Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test...Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test system for the examination of toxicity for antifouling paints. In this study, we examined the effect of four “tin free” self-polishing copolymer (SPC) antifouling paints on the larval development of Artemia nauplii. Based on the L(S/V)50 values the order of toxicity of the antifouling paints was: ANTI F > SHARKSKIN > OCEAN T/F > MICRON. Furthermore, the body size of Artemia nauplii was significantly affected at lethal and above lethal L(S/V)5024h values. The body size of 48 h-aged nauplii exposed for the last 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 48 h-aged controls (0.88 ± 0.030 mm). In addition, the body size of 72 h-aged nauplii maintained for the last 24 hours to pure synthetic seawater after exposure for 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 72 h-aged controls (0.96 ±0.027 mm). Overall, the SPCs examined here were substantially toxic to Artemia nauplii, but with different toxicities and modes of action, as a result of the synergistic action of distinct components of the antifouling paints.展开更多
Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreat...Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreational value of the coastal zone between Molos and Arkitsa, in prefecture of Fthiotida, in Sterea Ellada region, in Greece. The study area provides substantial benefits to host community and remains an advantageous natural setting for tourism sustainable development. An economic valuation of the benefits largely assists the efforts of the local authorities to establish viable tourism products and preferred destination attributes. The travel cost method was used to estimate recreation demand. Based on personal and on site interviews 1,433 questionnaires were collected. The consumer surplus per day enjoyed by the visitors is 22,352.28 （Euros）. The analysis assigned a considerable value to the coastal zone. Results shed light on core issues such as environmental management and proper resource allocation in view of finding areas for further improvement so as to increase consumer surplus by satisfying the needs and wants of coastal visitors.展开更多
Successful commercial aquaculture of crustacean species is dependent on satisfying their nutritional requirements and on producing rapidly growing and healthy animals.The results of the present study provide valuable ...Successful commercial aquaculture of crustacean species is dependent on satisfying their nutritional requirements and on producing rapidly growing and healthy animals.The results of the present study provide valuable information for feeding habits and growth of Nephrops norvegicus L.,1758)under laboratory conditions.The aim of the present study was to examine food consumption,growth and physiology of the Norway lobster N.norvegicus under laboratory conditions.N.norvegicus(15 g wet weight)were distributed into 100l tanks consisting of five numbered compartments each.They were fed the experimental diets(frozen mussels and pellets)for a period of 6 months.A group of starved Nephrops was stocked and fasted for 8 months.Although Nephrops grew well when fed the frozen mussels diet,feeding on a dry pellet feed was unsatisfactory.The starvation group,despite the fact that showed the highest mortality(50%),exhibited a remarkable tolerance to the lack of food supply.The study offers further insight by correlating the amino acid profiles of Nephrops tail muscle with the two diets.The deviations from the mussel’s diet for asparagine,alanine and glutamic acid suggest a deficiency of these amino acids in this diet.The results of the present study showed that the concentrations of free amino acids are lower in relative amount than those of protein-bound amino acids,except for arginine,proline and glycine.The present study contributes to the improvement of our knowledge on nutritional requirements of the above species.展开更多
The management of coastal zones in terms of tourism exploitation remains a crucial issue in achieving sustainable development and customer satisfaction. The interrelation between the coastal zone and the preference st...The management of coastal zones in terms of tourism exploitation remains a crucial issue in achieving sustainable development and customer satisfaction. The interrelation between the coastal zone and the preference structure of visitors form a desired tourism setting and a hospitable destination in which environmentally friendly practices dominate the tourism aspects. Conjoint analysis was used with a purpose of eliciting respondents＇ preferences and answering questions concerning the features that compose a sustainable tourism product. In the survey, 16 proposed combinations of tourism characteristics were rated by 1,433 respondents. The three most preferred factors of the proposed tourism product were the accommodation factor, the sea activities factor and the fishery tourism factor with averaged importance scores 27,351,22,900 and 2 1, 13 1, respectively.展开更多
In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus,more information about its reproductive biology and its larval behavior and morphogenesis is necessary.Currently,temperatures ranging from ...In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus,more information about its reproductive biology and its larval behavior and morphogenesis is necessary.Currently,temperatures ranging from 21 to 27°C are used in ornamental aquaculture hatcheries.Lower temperatures are preferred to reduce the costs of water heating,and 23°C is usually the selected temperature.However,there is limited information on culturing protocols for ornamental species and most of the information generated on this topic remains scarce.Thus,the present study examines the morphological development of Archocentrus nigrofasciatus during the yolk-sac period up to the age of 100 h post-hatching in relation to 2 temperature regimes used in ornamental aquaculture:a temperature of 27°C(thermal optimum)and a decreased temperature of 23°C(thermal tolerance).The results of this study suggest that the 27°C temperature generates intense morphological changes in yolk-sac development in a shorter period.This has advantages as it reduces the time of yolk-sac larval development,and,thus,minimizes the transition phase to exogenous feeding and maximizes the efficiency at which yolk is converted into body tissues.The present paper provides necessary information to produce freshwater ornamental fish with better practices so as to increase larval survival and capitalize on time for growth.展开更多
文摘Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test system for the examination of toxicity for antifouling paints. In this study, we examined the effect of four “tin free” self-polishing copolymer (SPC) antifouling paints on the larval development of Artemia nauplii. Based on the L(S/V)50 values the order of toxicity of the antifouling paints was: ANTI F > SHARKSKIN > OCEAN T/F > MICRON. Furthermore, the body size of Artemia nauplii was significantly affected at lethal and above lethal L(S/V)5024h values. The body size of 48 h-aged nauplii exposed for the last 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 48 h-aged controls (0.88 ± 0.030 mm). In addition, the body size of 72 h-aged nauplii maintained for the last 24 hours to pure synthetic seawater after exposure for 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 72 h-aged controls (0.96 ±0.027 mm). Overall, the SPCs examined here were substantially toxic to Artemia nauplii, but with different toxicities and modes of action, as a result of the synergistic action of distinct components of the antifouling paints.
文摘Recreation and beach use constitute core aspects of coastal tourism development since they incorporate various stakeholders at different levels and diverse activities. This research investigates the economical recreational value of the coastal zone between Molos and Arkitsa, in prefecture of Fthiotida, in Sterea Ellada region, in Greece. The study area provides substantial benefits to host community and remains an advantageous natural setting for tourism sustainable development. An economic valuation of the benefits largely assists the efforts of the local authorities to establish viable tourism products and preferred destination attributes. The travel cost method was used to estimate recreation demand. Based on personal and on site interviews 1,433 questionnaires were collected. The consumer surplus per day enjoyed by the visitors is 22,352.28 （Euros）. The analysis assigned a considerable value to the coastal zone. Results shed light on core issues such as environmental management and proper resource allocation in view of finding areas for further improvement so as to increase consumer surplus by satisfying the needs and wants of coastal visitors.
文摘Successful commercial aquaculture of crustacean species is dependent on satisfying their nutritional requirements and on producing rapidly growing and healthy animals.The results of the present study provide valuable information for feeding habits and growth of Nephrops norvegicus L.,1758)under laboratory conditions.The aim of the present study was to examine food consumption,growth and physiology of the Norway lobster N.norvegicus under laboratory conditions.N.norvegicus(15 g wet weight)were distributed into 100l tanks consisting of five numbered compartments each.They were fed the experimental diets(frozen mussels and pellets)for a period of 6 months.A group of starved Nephrops was stocked and fasted for 8 months.Although Nephrops grew well when fed the frozen mussels diet,feeding on a dry pellet feed was unsatisfactory.The starvation group,despite the fact that showed the highest mortality(50%),exhibited a remarkable tolerance to the lack of food supply.The study offers further insight by correlating the amino acid profiles of Nephrops tail muscle with the two diets.The deviations from the mussel’s diet for asparagine,alanine and glutamic acid suggest a deficiency of these amino acids in this diet.The results of the present study showed that the concentrations of free amino acids are lower in relative amount than those of protein-bound amino acids,except for arginine,proline and glycine.The present study contributes to the improvement of our knowledge on nutritional requirements of the above species.
文摘The management of coastal zones in terms of tourism exploitation remains a crucial issue in achieving sustainable development and customer satisfaction. The interrelation between the coastal zone and the preference structure of visitors form a desired tourism setting and a hospitable destination in which environmentally friendly practices dominate the tourism aspects. Conjoint analysis was used with a purpose of eliciting respondents＇ preferences and answering questions concerning the features that compose a sustainable tourism product. In the survey, 16 proposed combinations of tourism characteristics were rated by 1,433 respondents. The three most preferred factors of the proposed tourism product were the accommodation factor, the sea activities factor and the fishery tourism factor with averaged importance scores 27,351,22,900 and 2 1, 13 1, respectively.
基金The authors wish to thank Dr.R.Calado for useful discussions.
文摘In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus,more information about its reproductive biology and its larval behavior and morphogenesis is necessary.Currently,temperatures ranging from 21 to 27°C are used in ornamental aquaculture hatcheries.Lower temperatures are preferred to reduce the costs of water heating,and 23°C is usually the selected temperature.However,there is limited information on culturing protocols for ornamental species and most of the information generated on this topic remains scarce.Thus,the present study examines the morphological development of Archocentrus nigrofasciatus during the yolk-sac period up to the age of 100 h post-hatching in relation to 2 temperature regimes used in ornamental aquaculture:a temperature of 27°C(thermal optimum)and a decreased temperature of 23°C(thermal tolerance).The results of this study suggest that the 27°C temperature generates intense morphological changes in yolk-sac development in a shorter period.This has advantages as it reduces the time of yolk-sac larval development,and,thus,minimizes the transition phase to exogenous feeding and maximizes the efficiency at which yolk is converted into body tissues.The present paper provides necessary information to produce freshwater ornamental fish with better practices so as to increase larval survival and capitalize on time for growth.
