This book of collected chapters is based on a workshop organised by the Network of Aquaculture Centers in Asia Pacific (NACA) based in Bangkok shortly after Sena de Silva took the helm as Director General. The workshop, "Research needs to sustaining aquaculture to 2025 and Beyond", articulated the need for a response to an 'evolving demand and a clear opportunity to do more to better define future development-orientated research directions'. A comparative analysis of case studies based largely on the experiences of those present at the workshop was identified as an appropriate way forward and the outcome is this edited volume containing a scene setting introduction, eight case studies and a synthesis chapter. The aim was to inform development in areas where aquaculture has, thus far, had lesser impacts such as Africa and the Caribbean and Latin America. But the main idea was to headline to a broad public that aquaculture has 'worked' in Asia, home to probably more than 90% of the World's farmed aquatic products. A major claim of the book is that smaller-scale aquaculture has proved successful and this, intrinsically, becomes linked with the idea that it can be a vehicle out of poverty (chapter 1). These views have been challenged in recent years. Despite proclamations by scientists at high profile meetings and the extraordinary growth of commercially orientated aquaculture in certain countries in the last decade aquaculture has often attracted a bad press. Detractors, often in high profile academic and mainstream journals, have questioned the mantra that more aquaculture is better, and have drawn links between the industrialisation of aquaculture and both poorer people and the environment losing out. The culture of valuable carnivores using marine trash fish as feed has particularly attracted the ire of marine conservation constituency.

Freshwater aquaculture consists of a wide diversity of systems across physical and economic scales, infrastructure configurations, species, ownership, and value chains. It consists predominantly of household-managed ponds and small- to medium-scale commercial enterprises that produce a variety of carps and other fish in polyculture systems for local and regional consumption24. Freshwater aquaculture is widely recognized for the production of tilapia and striped catfish (Pangasianodon hypophthalmus) that are produced mainly in earthen ponds for export and national consumption. It also includes the cultivation of freshwater and brackish-water crustaceans, produced intensively in monoculture (for example, whiteleg shrimp (Litopenaeus vannamei)) or in polyculture systems (for example, black tiger shrimp (Penaeus monodon)) with a wide variety of other fish, molluscs, and aquatic plants. Urbanization has increasingly shifted the demand from subsistence to marketed fish25.

Success Stories In Asian Aquaculture Free Download

tag_hash_104 🔥 https://urllio.com/2yjXRQ 🔥

Aquaculture producers seeking to market sustainable products are therefore faced with the unintended environmental and social consequences of their feeding practices. For example, between 2000 and 2016, the Norwegian salmon aquaculture industry cut its shares of marine protein in feed from 33.5% to 14.5% and marine oils from 31.1% to 10.4%, and increased the shares of plant proteins from 22.2% to 40.3% and terrestrial oils from 0 to 20.2%76. Despite its success in substituting fishmeal and fish oil with plant-based alternatives, including non-genetically engineered soy, the industry has been under pressure to identify new feed sources to eliminate the environmental damages associated with forest conversion to crop production in Brazil77, and parts of the industry have already banned the use of Brazilian soy in aquafeed.

Even in sectors in which major investments and progress have been made in the detection, avoidance, and treatment of PPP, new threats frequently emerge. For example, the salmon aquaculture industry has successfully controlled some diseases, such as infectious pancreatic necrosis virus and infectious salmon anaemia, but other diseases and parasites (for example, salmon rickettsial syndrome and sea lice) remain costly for many producers and damaging to wild salmon as treatment options are either unavailable or the target organism has become resistant to treatment131,143,149,150. Similarly, despite the shift from black tiger shrimp to whiteleg shrimp, emerging diseases such as white spot disease, acute hepatopancreatic necrosis disease, shrimp hemocyte iridescent virus, and the microsporidian parasite (Enterocytozoon hepatopenaei) have resulted in substantial production losses and sustained economic costs to the shrimp industry136,151,152,153.

Increased attention has been directed to ecosystem-based management, system design, and new forms of private and public sector governance to manage biological and climate risks, and encourage sustainable aquaculture production86,169,170. Integrated multi-trophic aquaculture has shown high bioremediation capacity in China120,171, but has demonstrated limited commercial success globally despite considerable research interest172,173. Recirculating aquaculture systems and offshore aquaculture have promising growth potential.

Three key patterns emerge in this Review. First, freshwater fish have a central role in the global production, contributing more than any other aquaculture sub-sector to the total (live and edible) volume, rural livelihoods, and food security during the past two decades. Because most farmed freshwater fish do not enter the global market, however, there is currently little impetus for producers to engage in sustainable practices with recognized ratings or certification. Second, marked improvements have been made in the efficiency of marine resource use across all fed species and in the field of fish nutrition. Further gains in these areas may be more difficult and costly to achieve for carnivorous species, but the increasing costs of fishmeal and fish oil that are associated with marine resource limitation will provide continued incentives for innovation. Third, careful siting of aquaculture systems underpins the commercial and environmental success of the industry. Almost all freshwater and marine aquaculture systems interact with the ambient aquatic environment and both benefit from and provide environmental services to the ambient environment as a result. Prudent siting and scaling are essential for maximizing the ecosystem services provided by farmed extractive species and for mitigating critical challenges to the industry associated with PPP, coastal pollution, and climate change.

Looking ahead, the effective spatial planning and regulation of aquaculture sites will be paramount for achieving positive environmental outcomes, especially as aquaculture systems increase in scale and production intensifies. The industry is investigating recirculating and offshore technologies to reduce its exposure to and impact on aquatic environments; however, these systems will require innovative financial and environmental management to have any chance of widespread success. In addition, investments are needed in an array of PPP prevention strategies across different aquaculture sub-sectors, recognizing that treatments after PPP problems emerge are largely futile. Finally, future policies and programmes to promote aquaculture will require a food systems approach that examines nutrition, equity, justice, and environmental outcomes and trade-offs across land and sea. Tools such as life cycle analysis will need to be refined and deployed to ensure comparability between terrestrial livestock and aquaculture production on the basis of nutritional value and global environmental outcomes. Research along these lines, as advanced through new studies including the ongoing Blue Food Assessment203, will undoubtedly be documented in the next 20-year retrospective review. Aquaculture systems can be designed and implemented to be highly sustainable. The human dimension presents both the opportunity and the challenge.

The culture of African catfish, Clarias gariepinus, is constrained by the high mortality of fry, occasioning a shortage of high-quality seeds for stocking by farmers. Asia, a continent with many success stories for aquaculture, leads in farmed production of some catfishes, a diverse group of 37 different families. Globally, the culture of catfishes ranks fifth in global farmed finfish production. Globally, Vietnam leads in the production and export of farmed striped catfish, Pangasianodon hypophthalmus, with 1,400,000 tonnes produced annually from about 7,000 hectares. Similarly, China farmed the non-native Channel catfish, Ictalurus punctatus, into the major crop, with a current annual production of 250,000 tonnes. On the contrary, C. gariepinus, the main farmed catfish species in Africa, records low annual yields, with 240,000 tonnes for the whole continent. This paper explores the factors behind the high production of P. hypophthalmus and I. punctatus in Vietnam and China, respectively, and draws lessons for C. gariepinus farmers in Africa. Specifically, the use of differentiated hatchery and nursery husbandry practices was critical in boosting seed production, quantity, availability, and distribution for expanding the culture of P. hypophthalmus in Vietnam. Improvement of fish species through well-designed genetic improvement programs helped China substantially increase production of I. punctatus. For both species, intensive fish production, as well as the adoption and implementation of suitable policies, increased seed production from hatcheries in both countries. These are discussed as some of the factors that spurred catfish production in the two Asian countries. We argue that if these are adopted by farmers in Africa, they could help improve the production of farmed C. gariepinus on the continent for food and nutrition security as well as generation of livelihood for local communities. 0852c4b9a8

supernatural season 8 free direct download

evanescence my immortal video free download

7am arivu songs free download in telugu