The experiment was carried out from 23rd Junuary to 24th March 2011 at Sealab. Atlantic cod larvae were reared with water from three different systems: flow-though, maturated water and recirculation water. The water, larvae and feed specimens will be sampled from those three systems for microbial analysis by PCR-DGGE (denaturing gradient gel electrophoresis) and sequencing of bands. DNA will be extracted from water, feed and larvae, and used as template in PCR to amplify 16S rRNA encoding genes of bacteria. Subsequently, the PCR products will be separated by DGGE. The phylogenetic affiliation of the predominant community members, as represented in the DGGE band pattern, will be excised, re-amplified and sequences, and used for taxonomic assignment of the bacteria. Analyses of similarity (ANOSIM) with Bray-Curtis dissimilarity will be used to compare microbial community composition in three systems as well as microbiota of gut larvae.

Good nutritional quality is a key for a successful Atlantic cod (Gadus morhua) juvenile producer. Copepods are the natural prey for marine fish larvae, and its nutritional composition is believed to be optimal for the marine fish larvae. Despite the suitability for copepods in cod cultivation, only a few hatcheries have used this technique. When cultivating cod larvae and copepods intensively they can be produced in larger quantities and year-round, compared to the seasonal extensive cultivation. Intensive produced copepods have yet to be used in large-scale cod hatcheries. It has several times been documented that nutrition is important for survival, growth and the general quality of cod larvae. Even though these variables are something many farmers of juvenile cod (Gadus morhua) are struggling with, there has still not been developed any standard evaluation of quality. Codeggs were divided and after hatching given 4 different feeding regimes (3-28 dph). One was fed the copepod Acartia tonsa, a second fed the rotifer Brachionus ibericus enriched, a third fed Brachionus ibericus unenriched and a last with a mixture of copepods (7 days) and enriched rotifers. This was done to better see the effect of copepod feeding compared to the rotifer effect, and if there could be some benefits from only feeding with copepods for a small period. All treatments were fed Artemia sp. (20-40 dph) and dry feed (36-60 dph). In addition to growth and survival, the quality of the fish larvae was assessed. This was done by using the following quality parameters: Larval feeding activity, resistance to handling stress, skeletal deformations and shape variation.The study showed a clear trend where the larvae fed mostly copepods were the most successful in terms of growth, survival and quality, followed by those fed copepods for 7 days, and enriched and unenriched rotifers at the end. These results clearly showed that intensively cultivated copepods successfully could be used during intensive cod cultivation. All quality parameters gave results and combined gave a broad picture of the general quality of the cod larvae.

Production of high quality juveniles is still a bottleneck in the intensive culture of cod (Gadus morhua L.), and suboptimal nutrition at the larvae’s early life stages is one of the decisive factors for this. The cod larva hatches from small pelagic eggs, and has to start exogenous feeding shortly after hatching when it still lacks a functional stomach. Optimal feeding conditions are therefore crucial for the vulnerable larva at this early developmental stage. Copepod nauplii as live feed may provide nutritional benefits in terms of containing essential fatty acids in the phospholipid fraction that may be incorporated directly into membrane phospholipids, and also containing high amounts of free amino acids compared to rotifers and Artemia sp., which is applied as live feed in intensive production of cod today. The aim of the present study was to examine the effects of feeding with the intensively reared copepod Acartia tonsa compared to both enriched and unenriched rotifers (Brachionus ibericus), in terms of growth, survival, and functional development of the liver and gut. The liver and gut from larvae at 4 and 19 days post hatching (dph) was examined by performing quantitative measurements by stereology, and qualitative histological measurements on hepatocyte and enterocyte appearance. Mitochondrial development was given special emphasise to evaluate if there are tendencies implying a development in morphology of these energy producing organelles, and also whether they are affected by the nutritional composition of the live feed organisms.Feeding with copepod nauplii instead of enriched rotifers resulted in higher growth, survival, and increased pigmentation of the cod larvae. In addition it was found that feeding with rotifers, and especially with the unenriched type, showed signs of mitochondrial dysfunction in terms of cristae interdigitation within both hepatocytes and enterocytes. This was not found in the copepod-fed larvae, which might be attributed to providing phospholipid in the diet that may enhance normal development of biomembranes. Glycogen deposits were found in the hepatocytes in larvae at 19 dph, although to a much greater extent in the larvae fed rotifers, which might be due to differences in carbohydrate content in the different live feed organisms. The liver tissue was generally more evidently reflecting developmental processes between 4 dph and 19 dph and the effect of the live feeds nutritional value on the metabolic energy state of the larvae, than what the gut tissue did.

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Few data are available on distribution, abundance, and ecology of scyphozoans in the Northern California Current (NCC). This thesis is divided into four chapters, each of which contributes to our understanding of a different stage of the scyphozoan life history. The first study describes the settlement preferences of Chrysaora fuscescens planulae in the laboratory. Planulae were found to respond to the interaction of substrate and orientation. Artificial substrates were identified as viable habitat for C. fuscescens. In the second chapter, a population of scyphistomae in Charleston, Oregon were identified to species-level using DNA barcoding techniques. The third and fourth chapters focus on the medusa stage of the life history. Using surveys mailed to fishers in the Pacific Region, this study provides baseline data on the types and magnitudes of economic damages caused by jellyfish on different fisheries and helps assess fishers' perceptions of jellyfish population trends in the NCC. This thesis includes previously unpublished co-authored material.

This research provides an analysis of the disparate notions and ideas, to form an overview of the possible trends in residential property for the Victorian coastal areas of the Surf Coast and the Bellarine Peninsula. It examines the interaction of the consumers, space producers and infrastructure providers as they are influenced by the three key determinants of the market, the demographic factors, economic conditions and statutory factors. While examining the patterns of urban development on coastal Victoria over the next 20 years, the research also investigates the validity of myths that have emerged concerning the Sea Change experience, the investment market in coastal areas and the adequacy of the relevant infrastructure. The qualitative data used in this research comes from both primary and secondary sources. The primary qualitative and quantitative data was developed on the basis of the responses to a mail out questionnaire to residents from seven towns on the Bellarine Peninsula and the Surf Coast and from a number of interviews with local property experts from these areas. The secondary qualitative and quantitative data came from the results of various government surveys, demographers, the press and the census. The main thrust of this research is to answer the question

A mesocosm experiment was performed over 16 days during austral summer in 2010, in Northern Patagonia, Chile. Nutrients were added in 8 different concentrations along a gradient, simulating different levels of nutrients released by salmon farms. Nitrogen loading rate ranged from LN = 0 μg l-1 d-1 to LN = 42 μg l-1 d-1, and Silicate and Phosphorus were added in Redfield ratios. The goal of the study was to look at the effect of nutrient addition on the lower trophic levels of the marine pelagic food web represented by three groups of organisms: Phytoplankton, Ciliates and Copepods. Nutrient addition was found to have a very clear effect on chlorophyll a, POC and ciliate biomass, which showed a very clear linear increase with increasing loading rate. POC and chl a values showed that phytoplankton growth started immediately after nutrient addition. At the maximum level POC values had become 13 times larger than at the original level. Phytoplankton community composition, in the mesocosms with the highest loading rates, was found to shift from larger cells in the beginning of the experiment to smaller cells towards the end. Ciliate biomass was found to increase linearly with food concentration, indicating that ciliate population growth was closely tied to food availability. Ciliate biomass peaked on day 8 with 117 μg C l-1 found in the treatments with highest nutrient additions. A maximum of 91 ciliates ml-1 was found on day 16 during the experiment. Both these values are much higher than what has previously been reported in the area, indicating that ciliates might play a more important role in the Patagonian marine food web than previously thought. Copepod concentration and biomass were found to be uncorrelated to both nutrient addition and food concentration. This study found that nutrients released from fish farms have the potential to cause drastic increases in chl a and phytoplankton and ciliate biomass, as well as affect the community structure of phytoplankton.

The aim of this study was to enhance the knowledge on ecological and life-history parameters of Sclerocrangon boreas and Sclerocrangon ferox in Svalbard waters, including sex ratio, population structure, parasitism and prey preference. Little research has been done on S. ferox before. It has been subject to unprecedented research in the present study, considering size distribution, prey preference and DNA barcoding. The barcoding result gave a genetic distance of 13.7 % between S. boreas and S. ferox. This study shows a clear difference in size distribution between males and females. Females are considerably larger than the males. This is an indication of the two species being protandric hermaphrodite. These findings support earlier research, showing the same pattern, suggesting S. boreas being a protandric hermaphrodite. It has not been found studies looking on S. ferox considering this, but the present study shows also this species follow this pattern and are most likely protandric hermaphrodite. The largest groups of prey found in the stomach content were Crustacea, Echinoidea and Ophiuroidea. Individual specimens had mostly one type of prey in their stomach, but several types of prey were identified for both species. These findings suggest that S. boreas and S. ferox are specialists as individual specimens and generalists as species. The genetic results indicate that the specimens of S. boreas from Smeerenburg are distinguished from Grønfjorden and Rijpfjorden, and there were also variation within the specimens sampled in Smeerenburg. However, the results do not give a basis to conclude whether the populations have different genetic signatures between the fjords where S. boreas is found. It can be concluded that DNA barcoding and the CO1 gene do not together give ample information of genetic differences within populations, but it will still be able to give a genetic signal on differences between populations. Parasites were found on both S. boreas and on S. ferox. Genetic analyses, using CO1 and 18S, of the parasites conclude that they are cocoons from a piscicolid (fish) leech. The identity of this species has not been found.  

The stellate sturgeons as well as the other sturgeon populations inhabiting the Lower Danube River system (LDR) and the NW part of the Black Sea have experienced a severe decline due to heavy fishery, river regulation and water pollution. Traditionally, sturgeons have represented a great economic value for the countries along the Danube, being fished mainly for their eggs, the “black caviar”. The human population along the Danube River took advantage of the anadromous behaviour of these fishes and over decades of overfishing they depleted the stocks. In 2006 the Romanian government banned the commercial fishing of sturgeons for a period of 10 years and started a Supportive Stocking Programme of Danube with farmed juveniles originating from wild parents. The present study focuses on whether there are genetically isolated subpopulations among the adult cohorts of stellate sturgeons migrating into the LDR in the year 2010, and whether the genetic characteristics of YOY samples in the same year supports the existence of such subpopulations. Samples from fall and spring migrants and from YOY stellate sturgeons naturally born in the river in 2010 were genetically analyzed for mtDNA cyt b and D-loop regions as well as a panel of nuclear microsatellites, and revealed considerable individual variability. Hardy-Weinberg conformity tests revealed heterozygote deficit at 3 out of 4 microsatellite loci. Based on the genic differentiation at the microsatellite loci and mtDNA and cluster analyses, a genetically distinct group were demonstrated among the 2010 YOY samples, pointing to the existence of a previously unknown population substructure within the stellate sturgeons of The Lower Danube River. This was supported by biological characteristics of the YOY samples.

Sturgeons belong to one of the oldest families of bony fish in existence, having their first appearance in the fossil records approximately 200 million years ago. Their natural habitats are found in the subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. In the Romanian waters, five anadromous species of sturgeon, out of the total 25 species known by science, once migrated from the Black Sea into the Danube for spawning: beluga; Huso huso, Russian sturgeon; Acipenser gueldenstaedtii, stellate sturgeon; A. stellatus, ship sturgeon; A. nudiventris and the European Atlantic sturgeon; A. sturio (Knight, 2009). The NW Black Sea and Lower Danube River sturgeons, like many Acipenserids, were seriously affected by the rapid changes brought by human development. Being one of the finest caviar producers in the world they were intensively harvested for many centuries. Heavy uncontrolled fishing and destruction of habitat led to the collapse of most of the Acipenserids and the total disappearance of the European Atlantic sturgeon (A. sturio) from the NW Black Sea. Public attention was focused world wide on sturgeons after their listing in the IUCN Red List of Threatened species in 1996. In 1998, after evaluating their abundance in the wild, CITES also decided to strictly regulate the international trade in all Acipenserids. The paper aims to analyze and review conservation measures that were taken locally, nationally and internationally by humans and the effect they had on one of Europe’s only naturally reproducing sturgeon populations.