Globally, Atlantic salmon aquaculture is faced with a critical challenge: How best to deliver long-term sustainable growth, whilst optimising the opportunity for the expansion of the industry presented by an increasing global seafood demand? The thesis presents a novel framework of complementary decision support approaches to enable decision-makers to better understand the factors influencing aquaculture development, and examine alternative production (growout) technologies that more effectively address the challenges associated with intensification and expansion. The framework was developed through a combination of fieldwork (international data-gathering), key stakeholder discussions, and the application of targeted qualitative and quantitative analytical approaches; using the Tasmanian industry as a Case Study. The initial research focused on shorter-term (tactical) decision support. A situational analysis defined the business environment, and appraised viable expansion options (offshore, closed-containment and extractive bio-remediation). An economic analysis of selected options then provided a comparison of financial performance and risk. The outputs of this initial component next informed strategic decision-making approaches; employing scenario analysis to explore plausible strategies for the adoption of land-based recirculating aquaculture systems; and qualitative modelling to understand the causal dynamics driving and regulating the industry, and their impact on technology selection. Whilst it was clear that business economic viability is paramount, the results suggested that societal acceptance (the Social License to operate) is playing an increasingly important role in influencing business decisions. There is no single ‘right' technological solution; social acceptance, in particular considerations regarding human wellbeing, trust, and animal welfare concerns, will shape the business environment and therefore technology selection. The research emphasised the importance of employing a balance of tactical and strategic decision-making techniques, and of engaging with a broad range of industry stakeholders. It also highlighted the complexity and dynamic nature of the industry and that key variances (economic, regional, strategic, technological, and temporal) must be included in decision-making.

In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.

Abalone Haliotis midae farming in South Africa is highly intensive, employing pump-ashore, flow-through systems. Despite the known sensitivity of abalone to water quality, there is only a rudimentary understanding of water quality dynamics on South African abalone farms and its effects on abalone production. Furthermore, the potential for reusing the relatively dilute abalone farm effluent to culture other animal species has not been investigated. This study investigated the dynamics of water quality and growth on a South African abalone farm and assessed the suitability of the effluent for the culture of silver kob Argyrosomus inodorus and bloodworm Arenicola loveni loveni. Monitoring of water quality and abalone growth in abalone tanks revealed that oxygen concentrations decreased, while H⁺ ion and free-ammonia (NH₃) concentration increased in a gradient between the inflow and outflow. Abalone growth was positively correlated with oxygen concentration and negatively correlated with free-ammonia and H⁺ ion concentration. The oxygen (O) concentration of the farm influent was dependent upon the influents’ temperature (T) and was described by the relationship O (mg L⁻¹) = 11.244 – 0.208T (r²=0.74). Linear regression analysis of data collected from abalone farm tanks revealed that the concentration of total ammonia at the outflow of abalone tanks (μg TAN L⁻¹) was dependant upon temperature (°C), flow-rate (L s⁻¹ kg⁻¹ H. midae), abalone size (g) and length of time since the tank was last cleaned (d) (n = 125, r² = 0.80). The production of total ammonia (μg TAN s⁻¹ kg⁻¹) was related to temperature, abalone size and days that the tanks remained un-cleaned (n = 125; r² = 0.81). A diurnal cycle of respiration was evident in abalone tanks with higher oxygen consumption and H+ ion production at night. The oxygen concentration of farm effluent was related to temperature, farm biomass and flow rate by means of a linear regression equation (n = 40; r² = 0.69). The results demonstrated the importance of optimising the flow-rate per unit of biomass for various temperatures and sizes of abalone. As abalone size and temperature cannot be controlled under farm conditions, the flow-rate per unit of biomass which the abalone culture system receives will determine the quality of the culture water. The specific growth rate (0.48 ± 0.01 % BW d⁻¹), mortality (1.8 ± 0.5 %), feed conversion ratio (3.0 ± 0.2) and protein efficiency ratio (1.0 ± 0.1) of silver kob kept in either abalone farm effluent or control seawater for 120 days did not differ significantly (t-test, P>0.05). A 90 day growth trial indicated that abalone farm effluent is a suitable culture medium for bloodworm. Bloodworm supplied with control seawater lost weight at 0.19 ± 0.04 % BW d-1, while those given abalone effluent grew at 0.39 ± 0.07 % BW d⁻¹. Mortality was 6 ± 3 % in effluent and 11 ± 8 % in seawater. The bloodworm were efficient at processing solid waste. Abalone farm effluent initially contained 7.7 ± 13 mg L⁻¹ more suspended solids than control seawater, which contained 3.5 ± 0.5 mg L⁻¹, but after passing through bloodworm systems the concentration in abalone effluent was reduced to only 1.4 ± 3.5 mg L⁻¹ above that in control seawater. Therefore, abalone farm effluent could be reused as a culture medium for both silver kob and bloodworm. Future work is needed to investigate aspects of the feasibility of such systems such as growth rates at different sizes and stocking densities.

The South African coastline has a high potential for mariculture development, particularly in land-based systems, due to excellent water quality, good infrastructure, and relatively cheap land in certain areas. Development of mariculture however, has been slow primarily due to the absence of a national sector development plan to coordinate contribution to development by government, industry and academia. Recent mariculture development plans however, supported by government commitment to stimulate coastal development, offers new opportunity for the sector's growth. These new sector development plans require a multi-disciplinary intensive information base with a strong regional and national spatial component. Geographic Information System (GIS) is a spatial analytical tool, which is capable of handling such large coastal databases and analysing them. Nevertheless, many mariculture GIS planning applications, often developed in isolation and with limited practical use for decision makers, highlighted the need to develop GIS in relation to the mariculture sector development plan. Hence, the aim of this study was to develop and evaluate a GIS for the national and regional mariculture sector planning process in South Africa, in order to identify potentially suitable areas along the South African coastline for mariculture operations. The GIS development in this study was based on the mariculture planning approach developed by PAP/RAe (1996), which recognizes the variations of scales in mariculture planning. Three case studies, representing the diversity of the South African sector plan, were selected to develop the GIS. They included: a national suitability analysis for all land-based culture systems, a specific national analysis on abalone ranching, and a detailed regional analysis of land-based culture and abalone ranching along the Namaqualand coastline. The GIS was developed separately for each case study based on a strategy consisting of six main phases, including: identification of project requirements, developing analytical framework, selection and location of data sources, organization and manipulation of data, analysing data and verifying and evaluation of the outputs. Biophysical, coastal use, and infrastructure criteria were collected, sorted and analysed to identify development constraints. Based on a set of conditions, and Boolean logic and arithmetic operations, unsuitable areas were identified and eliminated. Main constraints for national land-based development included competition over space along KwaZuluNatal Province coastline and restricted access to the coast along the south region of the Northern Cape Province, Wild Coast along the Eastern Cape Province, and Maputaland along KwaZulu-Natal Province. Ten areas along the country coastline were therefore identified as potentially suitable for land-based mariculture. Furthermore, South African abalone ranching potential was found to be limited mostly along the Western and Northern Cape Province's coastline due to the high risk of Paralytic Shellfish Poison (PSP) occurrences, alternative resource use and activities such as commercial fishery, poaching, and conservation. Hence, a total of nine areas along the Northern Cape, Western Cape, and Eastern Cape coastlines were identified as premier areas for abalone ranching. The regional study along the Namaqualand coastline revealed potential conflict between mining activity and mariculture development due to security issues and restricted access to the coast. Land-based mariculture development was confined to the four main coastal urban areas. The highest potential for land-based mariculture was along Port Nolloth and Kleinsee coastlines, whereas marine-based (i.e. abalone ranching) potential was poor along the north part of the coast due to intense marine mining activities, restricted access to the coast, and low kelp bed density. High potential abalone ranching areas were identified south to Kleinsee, and around Port Nolloth. Potential conflict with marine mining activity was minimal since it was localised and not related to kelp bed locations. It was concluded that GIS is a relevant and compatible tool for South African mariculture sector planning. However, future development of GIS as integrated planning tool in mariculture and coastal planning, requires updated spatial data (e.g. recreational activity), and continued interaction among project planners, mariculture specialists and GIS analysts.

Inicialmente, os cultivos foram desenvolvidos empiricamente e voltados para a produção de alimento humano. Mais tarde, com a descoberta da utilidade dos ficocolóides, os cultivos passaram a ser realizados também para a produção de biomassa para sua extração. Entretanto, sustentabilidade da indústria de macroalgas reside em grande parte nos cultivos, uma vez que os bancos naturais não são suficientes para atender a demanda crescente. Apesar do ágar estar presente nas paredes celulares de espécies de Gracilaria, seu ágar não era explorado comercialmente por apresentar características consideradas inadequadas pela indústria. A descoberta de que a hidrólise alcalina dos grupos sulfato do ágar aumentaria sua força de gel impulsionou a exploração comercial deste gênero. Assim, espécies pertencentes ao gênero Gracilaria são cada vez mais empregadas para a produção de ágar alimentício e a sua tem sido consideravelmente aumentada por meio do desenvolvimento de técnicas de cultivo. Embora a explotação de macroalgas no Brasil tenha se iniciado por volta de 1940, seu impacto social e econômico é reduzido. Estudos sobre a viabilidade de cultivo de macroalgas foram realizados ao longo da costa brasileira, com resultados positivos sobre o potencial de algumas espécies. Apesar disso, o país ainda não possui cultivos de macroalgas em escala comercial. Com base nestes antecedentes, o presente trabalho avaliou o desempenho do cultivo no mar de Gracilaria domingensis e de G. caudata e caracterizou as propriedades do seu ágar (rendimento e qualidade), na Enseada de Armação do Itapocoroy (Penha, Santa Catarina). Os resultados mostraram que o sistema de cultivo testado para ambas espécies é viável na Enseada. O ágar de G. domingensis extraído com CaCl2 apresentou melhores rendimentos e teores de 3,6-anidrogalactose, enquanto a extração com NaOH mostrou ser a mais adequada para G. caudata e ambas espécies mostraram potencial como matéria-prima para extração de ágar alimentício. / Seaweed cultivation in the world began with empirical methodologies to propagate some species utilized as food. Later on, with the discovery of a process to extract and purify agar, it was soon realized that, because of the large volumes needed by a growing industry this activity would only be sustainable if based on mariculture once the natural beds were being depleted. Despite it was known that agar could also be extracted from Gracilaria species, besides the traditional species of Gelidium, that genus yielded a product with lower value. It was only after the discovery that an alkaline treatment could remove part of the sulphate that reduced the gel strength, and therefore improved the agar quality, that the commercial cultivation of Gracilaria species really got momentum and developed continuously. Nowadays, most of the agar produced in the world is based on Gracilaria spp. Although the exploitation of seaweeds for agar production in Brazil started as early as 1940, up to now our production is still very modest due to the limited biomass in the natural beds. Several attempts to cultivate local Gracilaria spp. have been made, some of which with promising results, but a real commercial mariculture never developed in Brazil so far. Based on that we developed this project aiming at the development of viable techniques to cultivate two species of Gracilaria common at the Enseada de Armação do Itapocoroy (Penha, Santa Catarina): Gracilaria domingensis and G. caudata. We also tested different protocols to better extract the agar from the selected species, comparing their yields and quality. Our results show that with some adaptations of the methodologies for cultivation and agar extraction utilized elsewhere it may be possible to make this a viable alternative.

Most of what is known about the ways in which strongly interacting species affect ecological communities stems from changes to community structure revealed in contemporary research. However, trophic downgrading has limited the temporal extent to which inferences can be drawn. The aim of my Dissertation was to expand on the strongly interacting species concept by examining species interactions at a historical scale, in a textbook example of a strongly interacting and keystone predator. The sea otter, Enhydra lutris, was driven to near-extinction but is recovering in parts of its range, providing a mosaic of areas with and without sea otters. This mosaic allowed for a series of natural experiments, which I conducted using behavioural observations, genetic tools, and archaeological methods, to examine sea otter effects spanning contemporary (last ~40 yrs.), and late-Holocene (~3500-150 yrs. ago) timeframes, and on an evolutionary scale that inferred middle-Pleistocene interactions. In Chapter 2, my coauthors and I found that sea otter use of clam-based niches increased as occupancy-time increased, and that bachelor groups of male otters primarily inhabited these niches, findings that informed and inspired subsequent questions. In Chapter 3, we found that where sea otters were established for 20-30 years, the disturbance to eelgrass (Zostera marina), caused by sea otters digging for clams and other infaunal prey, was correlated with ~25% greater eelgrass allelic richness than where otters were present <10 yrs, or absent. We posit that sea otter digging has long-influenced the genetic diversity and resilience of eelgrass – perhaps since the middle Pleistocene. In Chapter 4, we asked how two strongly interacting species – people and sea otters – co-existed for millennia where they both consumed clams. We used assemblages of live and otter-cracked butter clams (Saxidomus gigantea), to confirm the ecological effects that sea otters exert today. We measured clams from archaeological assemblages in areas densely populated with clam gardens – terraced beaches that enhance clam habitat and productivity – and found that sea otters reduced the sizes of ancient clams, acting as ecologically effective predators in the mid-to-late Holocene. However, clam harvests were stable for thousands of years, with or without otters. We suggest that clam gardening supported coexistence of people and otters in the past, and could function the same way today. Collectively, we found that a few, perhaps long-forgotten, interactions increased the breadth of the strongly interacting species concept. In Chapter 5, I suggest that such rediscoveries could occur in other systems. Many large vertebrates have suffered population declines, but the most insidious losses accompanying these, are the losses of ecological interactions that become unknowable, and thus cannot be intentionally restored. By searching out ancient interactions, long-forgotten relationships have the potential to be recovered, and to inform our understanding of contemporary systems. / Graduate / 2022-09-10

Cultivation of marine ecosystems began in the early Holocene and has contributed vital resources to humans over millennia. Several more recent cultivation practices, however, erode biodiversity. Emerging lines of evidence indicate that certain resource management practices may promote favourable ecological conditions. Here, I use the co-occurrence of 24 First Nations clam gardens, shellfish aquaculture farms, and unmodified clam beaches to test several hypotheses concerning the ecological implications of managing intertidal bivalve populations. To so do, in 2015 and 2016, I surveyed epifaunal (surface) and bivalve communities and quantified each intertidal sites’ abiotic conditions, including sediment characteristics and substrate composition. In 2017, I generated three-dimensional models of each site using structure-from-motion photogrammetry and measured several aspects of habitat complexity. Statistical analyses use a combination of non-parametric multivariate statistics, multivariate regression trees, and random forests to quantify the extent to which the intertidal resource cultivation structures nearshore biodiversity Chapter 1 outlines a brief history of humanity's use of marine resources, the transition from extracting to cultivating aquatic taxa, and the emergences of the northeast Pacific’s most prevalent shellfish cultivation practices: clam gardens and shellfish farms. Chapter 2 evaluates the ability of epifaunal community assessment methods to capture species diversity by conducting a paired field experiment using four assessment methods: photo-quadrat, point-intercept, random subsampling, and full-quadrat assessments. Conducting each method concurrently within multiple intertidal sites allowed me to quantify the implications of varying sampling areas, subsampling, and photo surveys on detecting species diversity, abundance, and sample- and coverage-based biodiversity metrics. Species richness, density, and sample-based rarefaction varied between methods, despite assessments occurring at the same locations, with photo-quadrats detecting the lowest estimates and full-quadrat assessments the highest. Abundance estimates were consistent among methods, supporting the use of extrapolation. Coverage-based rarefaction and extrapolation curves confirmed that these dissimilarities were due to differences between the methods, not the sample completeness. The top-performing method, random subsampling, was used to conduct Chapter 4’s surveys. Chapter 3 examines the connection between shellfish biomass and the ecological conditions clam garden and shellfish farms foster. First, I established the methodological implications of varying sediment volume on the detection of bivalve diversity, abundance, shell length, and sample- and coverage-based biodiversity metrics. Similar to Chapter 2, this examination identified the most suitable method, which I used during the 2015 and 2016 bivalve surveys. The analyses quantified several interactions between each sites’ abiotic conditions and biological communities including, the influence of substrate composition, sediment characteristics, and physical complexity on bivalve communities, and if bivalve richness and habitat complexity facilitates increases in bivalve biomass. Chapter 4 quantifies the extent to which managing intertidal bivalves enhance habitat complexity, fostering increased diversity in the epifaunal communities. This chapter combines 2015, 2016, and 2017 surveys of the sites' epifaunal communities and habitat complexity metrics, including fractal dimension at four-resolutions and linear rugosity. Clam gardens enhance fine- and broad-scale complexity, while shellfish farms primarily increase fine-scale complexity, allowing for insights into parallel and divergent community responses. Chapter 5 presents an overview of shellfish as a marine subsidy to coastal terrestrial ecosystems along the Pacific coast of North America. I identified the vectors that transport shellfish-derived nutrients into coastal terrestrial environments, including birds, mammals, and over 13,000 years of marine resource use by local people. I also examined the abundance of shellfish-derived nutrients transported, the prolonged persistence of shellfish subsidies once deposited within terrestrial ecosystems, and the ecological implications for recipient ecosystems. Chapter 6 contextualizes the preceding chapters relative to the broader literature. The objective is to provide insight into how multiple shellfish cultivation systems influence biological communities, how ecological mechanisms facilitate biotic responses, and summarize the implications for conservation planning, Indigenous resource sovereignty, and biodiversity preservation. It also explores future work, specifically the need to support efforts that pair Indigenous knowledge, and ways of knowing with Western scientific insights to address conservation challenges. / Graduate / 2022-12-13

Thesis (MTech (Oceanography))--Cape Peninsula University of Technology, 2010 / Coral reefs are in a worldwide state of crisis due to overexploitation. One of the factors contributing to the over exploitation is the marine ornamental industry. This industry utilises a diversity of organisms, comprising approximately 1470 species of fish and more than 300 species of invertebrates. Between April and December 2007, five of the 18 companies who had import permits for South Africa, imported a total of 359 different ornamental species, 252 of these were fish species while the remaining 107 species were invertebrates. During these nine months a total of 32 005 individual organisms were imported into South Africa by the five companies. There were two groups of fish that represented the highest import volumes. These were Amphiprion spp. and Pomacentradae spp., as well as the Gobidae spp. These groups represented 38% and 19% respectively of the total number of fish imported" Aquaculture has the potential to substantially reduce the harvesting pressure on coral reef organisms globally. A small-scale multi-species mariculture system was designed and constructed for benthic egg-laying species of fish (brood stock), corals, and ornamental algae. The system was designed to be low cost and easy to operate. The total capital costs for the system was R15 680.70. In order to estimate the potential yield of an aquaculture facility it is important to know the growth rate of the proposed species under pilot conditions. The use of artificial lighting regimes in aquaculture comes at a financial cost. It is for this reason that it is important to know what lighting scenario yields the highest growth rate of corals. The effects of photoperiod were tested on Sinularia sp. of coral. Two photoperiods were tested, namely: Groups (8:16 h Iight:dark cycle) and Group12 (12:12 h light:dark cycle). No significant difference in weight was found between Group8 and Group12 (p = 0.975). There was however a significant increase (p = 0.002) in Surface-area Pixel Value (SPV) for Groups (1996.73 millipixels pixel-1 day -1) compared to Group12 (983.73 millipixels pixel-1 day -1). The use of a 8:16 h lightdark cycle can thus yield coral of a larger size but not necessarily a higher mass.

A partir do Gerenciamento Costeiro Integrado como referencial teórico, este trabalho reconhece a necessidade de organização da sociedade civil para sua fundamental participação nos processos de discussão e elaboração de políticas públicas. A maricultura se apresenta como atividade emergente e alternativa às comunidades pesqueiras, no Litoral Norte de São Paulo, porém demanda organização para sua efetiva inserção nos espaços participativos. Para isto, foram identificadas e analisadas as instâncias participativas, relacionadas à maricultura, como associações, colônias e conselhos, existentes nos quatro municípios do Litoral Norte do Estado de São Paulo, Ilhabela, São Sebastião, Caraguatatuba e Ubatuba, com foco no processo de representação social. Foram feitos levantamentos das formas de associativismo e representação e dos conselhos de aquicultura atuantes na região; análises da estrutura organizacional destes conselhos e associações com base em seus estatutos sociais, leis ou decretos de criação e regimentos internos como forma de identificar maiores ou menores graus de institucionalidade e práticas de gestão que influenciem na viabilidade e eficiência da representação; e, análises da representação das associações nos conselhos, a partir da perspectiva de seus membros e da observação das reuniões. Grande sobreposição de funções sobre os poucos maricultores reconhecidos como lideranças pelos demais foi registrada, o que acaba por gerar um ciclo vicioso que mantém a maioria dos membros fora do processo de discussão por acreditarem que outra pessoa, mais bem preparada, irá fazê-lo. A hipótese de que a baixa capacidade de representação está diretamente relacionada à relativa pequena importância da maricultura na vida do associado e do representante foi discutida e respaldada com as observações realizadas. O envolvimento da sociedade civil nos processos participativos, como representantes e representados, mostrou-se dependente da organização e do próprio funcionamento dos espaços participativos (e.g., agenda definida, auxílio transporte e alimentação). / From the Integrated Coastal Management as a theoretical framework, this paper recognizes the need for civil society organizations for their participation in the fundamental processes of discussion and public policy development. The mariculture activity is presented as emerging alternative to fishing communities on the North Coast of São Paulo, but demand for their effective integration organization in participatory spaces. For this, we identified and analyzed the participatory bodies, related to mariculture, such as associations, councils and settlements, existing in the four municipalities of the North Coast of São Paulo, Ilhabela, São Sebastião, Ubatuba and Caraguatatuba, focusing on the process of social representation. There have been made surveys on the forms of associations, representation and advice from the current aquiculture in the region; analysis of the councils and associations\' organizational structure based on their social status, laws or decrees of creation and internal regulations; in order to identify greater or lesser degrees of institutional and management practices that influence the viability and efficiency of the representation analysis of representation on the boards of associations, from the perspective of its members and observation of meetings. Large overlapping functions on the few shellfishermen recognized as leaders by others was registered, which ultimately generates a vicious cycle that keeps most members out of the discussion process for believing that another person, better prepared, will do it. The hypothesis that the low capacity of representation is directly related to the relative importance of small mariculture in the life of the member\'s representative was discussed and supported with the observations. The involvement of civil society in participatory processes, as representatives and represented, has been shown dependent on the organization and proper functioning of participatory spaces (eg, set agenda, transportation and food aid).

Atualmente, o beijupirá é a espécie nativa que reúne o maior número de características em comum com outras espécies aquáticas cultivadas comercialmente, sendo assim, indicada para ser a espécie pioneira na piscicultura marinha brasileira. No entanto, sua criação é incipiente. Neste trabalho, foram realizados dois estudos pontuais: um para monitorar a criação de beijupirás em gaiolas, sistema offshore, no litoral de Pernambuco; e outro para monitorar a criação de beijupirás em tanques-redes, sistema nearshore, no litoral de São Paulo. O objetivo foi aferir parâmetros ambientais de qualidade da água de criação, físico-químicos e microbiológicos do beijupirá, que possam ser utilizados na elaboração de um sistema modelo de rastreabilidade da cadeia produtiva dessa espécie. Em ambos os estudos foram realizadas quatro coletas em diferentes meses do ano, com o intuito de se avaliar as possíveis correlações existentes entre os parâmetros ambientais - índice pluviométrico e temperatura do ar - e os parâmetros de qualidade avaliados na água de criação - oxigênio dissolvido, temperatura, demanda bioquímica de oxigênio, demanda química de oxigênio, salinidade, amônia, nitrito, nitrato, fosfato, carbono orgânico total, turbidez, transparência, CO2, pH, clorofila a e contagem microbiológica - e nos peixes - biometria, rendimento, composição centesimal, ácidos graxos, aminoácidos, pH, bases voláteis totais e contagem microbiológica. Verificou-se que a maioria dos parâmetros físico-químicos e microbiológicos avaliados na água de criação, estavam em conformidade com a legislação brasileira vigente ou dentro dos limites sugeridos pela literatura para criação dessa espécie. Todavia, esses parâmetros apresentaram variação nos diferentes meses de coleta, principalmente no estudo realizado no sistema nearshore, o que dificulta afirmar as possíveis interferências desses parâmetros na qualidade e desempenho dos animais. Os peixes amostrados apresentaram baixo desenvolvimento zootécnico, se comparado ao peso total final previsto na literatura para essa espécie. No entanto, o rendimento em filé apresentou-se satisfatório, principalmente no sistema nearshore, aproximadamente 40%. Todas as amostras de filés de beijupirás avaliadas apresentaram conformidade microbiológica, frescor e qualidade nutricional, principalmente no que se refere à composição dos seus aminoácidos e ácidos graxos, com destaque para presença de lisina e ácidos graxos Eicosapentaenoico (EPA) e Docosahexaenoico (DHA), sendo, estas informações úteis para efeitos de marketing na divulgação e estimulo do consumo dessa espécie. O mesmo foi observado para o resíduo gerado após o processamento dos filés, o que sugere a possibilidade de elaboração de coprodutos com qualidade nutricional, tornando a cadeia produtiva dessa espécie mais rentável e sustentável. Os alimentos fornecidos aos animais, não eram adequados para satisfazer as exigências nutricionais dos mesmos, sendo a falta no mercado de rações elaboradas com formulações específicas um entrave para o sucesso dessa atividade. Conclui-se que os parâmetros, temperatura da água de criação; rendimento em filé, destreza do filetador; quantidade e tipo de resíduo gerado na filetagem; frescor e qualidade microbiológica dos filés; assim como, composição centesimal dos filés, resíduos e alimento fornecido aos animais, especificamente composição em aminoácidos e ácidos graxos, devam ser monitorados no sistema de rastreabilidade. Quando implementado, o sistema de rastreabilidade permitirá uma tomada de decisão mais consciente a respeito das condições de criação ideais do beijupirá, no intuito de dispor respostas práticas e aplicadas ao setor produtivo quanto ao atendimento às exigências da legislação, do mercado e do consumidor final / Currently, cobia is the native species with the largest number of characteristics in common with other aquatic species commercially farmed; therefore, it is indicated as the pioneer species in Brazilian marine fish farming. However, its rearing is incipient. In this work, there were two specific studies: one to monitor cobia rearing in cages offshore on the coast of Pernambuco State, Brazil; and another to monitor cobia rearing in nearshore cages on the coast of São Paulo State. The objective was to measure farm water quality, physico- chemical and microbiological parameters of cobia that can be used in the preparation of a model system traceability of the production chain of this species. In both studies, four collections were performed in different months of the year to evaluate possible correlations between environmental parameters, such as rainfall and environment air temperature, and the quality parameters evaluated in the water rearing, such as dissolved oxygen, temperature, biochemical oxygen demand, chemical oxygen demand, salinity, ammonia, nitrite, nitrate, phosphate, total organic carbon, turbidity, transparency, CO2, pH, chlorophyll a and microbiological contamination, as well as fish, such as biometrics, yield, proximate composition, profile of fatty acids and amino acids, pH, totals volatile bases and microbiological contamination. Most of the physico-chemical and microbiological parameters evaluated in the rearing water were in line with the current Brazilian law or within the threshold suggested in the literature for rearing this kind of species. However, these parameters showed great variation for different months of collection, especially in the study conducted in a nearshore system, making it difficult to state the possible interference of these parameters on the quality and performance of the animals. The sampled fish had low livestock development, compared to growth rates reported in the literature for this species. However, fillet yield was satisfactory, especially in the nearshore system, close to 40%. All samples of cobia fillets showed microbiological compliance, freshness and nutritional quality, especially in terms of composition of its amino acids and fatty acids, mainly in the presence of lysine and fatty acids, respectively, Eicosapentaenoic (EPA) and Docosahexaenoic acid (DHA). This information can be used as an excellent marketing tool to disseminate and stimulate consumption of this species. The same was observed for the waste generated after processing the fillets, suggesting the possibility of developing by-products with nutritional quality, making the supply chain of cobia more sustainable and profitable. The feed provided to the animals was not adequate to meet their nutritional requirements, and the short supply of prepared feed with specific formulations is an obstacle to the success of this activity. We conclude that the parameters of water temperature, fillet yield, skill of take fillet, amount and type of waste generated in filleting, freshness and microbiological quality of steaks, as well as chemical composition of fillet, waste and feeding for the animals, mainly amino acid composition and fatty acids, should be monitored in the traceability system. When implemented, the traceability system regarding the decision-making process for the ideal conditions of cobia production, providing practical answers, and it can be applied to the productive sector as a way to comply with requirements of legislation, market and consumers