Biofouling has become a serious problem for farmers in the Norwegian finfish aquaculture industry in recent years; with the hydroid Ectopleura larynx dominating the fouling community in southwestern and mid-Norwegian waters. Most farmers in Norway use a combination of strategies to deal with fouling: the use of copper coated nets combined with washing, the use of copper coated nets combined with drying, and the use of uncoated nets combined with frequent washing. Concerns have been raised about the use of copper coatings on nets due to possible environmental threats. A better understanding of fouling patterns with depth and time; as well as the effectiveness of environmentally friendly treatments is needed. The aims of the study were to identify the temporal and depth variability of biofouling on salmon cage nets from a farm in mid-Norway. Additionally, the effect of drying on hydroid survival and the effects of environmentally friendly anti-fouling treatments on the survival of E. larynx were investigated. The first experiment was to look at the development of biofouling on salmon cage nets at 3 different depths (1, 5 and 10 m) over a six month period (June-November). The second experiment involved the drying of hydroid colonies at 6 different drying times to determine the shortest time needed to ensure complete mortality of hydroids. The third experiment was to determine the effects of washing and drying on the recovery of hydroid colonies, using 5 different treatments; after which hydroids were allowed to recover for a two week period and analysed. The results showed that the major fouling groups were algae, molluscs, hydroids, crustaceans and bryozoans, with hydroids becoming abundant from August onwards. Hydroids began to completely colonise the nets from 10 m in September and then completely colonized the nets at all three depths in October and November. 48 hours of air drying caused a complete mortality of hydroids. Dead hydroids shed their hydranths and cut or damaged hydroids were capable of regeneration. Nets which had hydroids removed, damaged or cut by the washing process had the highest percentage growth increase after a two week recovery period. This study demonstrated that fouling communities differ with depth and time but are driven by some ecological interactions, and that, a combination of washing and then killing of hydroids with hot water; or washing and then drying can help farmers deal effectively with fouling. Further research into the feasibility of these on an industrial scale is recommended.

I investigated hoe different spacing of breeding sited affects different aspects of mating behaviour in the two-spotted goby. I found that clumped nest spacing affects nest occupations and reproductive success negatively. Clumped nest spacing incresed male agonistic behaviour and led to a higher variance in reproductive success.

The financial crises and global change have caused setbacks to the improvements in many undeveloped countries. To be able to achieve the ‘Millennium developmental goals’ within 2015, it will require a higher effort. Sub-Saharan African countries show the slowest economic growth and have experienced the highest setbacks. Malawi is one of these countries and is struggling with a high share of poverty and poverty related issues. Trade is believed to be the most prominent tool to fight world poverty, as it will provide economic growth and employment. Cichlid fishes from Lake Malawi are popular ornamentals for hobby aquarist’s world wide, representing yearly turnover of 340 million US dollars. It is suggested that ornamental Malawi cichlids can be developed into an industry benefiting country and the local poor people. This can be achieved without pressure upon the lake biodiversity if the wild-collected fishes are used for breeding purpose and not for export. To be able to deliver a high quality fish, it will be necessary to establish proper handling strategies that will ensure fish health and welfare. Stress from handling procedures is known to have negative impact on fish growth, reproduction, immune function and survival. Anesthetics may be a useful tool during handling procedures of the fish, as it can reduce the perception of the stressor and thus prevent activation of the hypothalamus-pituitary-interrenal (HPI) axis. In this study the three commercial anesthetics; MS-222, Benzoak® and Aqui-S™ were evaluated for; (1) anesthetic efficacy, (2) safety margin, (3) prolonged exposure and (4) stress-reducing capacity on the Malawi cichlid, red zebra (Metriaclima estherae). The overall results show that concentration of 150 mg/L MS-222, 120 mg/L Benzoak® and 50 mg/L Aqui-S™ gave satisfying introduction and recovery time for anesthesia. Both MS-222 and Aqui-S™ gave high safety margins as no fish mortality was recorded after anesthetic exposure for 30 minutes. Benzoak® gave a lower safety margin as there was recorded 50 % mortality following 10 minutes exposure. High mortality rate and sign of insufficient blockage upon the red zebra fish, suggested that prolonged exposure to the tested sedative dosages did not benefit the fish. MS-222 exposure reduced the stress response while Benzoak® and Aqui-S™ seemed to self-induce an increase in plasma cortisol concentration after anesthetic exposure. In conclusion; for short-term treatment on red zebra fish, a concentration of 150 mg/L MS-222 is recommended.

!

The aim of this thesis is to give insight into how a short term exposure to higher water temperatures affect photosynthesis in two of the most important species of the Norwegian kelp forest; Laminaria digitata and Saccharina latissima. In addition the effect of increased water temperature on kelp growing in the temperate regions, Trondheimsfjorden, will be compared the effect on kelp growing in the arctic region, Svalbard.

The snail fauna (class Gastropoda) associated with the two kelp species Laminaria hyperborea and Saccorhiza polyschides was sampled during September and December 2009, and March 2011. Over 1000 gastropod individuals comprising 35 identied taxa were found in the 29 kelp individuals sampled in total. The attractiveness for settlement for gastropods of L. hyperborea was clearly higher than S. polyschides, which also had very little epigrowth compared to L. hyperborea. Highest number of gastropod individuals were found on lamina and the highest number of species were found on haptera for both kelp species. High variation in gastropod numbers was found both between kelp individuals and between seasons. Detailed still images were taken of the kelp before sampling, for comparison to the sampled material. 81 % of the gastropod fauna visible in images was identied to either species or family, but only 17 % of the actual number of gastropods (sampled) were visible in images. Visibility of gastropods in images decreases with increasing complexity of the habitat (i.e. kelp part), both structural complexity in the kelp or added complexity by epigrowth. The ratio of gastropods identied from images to gastropods identied from sampled material (image detection success), showed high variation between gastropod taxa, mainly dependent on gastropod size, degree of camouflage or conspicuousness, and what habitat (i.e. kelp part) they live in.

Marine migration and habitat use of sea trout Salmo trutta from the watercourse Søa and the river Snilldalselva in Sør-Trøndelag in Central Norway was studied during summer in 2012 and 2013. Fishes were tagged with acoustic transmitters and their movements and behaviour recorded by automatic listening stations. Significant individual variation in the time spent in the marine environment was found, ranging from 7 days to 183 days during the months from April to September. The spatial distribution in the fjord system varied greatly between the tagged fishes. The innermost parts of the fjords near the tagging watercourses were particularly important areas for the tagged fishes. Both fish from Søa and Snilldalselva had significantly longer residence time in the inner areas compared other parts of the fjord system. Average swimming depth in the period from April to September (1.87 m) turned out to vary significantly between habitats. In littoral (2.11 m) and cliff habitats (2.53 m) the average swimming depth was significantly deeper than in pelagic areas (1.26 m), suggesting differences in prey selection or anti-predator behaviour between the various habitats. The average swimming depth was furthermore significantly deeper during day (1.98 m) than night (1.28 m). The sea trout had a progressively deeper swimming pattern from April towards late summer, positively correlating with water temperature, suggesting that the sea trout actively regulated its internal body temperature. While some individuals remained close to tagging watercourse (< 4 km) throughout the summer, other individuals migrated far out (> 16 km) in the fjord system. Large individuals (> 450 mm) seemed to be more likely to conduct long distance migrations than remaining in inner areas. Long distance migrants furthermore had poorer body condition in spring prior to migration, were found to have greater length at smoltification, and tended to be older and more experienced migrants. Long distance migrants seemed to use pelagic areas more than short distance migrants and tended to maintain pelagic swimming behaviour even when recorded in littoral habitat, suggesting that the migration distance might be linked to feeding behaviour. Furthermore, the observed differences in morphological characteristics and life history indicate, as suggested by previous studies, that the marine behaviour might be a continuum of a conditional strategy in partial migrating sea trout populations, affecting whether the sea trout remain in the innermost parts of the fjord, or migrate far out in the marine system. This implies that the marine behaviour of sea trout might be altered if the conditions in the marine environment change. Furthermore, variation in the marine environment might thus have great impact on an individual’s growth and survival, and potentially alter the recruitment and population structure of sea trout stocks. In terms of conservation, the present study illustrates the importance of mapping the marine behaviour of sea trout, as the threats depends heavily on the marine areas it utilises. Gathering of long term data sets on marine environmental conditions, as well as more research on the underlying causes determining the wide range of the sea trout’s marine behaviour is advocated, as it might prove to be essential for evaluating and modelling sea trout distribution, behaviour and main threats, and for identifying necessary conservation measures for Norwegian sea trout stocks.

Tidal power is a clean renewable energy. Furthermore, electricity is acknowledged as a key need for development. However, until recently, due to high capital costs and extensive environmental concerns, few tidal power plants are operative around the world. These problems are now being mitigated by the application of appropriate, modern practices and technologies. In particular the use of small scale technologies, innovative financing and the involvement of local communities creates the potential for tidal power to be a tool in coastal development. This thesis examines the appropriateness of tidal power in the rural coastal community of Bangladesh, where electricity demand is a major development problem. Coastal Bangladesh is highly vulnerable to natural disasters, especially from cyclones, tidal surges and the effects of global warming on sea-level rise. Consequently, most of this coastal area has been protected by embankments and sluice gates, which can accommodate the normal tidal head rise and fall. The potential of tidal power to use this infrastructure, together with its associated problems and mitigation measures, have been analysed by comparing existing and potential tidal power technologies around the world, including a proposed Kimberley tidal power project in Western Australia. The research has identified that a significant amount of power could be produced from the tidal range of coastal Bangladesh by using the simple low-cost technology of tidal wheels in the tidal embankment sluice gates. The electricity produced could be utilised by various coastal interests, such as agriculture, shrimp aquaculture and other resource producing activities. However, the real benefits of this technology are that it can be applied in a way that simultaneously enables the development of local infrastructure and the improvement in living conditions of the local people by creating income generation and employment opportunities in these coastal communities. The thesis puts forward a community based co-management model as a means of effectively integrating tidal power in coastal area management in Bangladesh.

La réglementation actuelle, reposant sur la loi de 1976 sur la protection de la nature, impose aux maîtres d’ouvrage de respecter le principe « éviter – réduire – compenser » lors de la conception de les projets d’exploitation et d’aménagement. Lorsqu’un projet n’a pu ni éviter ni réduire les impacts environnementaux, il est nécessaire de définir des mesures compensatoires pour les impacts résiduels qualifiés de significatifs. Concernant les écosystèmes marins, ces mesures font appel à des actions écologiques ainsi qu’à des mesures de gestion et d’amélioration des connaissances sur le milieu marin. Alors que le développement de l’activité économique maritime est encouragé, en particulier, suite aux appels à la croissance bleue (e.g. tourisme maritime, EMR, pêche, aquaculture, ressources minérales marines, biotechnologies, transport maritime, construction navale), il est primordial de questionner nos capacités à prendre en compte les impacts de ces activités. A partir d’un état des lieux de la compensation sur le milieu marin en France, il s’agit d’identifier les limites du système actuel et de proposer des pistes d’amélioration. Ces dernières peuvent être méthodologiques et techniques, liées à la prise en compte de nouvelles approches ou à l’émergence de nouveaux systèmes de gouvernance. A travers l’analyse d’une cinquantaine d’études d’impacts françaises, les pressions et impacts générés par différents projets d’aménagements (infrastructures portuaires, dragages, extractions de granulats, prises et rejets d’eau, etc.) sont examinés et la pertinence des mesures ERC proposées est discutée. Ensuite, en se basant sur une revue bibliographique, la faisabilité et l’efficacité des techniques d’ingénierie écologique (écoconceptions portuaires, bio-remédiation et techniques de restauration des herbiers, macro-algues, récifs coralliens, populations d’ichtyofaune et bivalves) sont évaluées au regard des exigences de la séquence ERC. Cette analyse permet de discuter de la notion d’équivalence écologique et de proposer un arbre de décision original. D’autre part, constatant que les mesures compensatoires proposées dans les études d’impact ne sont que très rarement dimensionnées, une méthode opérationnelle permettant d’évaluer les besoins compensatoires est élaborée. Cette méthode associe une analyse multicritère de l’état de l’environnement inspirée de l’Unified Mitigation Assessment Method (UMAM, méthode utilisée en Floride pour les impacts autorisés) et une évaluation plus fine à l’échelle d’un indicateur empruntée à l’Habitat Equivalency Analysis (HEA, développée par la NOAA pour la compensation des dommages accidentels). Il s’agit ensuite d’examiner l’utilisation actuelle de l’approche par les services écosystémiques dans la compensation à travers la réglementation, les standards internationaux et la littérature scientifique. L’objectif est d’étudier en quoi cette approche permettrait d’améliorer la mise en place de la compensation mais aussi d’en souligner les limites. Enfin, l’approche sociologique de l’acteur-réseau (Callon, Latour) permet d’analyser les différents types organisationnels ayant émergé autour de la compensation en Californie. L’objectif est de critiquer, à partir de situations constatées en France et aux Etats-Unis, les réponses formulées en termes de gouvernance par ces deux sociétés côtières exigeant un principe de compensation. Ce travail souligne la nécessité de mettre en place des mesures ambitieuses et efficaces de compensation afin que le développement économique maritime cesse de contribuer à l’érosion de la biodiversité. / My research topic is multidisciplinary combining geography, ecology and economics and addressing the efficiency of current marine offset practice. Building on a state of the art of current practice, I am working on a more prospective approach (compared to current research on mitigation targeting terrestrial ecosystems). By offset, I am referring to legal mitigation that consists in avoiding – reducing – offsetting adverse impacts of development projects such as dredging, port infrastructure, oil exploration, marine aggregate extraction, beach nourishment, etc. on marine and coastal ecosystems. Based on a review of around fifty French marine Environmental Impact Assessments (EIAs), I analyzed the assessment of impacts, the use of offset sizing methods (robust method to assess ecological losses due to development projects and ecological gains created by offset measures) and the kind of measures proposed. Within these EIAs, sizing methods were seldom used and the very few measures suggested to offset residual impacts could be questioned in terms of equivalency and appropriateness. These measures were either ecological engineering techniques (such as seagrass or coral restoration), management measures (used to reduce pressure on the impacted ecosystems through the funding of management measures in Marine Protected Areas for example) or even knowledge acquisition. Thus, I am also looking at the efficiency of ecological engineering techniques on marine and coastal ecosystems. My research mainly focuses on the offset of authorized impacts but could also deals with some aspects of the offset of accidental damages.

In thirty years, the number of second homes for recreation fishers in coastal Terrebonne Parish has grown from 244 in the late 1970s to an estimated 2,500 in 2005. This thesis considers the ramifications of the tourism boom along the parish's historically isolated and undeveloped coastline. Four coastal communities are examined: (1) Montegut, Pointe-aux-Chenes and Isle de Jean Charles; (2) Cocodrie and Chauvin; (3) Dulac; and (4) Dularge and Theriot. The research question is twofold: Why has coastal tourism been allowed to develop in the fragile wetlands that protect residents from dangerous storms?; and What does tourism development mean for the indigenous American Indian and Cajun people who live along the coast? The author argues the proliferation of recreation fishing camps has had a serious dislocating effect on coastal Terrebonne's population, and the ongoing development of the tourism industry will devastate culturally rich bayou regions.