effect of either displacing this contribution to another phase, or increases the contribution of production towards different environmental impacts. Despite its apparent suitability, LCA has not previously been fully applied to the environmental impact modelling of open-water IMTA systems. The work presented in the following thesis advances this research front, by using LCA to explore the potential for environmental problem shifting occurring as a consequence of replacing intensive monoculture production, with IMTA. Comprehensive datasets have been acquired from the Chilean aquaculture industry, describing the production of aquafeed and Salmo salar, as well as for the production of the Phaeophytic macroalga, Macrocystis pyrifera, and the molluscan bivalve, Mytilus chilensis. Using LCA methodology, the production of salmon feed, and the production of S.salar, M.pyrifera and M.chilensis, have been assessed for their capacity to contribute towards a variety of global-scale, environmental impacts. IMTA consisting of either S.salar and M.pyrifera, S.salar and M.chilensis, or all three of these species, and combined at ratios required for a bioremediation efficiency of 100 %, 50%, or 20 % of either nitrogen or phosphorous emission from fish, is compared to the monoculture production of S.salar. The comparison is based upon a standardised functional unit, with each species produced through IMTA, being modelled as part of the reference flow required to fulfil the functional unit. Monoculture is compared to IMTA upon the basis of nutritional function, by using a functional unit of mass-adjusted protein content, and mass-adjusted economic value. The use of economic value is based upon the ‘best-case’ assumption, that it serves as a proxy for the total nutritional function that each product offers to human society. The LCAs presented in this study have produced a number of results. Salmon ingredients derived from agricultural crops and animals account for the majority (between 71 % to 98 %) of contributions towards the impacts of compound salmon feed. In general, agricultural crops ingredients contribute more to these impacts than do agricultural animal ingredients, and account for between 31 % and 87 % of the contributions from all ingredients and inputs. In contrast, the combined supply of fish meal and fish oil from capture fisheries is responsible for between 0.13 % and 11 % of all impacts. Vegetable oil accounts for the vast majority of contributions from ingredients derived from agricultural crops. Vegetable oil is modelled as a 50 : 50 blend of sunflower oil and rapeseed, oil, but sunflower oil accounts not only for most of the contributions from vegetable oil, it is responsible for over 50 % of the contributions that all agricultural crop based ingredients contributes towards some impact categories. Replacing sunflower oil with rapeseed oil reduces the contributions of salmon feed by between 6 % and 24 % across 10 out of the 11 impact categories. When compared upon the basis of equal weight, the contributions of fish oil are between 18 % and 99 % lower than those from rapeseed oil. The production of feed is responsible for the majority of contributions (between 32 % and 86 % ) to all impacts of salmon grow-out production. The production of salmon-smolts accounts for between 3 % and 18 %. The majority (64 %) of contributions towards the eutrophication potential of salmon production are from nutrient emissions, which are the result of fish metabolism, whilst nutrients released through the production of feed, the majority of these being from the agricultural production of crop and animals, account for 32 %. Feed production is also a major contributor to the impacts of land-based smolt production, but these contributions (between 12 % and 37 % across all impact categories) are of a lower magnitude than those from the supply of feed to the grow-out phase. Inputs of salt, and inputs of both electricity produced in a diesel power generator and obtained from the national electricity network, are also notable contributors (between 5 % and 67 %, 4 % and 29 %, and 2 % 47 %, respectively) towards the impacts of smolt-production. The main contributors towards the potential impacts of kelp grow-out production (excluding eutrophication potential) are the supply of infrastructure (between 14 % and 89 %), operation of a diesel-powered motorboat for maintenance purposes (between 1 % and 89 %), and the supply ‘of seeded cartridges’ (between 9 and 49 %). The major contributors from the production of ‘seeded cartriges’ in a land-based facility are the supply of electricity from the national electricity network, the supply of fresh water, and the treatment of waste water. The impact potentials of producing seed in this facility might be reduced if the scale of operation is increased. Removal of nitrogen and phosphorous upon the harvesting of kelp is calculated based upon kelp tissue contents of these nutrients. The harvesting of 200 tonnes ha / yr-1, results in a eutrophic potential with a negative value (-376.51 kg of phosphate equivalents). The removal of such a quantity of nutrients might be beneficial if the local marine environment is at risk of hypernutrification, but when no such problem is present, the potential for undesirable consequences of nutrient sequestration should be considered. The major contributor towards the impacts of mussels is the provision of infrastructure (between 25 % and 99.5 %, excluding eutrophication potential). Infrastructure is also responsible for the majority of contributions from mussel seed production. The provision of cotton mesh bags, which are used to aid attatchment of seed to drop-ropes in the grow-out phase, account for between 37% and 99 % of the contributions from the infrastructure from the grow-out phase. This result suggest that either the impacts of mussel production can be reduced by using an alternative material with lower environmental impact potentials, or the inventory data describing the producing of cottonmesh bags requires some improvement. The outcomes of the LCAs of the different IMTA scenarios, are interesting. The results show that choice of species, and the ratios of their combination as required for the different efficiencies of bioremediation, can have a significant effect upon the comparison between IMTA and monoculture. / The study demonstrates a potential for environmental problem shifting as being a consequence of IMTA, especially when the functional unit is mass-adjusted economic value. As bioremediation efficiency increases, contributions towards eutrophication decrease. However, this reduction is achieved at the cost of increasing the contributions of IMTA towards those impact categories, such as ‘ozone layer depletion,’ for which it has a greater contribution than does monoculture. In general, it cannot be concluded from these results that open-water IMTA represents a more sustainable alternative to the monoculture production of Atlantic salmon. The sustainability of IMTA is shown to be dependent upon a variety of trade-offs, between individual environmental impacts, and between these impacts and the nutritional function that the system is capable of providing.