Uncertainties and values in European aquaculture: communication, management and policy issues in times of “changing public perceptions”

The hypothesis that forms the basis of debatefor this paper is that in order for theEuropean aquaculture industry to achieve itsgrowth potential in terms of consumer andpublic acceptance then it must establishparticipatory fora that adopt open andtransparent discussions on the current andfuture issues surrounding sustainabledevelopment. Fundamental to this goal iseffective communication of easy-to-digestinformation. Also, interested parties should begiven the option to be involved in thedevelopment of recommendations.This paper recommends among others the followingmeasures:Full adoption of the Integrated Coastal Zone Management Strategy, based on a multidisciplinary framework and extended peer-reviews;More openness and debate, including the broadening of perspectives, regarding the issues of sustainability and food safety;The wider use of various participatory mechanisms on different levels, e.g. through national consensus conferences.     

Detection of post‐F1 fish hybrids in broodstock using molecular markers: approaches for genetic management in aquaculture

Herein, we have developed molecular markers for nuclear genes to use in multiplex‐PCR and PCR‐RFLP, with the goal of characterising hybrid lines derived from crosses between pintado Pseudoplatystoma corruscans and cachara P. reticulatum. These markers, together with others described previously, were used to perform molecular identification analyses as genetic subsidies for Brazilian aquaculture. These analyses were performed due to the problems of high mortality in the offspring reported by the aquaculturist. From a total of 16 broodstock samples, 13 were genetically identified as hybrids; surprisingly, nine of these hybrids were found to be post‐F1 lineages. These data show that the fertility of these animals can seriously affect the cultivated stocks, thus causing financial damage in this aquaculture system. The establishment of PCR‐RFLP and multiplex‐PCR as molecular techniques allows for both the correct management of these animals and the routine monitoring of production and trade of fish hybrids in aquaculture. Consequently, such tools will enable a sustainable development in the aquaculture industry.     

The future of genetic engineering to provide essential dietary nutrients and improve growth performance in aquaculture: Advantages and challenges

Advancements in gene technology in recent years have been driving the aquaculture industry forward. Improvements in growth performance, feed efficiency, and omega‐3 content are goals of the industry that could capitalize on applications of genetic engineering. One of the major challenges in the industry is to reduce the use of fish meal and oil, to improve the environmental and economic sustainability of aquaculture. The recent development of genetically engineered feed ingredients is one potential solution to the looming problem of fish meal and oil dependency. Furthermore, the development of transgenic fish has potential to improve production efficiency and other future desirable characteristics that relate to feed utilization and product quality. New gene technologies are beginning to revolutionize how we produce our food, and in aquaculture, will ultimately reduce pressure on wild fish stocks, help to preserve natural aquatic ecosystems, and improve nutritional profiles of farmed fish for human consumption. The purpose of this review is to provide an update on the current applications of genetic engineering technology to improve aquaculture through nutrition, including the development and use of transgenic feed ingredients, transgenic fish, and ultimately their impacts on nutrition, product quality, and consumers.     

Ecological effects of major injuries in diamondback terrapins: implications for conservation and management

• 1. Many turtle species frequently suffer major injuries due to attempted predation or anthropogenic factors. Diamondback terrapins (Malaclemys terrapin) are one species known to be affected by anthropogenic activity, but little is known about the causes of injuries. In declining diamondback terrapin populations, learning more about causes and results of injuries can be helpful in developing sound management plans.
• 2. Patterns of limb loss and major shell injuries were examined in a population of terrapins studied for 24 years at Kiawah Island, South Carolina to infer the causes and effects of injuries and possible predators on terrapins.
• 3. The rate of shell injuries increased temporally, possibly as a result of increased watercraft activity. Because no differences in rates of limb loss were found between males and females, limb loss probably results from aquatic encounters (i.e. limb loss does not appear to be the result of terrestrial predation during nesting). Furthermore, males experienced reduced body condition when injured, and terrapins with a major injury had lower survivorship than uninjured terrapins.
• 4. Therefore, in addition to reducing sources of mortality and protecting nesting habitat, measures to protect terrapins from watercraft activity may increase the survivorship of adult terrapins.

Copyright © 2008 John Wiley & Sons, Ltd.     

Particularities of early life stages in temperate freshwater fish species: comparisons with marine species and implications for aquaculture practices

Both egg and larvae are different between freshwater and marine fish species. Freshwater fish species have generally larger and fewer eggs than marine species. Most freshwater fish species have demersal eggs that develop stuck to various substrata, such as plants or gravels, while eggs of most marine fish species develop in the water column. These differences have consequences for both the evaluation of the quality and the incubation of eggs of freshwater fish species compared with marine species. The larvae of many freshwater fish species are larger and more developed at hatching than their marine counterparts: thus, larval feeding regimes could be different and cannibalism may emerge sooner in certain freshwater fish species. The main differences of egg and larvae between freshwater and marine species are highlighted and the possible implications for aquaculture practices are discussed.     

Polyaromatic hydrocarbons in aquafeeds,source, effects and potential implications for vitamin status of farmed fish species: a review

Access to marine feed ingredients is considered a limiting factor for the rapidly growing aquaculture industry. With increasing inclusion of vegetable feed ingredients in aquafeeds, new challenges have arisen. Substituting marine oils and meals with vegetable ingredients has decreased the level of persistent organic pollutants (POPs) in marine farmed fish such as Atlantic salmon. Consequently, this shift in feed ingredients has led to increased levels of polyaromatic hydrocarbons (PAHs) in aquafeeds. Several of the PAHs listed are on EFSAs and EPAs list of priority substances. Not only are the carcinogenic and genotoxic properties of PAHs of concern, but also their ability to interact with and disrupt metabolic pathways such as vitamin metabolism and signalling. The interactions, and the potential depletion of vitamin stores that follows, are of particular interest as marine ingredients are naturally rich in micronutrients such as vitamins A and D. This study has summarized the current knowledge on the effect of PAHs commonly found in vegetable feed ingredients on vitamin metabolism/signalling and their possible implications in fish.     

Molecular identification and distribution of mangrove oysters ( Crassostrea) in an estuarine ecosystem in Southeast Brazil: implications for aquaculture and fisheries management

This study investigated the existing species of Crassostrea in the natural environment, farming systems and artificial spat collectors at a protected estuarine area in Brazil, through PCR‐RFLP of mitochondrial 16S rRNA. Among 450 samples collected in the natural environment, 303 were C. brasiliana and 147 C. rhizophorae. Oysters present in the rocky subtidal zone were C. brasiliana. However, both species occurred on mangrove roots in the intertidal zone. Farm‐raised samples included only C. brasiliana. It was observed that attached specimens in commercial collectors had a banding pattern distinct from C. brasiliana and C. rhizophorae, indicating the presence of a third species in the estuary. The 16S rRNA sequence analysis showed that these specimens are clustered with the oysters from Pacific and Indian Oceans, and genetically close to the oysters of Beihai, China (0.3% genetic distance). Oysters obtained from the seed capture showed 17.8% distance of in relation to C. brasiliana, 17.6% for C. rhizophorae and 10.3% for C. gigas, demonstrating high genetic divergence from these species. The occurrence of an exotic species in the Cananéia estuary may have strong ecological and economic implications which require new guidelines for farming, conservation and sustainable fisheries management for the native oyster species.     

Population genetic structure of common bottlenose dolphins (Tursiops truncatus) in the Adriatic Sea and contiguous regions: implications for international conservation

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Population structure of short‐finned pilot whales in the oceanic archipelago of Madeira based on photo‐identification and genetic analyses: implications for conservation

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Feeding on the edge: δ13C analysis of a macrofauna food web from disappearing seagrass beds in a polluted urban harbour – implications for biomonitoring and restoration efforts

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从河蟹市场分析看中华绒螯蟹养殖的发展方向

中华绒螯蟹 (Eriocheir sinensis)“长荡湖1号”A系 (雌体大于200 g) 和B系 (雌体大于250 g) 的选育工作已进行到子一代 (G1代),前期研究表明,G1代在扣蟹阶段的生长性能及养殖效果表现出一定的优势,但成蟹的养殖性能尚不清楚。文章系统比较了“长荡湖1号”2个选育品系 (A系和B系) 与未选育群体在成蟹养殖阶段的生长性能、成活率和产量等指标。结果显示：1) 在养殖中后期 (9—11月),选育组平均体质量略高于对照组,其中B系雌体显著高于对照组 (P<0.05);此外,B系在5—7月的增重率和特定生长率均显著高于A系 (P<0.05);2) A系和B系雄体生殖蜕壳率和性腺指数均略低于对照组;B系肝胰腺指数在10月20日显著低于另外2组,而11月15日又显著高于另外2组 (P<0.05);3) 两选育品系雌雄体大规格成蟹 (雄蟹≥195 g,雌蟹≥120 g) 比例均高于对照组,其中B系G1代雄蟹 (195~219.9 g) 显著大于对照组 (P<0.05);此外,在最终平均体质量、成活率、产量及饵料系数等方面,两选育品系均优于对照组。综上,A系在成活率、产量和饲料系数等方面具有优势,B系具有大规格蟹比例高、最终平均体质量大的特点。     

Ecological influences on the difference in δ15N and δ13C values between fish tissues: implications for studies of temporal diet variation

Temporal diet changes can be detected by comparing δ¹³C and δ¹⁵N values between tissues with different isotopic turnover times. However, other factors contribute to disparities in δ¹³C and δ¹⁵N signatures between tissues and could confound the interpretation of stable isotope data. We examined the effects of ecological factors on differences in muscle and liver δ¹³C and δ¹⁵N signatures of Arctic charr [Salvelinus alpinus, (L.)] to determine whether their effects were large enough to influence studies of diet change. In addition, we examined whether differences in lipid content accounted for a significant portion of the differences in δ¹³C values between tissues. Results indicated that life history, diet, reproductive status and gender had significant effects on the differences in δ¹³C values between tissues, while gender and diet significantly affected differences in δ¹⁵N values. Differences in % lipid content between tissues also explained approximately 74% of the observed variation in the difference in δ¹³C values between tissues. The differences in δ¹³C values observed between muscle and liver tissues may be partially explained by physiological differences in lipid storage and use between tissues associated with ecological factor effects. These results demonstrate that ecological factors other than a change in diet can influence the differences in δ¹³C and δ¹⁵N signatures between muscle and liver tissues. However, the impact of ecological factors on studies of diet change depends on how the magnitude of the factor effects compared with a biologically meaningful change in diet.