The South African mariculture industry is developing the rearing technology of indigenous fish species. Dusky kob (Argyrosomus japonicus) has high-quality flesh and a good market demand. Research is needed to determine the environmental requirements under which growth of dusky kob is optimised. This study assessed the effect of temperature, light intensity, feeding frequency and stocking density, respectively, on growth, feed conversion ratio (FCR) and survival of juvenile dusky kob within a weight range of 10-60 g fish⁻¹) in a series of four growth trials. The effect of temperature on growth and FCR was assessed at 14 temperatures from 17 to 28°C. The temperature for best growth was estimated to be 25.3 °C, while 21.4 °C was the temperature at which the best FCR was achieved. A growth trial testing the effect of light intensity on growth showed that light intensity did not affect growth in the range of 23 – 315 lx. Fish fed a restricted ration of 3.6% body weight per day (chapter 2) or 3.41% body weight per day (chapter 4) had a better FCR than fish fed to satiation. A trial to assess the effect of feeding frequency on growth and FCR showed that fish fed both two or three times daily grew better than those fed once daily. FCR was best in fish that were fed once or twice daily. Preliminary analysis of the results from a stocking density trial showed that stocking density in the range of 10 – 50 kg m⁻³ did not affect growth of juvenile dusky kob. It is recommended to culture dusky kob at a temperature of 25.3 - 21.4 °C at stocking densities up 50 kg m⁻³ to maximise growth. However, a study is needed to determine the environmental conditions needed to maximise profit under commercial conditions. The results allow the South African industry the opportunity to assess the culture potential of this species. In addition, the results will help develop protocols that can be used in other South African candidate aquaculture species such as silver kob, yellowtail, white-stumpnose and sole.

Magister Artium (Development Studies) - MA(DVS) / The seaweed Gracilaria gracilis has been shown in previous studies to have potential for mariculture along the West Coast of South Africa. However, the selection of suitable sites is crucial for the success of a farming enterprise. The variables important in the success or sustainability of suspended raft culture, and the environmental factors influencing these variables, were identified through a literature review. A suitable site was defined as a site with surface water temperature of between 10 and 17 "C, water depth of between 2 and 10 m below surface, and wave heights of less than 4 m. Data and information about these factors were obtained from sources such as the Sea Fisheries Research Institute, the SADCO database, the CSIR and from volunteers in St Helena Bay. The objectives of this study were to convert available data into formats that could be used in a Geographical Information System (GIS), and to predict suitable and available sites for suspended cultivation of Gracilaria gracilis in Saldanha Bay, Langebaan Lagoon and St. Helena Bay. Data were converted to digital format and data layers created. Each data layer represented suitable and unsuitable areas. Areas with existing mariculture, harbours, ship traffic zones and other uses were excluded to determine the real available areas. The Saldanha Bay-Langebaan lagoon system and St Helena Bay, have sites that show potential for suspended cultivation of G. eracilis. The total sizes of the areas selected as suitable are 975.4 ha in Saldanha Bay and 474.8 ha in St. Helena Bay. Some sites predicted as suitable are located in areas known to be subject to conditions not suitable for seaweed mariculture, and led to the conclusion that the accuracy of input data or method of analysis must be improved.

Thesis (MA)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: This study addresses the sustainable development and employment creation potential of bivalve mariculture with reference to the case of Saldanha. The first section of the study looks at various theoretical perspectives relating to sustainable development. The development of modernist theory is presented, as are its shortcomings. The People-Centred Development theory is presented as an alternative theoretical perspective. This theory is relevant to the present study because it prioritises the participation of local individuals in the development process, rather than prioritising the increase of capital gain. One of the development approaches within people-centred development is the Learning Process Approach. The learning process approach provides a development model through which people-centred development can take place. The study then focuses on empirical cases. The development of four mariculture case studies from different countries and farming different organisms is then considered. The development process of these case studies is used to draw lessons on what factors affect the sustainable development of a mariculture sector. It is shown that five key factors play a role in the sustainable development of each of the four cases. The five factors are the state, the market, funding, the environment and the local community. These five factors provide a typology with which to measure the potential for the sustainable development of the bivalve mariculture sector in Saldanha. Literature on Saldanha is then reviewed, giving a background to rising unemployment in Saldanha and the need to consider the expansion of alternative sectors. This is followed by presenting the methods and results of empirical research involving the collection of primary data in Saldanha. The research methods used in conducting empirical research in Saldanha are presented. This research elicited data on bivalve mariculture employees and bivalve mariculture directors in Saldanha as well as state representatives. The key findings of this study are that the restrictive state policies on mariculture and a lack of funding are the primary limitations to the sector‟s expansion. The sector has the potential to expand by a factor of four, providing employment for over 200 households in Saldanha. / AFRIKAANSE OPSOMMING: Hierdie ondersoek fokus op die volhoubare ontwikkeling en werkskeppingspotensiaal van tweekleppige marikultuur met verwysing na die geval van Saldanha. Die eerste gedeelte van die ondersoek handel oor verskillende teoretiese perspektiewe met betrekking tot volhoubare ontwikkeling. Die ontwikkeling van modernistiese teorie word aangebied, tesame met sy tekortkominge. Die Mens-Gesentreerde Ontwikkelingsraamwerk word as 'n alternatiewe teoretiese perspektief aangebied. Die mens-gesentreerde ontwikkelingsraamwerk is relevant tot die huidige ondersoek omdat dit die deelname van plaaslike individue in die ontwikkelingproses, eerder as die verhoging van kapitaalwins, vooropstel. Een van die ontwikkelingsbenaderings binne mens-gesentreerde ontwikkeling is die Leerproses Benadering. Die leerproses benadering bied 'n ontwikkelingsmodel waardeur mens-gesentreerde ontwikkeling kan plaasvind. Die leerproses benadering word dan gebruik om die ontwikkeling van ander marikultuur gevalleondersoeke te bespreek. Die tweede deel van die huidige ondersoek beskou die ontwikkeling van vier marikultuur gevalleondersoeke uit verskillende lande wat met verskillende organismes boer. Die ontwikkeling van hierdie gevalleondersoeke is gebruik om lesse op te stel oor watter faktore 'n invloed op die ontwikkeling en volhoubaarheid van 'n marikultuursektor het. Dit is getoon dat die vyf belangrikste faktore wat 'n rol in die volhoubaarheid en uitbreidingspotensiaal van elk van die gevalle gespeel het die staat, die mark, finansiering, die omgewing en die plaaslike gemeenskap behels. Hierdie vyf faktore is gebruik as 'n tipologie om die volhoubaarheid en uitbreidingspotensiaal van die tweekleppige marikultuursektor in Saldanha te meet. Die geval van Saldanha word eerstens in die literatuur aangebied vir 'n agtergrond oor stygende werkloosheid in Saldanha en die noodsaaklikheid om die uitbreiding van alternatiewe sektore te oorweeg. Derdens is primêre navorsing oor Saldanha se tweekleppige marikultuursektor onderneem. Data is versamel vanaf werknemers, direkteure en staatsverteenwoordigers. Die belangrikste bevindings van hierdie ondersoek is dat die beperkende staatsbeleid oor marikultuur en 'n gebrek aan fondse die primêre beperkings op die uitbreiding van die sektor is. Die sektor het die potensiaal om met 'n faktor van vier uit te brei. Teen hierdie grootte sal meer as 200 huishoudings in Saldanha 'n inkomste hê.

Sustainable development of global marine resources has been the focus of various United Nations' agencies and coastal nations since World War II. As capture fisheries resources have come under pressure and perhaps reached their sustainable limit concern has been expressed over the ability to continue to meet the protein needs of expanding populations. One potentially significant contributor to addressing the food needs of the world is marine farming (mariculture). The expansion of marine farming in developing countries has been well-addressed in the literature, but marine farming in developed countries has received less attention. The traditional biophysical requirements of marine farming (sheltered clean water of appropriate depth) have led to conflicts with other users of the coastal environment. In the developed countries in particular, suitable sites are contested places of consumption (recreation, tourism) as well as production (capture fisheries). Moreover, the adjacent terrestrial land and water uses can significantly affect acceptability of marine farming. The avoidance of conflicts and the achievement of sustainable development in such settings are largely dependent on the systems of governance. In developed countries, these are often articulated through planning regimes and associated 'rights'. The global terrestrial planning response in the first two thirds of the 20th Century was dominated by a modernist approach to planning. In the later stages, a post-modern challenge coincided with the rise of neo-liberalism in many developed countries. Planning in New Zealand has shown a similar pattern. The extent to which modern, postmodern and neo-liberal approaches might have been manifest in the marine environment, especially with regard to marine farming, has received little attention. In most developed countries there has been an institutional separation between terrestrial and marine administrative agencies that has resulted in conflict between these agencies and between the regimes they work within and help create. Integrated Coastal Management emerged as a response to this situation and had become the dominant planning regime for coastal resources by the last decade of the 20th Century. It was largely uncritically promoted and accepted, especially by United Nations and coastal state government agencies. These themes provide the broad theoretical and practical context for this thesis. Since the 1970s, there has been a revolutionary break in New Zealand's resource management from a centralized command and control style of modernist planning to a neo-liberal, planning regime characterised by elements of modernism and postmodernism. Concurrently it has revamped, but failed to integrate, coastal and fisheries management and planning. Ironically, each of the resulting primary marine resource management statutes (the Resource Management Act 1991 (RMA) and the Fisheries Act 1983/1996 (FA83/96)) is considered to implement a world-leading model. Marine farming lies at the interface between the regimes created by these and preceding Acts and the nature of the regimes is explored in relation to marine farming. The development of the regimes and the rationale for them is set out with the aid of Scott's (1989, 2000b) axial model of the characteristics of a property right. The thesis groups the development of the New Zealand planning regimes for marine farming into four era: pre-modern (1866-1964), proto-modern (1964-1971), modern (1971-1991), and transitional (1991-2001). The evolution of the industry is shown largely to follow a generalized model of the industry in developed countries. This suggests that the nature of the property rights available for marine farming in New Zealand is not of great significance in the general development of the industry. The planning regime, however, significantly affects the spatial pattern of development of the industry. An analysis of provisions for marine farms in various plans suggests quite different planning 'styles' and approaches have been adopted in different parts of the country at different times. A Geographic Information System of all individual marine farms in New Zealand is developed to the stage where it can be combined with other data to investigate the spatial patterns that have evolved in New Zealand. A typology of patterns of farm arrangement in relation to other farms is apparent from the resultant mapped information. These patterns are shown to represent the outcomes of a combination of competing rights and the responses of and to the contemporaneous planning regimes. The consequences of adopting different styles of planning are apparent. This macro-level research is extended to the micro-level by an exploration of variables affecting the individual farmer's locational decisions. A national postal questionnaire survey of marine farm owners yielded 148 usable responses (32% response rate). Inferential statistical analytical tools were used to test the significance of relationships between particular variables. Multivariate analyses were used to cluster the respondents and the variables and to search for latent factors. These analyses supported field interview findings with regard to the importance of particular variables, especially planning regimes in directing the location and nature of marine farming. The results enabled development of a descriptive model for exploring and comparing the quality of different means of acquiring marine space for marine farming. The analyses also confirmed that significant changes were occurring within the structure of the industry. Analysis of the field interviews, maps, policy documents, Environment Court decisions and other secondary material shows the major capture fishing companies are increasingly dominating the industry. There was a notable presence of a category of 'entrepreneur site developers' exploiting the neo-liberal nature of the planning regimes of the 1990s to open up new areas for marine farming on scales unprecedented in the rest of the world. The consequent race for space has met with stiff resistance from the capture fishing industry, but more especially from the recreational sector. This has led to significant transaction costs. The Government response, a partial moratorium on marine farm development in November 2001, is shown to emulate the modernist command and control style of planning of twenty years earlier and to signal a failure of neo-liberal ideology to meet the needs of the industry and the public at large.

Dans le cadre du thème "Biodiversité et ressources marines" développé par le Laboratoire d'écologie marine de l'Université de La Réunion, une étude sur la colonisation du récif frangeant de la Saline par les post-larves de poissons a été réalisée en utilisant la technique du filet de crête. Le but de ce travail était, de comprendre les mécanismes qui régissent le retour des post-larves dans les populations parentales, de suivre l'installation des nouvelles recrues dans le milieu, puis enfin d'apporter des éléments sur la biologie de ces jeunes poissons en les plaçant dans des conditions d'élevage. Les résultats montrent que la colonisation des platiers a lieu essentiellement du mois d'août au mois de mars, avec deux pics d'abondance et de richesse spécifique au mois d'août-septembre et au mois de février. Un cycle annuel de colonisation apparaît et correspondrait à une période de reproduction plus intense de juin à décembre pour de nombreuses espèces. Les variations de la température de l'eau de mer semblent déclencher ce phénomène de colonisation et les nuits calmes de nouvelle lune seraient les plus favorables à l'arrivée des post-larves sur les récifs. Avec un total de 106 espèces échantillonnées, la colonisation des platiers ne concerne que 40 à 50 % des espèces coralliennes recensées sur l'île. Le flux moyen de post-larves est de 5,2 individus par jour et par mètre linéaire de crête récifale, ce qui correspond à une biomasse de 1,2 kg de post-larves par an, soit 100 à 400 fois moins que sur certains récifs du Pacifique. Les platiers de La Réunion seraient ainsi proches du modèle de "recrutement limitant" basé sur un faible apport larvaire, alors que les ressources et l'habitat seraient toujours en quantité suffisante. La taille standard des poissons au moment de la colonisation est extrêmement variable selon les familles ou les genres et va de 4,5 mm (Monodactylus argenteus) à 142 mm (Aulostomus chinensis), mais elle reste le plus souvent homogène au sein d'une même espèce, montrant ainsi que les poissons colonisent les platiers à un stade de développement bien précis. Les chances de survie de ces post-larves sont de 0,8 à 4,6 %. La prédation serait l'une des principales causes de la diminution rapide de ces poissons durant cette phase critique de colonisation. La densité de jeunes poissons qui recrutent et se répartissent ensuite sur toute la superficie du platier est de 0,04 à 0,22 ind.m-2. Ils sont surtout observés de novembre à mai, soit un décalage d'environ 3 mois par rapport à la période de colonisation. Un total de 50 espèces de poissons juvéniles a pu ainsi être répertorié, principalement dans la zone de platier interne où se développent les colonies coralliennes, mais également dans le chenal d'arrière récif pour certaines espèces. Ces juvéniles installés dans leur nouveau milieu ont, 30 jours après le recrutement, une chance de survie de 33 à 40 %. Certaines espèces comme Naso unicornis migreraient ensuite vers la pente externe après une phase de croissance de 4 à 5 mois sur le platier. L'élevage des post-larves a été réalisé pour 10 espèces parmi les plus abondantes. La quantité de nourriture à base de granulés, distribuée à ces nouvelles recrues peut représenter jusqu'à 20 % du poids du poisson par jour, notamment lorsque les individus sont de petite taille comme Scarus sordidus. Elle se stabilise ensuite pour l'ensemble des espèces étudiées autour de 3 à 4 % de la biomasse par jour. La plupart de ces poissons ont une croissance qui se rapporche du type puissance (paramètre puissance de 1,07 à 3,5) avec un Taux de Croissance Spécifique journalier de 0,9 % (Chromis viridis) à 3,8 % (Monodactylus argenteus) et des Indices de Conversions moyens de 1,1 (Monodactylus argenteus) à 6,1 (Chromis viridis). La survie de ces post-larves et juvéniles en captivité est de 60 à 92 % après 196 jours d'élevage, ce qui montre les capacités d'adaptation importantes des poissons coralliens à ce stade de développement. Le grossissement des post-larves est donc possible et ouvre de nouvelles perspectives dans de nombreux domaines comme la recherche, l'aquaculture, l'aquariologie ou la gestion des milieux naturels.

Mariculture has currently brought greatly valuable products in many fields simultaneously released a large amount of wastewater contributing to water pollutions on account of its organic and inorganic constituents. Nowadays, with the development of environmental engineering, more and more approaches, especially friendly-environmental and highly effective wastewater biological methods, are being applied to tackle pollutions and minimize adverse effects of treatments to reach the sustainable development. This report focuses on the study of proliferation combined with elimination of polluting substances of marine algae species Tetraselmis suiscica, Tetraselmis sp., Platymonas sp. in aquaculture wastewater sampled from Can Gio District, Ho Chi Minh City, Vietnam with levels of concentration during 14 days under normal marine algae culture conditions, and compared to that in Daigo’s IMK media. The results shown that, the algae species all grew rapidly simultaneously gave high nutrients removal yields (COD, N, P) and created a considerable amount of biomass within a short period of culture. Particularly, Platomonas sp. and Tetraselmis suiscica could proliferate aswell as give high treatment yields of organic substances (COD), PO43-, NO3-, NH4+ and Total Nitrogen in concentrated wastewater. To sum up, this study showed the potential of using microalgae to reduce COD, nitrogen and phosphorus in mariculture wastewater. / Ngành nuôi trồng thủy hải sản trong những nằm gần đây đã mang lại nhiều sản phẩm có giá trị trong nhiều lĩnh vực đồng thời thải ra một lượng lớn nước thải gây ô nhiễm nguồn nước bởi các thành phần vô cơ và hữu cơ có trong nước thải. Ngày nay, với sự phát triển của kỹ thuật môi trường, ngày càng nhiều cách tiếp cận, đặc biệt là các phương pháp sinh học hiệu quả cao và thân thiện với môi trường đang được ứng dụng để xử lý ô nhiễm và giảm thiểu hậu quả bất lợi sau xử lý, nhằm hướng tới sự phát triển bền vững. Bài báo cáo tập trung nghiên cứu khả năng sinh trưởng và phát triển của ba loài vi tảo biển Tetraselmis suiscica, Tetraselmis sp., Platymonas sp. kết hợp với việc loại bỏ các hợp chất gây ô nhiễm có trong nước thải từ ao nuôi tôm của huyện Cần Giờ, Việt Nam và so sánh đối chiếu với môi trường dinh dưỡng Daigo’s IMK trong 14 ngày nuôi trồng. Kết quả cho thấy những vi tảo sinh trưởng rất nhanh nhờ vào việc sử dụng các chất ô nhiễm trong nước thải, đặc biệt hiệu suất xử lý COD, PO43-, NO3-, NH4+ và nitơ tổng của Platomonas sp. và Tetraselmis suiscica rất cao thậm chí trong môi trường nước thải đậm đặc. Do đó, chúng tôi kết luận, vi tảo có tiềm năng rất lớn trong việc giảm nồng độ chất hữu cơ, phốt pho và nitơ trong nước thải nuôi trồng thủy hải sản.

Fisheries management regulations for dusky kob Argyrosomus japonicus, an important commercial and recreational fisheries species, have failed and the stock is considered collapsed. It is important to take an ecosystems approach to management which includes understanding the effect of environmental factors on recruitment, abundance and distribution. The distribution of early juveniles (20-150 mm TL) in the wild appears to be restricted to the upper reaches of estuaries at salinities below 5 psu. Food availability could not explain the distribution of early juveniles. The aim of this study was to investigate the role of salinity on the distribution of early juvenile dusky kob (<150 mm TL) by examining physiological responses of juveniles exposed to a range of salinities under laboratory conditions. The hypothesis was that the physiological functioning of early juveniles would be optimised at the reduced salinities which they naturally occur at. The objectives of this study were to investigate the effect of salinity on: i) plasma osmolality; ii) growth, food conversion ratio and condition factor; and iii) gill histology with emphasis on chloride cell size and number. A preliminary study was undertaken to determine whether the use of 2-phenoxyethanol had an effect on plasma osmolality. Juveniles pithed prior to blood sampling were used as the control. Plasma osmolality was not affected by exposure or duration of exposure (2, 4, 6, 8, 10 min) to 2-phenoxyethanol. The ability of teleosts to regulate plasma osmolality over a wide range of salinities indicates their degree of ‘physiological euryhalinity’. Plasma osmolality of juveniles exposed to 5, 12 and 35 psu was measured every two weeks over a total of six weeks. Although juveniles were able to regulate plasma osmolality over the duration of the experiment, plasma osmolality at 5 and 12 psu was significantly lower than in fish maintained at 35 psu. Growth is used as an indicator of the relative energy used for osmoregulation at different salinities, as the energy used for osmoregulation becomes unavailable for growth. A nineweek growth experiment was conducted on juveniles exposed to 5, 12 and 35 psu. Juveniles grew and survived at all three salinities. However, growth of juveniles at 5 psu was significantly lower than at 12 and 35 psu. Other than a significantly greater weight gain at 35 psu relative to 12 psu, there was no significant difference in specific growth and length gain between juveniles at 12 and 35 psu. Food conversion ratio and condition factor at 12 and 35 psu were not significantly different, but food conversion ratio and condition factor at 5 psu was significantly greater and lower than at 35 psu respectively. In fish, gills are considered the major organ involved in osmoregulation. Within the gills, chloride cells are the predominant site of ion exchange which is driven by the Na⁺, K⁺- ATPase enzyme. Gill samples of juveniles exposed to 5, 12 and 35 psu for six weeks were examined histologically using light microscopy. Chloride cells of juveniles maintained at 5 psu were significantly more abundant than in juveniles at 12 and 35 psu. Chloride cells of juveniles at 5 psu were significantly larger than in juveniles kept at 12 psu, but not significantly different to those of juveniles kept at 35 psu. The ability of the juvenile fish to regulate plasma osmolality indicates that they are 'physiologically euryhaline', but the reduced growth and proliferation of chloride cells at 5 psu suggests that energy expenditure for osmoregulation is increased at hypoosmotic salinities. Salinity induced physiological responses could therefore not explain the natural distribution of early juvenile dusky kob and it is proposed that other environmental factors (e.g. temperature) are also important. It is also hypothesised that the high conductivity of an estuary in South Africa, to which our understanding is limited, may negate the effect of reduced salinity. Although freshwater input into estuaries is an important factor, further investigations to explain the distribution and abundance of early juveniles is required to make management recommendations. Dusky kob is also becoming an increasingly popular aquaculture species in South Africa. In this regard, early juvenile dusky kob can be grown at salinities as low as 12 psu without negatively affecting growth and production.

There is considerable opportunity to develop new modelling techniques within a Geographic Information Systems (GIS) framework for the development of sustainable marine cage culture. However, the spatial data sets are often uncertain and incomplete, therefore new spatial models employing “soft computing” methods such as fuzzy logic may be more suitable. The aim of this study is to develop a model using Neuro-fuzzy techniques in a 3D GIS (Arc View 3.2) to predict coastal environmental vulnerability for Atlantic salmon cage aquaculture. A 3D hydrodynamic model (3DMOHID) coupled to a particle-tracking model is applied to study the circulation patterns, dispersion processes and residence time in Mulroy Bay, Co. Donegal Ireland, an Irish fjard (shallow fjordic system), an area of restricted exchange, geometrically complicated with important aquaculture activities. The hydrodynamic model was calibrated and validated by comparison with sea surface and water flow measurements. The model provided spatial and temporal information on circulation, renewal time, helping to determine the influence of winds on circulation patterns and in particular the assessment of the hydrographic conditions with a strong influence on the management of fish cage culture. The particle-tracking model was used to study the transport and flushing processes. Instantaneous massive releases of particles from key boxes are modelled to analyse the ocean-fjord exchange characteristics and, by emulating discharge from finfish cages, to show the behaviour of waste in terms of water circulation and water exchange. In this study the results from the hydrodynamic model have been incorporated into GIS to provide an easy-to-use graphical user interface for 2D (maps), 3D and temporal visualization (animations), for interrogation of results. v Data on the physical environment and aquaculture suitability were derived from a 3- dimensional hydrodynamic model and GIS for incorporation into the final model framework and included mean and maximum current velocities, current flow quiescence time, water column stratification, sediment granulometry, particulate waste dispersion distance, oxygen depletion, water depth, coastal protection zones, and slope. The Neuro-fuzzy classification model NEFCLASS–J, was used to develop learning algorithms to create the structure (rule base) and the parameters (fuzzy sets) of a fuzzy classifier from a set of classified training data. A total of 42 training sites were sampled using stratified random sampling from the GIS raster data layers, and the vulnerability categories for each were manually classified into four categories based on the opinions of experts with field experience and specific knowledge of the environmental problems investigated. The final products, GIS/based Neuro Fuzzy maps were achieved by combining modeled and real environmental parameters relevant to marine fin fish Aquaculture. Environmental vulnerability models, based on Neuro-fuzzy techniques, showed sensitivity to the membership shapes of the fuzzy sets, the nature of the weightings applied to the model rules, and validation techniques used during the learning and validation process. The accuracy of the final classifier selected was R=85.71%, (estimated error value of ±16.5% from Cross Validation, N=10) with a Kappa coefficient of agreement of 81%. Unclassified cells in the whole spatial domain (of 1623 GIS cells) ranged from 0% to 24.18 %. A statistical comparison between vulnerability scores and a significant product of aquaculture waste (nitrogen concentrations in sediment under the salmon cages) showed that the final model gave a good correlation between predicted environmental vi vulnerability and sediment nitrogen levels, highlighting a number of areas with variable sensitivity to aquaculture. Further evaluation and analysis of the quality of the classification was achieved and the applicability of separability indexes was also studied. The inter-class separability estimations were performed on two different training data sets to assess the difficulty of the class separation problem under investigation. The Neuro-fuzzy classifier for a supervised and hard classification of coastal environmental vulnerability has demonstrated an ability to derive an accurate and reliable classification into areas of different levels of environmental vulnerability using a minimal number of training sets. The output will be an environmental spatial model for application in coastal areas intended to facilitate policy decision and to allow input into wider ranging spatial modelling projects, such as coastal zone management systems and effective environmental management of fish cage aquaculture.