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1.
ABSTRACT

Aquaculture is contributing at an increasing rate to the world seafood supply. The interaction between fisheries and aquaculture is especially important for the seafood market where supply of wild and farmed fish can affect price dynamics. We examine market interactions in the French fresh sea bass and sea bream markets. We test for long-term price parity between farmed and wild products for these two species, applying a bivariate cointegration approach to market delineation. We also conduct the Law of One Price (LOP) test between price series. Our data base consists of monthly domestic price series for fish purchased by French households from 2007 to 2012. Our empirical results show that the fresh fish markets for whole wild and farmed sea bream are partially integrated, yet those for whole wild and farmed sea bass are not integrated. The substantially higher price for wild sea bass relative to farmed sea bass suggests that consumers may be more sensitive to seafood production processes when it comes to higher-value species.  相似文献   

2.
We investigate empirically market interactions in the Turkish wild and farmed sea bass and sea bream markets. For gilthead sea bream and European sea bass, we conduct a Granger causality test between the prices of the wild and farmed products, based on the estimation of a vector autoregressive model. Our data set consists of annual fish prices from 1996 to 2016. Our empirical results show that the wild and farmed sea bass are neither substitutes nor complements: the markets for each product are independent. However, in the case of sea bream, the price variations for farmed sea bream have a causal impact on the price of wild sea bream. Moreover, the price of wild sea bream Granger-causes the price variation of farmed sea bream. Thus, the wild and farmed sea bream markets are integrated.  相似文献   

3.
Interactions between fisheries and aquaculture have become a major issue that is still insufficiently studied. Therefore, the objective of this article is to test whether the cultured and wild gilthead sea bream in the Spanish seafood markets are integrated. By using the Johansen methodology, cointegration of the price series of farmed and wild gilthead sea bream was tested. In contrast to previous studies, our econometric results show that wild and the farmed gilthead sea bream form two heterogeneous products in the Spanish market. These new results question the generalization currently accepted by the scientific literature that farmed and wild fish are substitutes when they belong to the same species. The binomial product-market, along with some specific features of the Spanish market, such as the negative perceptions of aquaculture by some significant groups of consumers, appeared to have a great explanatory power for justifying these different results.  相似文献   

4.
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5.
Three trials, with classical experimental designs for in vivo digestibility studies, were conducted to determine the apparent digestibility coefficient (ADC) of protein (ADCp), lipid (ADCl), energy (ADCe) and amino acids (AA) in selected animal by-products fed to European sea bass, Dicentrarchus labrax (Trial 1), gilthead sea bream, Sparus aurata (Trial 2), and turbot, Psetta maxima (Trial 3). In each trial, five experimental diets [including a reference diet (RD)] where fish meal (FM) was used as the sole protein source were fed ad libitum to the fish for a period of 4 weeks. Test diets were based on the FM RD and obtained by replacing 30% of the RD with a category III designated European animal by-products (fit for human consumption), namely: steam hydrolysed feather meal (HFM), enzyme-treated feather meal (EFM), poultry meat meal (PMM) and spray-dried haemoglobin meal (SDHM). Faecal material was collected using the 'Guelph system', and nutrient and energy digestibility coefficients were related to the measurement of chromic oxide (Cr2O3) incorporated into the diet at a rate of 0.5%. Without any exception, FM diets yielded the best digestibility values for all macro-nutrients and by all fish. Among the test ingredients, ADCp was consistently higher for PMM and SDHM in the three species (85.5%, 91.1% in sea bass; 79.2%, 82.8% in sea bream; and 78.4%, 74.8% in turbot). Conversely, ADCp of HFM and EFM were less efficiently digested (67.2%, 68.2% in sea bass; 21.5%, 21.7% in sea bream; and 46.6%, 36.0% in turbot). However, the novel processing method applied to feather meal did not considerably influence the digestibility of most of the nutrients in this feedstuff. The current investigation yielded valuable numerical ADC for EAA considered to be of prime importance in generating balanced diet formulations.  相似文献   

6.
More than 25% of Greek fish farms and 20% of Greek hatcheries of gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) are located along the Western Hellenic coast. The part of sea bream production is about 60% of the total production of these species. During the last decade, a spectacular increase in both the number of farms and their production, accompanied by a substantial price decrease and modification of their structure and functioning, has been recorded. These changes resulted in the maintenance in cages of large individuals (more than 500 g) of gilthead sea bream which are potential spawners. The study, based on both the maturity stage and the decrease in individual mean weights during the reproductive period of the species, confirmed reproduction in cages. In parallel, during the last 5 years a remarkable increase (about 80%) in sea bream landings from the fish trap fisheries of the Messolonghi‐Etoliko lagoon, which is a typical nursery for the species, was recorded. The increase was accompanied by a decrease both in price and mean size of the 0‐group individuals. The possible influence of the rearing activities in the area, the density‐dependent mechanisms and the negative impacts of this unintentional enhancement of the traditional lagoon fisheries of the area are discussed.  相似文献   

7.
European sea bass (Dicentrarchus labrax) and gilthead sea bream(Sparus aurata) are amongst the most important finfish speciescultured in the Mediterranean region. Production of these species isnowadays a well-controlled process, but knowledge of their nutritionalrequirements is still very limited. Nevertheless, a considerable amountof data has been accumulated in recent years, and the purpose of thispaper is to review the recent advances on the nutritional requirementsof sea bass and sea bream. The optimum protein to energy ratio of thediets of sea bass and sea bream seem to be higher than for salmonids,and there is some evidence that high dietary lipid levels have nobeneficial effects on fish performances. Although the essential aminoacid requirements were estimated by the ideal protein method, data basedon the dose-response method is only available for a few amino acids.Essential fatty acid requirements were estimated for sea bream juvenilesbut data is lacking for sea bass. Vitamin and mineral requirements ofthese species are practically unknown. Although the importance ofbroodstock nutrition on gonadal development, spawning and egg quality isrecognized, few studies were done to elucidate these aspects. The recentdevelopment of microparticulate diets for larvae will contribute to theaccurate evaluation of their nutritional requirements.  相似文献   

8.
The present study was performed to determine the effect of soybean meal (SBM) on the performance and gut histology of gilthead sea bream and European sea bass. Three isonitrogenous and isolipidic extruded diets (crude protein, 470 g kg−1 diet; crude fat, 200 g kg−1 diet) were formulated containing 0 (0 SBM), 180 (180 SBM) and 300 (300 SBM) g kg−1 diet SBM and tested on both species in two separate experiments. Fish at an initial average weight of around 18 g were randomly allocated to 800 L square tanks connected to a closed recirculating system. The trials lasted 80 days for sea bream and 89 days for sea bass. Fish were hand-fed to apparent satiation. Increasing the level of SBM had no significant effects on the specific growth rate, feed intake and feed conversion rate in both the species. In the sea bream distal intestine, lamina propria was moderately and diffusely expanded in some fish due to an increase in cell infiltration represented by mononuclear cells, this finding being more frequent in animals fed diet 300 SBM. No other morphological alterations in intestinal folds, enterocytes or other inflammation signs were noticed in the sea bream distal intestine of any group. No histological differences were found in sea bass in any experimental group.  相似文献   

9.
ABSTRACT

Soluble gas stabilization (SGS) is a relatively recent methodology of active packaging that has been proposed to extend the shelf life of packaged fish. The aim of the present work was to study the effect of SGS applied at different extents (2 bars: 30 and 60 min) on the shelf life of sea bream and sea bass fillets packed in air during chilled storage. Quality changes were evaluated by sensory assessment, microbiological analysis (TVC), TBARs, pH value, TVB-N, and TMA-N. No significant extension of sensory shelf life was visible as a function of SGS treatment. The treatment of fillets in CO2 at 2 bars during 60 min had a positive effect on the microbiological shelf life of both species. On the other hand, TMA-N and TVB-N showed similar changes during storage period and were not affected by the CO2 treatment. Sea bream treated with SGS always presented higher TBARs than control samples. Nevertheless, oxidation of sea bream and in particular, of sea bass fillets, did not appear to be a significant problem during chilled storage.  相似文献   

10.
Abstract Using underwater cameras, data were collected on the feeding behaviour and swimming speeds of Atlantic salmon Salmo salar L., gilthead sea bream Sparus aurata L. and European sea bass Dicentrarchus labrax L. in sea cages. Comparisons were made between the behaviours of fish fed on demand using interactive feedback systems and those of fish fed under the standard feeding practice of each farm (control). In all three species, swimming speeds were similar before feeding , but they were significantly higher in the control regimes during feeding. When fed on demand, sea bass had reduced swimming speed just before and during feeding compared with that observed during the non‐feeding periods. Higher proportions of feeding fish were observed in the control regime cages than in fish fed on demand for all three species, indicating a greater feeding intensity during meals in the control regimes. This was further supported by observations of an increase in the density of sea bass in the upper water in the control cages during feeding. The results suggest decreased levels of competition between the on demand‐fed fish during feeding, which might be hypothesized to lead to improved growth and production efficiency in aquaculture.  相似文献   

11.
ABSTRACT:   Seawater fishes are affected by a pathology commonly called 'myxobacteriosis', caused by Tenacibaculum maritimum (formerly Flexibacter maritimus ). The disease is characterized by fin erosion and necrotic ulcers of skin and muscle, and by low but constant mortality in cultured marine fish; in Italy is one of the most important and widely spread diseases affecting sea bass Dicentrarchus labrax , gilthead seabream Sparus aurata , sharp-snouted bream Diplodus puntazzo , white bream Diplodus sargus , and six-tooted bream Dentex dentex . In order to obtain an effective vaccine against the disease, formalin killed cells (FKC), extracellular products (ECPs) and crude lipopolysaccharide (LPS) preparations were obtained from the T. maritimum strain SPVId and injected intraperitoneally twice into the sea bass. The fish immune response to the preparations was studied: agglutinating antibody titer and in vitro phagocytosis were determined after the first and second injection in order to evaluate whether the preparations are immunogenic or not and if the booster effect took place. The results show that FKC and LPS preparations increased the antibody titer after the first injection when compared to the control sea bass. Moreover, all the preparations stimulated a secondary (booster) response. In vitro phagocytosis of the total blood was significantly higher for all the preparations when compared to the controls, but the crude LPS immunized sea bass showed the highest activity.  相似文献   

12.
《水生生物资源》1999,12(1):23-30
The common dentex (Dentex dentex) is a sparid fish which is considered a suitable candidate for Mediterranean aqua-culture. A seven-weeks feeding trial was conducted over the summer period with common dentex, sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). All three species were fed to visual satiety with two practical diets with varying crude protein and crude fat levels (55 % protein, 9 % lipids; 46 % protein, 17 % lipids). The initial body weights were 8.2, 11.6 and 17.3 g for common dentex, sea bass and sea bream, respectively. In all cases, specific growth rates were not significantly affected by dietary treatment, but they varied among species (sea bass 1.7–1.8 %; sea bream 2.1–2.3 %; common dentex 3.1–3.2 %). When comparisons between fish species were made, we observed that the increase in growth rates was linked to a decrease of the whole body fat content, as a consequence of a greater utilisation of dietary lipids as energy substrates. Furthermore, in common dentex, the 17 % lipid diet was able to improve protein retention, but this diet effect was less significant in sea bream and sea bass. In contrast to sea bream, the 17 % lipid diet did not up-regulate plasma GH levels in common dentex, which provides additional evidence for a more efficient utilisation of dietary lipids.  相似文献   

13.
This paper reviews the stock enhancement programme for black sea bream ( Acanthopagrus schlegelii ) in Hiroshima Bay. This bay is one of the biggest production areas for black sea bream in Japan, accounting for about 10% of the total catch of the species in this country in 2004. After intensive fishing pressure caused a drastic decline in the catch of the species in this bay in the 1970s, a stock enhancement programme was conducted in its northern part since 1982 to restore the depleted population. The number of black sea bream juveniles released in 1996 surpassed 9 million, representing the third main species stocked in Japan. Almost 1.4 million of these juveniles were released into Hiroshima Bay. The fast acclimatization of hatchery-reared juveniles released into the bay may have contributed to the recovery of landings in the late 1980s and 1990s. However, this recovery was accompanied by a reduction in the market price of black sea bream. Further studies to assess the effectiveness of the stock enhancement programme as well as the carrying capacity of Hiroshima Bay to maintain the stock of black sea bream at a stable, healthy level are desirable. The necessity of evaluating the secondary effects derived from using a reduced number of breeders as well as finding new markets are suggested.  相似文献   

14.
海水鱼类必需脂肪酸营养与需要的研究进展   总被引：15，自引：0，他引：15  
综述了牙Ping、大菱Ping、鲷和鲈等海水主要养殖鱼类的必需脂肪酸营养及其需要量；讨论了为海水养殖鱼类提供必需脂肪酸的有效途径。  相似文献   

15.
The influence of oil-in-water nanoemulsion on the sensory, chemical, and microbiological qualities of sea bream and sea bass fillets stored at 2 ± 2°C was investigated. The results showed that the use of nanoemulsion extended the shelf life of fish one or two days when compared with the control. Treatment with nanoemulsion significantly (p < 0.05) decreased the values of chemical parameters throughout the storage period. Bacterial growth was inhibited by the use of nanoemulsion. Nanoemulsion had an inhibitory effect on protein denaturation during refrigerated storage and microwave cooking. Based on the results, it can be concluded that sunflower oil-based nanoemulsion extended the shelf life and improved the quality of both sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) fillets during storage.  相似文献   

16.
Abstract. Turbot, Scophthalmus maximus (L.), and sea bass, Dicentrarchus labrax (L.), are susceptible to vibriosis, a septicaemia caused in France by Vibrio anguillarum 408. A bacterin produced with this strain by Rhône–Merieux has been tested orally in both species and, as a comparison, by intraperitoneal injection. During a challenge carried out 4 weeks later by intraperitoneal inoculation, the protection observed in orally vaccinated fishes was significant (72 % in sea bass and 70 % in turbot). Eleven weeks after vaccination, this protection is still significant. The mean titre of serum agglutinins was weakly increased in orally vaccinated fishes. Bacteriostatic antibodies have also been searched for in serum, but compared to agglutination, the applied technique leads to lower titres and it has not been possible to prove the presence of such antibodies after oral vaccination. Passive immunizations using serum from orally vaccinated fishes (2 months after vaccination) confers some protection against a challenge carried out by inoculation of virulent vibrio. Therefore, the production of serum factors following oral vaccination of sea bass and turbot may be involved in generalized protection of fish.  相似文献   

17.
Marine aquaculture in Greece is a relatively new industry based on the culture of aquatic species such as the Mediterranean sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), and Mediterranean mussel (Mytilus galloprovincialis). In the early 1980s, the results of research and development were applied to develop pilot semiacademic commercial farms. Such farms were gradually moved to the industrial scale of today, producing some 80,00–120,000 tons of finfish and up to 25,000–35,000 tons of mussels annually. The problems encountered during the adaptation of innovation to the production and management of this blue revolution is critically discussed from the early developmental phases up to the present.  相似文献   

18.
The aim of the study was to compare theantioxidant systems in juvenile marine fish ofcommercial importance to European aquaculture,namely turbot (Scophthalmus maximus),halibut (Hippoglossus hippoglossus) andgilthead sea bream (Sparus aurata). Thepresent dietary trial was specifically designedto investigate the antioxidant effects ofvitamin E under moderate oxidising conditions,including high dietary levels of highlyunsaturated fatty acids and the feeding ofoxidised oils. The objective was to induce astressful pro-oxidant status to enablecharacterisation of the biochemical responsesto peroxidative stress without causingunnecessary suffering to the experimentalanimals or high mortalities during the trials. Both sea bream and turbot showed excellentgrowth, whereas growth was poorer in halibut.Dietary oxidised oil significantly reducedgrowth in turbot and especially in halibut, butnot in sea bream. Vitamin E improved growth insea bream fed oxidised oil but not in turbot orhalibut. However, vitamin E supplementationappeared to improve survival in all threespecies. In sea bream and turbot, liverantioxidant defence enzyme activities weregenerally increased by feeding peroxidised oiland reduced by vitamin E. Conversely, inhalibut, the liver antioxidant defence enzymeactivities were not increased by feedingperoxidised oil and only superoxide dismutasewas reduced by feeding vitamin E. Consistentwith these data, feeding oxidised oil increasedlipid peroxidation products in halibut, butgenerally not in sea bream or turbot.Furthermore, lipid peroxidation products weregenerally reduced by dietary vitamin E in bothsea bream and turbot, but not in halibut. Therefore, halibut liver antioxidant defenceenzymes did not respond to dietary oxidised oilor vitamin E as occurred in turbot and,especially sea bream. This resulted inincreased levels of lipid peroxides in halibutcompared to turbot and sea bream in fish givendietary oxidised oil. In addition, supplementalvitamin E did not reduce lipid peroxides inhalibut as it did in turbot and sea bream. Theincreased peroxidation stress in halibut mayaccount for their poorer growth and survival incomparison to turbot and especially sea bream.Halibut were reared at a lower temperature,although relatively high for halibut, thaneither turbot or sea bream but they were alsoslightly younger/smaller fish and possibly,therefore, more developmentally immature, andeither or all of these factors may be importantin the lack of response of the liver enzymes inhalibut.  相似文献   

19.
The objective of this study was to evaluate the effect of harvest practices and slaughter method on stress, quality and shelf life of whole fish (gilthead sea bream, European sea bass and red sea bream) towards the development of a humane slaughter practice. The use of hook and line resulted in significantly lower plasma cortisol and glucose in European sea bass and gilthead sea bream. Water temperature at harvest affected significantly the concentrations of stress indicators (plasma cortisol and glucose), mainly in European sea bass and gilthead sea bream. No significant differences were observed between the harvesting methods, regarding fish appearance, microbial spoilage and sensory scoring and subsequently shelf life. However, significantly lower hardness was recorded in fish harvested using the electric stunner, compared to the fish killed with slurry ice of the same harvesting period. Shelf life ranged between 13–18 days for gilthead seabream, 10–16 days for European sea bass and 10–14 days for red sea bream, depending on harvesting period.  相似文献   

20.
ABSTRACT:   Ontogenetic changes of tolerance to, and avoidance of, ultraviolet-B radiation (UV-B) were examined in red sea bream Pagrus major and black sea bream Acanthopagrus schlegeli . In the tolerance experiment, larvae and juveniles (age 13–46 days) were put in beakers, and were exposed to one of five different levels of UV-B radiation (1.8, 1.1, 0.2, 0.1, and 0 W/m2) for one hour. Their survival rates were calculated either 12 or 24 h later. In the avoidance experiment, fish (age 3–49 days) were put in a long experimental tank, half of which was covered with UV-blocking film and placed under two levels of UV-B radiation (1.1 and 0.2 W/m2), and their avoidance indices were calculated. Black sea bream had significantly better survival compared to red sea bream for most ages. Only black sea bream of ages 37 and 49 days showed significant avoidance of UV radiation under the higher level of UV-B, whereas both species did not show avoidance on any days at the lower level. The present results suggest that black sea bream are significantly better adapted to habitats with high UV-B radiation, than red sea bream, reflecting that back sea bream live in shallower waters through their early life stages.  相似文献   

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