Membrane adsorption characteristics determine the kinetics of flow-through transductions

Retrovirus-mediated gene transfer is currently limited by random Brownian motion of the retrovirus. This limitation can be overcome by flowing the retrovirus solution through a porous membrane that supports the target cells, leading to a significant increase in the transduction efficiency. This procedure is termed "flow-through transduction." In this study, we characterized the effects of the fluid flowrate and the influence that membrane characteristics have on the flow-through transduction procedure. The transduction efficiencies increased with flowrate until a plateau was reached at average flow velocities exceeding 0.3 cm/h for flow times of 3 to 4 h, using a collagen-coated depth (COL) membrane. A correlation between the optimal time for maximal gene transfer using flow-through transductions and the optimal time for maximal virus activity on the membrane was found, suggesting that the membrane adsorption capacity for virus determined the amount of gene transfer that could occur.Membrane adsorption characteristics were further investigated using two different membrane types: a tracketched polyester screen (PE) membrane and the COL membrane. Flow-through transductions using the PE and COL membranes showed that a high level of gene transfer could be attained using the COL membrane while the PE membrane gave much lower transduction efficiencies. The addition of the polycation polybrene (PB) changed these results markedly, making transductions achieved on the PE membrane similar in number to those obtained on the COL membrane. Since PB is believed to influence the virus adsorption to PE membrane, these results further support the conclusion that the increase in gene transfer achieved by the flow-through transduction procedure is due to virus adsorption to the membrane. The flow-through transduction procedure thus leads to co-localization of the viral vector and the target cell that in turn leads to a high transduction efficiency. (c) 1996 John Wiley & Sons, Inc.     

Suitability of aquaculture effluent solids mixed with cardboard as a feedstock for vermicomposting

Recirculating aquaculture systems are highly intensive culture systems that actively filter and reuse water, thus minimizing water requirements and creating relatively small volumes of concentrated waste (compared to flow-through aquaculture systems). Vermicomposting, which uses earthworms to stabilize and transform organic wastes into valuable end-products, has been proposed as an alternative treatment technology for high-moisture-content organic wastes from agricultural, industrial and municipal sources. This study was conducted to determine if the effluent solids from a large recirculating aquaculture facility (Blue Ridge Aquaculture, Martinsville, Virginia) were suitable for vermicomposting using the earthworm Eisenia fetida. In two separate experiments, worms were fed mixtures of solids removed from aquaculture effluent (sludge) and shredded. Mixtures containing 0%, 5%, 10%, 15%, 20%, 25%, and 50% aquaculture sludge (dry weight basis) were fed to the worms over a 12-week period and their growth (biomass) was measured. Worm mortality, which occurred only in the first experiment, was not influenced by feedstock sludge concentration. In both experiments worm growth rates tended to increase with increasing sludge concentration, with the highest growth rate occurring with feedstocks containing 50% aquaculture sludge. Effluent solids from recirculating aquaculture systems mixed with shredded cardboard appear to be suitable feedstocks for vermicomposting.     

稻渔综合种养的科学范式

21世纪是渔业的世纪。中国和世界水产业历经数十年的发展为人类应对食品危机做出了巨大贡献。然而,我国传统的水产业对产量的片面追求导致养殖环境日趋恶化,养殖生态系统不断退化,养殖业的可持续发展受到限制。传统稻田其氮素的流失亦是导致农业面源污染的主要原因之一。我国当前的环境问题源于复合生态系统演化进程的缺陷,解决当前的环境问题,必须从优化复合生态系统演化进程着眼。采用优化的生态循环水产养殖模式,如综合水产养殖则可以大大提高氮、磷等养分物质的利用率。稻渔综合种养是一种科学的复合生态模式,可以概括为三种模式,一种是在我国传统稻田养鱼的基础上,逐步发展起来的一种稻渔共生模式,可采取稻鱼、稻蟹、稻虾等多种共作形式;二是稻田作为湿地用于处理水产养殖尾水的模式,属于异位处理形式;三是将稻渔共生和水产养殖相耦合的模式,尤其是与多种水产养殖形式结合或与复合水产养殖系统相结合,甚至是与农牧系统相结合。这第三种稻渔共作模式又称为陆基生态渔场,具有高产、高品质、高生态可持续性等特点,应加强对该创新养殖模式中有机碳、氮、磷等营养收支平衡和循环利用的相关机制以及复合生态系统对外源营养输入的整体响应机制开展研究。概括而言,尾水排放是传统池塘养殖中氮源的主要流失途径,颗粒物吸附沉降是池塘养殖中磷源的主要流失途径,而系统中的碳源则主要是通过鱼类等生物的呼吸作用进行消耗。基于生态循环的"稻渔共生-池塘复合生态系统"则恰好可以解决这三大类营养物质在生态系统中的高效保持和利用问题,实践业已证明该复合系统拥有较高的产量、品质和生态效益,是一种可持续的农业发展模式。稻渔复合生态系统的创新模式因其特有的生态循环机制及系统的高弹性、高缓冲性、高可持续性,将成为我国乃至世界应对农田、渔业生态系统的退化,复合高效解决渔业、农业或农牧业生态环境问题的典型范式。     

Biologically Induced Deposition of Fine Suspended Particles by Filter-Feeding Bivalves in Land-Based Industrial Marine Aquaculture Wastewater

Industrial aquaculture wastewater contains large quantities of suspended particles that can be easily broken down physically. Introduction of macro-bio-filters, such as bivalve filter feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve filter feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended particles by C. gigas (shell height: 8.67±0.99 cm) and M. galloprovincialis (shell height: 4.43±0.98 cm) was 77.84±7.77 and 6.37±0.67 mg ind⁻¹•d⁻¹, respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73±0.27 and 2.76±0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P<0.001). Furthermore, organic matter and C, N in the sediments of bivalve treatments were significantly lower than those in the sediments of the control (P<0.05). It was suggested that the filter feeders C. gigas and M. galloprovincialis had considerable potential to filter and accelerate the deposition of suspended particles from industrial aquaculture wastewater, and simultaneously yield value-added biological products.     

Aquaculture facilities drive the introduction and establishment of non-native Oreochromis niloticus populations in Neotropical streams

This study investigated whether aquaculture facilities drive the introduction and establishment of the non-native Nile tilapia (Orechromis niloticus) in Neotropical streams, Brazil. Samples were taken from nine streams with different aquaculture occupation intensities (no, moderate, and intense) using the percentage of occupation of micro-watersheds by aquaculture ponds as a proxy for propagule pressure. The presence of aquaculture facilities and the percentage of aquaculture occupation were good predictors of the catch frequency and of densities of tilapias in the adjacent natural environment. In the streams under intense propagule pressure, females prevailed and high densities of young individuals comparing to adults were recorded. It suggests that the species was reproductively successful in the natural environment. In the streams under moderate propagule pressure, males prevailed, which indicates the likely capture of individuals escaped from aquaculture facilities. In general, our results show the positive influence of propagule pressure on the introduction and establishment of Nile tilapia in natural ecosystems, showing that aquaculture expansion of O. niloticus poses a threat to the conservation of aquatic biodiversity.

     

Using USP I and USP IV for Discriminating Dissolution Rates of Nano- and Microparticle-Loaded Pharmaceutical Strip-Films

Recent interest in the development of drug particle-laden strip-films suggests the need for establishing standard regulatory tests for their dissolution. In this work, we consider the dissolution testing of griseofulvin (GF) particles, a poorly water-soluble compound, incorporated into a strip-film dosage form. The basket apparatus (USP I) and the flow-through cell dissolution apparatus (USP IV) were employed using 0.54% sodium dodecyl sulfate as the dissolution medium as per USP standard. Different rotational speeds and dissolution volumes were tested for the basket method while different cell patterns/strip-film position and dissolution media flow rate were tested using the flow-through cell dissolution method. The USP I was not able to discriminate dissolution of GF particles with respect to particle size. On the other hand, in the USP IV, GF nanoparticles incorporated in strip-films exhibited enhancement in dissolution rates and dissolution extent compared with GF microparticles incorporated in strip-films. Within the range of patterns and flow rates used, the optimal discrimination behavior was obtained when the strip-film was layered between glass beads and a flow rate of 16 ml/min was used. These results demonstrate the superior discriminatory power of the USP IV and suggest that it could be employed as a testing device in the development of strip-films containing drug nanoparticles.Key Words: BCS class II, dissolution, drug nanoparticles, flow-through cell, pharmaceutical strip-films     

Observations of growth changes during the embryonic-larval-transition of pikeperch (Sander lucioperca) under near-natural conditions

Sander lucioperca is an organism of growing importance for the aquaculture industry. Nonetheless, the rearing of S. lucioperca larvae is proving to be a difficult task as it is facing a high mortality rate during hatching and the change to exogenous feeding. To gain insight into growth patterns during this period, the authors analysed pikeperch embryos and larvae from 9 days before hatching to 17 days after hatch. Hereby they were able to describe a natural development by using close to natural conditions based on using a direct flow-through supply of lake fresh water on specimens from a local wild population. The results show that between the early embryonic stages a steady growth was visible. Nonetheless, in between hatching and the start of exogenous feeding, a phase of growth stagnation took place. In the following larval stages, an increased growth with large size variations between individual specimens appeared. Both factors are conspicuous as they can indicate a starting point for cannibalism. With this analysis, the authors can provide a fundament to support the upcoming research on S. lucioperca and aid to optimize size-sorting procedures for a higher survival of pikeperch stock in aquaculture.     

‘HALOPHYTE FILTERS’: THE POTENTIAL OF CONSTRUCTED WETLANDS FOR APPLICATION IN SALINE AQUACULTURE

World consumption of seafood continues to rise, but the seas and oceans are already overexploited. Land-based (saline) aquaculture may offer a sustainable way to meet the growing demand for fish and shellfish. A major problem of aquaculture is nutrient waste, as most of the nutrients added through feed are released into the environment in dissolved form. Wetlands are nature's water purifiers. Constructed wetlands are commonly used to treat contaminated freshwater effluent. Experience with saline systems is more limited. This paper explores the potential of constructed saline wetlands for treating the nutrient-rich discharge from land-based saline aquaculture systems. The primary function of constructed wetlands is water purification, but other ancillary benefits can also be incorporated into treatment wetland designs. Marsh vegetation enhances landscape beauty and plant diversity, and wetlands may offer habitat for fauna and recreational areas. Various approaches can be taken in utilizing plants (halophytes, macro-algae, micro-algae) in the treatment of saline aquaculture effluent. Their strengths and weaknesses are reviewed here, and a conceptual framework is presented that takes into account economic and ecological benefits as well as spatial constraints. Use of the framework is demonstrated for assessing various saline aquaculture systems in the southwestern delta region of the Netherlands.     

Silica gel: an improved support for the solid-phase phosphotriester synthesis of oligonucleotides.

The phosphotriester method for the stepwise synthesis of deoxyoligonucleotides has been employed using HPLC-grade silica gel (Porasil B) as the solid support. The procedure results in a convenient flow-through system for the synthesis of oligomers where all the reaction steps including the zinc bromide method of detritylation are compatible with the selected support. Deoxyoligonucleotides of 25-30 nucleotides in length can be synthesized in high yields utilising stable phosphotriester intermediates. Ease of handling of the solid support allows convenient synthesis of mixed oligonucleotide sequences.     

Phosphate release and heavy metal accumulation by biofilm-immobilized and chemically-coupled cells of a Citrobacter sp. pre-grown in continuous culture

A heavy metal-accumulating Citrobacter sp. was grown in carbon-limiting continuous culture in an air-lift fermentor containing raschig rings as support for biofilm development. Planktonic cells from the culture outflow were immobilized in parallel on raschig rings by chemical coupling (silanization), for quantitative comparison of phosphatase activity and uranyl uptake by both types of immobilized cell. The flow rate giving 50% conversion of substrate to product (phosphate) in flow-through reactors was higher, by 35-40%, for the biofilm-immobilized cells, possibly exploiting a pH-buffering effect of inorganic phosphate species within the extracellular polymeric material. Upon incorporation of uranyl ions (0.2 mM UO22+), both types of cell removed more than 90% of the input UO22+ at slow flow rates, but the chemically-coupled cells performed better at higher flow rates. The deposited material (HUO2PO4) subsequently removed Ni2+ from a second flow via intercalative ion exchange of Ni2+ into the crystalline HUO2PO4.4H2O lattice. This occurred irrespective of the method of coupling of the biomass to the support and suggested that uranyl phosphate accumulated by both types of cell has potential as a bio-inorganic ion exchanger-a potential use for the uranium recoved from primary waste treatment processes.     

Algal Bioremediation of Waste Waters from Land-Based Aquaculture Using Ulva: Selecting Target Species and Strains

The optimised reduction of dissolved nutrient loads in aquaculture effluents through bioremediation requires selection of appropriate algal species and strains. The objective of the current study was to identify target species and strains from the macroalgal genus Ulva for bioremediation of land-based aquaculture facilities in Eastern Australia. We surveyed land-based aquaculture facilities and natural coastal environments across three geographic locations in Eastern Australia to determine which species of Ulva occur naturally in this region and conducted growth trials at three temperature treatments on a subset of samples from each location to determine whether local strains had superior performance under local environmental conditions. DNA barcoding using the markers ITS and tufA identified six species of Ulva, with U. ohnoi being the most common blade species and U. sp. 3 the most common filamentous species. Both species occurred at multiple land-based aquaculture facilities in Townsville and Brisbane and multiple strains of each species grew well in culture. Specific growth rates of U. ohnoi and U. sp. 3 were high (over 9% and 15% day⁻¹ respectively) across temperature treatments. Within species, strains of U. ohnoi had higher growth in temperatures corresponding to local conditions, suggesting that strains may be locally adapted. However, across all temperature treatments Townsville strains had the highest growth rates (11.2–20.4% day⁻¹) and Sydney strains had the lowest growth rates (2.5–8.3% day⁻¹). We also found significant differences in growth between strains of U. ohnoi collected from the same geographic location, highlighting the potential to isolate and cultivate fast growing strains. In contrast, there was no clearly identifiable competitive strain of filamentous Ulva, with multiple species and strains having variable performance. The fast growth rates and broad geographical distribution of U. ohnoi make this an ideal species to target for bioremediation activities at land-based aquaculture facilities in Eastern Australia.     

Structural and functional aspects of treated mine water and aquaculture effluent streams

Multiple effluent streams may flow into a single receiving stream making it difficult to understand the effects of a single effluent source or the interactions between effluents. In this study, we examined benthic community structure and function in an effluent stream formed by the release of treated mine water, in treated mine water that had been used as a water source for flow-through aquaculture and below the confluence of the two. This study demonstrated that macroinvertebrate communities, while taxonomically simple, developed in treated mine water. The addition of aquaculture effluent to the treated mine water allowed colonization by additional taxa, increased leaf decomposition rates and may have conferred resistance to a turbidity event. Ecosystem responses were mediated by the surrounding terrestrial environment. In shaded conditions macroinvertebrate densities could be as much as 10× higher and the taxa were dominated by simuliids and chironomids, while in open conditions filamentous algae flourished and the taxa were dominated by hydroptilids and chironomids. Consequently, consideration of stream processes that promote preferred ecological processes, such as macroinvertebrate production and organic matter processing, when siting effluent streams may reduce impacts on receiving streams.     

Genetic interactions between marine finfish species in European aquaculture and wild conspecifics

The principal species of marine aquaculture in Europe are Atlantic salmon (Salmo salar), sea bass (Dicentrarchus labrax) and sea bream (Sparus auratus). For Atlantic salmon and sea bass, a substantial part of total genetic variation is partitioned at the geographical population level. In the case of sea bream, gene flow across the Azores/Mediterranean scale appears to be extensive and population structuring is not detected. For Atlantic salmon and sea bass, natural population structure is at risk from genetic interaction with escaped aquaculture conspecifics. The locally adaptive features of populations are at risk from interbreeding with non‐local aquaculture fish. Wild populations, generally, are at risk from interactions with aquaculture fish that have been subject to artificial selection or domestication. Atlantic salmon is the main European aquaculture species and its population genetics and ecology have been well‐studied. A general case regarding genetic interactions can be based on the information available for salmon and extended to cover other species, in the appropriate context. A generalized flow chart for interactions is presented. Salmon escape from aquaculture at all life stages, and some survive to breed among wild salmon. Reproductive fitness in the escaped fish is lower than in native, wild fish because of behavioural deficiencies at spawning. However, as the number of salmon in aquaculture greatly exceeds the number of wild fish, even small fractional rates of escape may result in the local presence of large numbers, and high frequencies, of escaped fish. At present, policy and legislation in relation to minimizing genetic interactions between wild and aquaculture fish is best developed for Atlantic salmon, through the recommendations of the Oslo Agreement developed by the North Atlantic Salmon Conservation Organization and subsequent agreements on their implementation. In future, the potential use of genetically modified fish in aquaculture will make additional policy development necessary. Improved containment is recommended as the key to minimizing the numbers and therefore the effects of escaped fish. Emergency recovery procedures are recommended as a back‐up measure in the case of containment failure. Reproductive sterility is recommended as a future key to eliminating the genetic potential of escaped fish. The maintenance of robust populations of wild fish is recommended as a key to minimizing the effects of escaped fish on wild populations.     

Application of 16s rDNA and cytochrome <Emphasis Type="Italic">b</Emphasis> ribosomal markers in studies of lineage and fish populations structure of aquatic species

The most economically important form of aquaculture is fish farming, which is an industry that accounts for an ever increasing share of world fishery production. Molecular markers can be used to enhance the productivity of the aquaculture and fish industries to meet the increasing demand. Molecular markers can be identified via a DNA test regardless of the developmental stage, age or environmental challenges experienced by the organism. The application of 16s and cytochrome b markers has enabled rapid progress in investigations of genetic variability and inbreeding, parentage assignments, species and strain identification and the construction of high resolution genetic linkage maps for aquaculture fisheries. In this review, the advantages of principles and potential power tools of 16s and cytochrome b markers are discussed. Main findings in term of trend, aspects and debates on the reviewed issue made from the model of aquatic species for the benefit of aquaculture genomics and aquaculture genetics research are discussed. The concepts in this review are illustrated with various research examples and results that relate theory to reality and provide a strong review of the current status of these biotechnology topics.     

Development of a flow-through system to create occluding thrombus

Occlusive thrombosis accounts for many heart attacks and strokes. These acute events are difficult to catch in patients and animal test methods may be misleading because anti-thrombotic therapeutics often do not cross-react with different species. This paper presents a new flow-through system that leads to rapid occlusive thrombosis in arterial flow conditions. Whole porcine blood is perfused through a tubular test section. The growing thrombus is visualized in real time from early platelet attachment, through accumulation, to occlusion. The progression of flow rate reduction provides a clear distinguishing parameter between thrombus formation and embolization. Thrombus growth rate is a linear function of very high shear rate beyond 40,000 s(-1). The histology of the thrombus reveals predominantly platelet accumulation and growth as a rough surface with tendrils. This flow-through system may be useful for the economic testing of new anti-thrombosis therapies.     

Intrinsic pump-conduit behavior of lymphangions

Lymphangions, segments of lymphatic vessels bounded by valves, have characteristics of both ventricles and arteries. They can act primarily like pumps when actively transporting lymph against a pressure gradient. They also can act as conduit vessels when passively transporting lymph down a pressure gradient. This duality has implications for clinical treatment of several types of edema, since the strategy to optimize lymph flow may depend on whether it is most beneficial for lymphangions to act as pumps or conduits. To address this duality, we employed a simple computational model of a contracting lymphangion, predicted the flows at both positive and negative axial pressure gradients, and validated the results with in vitro experiments on bovine mesenteric vessels. This model illustrates that contraction increases flow for normal axial pressure gradients. With edema, limb elevation, or external compression, however, the pressure gradient might reverse, and lymph may flow passively down a pressure gradient. In such cases, the valves may be forced open during the entire contraction cycle. The vessel thus acts as a conduit, and contraction has the effect of increasing resistance to passive flow, thus inhibiting flow rather than promoting it. This analysis may explain a possible physiological benefit of the observed flow-mediated inhibition of the lymphatic pump at high flow rates.     

Effect of an integrated mangrove-aquaculture system on aquacultural health

Mangroves are unique intertidal halophyte formations growing in sheltered tropical and subtropical coastal areas. Due to the increasing population and economic development, mangroves have faced degrada-tion and loss, which has been mainly caused by land conversion into aquaculture ponds in Asia. In the past several decades, the rapid growth of aquaculture has induced water pollution. Using mangroves for effluent treatment from coastal aquaculture ponds could be a suitable approach for wastewater treatment and healthy aquaculture development. An Integrated Mangrove-Aquaculture System (IMAS) was established to test whether the idea of a mangrove in situ treatment for aquaculture wastewater is feasible. The monocultures of three mangroves, Sonneratia caseolaris, Kandelia obo-vata, and Aegiceras corniculatum were established with area proportions of 45%, 30%, or 15%, respectively. One control pond without mangroves was also set up. The results indicated that the mangroves had different toler-abilities to long-term inundation. The aquaculture ponds had different fishery yields, considering the mangrove species and area proportions. The water quality of most of the experimental ponds was better than the control pond, except for the planted Sonneratia. It is concluded that mangroves can reduce the concentration of dissolved inorganic nitrogen and phosphate, buffer the pH value and increase the concertration of dissolved oxygen in aqua-culture water bodies effectively. It is suggested to use 15% of the Aegiceras corniculatum area to conduct in situ purification of aquaculture wastewater and to enhance aquaculture production.     

Stress-associated impacts of short-term holding on fishes

Most sources of stress in aquaculture, fish salvage, stocking programs, and commercial and sport fisheries may be unavoidable. Collecting, handling, sorting, holding, and transporting are routine practices that can have significant effects on fish physiology and survival. Nevertheless, an understanding of the stressors affecting fish holding can lead to practices that reduce stress and its detrimental effects. The stress-related effects of short-term holding are influenced by water quality, confinement density, holding container design, and agonistic and predation-associated behaviors. Physiological demands (e.g., resulting from confinement-related stresses) exceeding a threshold level where the fish can no longer compensate may lead to debilitating effects. These effects can be manifested as suppressed immune systems; decreased growth, swimming performance, or reproductive capacity; even death. Furthermore, holding tolerance may depend upon the species, life stage, previous exposure to stress, and behavior of the held fish. Water quality is one of the most important contributors to fish health and stress level. Fish may be able to tolerate adverse water quality conditions; however, when combined with other stressors, fish may be quickly overcome by the resulting physiological challenges. Temperature, dissolved oxygen, ammonia, nitrite, nitrate, salinity, pH, carbon dioxide, alkalinity, and hardness are the most common water quality parameters affecting physiological stress. Secondly, high fish densities in holding containers are the most common problem throughout aquaculture facilities, live-fish transfers, and fish salvage operations. Furthermore, the holding container design may also compromise the survival and immune function by affecting water quality, density and confinement, and aggressive interactions. Lastly, fishes held for relatively short durations are also influenced by negative interactions, associated with intraspecific and interspecific competition, cannibalism, predation, and determining nascent hierarchies. These interactions can be lethal (i.e., predation) or may act as a vector for pathogens to enter (i.e., bites and wounds). Predation may be a significant source of mortality for fisheries practices that do not sort by size or species while holding. Stress associated with short-term holding of fishes can have negative effects on overall health and well-being. These four aspects are major factors contributing to the physiology, behavior, and survival of fishes held for a relatively short time period.     

New methods for separation and recovery of biomolecules.

New methods and applications in the separation of biomolecules are reviewed, with an emphasis on the large-scale recovery of proteins. Highlights include the advent of flow-through particles in perfusion chromatography, which allows for very high flow rates, while retaining a high chromatographic efficiency.     

Present status of fisheries in Turkey

Turkey’s natural and ecological situations are very suitable for aquaculture. Turkey also has a wide variety of freshwater and marine species comprising trout, carp, sea bass, sea bream, turbot, mussel, crayfish, etc. The total production of fish and shellfish was 646,310 tons in 2008. The contribution of freshwater catch to total fishery production is relatively small. Capture fisheries production amounted to 494,124 tons whilst aquaculture production was 152,186 tons in the same year. In Turkey, Engraulis encrasicholus (anchovy) is the main caught sea fish species. Fisheries in the Black Sea are the most important fishery by far and show the greatest variations in total catch. Alburnus tarichii (a local species belonging to Cyprinidae) and Cyprinus carpio (the common carp) are the most important species caught from freshwaters. Aquaculture is going to play an increasingly important role in the Turkish economy, as fishery products are the only products of animal origin that can be exported to the EU. There has been a fast increase in the aquaculture production in Turkey with the implementation of scientific and technological modernization. For example, total aquaculture production for 1986 and 2008 was 3,075 and 152,186 tons, respectively. The percentage of aquaculture in total fish production has been rising every year. The ratio of cultured fish production to total fish production was 1.5% in 1990 s, 13.57% in 2000 and more than 20% in 2005. It was 23.55% in 2008. Trouts are the main cultured freshwater fish species. Raceways and floating cages are employed in culture of trout. Carps are also important cultured freshwater fish species. Sea bass and gilthead sea bream are grown marine fish species. Floating cages, off-shore and earthen ponds are used for marine fish species culture. There has been an increase in fishery exports and imports in recent years. It was more than US500 million in 2008, but that of 2004 was just over US 500 million in 2008, but that of 2004 was just over US 233 million. However, aquaculture production is still far away from the production targets and fisheries sector is not an important part of the economy at present.