The development of Brazilian aquaculture: Introduced and native species

Brazil’s aquaculture production has increased rapidly during the last two decades, growing from basically zero in the 1980s to over one half million (metric) tons in 2011. However, with an increased focus on the domestic market and native species, the development in Brazil has been very different from most other successful aquaculture producers, particularly in Latin America. As in many other countries, the development started with introduced international species such as shrimp and tilapia in a typical developing country fashion, but has shifted to an increasing share of native species and focus on the domestic market. This article analyzes the main aspects concerning this development by the relative productivity of the main species, regulations and markets. Regulations and the technology spreading from international species may be considered as important factors for this somewhat unusual development. The future prospects for the Brazilian aquaculture industry development are positive, since there is not only space available for expansion for both exotic and native species, but also an untapped domestic market.     

A survey of aquaculture production economics and management

Abstract

The literature on production economics and management of fish culture has grown as aquaculture has matured as a commercial industry. Salmon, catfish, shrimp and trout are the focus of this literature survey as a reflection of the volume of research that has been completed on these species and their importance in US production and world trade. In addition, a discussion of low resource production systems is included that is dominated by tilapia and carp culture systems. A brief overview of the principles of aquaculture production economics and management is presented followed by a review of economic studies.     

Understanding the economic and farming practices driving species selection in aquaculture within the Mymensingh division of Bangladesh

Aquaculture is a major supplier of animal protein for Bangladesh’s population, and the Mymensingh division is a major contributor to finfish aquaculture, producing 43% of the total pond pangasius and 9% of the total amount of tilapia (figures from 2018). We conducted a finfish farmer survey covering Netrokona, Jamalpur and Mymensingh districts to understand current finfish farming practices and identify factors that drive farmers in their species choice between pangasius or tilapia cultivation. We found that most finfish farmers in Mymensingh are experienced practitioners and practise polyculture with a range of stocking densities for each species. Using an economic model of polyculture practice, we have shown that over a production cycle, pangasius gain body mass at a rate nearly 4 times greater than that for tilapia, resulting in substantially larger revenues and providing a strong incentive for their culture. High levels of tilapia aquaculture likely persist due to their short production cycle and an associated decreased economic risk due to crop loss from disease, both factors providing a strong incentive for their culture. Our findings also indicate production yield differences through different species selection in polyculture systems. For example, co-culturing pangasius, tilapia and carp together was less productive than co-culture of pangasius with tilapia. Furthermore, higher yields of tilapia were obtained when co-cultured with carp compared with pangasius, the reasons for which are not known and warrant further investigation. Our study uses information provided by finfish farmers to produce a useful guide on fish species choices to maximise production yields, and therefore food production, from their ponds.

     

Growth Performance,Biochemical Responses,and Skeletal Muscle Development of Juvenile Nile Tilapia,Oreochromis niloticus,Fed with Increasing Levels of Arginine

Tilapia, Oreochromis niloticus, is among the fish species with high potential for aquaculture in intensive farming, and Brazil is among the largest producers worldwide. Some of the amino acid requirements in practical diets for tilapia are still unknown. Thus, this study determined the dietary arginine requirements for Nile tilapia juveniles based on growth performance, hematological and biochemical responses, and muscle growth. Three hundred Nile tilapia juveniles (2.95 ± 0.79 g) were distributed into 20–500 L fiberglass aquaria and fed five extruded isoproteic (28% crude protein) and isoenergetic (3160 kcal/kg) diets formulated to contain 0.95, 1.10, 1.25, 1.40, and 1.55% arginine. Based on the quadratic regression analysis, the best results in weight gain, feed conversion, protein efficiency ratio, and protein retention were estimated in fish fed diets containing 1.36, 1.34, 1.36, and 1.37% arginine, respectively. The best amino acid body retention values were estimated in fish fed diets containing 1.31–1.37% arginine. Muscle growth occurred mainly by hyperplasia in fish fed 0.95% arginine, whereas reduction in the hyperplasia time and signs of hypertrophy occurred in fish fed 1.10–1.55% arginine diets. It was concluded that a diet with 1.36% of arginine (with 1.53% lysine in diet) meets the requirements of Nile tilapia juveniles.     

Natural foods utilized by Nile tilapia, <Emphasis Type="Italic">Oreochromis niloticus</Emphasis>, in fertilizer-based fish ponds in Lao PDR identified through stable isotope analysis

Nile tilapia, Oreochromis niloticus, is one of the most popular freshwater aquaculture species in developing countries. Although formulated feed provides higher fish yield, it is expensive. Therefore, fertilizer-based fish culture using natural food sources is generally implemented in developing countries. The aim of this study was to identify the major natural foods contributing to tilapia growth in fertilizer-based fish ponds. The stomach contents of tilapia in a fertilizer-based fish pond in Lao PDR were analyzed to estimate their feeding behaviors; stable isotope ratios of carbon and nitrogen in the potential food organisms and suspended solids were measured and compared with the ratios in the fish muscle tissues. Further, the feed efficiency of chironomid larvae was compared with that of chlorella and formulated feed in a laboratory feeding experiment. Consequently, chironomid larvae were identified as the main contributors to tilapia growth in the fertilizer-based fish pond. In conclusion, benthic larvae of insects belonging to the family Chironomidae are confirmed to be a natural food source for tilapia in the fertilizer-based fish pond.     

The effects of two fish species mullet,Mugil cephalus,and tilapia,Oreochromis niloticus,in polyculture with white shrimp,Litopenaeus vannamei,on system performances: A comparative study

A comparative study was carried out to compare the effect of caging mullet and tilapia in a shrimp polyculture system. In six shrimp tanks (three tanks for each fish species), either mullet, Mugil cephalus (CCT‐SM), or tilapia, Oreochromis niloticus (CCT‐ST), was stocked in cages. In three other tanks, mullets were allowed to roam freely in shrimp tanks (D‐SM). White shrimp, Litopenaeus vannamei (0.50 g), was cultured as the predominant species were distributed randomly into nine fibreglass tanks (5 m³) at a density of 300 shrimp/tank, while fish (1.50 g) were stocked at the same density of 10% of the initial total shrimp biomass. The results showed that water quality parameters were not significantly different among treatments (p > .05), except for total suspended solids (TSSs). System performances based on parameters such as total weight gain (2,808.15 g/tank) and nutrient recovery were higher in D‐SM treatment (39.80% for nitrogen and 27.40% for phosphorus) than in CCT‐SM and CCT‐ST treatments (p < .05). These system performance parameters were significantly affected by the mullet‐holding strategy; however, they were not affected by fish species. The addition of mullet or tilapia in shrimp tanks did not affect shrimp growth differentially. Fish growth performances based on parameters such as final weight (98.43 g/fish) and DGR (1.29 g/day) were significantly higher in D‐SM treatment and were significantly different among D‐SM, CCT‐SM and CCT‐ST treatments (p < .05). It is concluded that in shrimp–fish polyculture with a stocking density of fish at 10% of the initial total shrimp biomass, tilapia is more effective than mullet, when caged. However, under free‐roaming conditions, the use of mullet is more effective in terms of system performances relative to a system holding caged tilapia.     

Aquaculture and international trade

Abstract

In contrast to the stabilization or decline of wild fishery harvests, aquaculture's contribution to the world fish supply is steadily increasing. Aquaculture has begun to have a major influence on the trade of export‐orientated species such as salmon and shrimp. This paper reviews the role of aquaculture in international trade and the research which has been conducted to examine its influence. Despite the growing significance of aquaculture on international trade, especially for shrimp and salmon, formal analysis of the shrimp trade is sparse, only moderate for salmon, and essentially nonexistent for other species. This paper also presents specific examples of how aquaculture has played an important role in international trade. These include an examination of: (1) the influence of shrimp aquaculture and trade on the development of a shrimp futures contract; and (2) the countervailing duty and antidumping case against the Norwegian farmed salmon industry.     

Profitability and technical efficiency of aquaculture systems in pampaanga,philippines

Abstract

We evaluate the profitability and technical efficiency of aquaculture in the Philippines. Farm‐level data are used to compare two production systems corresponding to the intensive monoculture of tilapia in freshwater ponds and the extensive polyculture of shrimps and fish in brackish water ponds. Both activities are very lucrative, with brackish water aquaculture achieving the higher level of profit per farm. Stochastic frontier production functions reveal that technical efficiency is low in brackish water aquaculture, with a mean of 53%, explained primarily by the operator's experience and by the frequency of his visits to the farm. In freshwater aquaculture, the farms achieve a mean efficiency level of 83%. The results suggest that the provision of extension services to brackish water fish farms might be a cost‐effective way of increasing production and productivity in that sector. By contrast, technological change will have to be the driving force of future productivity growth in freshwater aquaculture.     

Bioenergetic modelling of effects of fertilization, stocking density, and spawning on growth of the Nile tilapia, Oreochromis niloticus (L.)

Abstract. A bioenergetic growth model was developed to examine the integrated effects of fertilization, stocking density, and spawning on the growth of tilapia, Oreochromis niloticus (L.), in pond aquaculture. The analyses showed that growth rates increase with higher levels of organic fertilization up to 500kg/ha/week. Growth rates increased with added food rations in ponds, reaching a maximum growth of 2-07g/day at about 44–48 days after stocking. Fish growth rates decreased with increased levels of stocking density. The stocking density for optimal growth is 1fish/m²; the optimal density for total harvesting weight and fish size is 2 fish/m². Model sensitivity analysis indicated that tilapia growth is most sensitive to catabolism (metabolism) and anabolism (synthesis) coefficients, both of which are geometrically related to the fish body weight. Food assimilation efficiency (b) and the food consumption coefficient (h) have a modest effect on fish growth. Spawning in grow-out ponds can have a major effect on fish growth.     

Tilapia fisheries in Guangdong Province,China: Socio‐economic benefits,and threats on native ecosystems and economics

Tilapia is one of the groups of fish species most widely cultured globally. China has been the largest producer of tilapia in the world since 1990s. Guangdong Province produces almost 40% of all tilapia in China because of its suitable geography and weather conditions, and tilapia culture has brought considerable economic benefits. Unfortunately, many of the biological traits that make tilapia popular for culture also contribute to its success as an invader. Tilapia has invaded natural waters and has become the dominant fish in many rivers of Guangdong Province, causing economic loss in capture fisheries, and affecting native fish species, biodiversity and aquatic ecosystems. Poor fishery management, water quality degradation and biodiversity loss have all facilitated the tilapia invasion. Tilapia have filled the niches left vacant by now locally extinct native species resulting from environmental changes in freshwater ecosystems of the province. The introduction of tilapia has both advantages and disadvantages, which should be managed to use effectively the various tilapia species in aquaculture while controlling their spread in natural waters.     

DEMAND FOR AQUACULTURE PRODUCTS IN TAIWAN: AN APPLICATION OF THE GENERALIZED MODEL

ABSTRACT

Policy decisions on what aquaculture products to develop require information on consumer demand for cultured species. However, information on the structure of demand for aquaculture products is limited and what few studies there are in Taiwan, where aquaculture is a major industry, suffer from methodological problems. To clear up some of these problems, we used modified nonnested testing techniques and performance forecasting to determine which generalized models could best estimate the demand for Taiwanese aquaculture products. The results of modified nonnested testing of the aquaculture demand system showed that prices predetermined and quantities predetermined could be used to estimate demand. The generalized ordinary demand model was able to better forecast performance than the generalized inverse demand model. We used the likelihood ratio test to discriminate among the four competing models for the generalized ordinary model; the AIDS model could be more suitably applied to the data. A more general model that is able to incorporate different dynamic structures (partial adjustment, first autoregressive, and static). This general framework is applied to the AIDS model. The first autoregressive AIDS model we used to calculate the own and cross-price elasticities for milkfish, tilapia, shrimp, shellfish, and carps found that price elasticities varied across fish type, that some products had high long-run own price elasticities, and that the demand for aquaculture products was largely determined by inertia.     

Fish to 2030: The Role and Opportunity for Aquaculture

Seafood sector can contribute to the global food supply in an important way, and provide an important source of animal protein. Based on observed regional trends in seafood production and consumption and using a global, partial-equilibrium, multi-market model, this study investigates what the global seafood market may look like in 2030. The model projects that the total fish supply will increase from 154 million tons in 2011 to 186 million tons in 2030, with aquaculture entirely responsible for the increase. The fastest aquaculture growth is expected for tilapia and shrimp, while the largest expansion is expected in India, Latin America and Caribbean and Southeast Asia. Fast-growing seafood demand in China and elsewhere represents a critical opportunity for global fisheries and aquaculture to improve their management and achieve sustainable seafood economy.     

Cortisol Response of Nile Tilapia,Oreochromis niloticus (L.), to Temperature Changes

Abstract

Nile tilapia, Oreochromis niloticus (L.), is a commercially-valuable fish species with high nutritional value. As a result of the intensive aquaculture of this species, handling, transport, and environmental changes that causes stress on these fish are unavoidable. The objective of this study was to determine the effects of gradual and acute temperature changes on juvenile tilapia. No significant difference (P > 0.05) was found among serum cortisol levels in juvenile tilapia when the water temperature was gradually increased from 27°C to 32°C, or 40°C, and maintained for 1 hour, although the levels were five times pretreat-ment levels. When tilapia acclimated to 27°C were subjected to 18°, 27°, 30°, 32°, 34°, 36°, 38°, or 40°C water for 10 minutes in a water bath, followed by a recovery period of 10 minutes at 27°C in the original aquaria, no significant difference (P > 0.05) in cortisol levels was observed among treatments except for significantly elevated levels at 38°C and 40°C. When tilapia acclimated to 27°C were subjected to the same temperature exposures but given a recovery period of 60 minutes at 27°C in the original aquaria, there was no significant (P > 0.05) increase in cortisol levels in tilapia among treatments from 18° to 36°C; but there was a significant (P > 0.05) increase between values from those treatments at 38° and 40°C. Acute temperature changes initiated the cortisol response as early as 10 minutes in fish following exposure to 38°C or 40°C and resulted in significant increases in the 38°C and 40°C treatments following 1 hour of recovery at 27°C. These results have implications for the management of tilapia during bacterial challenge, vaccination, and handling and transport during aquacultural activities.     

The diet of hybrid red tilapia Oreochromis niloticus (L.) Oreochromis mossambicus (Peters) reared in the freshwater ponds of north-eastern Brazil

To assess potential competition for food with indigenous species prior to their release into reservoirs in north-eastern Brazil, the diet of hybrid red tilapia, Oreochromis niloticus O. mossambicus, maintained without supplementary feed in monocultures in freshwater ponds, was studied. The stomach contents of 160 fish (140–220 mm total length), collected monthly from February to September 1993, were analysed. Fish of all size categories were found to be phytoplanktivores. A total of 40 microalgal species were observed in the stomach contents (17 species of Chlorophyceae, 11 species of Bacillariophyceae, eight species of Cyanophyceae, three species of Chrysophyceae and one of Euglenophyceae), together with a few rotifers and some organic material. In terms of cell numbers, the overall composition of the diet was 70% Chlorophyceae, 21% Bacillariophyceae, 3% Chrysophyceae, 2% Cyanophyceae, 1% Euglenophyceae and 3% organic matter. Neither diet composition nor stomach fullness varied with fish size. However, fish had relatively fuller stomachs, with higher proportions of Chlorophyceae, Bacillariophyceae and Cyanophyceae, during the rainy season. Hybrid red tilapia appear unlikely to compete for food with a native species and so may have a role in aquaculture or for deliberate release into reservoirs in north-eastern Brazil.     

The Effect of Ammonia,Nitrite, and Nitrate on the Oxygen Consumption of Juvenile Pink Shrimp Farfantepenaeus brasiliensis (Latreille, 1817) (Crustacea: Decapoda)

The pink shrimp Farfantepenaeus brasiliensis is native in southern Brazil and is potentially suited for aquaculture. Under intensive culture, the accumulation of nitrogenous compounds results from excretion by the shrimp and from the processes of feed decomposition and nitrification. The objective of this study was to evaluate ammonia, nitrite, and nitrate toxicity effects on oxygen consumption of juvenile pink shrimp. Shrimps (initial weight 0.7 ± 0.15 g) were exposed over a period of 30 days to 50%, 100%, and 200% of the safe levels of total ammonia (TAN = 0.88 mg/L), nitrite (NO₂^? = 10.59 mg/L), and nitrate (NO₃^? = 91.20 mg/L) for the species. The specimens were individually collected and placed in respirometry chambers, where the oxygen consumption was measured over a period of two hours. Throughout the experiment there was no significant difference (p > 0.05) among treatments in terms of survival and growth. The pink shrimp juveniles exposed to nitrogen concentrations of 200% of the nitrite and nitrate safe level showed the highest oxygen consumption (p < 0.05).     

中国水产苗种进口特征及其对养殖产业发展的影响分析——基于2013—2018年的数据

水产种业是水产养殖业的战略性、基础性核心产业,水产苗种引进是促进水产养殖业绿色发展的一个重要途径。中国水产苗种引进品种繁多,水产观赏动物成为新宠,通过分析2013—2018年水产苗种进口贸易数据,其主要特征为:进口额呈下降趋势,进口种类涉及24种,部分种类的进口频率达到100%,用于水产养殖的苗种和受精鱼卵进口额分别为14061.19×104美元和632.02×104美元。从进口额数据来看,小虾及对虾、鳗鱼、受精鱼卵及其他鱼种等主要进口苗种种类对水产养殖业发展的影响较大,其中鳗鱼增养殖业对进口鳗苗的依赖程度较高,平均依赖度为50.86%。提出构建养殖鱼类苗种进口预警机制,谋划养殖鱼类品种的替代策略,提高对虾苗种控制能力,做好水产苗种进口质量安全防范等建议,以保障水产养殖产业健康稳定发展。     

The effects of introduced tilapias on native biodiversity

• 1. The common name ‘tilapia’ refers to a group of tropical freshwater fish in the family Cichlidae (Oreochromis, Tilapia, and Sarotherodon spp.) that are indigenous to Africa and the southwestern Middle East. Since the 1930s, tilapias have been intentionally dispersed worldwide for the biological control of aquatic weeds and insects, as baitfish for certain capture fisheries, for aquaria, and as a food fish. They have most recently been promoted as an important source of protein that could provide food security for developing countries without the environmental problems associated with terrestrial agriculture. In addition, market demand for tilapia in developed countries such as the United States is growing rapidly.
• 2. Tilapias are well‐suited to aquaculture because they are highly prolific and tolerant to a range of environmental conditions. They have come to be known as the ‘aquatic chicken’ because of their potential as an affordable, high‐yield source of protein that can be easily raised in a range of environments — from subsistence or ‘backyard’ units to intensive fish hatcheries. In some countries, particularly in Asia, nearly all of the introduced tilapias produced are consumed domestically; tilapias have contributed to basic food security for such societies.
• 3. This review indicates that tilapia species are highly invasive and exist under feral conditions in every nation in which they have been cultured or introduced. Thus, the authors have concluded that, despite potential or observed benefits to human society, tilapia aquaculture and open‐water introductions cannot continue unchecked without further exacerbating damage to native fish species and biodiversity. Recommendations include restricting tilapia culture to carefully managed, contained ponds, although exclusion is preferred when it is feasible. Research into culture of indigenous species is also recommended.

Copyright © 2005 John Wiley & Sons, Ltd.     

Viral infections in cultured fish and shrimps: current status and treatment methods

Aquaculture is growing post-haste in recent years particularly in the fish and shrimp production. The rapid growth of aquaculture and increasing demand for fish have led to a rapid development of the fish and shrimp industry, resulting in increased production of both fish and shrimps. As a result, there is a greater risk of disease outbreaks. Mass mortalities in aquaculture are primarily due to infectious diseases caused by bacteria, viruses, and fungi. Among them, viral diseases are the most devastating, causing huge loss in the production of both cultured fish and shellfishes. There are several effective methods of treatment for these disease outbreaks. This review focuses on various methods of controlling the viral pathogens using various treatment methods like use of medicinal plants and seaweed extracts, bioactive compounds from actinomycetes, vaccines, probiotic microbes, chemicals, nanoparticles, and green synthesis of nanoparticles.

     

Bio-filters: The need for an new comprehensive approach

The aquaculture industry struggles to profit in light of low product prices, increasing costs of inputs and constrains due to environmental, water and land limitations.

Intensive aquaculture systems are relevant to efficiently produce fish and shrimp. The two important limiting factors of intensive aquaculture systems are water quality and economy. An intrinsic problem of these systems is the rapid accumulation of feed residues, organic matter and toxic inorganic nitrogen species. This cannot be avoided, since fish assimilate only 20–30% of feed nutrients. The rest is excreted and typically accumulates in the water. Often, the culture water is recycled through a series of special devices (mostly biofilters of different types), investing energy and maintenance to degrade the residues. The result is that adding to the expenses of purchasing feed, significant additional expenses are devoted to degrade and remove 2/3 of it.

There is a vital need to change this vicious cycle. One example of an alternative approach is active suspension ponds (ASP), where the water treatment is based upon developing and controlling heterotrophic bacteria within the culture component. Feed nutrients are recycled, doubling the utilization of protein and raising feed utilization. Other alternatives, mostly based upon the operation of a water treatment/feed recycling component within the culture unit are discussed.

The present paper was presented in the biofilter workshop held in Honolulu, 8–11 November 2004. The main purpose of this paper was to raise new ideas and new options toward the planning and operation of intensive fish/shrimp ponds.