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The management of complex water problems is nowadays being practised through new ways and approaches. Therefore, water engineers, planners and managers should be appropriately educated through modern undergraduate curricula and by well-designed postgraduate specialisation programmes. Within this framework, a study of the specific characteristics of an ensemble of 14 postgraduate programmes in various fields of environmental water resources engineering and management, offered by Greek universities, is presented. Detailed information and data regarding the formats, structures, educational processes and curricula contents of these programmes are analysed and critically discussed. Similarities and differences among them are depicted and synthesised, in order to reveal individual as well as collective qualities and deficiencies in relation with the overall current needs for engineering postgraduate specialisation in water-related issues.

Until recently, most cases of humans been affected by fish pathogens, bacterial and parasitic, were limited in certain countries, either due to the inappropriate sanitary measures used in those areas, or due to the local habit of eating raw or undercooked fish. However, as new reliable methods to identify fish pathogens in samples collected from sick humans have been developed, the confirmed cases worldwide have increased. The most common fish bacterial pathogens that can affect humans belong to the genera: Mycobacterium spp. (mainly M. marinum, M. chelonei, M. fortuitum), Nocardia spp., Streptococcus spp (S. iniae), Vibrio spp. (mainly V. vulnificus, V. alginolyticus and V. parahaemolyticus) and Aeromonas spp. (mainly A. hydrophila and rarely A. sorbia and A. caviae). Less often, infections of humans with Edwardsiella tarda and Photobacterium damselae sbsp. damselae have been reported. Fish usually act as intermediate hosts to many important parasites of human, as for example the tapeworm Diphyllobothrium latum. To fish, these parasites cause no or little damage, as they are usually found encysted in many fish tissues. Of particular interest are someanisakids (e.g. Anisakis simplex and Pseudoterranova decipiens) which can produce some thermostable allergens. Most of the above pathogens can infect humans through skin wounds or after ingesting infected fish. Compromised immune system of the infected humans may result in extensive spread of the pathogens within the body, often causing death.There are no fish viruses or fungi that can affect humans. Fish can also act as carriers for human pathogens, such as Salmonella spp., Escherichia coli and Listeria spp. Recently, few human pathogens have also been isolated from the internal organs of fish, as for example Brucella melitensis. The effects of these human pathogens to fish are still not known.

In the present study, the effects of Dimilin® on the survival and histology of two commercially important marine fish species, sea bream and sea bass, after a short-term exposure, were examined. Sea bream and sea bass fry of similar mean weight (0.25±0.05g SD) were exposed to three concentrations of the pesticide (diflubenzuron), 1500, 1000 and 500 ppm, for 96 h. For each species, three groups of ten fish (replicates) were exposed to each concentration,while three groups were not exposed and kept as controls. The mortality was recorded daily and tissue samples from fish of allgroups were collected for histological examination, after 24 and 96 h exposure. During the first 24 h of exposure, almost all seabream exposed to 1500 and 1000 ppm died. Similarly, almost all sea bass fry exposed to 1500 ppm also died but few fishexposed to 1000 ppm survived. Throughout the exposure period, sea bream fry exposed to 500 ppm exhibited similar survivalwith this of the control groups (percentage of alive fish after 96 h: 73.3±25.1% SD and 70±17.3% SD respectively), while seabass fry exposed to the same concentration exhibited significantly lower survival rate compared to that of the control groups(percentage of alive fish after 96 h: 26.6±20.8% SD and 86.6±5.7% SD respectively). The histological examination indicatedsimilar findings for both species. As the fish exposed to 1500 and 1000 ppm died in the first 24 h of exposure, before collectingthe tissue samples, the gills exhibited severe lesions of autolysis.The tissue samples of the fish exposed to 500 ppm werecollected from live fish and these revealed severe extensive hyperplasia and hypertrophy of the gill respiratory epithelium.These lesions became more pronounced after 96 h exposure. Only areas of mild hyperplasia / hypertrophy of the respiratory epithelium were observed in fish from the control groups, after 24 and 96 h exposure. No lesions in the internal organs of the fish exposed to Dimilin® were observed neither after 24 nor after 96 h exposure.

Recent trends towards extending the shelf-life of fresh eel during refrigerated storage have rendered the control of lipid oxidation increasingly important. Eel fat is very sensitive to oxidative deterioration because of its high content of polyunsaturated fatty acids. To delay or minimise oxidative deterioration of fresheel fat during refrigerated storage, the use of vacuum packaging was investigated. Lipid oxidation was assessed by monitoring malonaldehyde (MDA) formation in wild (n=10) and farmed (n=10) eel flesh samples at 0, 1, 2, 5 and 8 days of refrigerated storage in atmospheric air or under vacuum packaging, using a selective third-order derivative spectrophotometric method. The results clearly demonstrated the oxidative stability of vacuum packed eelflesh following storage for 8 days at 3±1oC and the significant oxidation of the atmospheric air stored eel flesh even after 1 day of refrigerated storage.

In the present study the effect of two levels of nitrate on the skin morphology and particularly on the number and diameter of skin mucous cells of sea bass were examined histologically. A softwarecontaining a visual basic script macro, that allowed quantification of skin parameters, was used to analyze the skin tissue sections. In total 45 sea bass (mean weight 155.6g±10.3g SD) were divided into 3 groups and placed into nine 100 litter tanks (3 replicates in each group). In the water of three tanks (Group A) nitrate was added toapproximate 100 ppm final concentration, in the next 3 tanks (Group B) nitrate was added to approximate 700 ppm final concentration, while the fish in the remaining 3 tanks (Group C) kept as controls. During the experimental period (48 hours) the tank water was constantly aerated. At the end of the experimental period 3 fish per tank (9 per group) were sampled and examined. The fish of the group that were maintained in the highest concentration of nitrate exhibited significantly (P0.05). The increased number of the mucus cells in the skin is probably the reaction of the fish to this stressful condition.

A collection a pathogenic bacterial strains isolated from natural disease outbreaks in Greek fish farms was founded in Greece by the cooperation of three laboratories: a) Lab. of Ichthyology, School of Veterinary Medicine, Aristotle University of Thessaloniki, b) Lab. of Ichthyopathology Faculty of Veterinary Medicine, University of Thessaly and c) Institute of Aquaculture, Hellenic Center for Marine Research Athens. This project is funded by the Hellenic Ministry of Rural Development and Food - Fisheries Department. After isolation the bacteria are characterized biochemically and molecularly (PCR). Their pathogenicity is tested using experimental challenges. Theisolates are then lyophilizised and stocked at -80 oC. The results so far indicate that Listonella anguillarum, Vibrio alginolyticus and Photobacterium damsela subsp piscicida are the main pathogens that occur in Greek mariculture.

To optimize fish growth grading is strongly recommended. In our experiment the glass eels (450,000, mean individual body weight 0.31+0.22g sd) start feeding for 15 and then they were selected according to their appetite. After selection all the fish of the 10 tanks were fed at liberty and they were weighed on the 10th and 30thday after the grade day. No differences were seen in the fish weight of the eels of the two groups on the 10th day (P>0.01) but the selected fish doubled their weight on the 30th day (selected fish 0.71+0.22g sd, unselected 0.39+0.20g sd, P

The nutritional requirements of shellfish are satisfied by the phytoplankton and the nutrients of the estuary waters. Bivalves (mussels, oysters, clams, cockles, scallops and razors) can be there produced. The shellfish are cultured on the sea bottom or suspended. For shellfish culture no food is required and the investment cost is low. If the quality of the water is high then they can be considered as bio or organic products. The disadvantages concern their sanitary status (contamination by heavy metals, radio nucleotides, phytotoxines, viruses, bacteria and parasites). No medications or vaccines are applied.

The article investigates the potential use of frozen mussel (Mytilus galloprovincialis) and mussel meal in the diet of marine fishes sea bass (Dicentrarchus labrax Linnaeus) and sea bream (Sparus aurata Linnaeus). It examines the effect of the dietary inclusion of mussels on the growth of the fingerlings. It concludes that dietary inclusion of mussels can improve the color and quality of the fish due to the presence of carotenoids and also increases the protein efficiency of commercial feeds.

The management of complex water problems is nowadays being practised through new ways and approaches. Therefore, water engineers, planners and managers should be appropriately educated through modern undergraduate curricula and by well-designed postgraduate specialisation programmes. Within this framework, a study of the specific characteristics of an ensemble of 14 postgraduate programmes in various fields of environmental water resources engineering and management, offered by Greek universities, is presented. Detailed information and data regarding the formats, structures, educational processes and curricula contents of these programmes are analysed and critically discussed. Similarities and differences among them are depicted and synthesised, in order to reveal individual as well as collective qualities and deficiencies in relation with the overall current needs for engineering postgraduate specialisation in water-related issues. [ABSTRACT FROM PUBLISHER]

An effective anesthetic scheme would significantly contribute to the investigation of disease in the Mediterranean mussel (Mytilus galloprovincialis), especially when biopsy is required. In this study, we evaluated the efficacy of six anesthetics: 2-phenoxyethanol (2 ml/l), MS222 (0.4 and 1 g/l), MgCl2 (20 and 50 g/l), clove oil (1.5 ml/l), benzocaine (1.5 g/l), and 1-phenoxy-2-propanol (2.5 ml/l) when used to anesthetize Mediterranean mussel. For this purpose, 810 mussels were allocated to nine groups of 90 mussels each (three replicates of 30 individuals in each group). Each group was exposed to one of the above concentrations of anesthetics for 24 h, except for one group kept as the control. Mussels were considered anesthetized when they did not close their valves after tapping them with a pair of forceps. The most effective anesthesia was MS222 at the concentration of 1 g/l; it induced anesthesia in 58.8±1.92% of the exposed mussels with negligible mortality (5.7±5.8%) of the anesthetized mussels one week after anesthesia. Further, when using MS222 there was no correlation between the number of anesthetized mussels and temperature. However, the number significantly increased as the size of the mussels decreased. MgCl2 at the concentration of 20 g/l resulted in notable retardation of valve movement. [ABSTRACT FROM AUTHOR]

The efficacy of a commercial bivalent Listonella anguillarum (serotype 01 and 02) vaccine (MICROViB, Microtek International) was tested on prime- and booster-immersion vaccinated sea bass Dicentrarchus labrax juveniles. We carried out 2 challenge tests on the prime-vaccinated fish, 50 and 90 d after initial vaccination. A second group of fish received a booster vaccination 60 d after the prime vaccination, and were tested with a single challenge 30 d later. Relative percent survival (RPS) was 92 and 84% (both p < 0.01) among the prime-vaccinated fish on the first and second challenges, respectively. The RPS of the booster-vaccinated sea bass was 100% (p < 0.01). Antibody titres were tested only among 10 prime-vaccinated and 10 unvaccinated (control) sea bass, 60 d post-immunisation, and were found to rise to 1/32 in the vaccinated fish. Our results demonstrate that MICROViB immersion vaccine can effectively protect juvenile sea bass from L. anguillarum infection.