Title: Improving Sustainability and Reducing Environmental Impacts of Aquaculture Systems in China and South and Southeast Asia

Theme: Environmental Management for Sustainable Aquatic Resources Use

Lead US University: University of Michigan

Host Country & Partner Institutions:

  • Asia: World Wildlife Fund in Asia
  • Bangladesh: Bangladesh Agricultural University
  • China: Shanghai Fisheries University, Hainan University, Huazhong Agricultural University, Wuhan University, Shanghai Ocean University, Network of Aquaculture Centres in Asia-Pacific
  • Nepal: Institute of Agriculture & Animal Science
  • Thailand: Network of Aquaculture Centres in Asia-Pacific
  • Vietnam: University of Agriculture & Forestry, Nong Lam University


  • Incorporation of tilapia (Oreochromis niloticus) and Sahar (Tor putitora) into the existing carp polyculture system for household nutrition and local sales in Nepal - 09BMA03UM (Final Report)
  • Study on the effectiveness of a pond-based recirculating system for shrimp culture - 09BMA04UM (Final Report)
  • Development of polyculture technology for giant freshwater prawns (Macrobrachium rosenbergii) and mola (Amblypharyngodon mola) - 09QSD03UM (Final Report)
  • Invasion of the red swamp crayfish (Procambarus clarkii) in China: genetic analysis of the invasion and the impacts evaluation - 09MNE01UM (Final Report)
  • Development of indoor recirculating culture systems for intensive shrimp production in China - 09BMA05UM (Final Report)
  • Integrating environmental impacts, productivity, and profitability of shrimp aquaculture at the farm-scale as means to support good aquaculture practices and eco-certification - 09MNE03UM (Final Report)
  • Identifying best practices to improve the giant river prawn industry in Thailand - 09BMA06UM (Final Report)
  • The impact of fish stocking on wild fish populations, fish production and the ecosystem of irrigation reservoirs in South Vietnam - 09MNE05UM (Final Report)
  • Evaluating the relationship between semi-intensive aquaculture and natural biodiversity 09MNE06UM (Final Report)
  • Sustainable feed and improved stocking densities for gar (Atractosteus spp.) culture - 09SFT07UM (Final Report)
  • Development of sustainable feeds, improved stocking densities, and salinity management in closed recirculating systems for gar (Atractosteus spp.) culture - 09IND11UM (Final Report)
  • Experimental Pond Unit Assessment Nepal - 09BMA14UM (Final Report)
  • Value Chain Analysis of Carp Polyculture Systems in Southern Nepal - 09MER11UM (Final Report)

Project Summary

This proposal represents a collaboratively defined series of studies with host country counterparts in China, Nepal, Thailand, Bangladesh, and Vietnam. The experiments listed were defined largely by the host country scientists, in consultation with their university and government colleagues in each country. The priority of each experiment or study is exemplified by the fact that of all possible studies to be done, each investigator believed this was the most important one, currently. 

Investigation #1 (09BMA03UM) is the next step of our continuing work in Nepal. We have done experiments testing various species combinations in polyculture, and this experiment adds tilapia and sahar, a highly valued local fish, to the mix. It intends to use sahar as a biological control to limit natural reproduction of tilapia, producing a cash crop of its own as well as allowing for tilapia culture without extensive hatchery systems to produce sex-reversed fish. 

Investigation #2 (09BMA04UM) tries to use recirculating technology from indoor shrimp systems to improve water quality and reduce the effects of effluents and solid waste from outdoor pond systems on the local environment. Shrimp culture is very important to China for internal food uses as well as export. However, water quality is equally important, given the difficult state of many natural waters there. This system, if successful, should create a cost effective way for small- scale farmers to adopt recirculating technology without a large investment in water treatment systems. It is also related to Investigation #5 (09BMA05UM). 

Investigation #3 (09QSD03UM) returns the AFCRSP to Bangladesh with work on prawn culture in Bangladesh, this time using polyculture of prawns with mola, an important indigenous fish. Prawns are quite valuable and can produce high economic value, but most farmers rely on their ponds for household consumption as well. Adding mola to prawn ponds should provide a food resource for the household along with a cash crop, and allow small-scale farmers to benefit nutritionally as well as economically. This study is also related to Investigation #7 (09BMA06UM). 

Investigation #4 (09MNE01UM) continues our work on invasive species, this time looking at the invasion dynamics of red swamp crayfish in China. This species has caused problems in many areas, because it is often introduced by aquaculture systems but escapes and becomes a damaging invasive species. This study will apply genetic techniques, along with population dynamic studies, to evaluate the extent, sources, and routes of invasion of the crayfish in China. This study relates to Investigation #8 (09MNE05UM) as well. 

Investigation #5 (09BMA05UM) is another study on improving shrimp aquaculture systems, this time using indoor recirculating technology in China. The study will conduct experiments in a commercial indoor recirculating system, and look at various water treatment options as well as existing technology to determine their effects on water quality and shrimp production. In addition, this study will continue our work on microcystins in pond aquaculture by evaluating a number of natural shrimp ponds and other systems for the existence of microcystins in algae blooms, and the limnological characteristics associated with these blooms. It is similar in nature to Investigation #3 (09QSD03UM). 

Investigation #6 (09MNE03UM) continues the work from the last work plan on life cycle assessment of shrimp production in China. This study applies other techniques, including mass balance models, economic analyses, and best management practices to evaluate the environmental effects of various culture options, and in doing this to assess the likely outcome of some practices from an ecological, social, and economic perspective. It has some related elements to Investigations #3 and #5. 

Investigation #7 (09BMA06UM) continues work from our earlier surveys in Thailand, Bangladesh, and Vietnam on prawn culture systems. This study is a workshop to inform practitioners in Thailand on various management practices used in the country, the economic analyses of their success, and other aspects of aquaculture practice for prawns. It will also encourage exchange of information from participants, especially farmers, in an attempt to better educate each other on sustainability of prawn culture. 

Investigation #8 (09MNE05UM) will refocus our work on biodiversity in reservoirs and the effects of introduced species on native fauna. Our studies to date have been on larger reservoirs with numerous introductions and large fisheries. While these systems are interesting, they are very difficult to evaluate quantitatively. This study will use surveys of a number of small irrigation reservoirs, as well as local studies on several of these reservoirs, in an effort to better define the effects of introduced fishes on the native fauna. 

Finally, investigation #9 (09MNE06UM) will convene a symposium to review the interactions between semi-intensive aquaculture and biodiversity. Participants will include CRSP scientists as well as other recognized experts in this field. The effects of aquaculture on biodiversity is controversial, and needs better resolution and broader analysis in order to gain a better perspective on what aquaculture should do to minimize these deleterious effects. This symposium will focus on semi-intensive aquaculture to deal more effectively with the CRSP mission as well as utilize our experiences in research, and also to help understand the factors involved in small-scale fish farming. 

Overall, these nine investigations span a wide variety of university participants, countries, subjects, and methodologies. This breadth is very important to the aquaculture community as well as to the vitality of our research group. We believe that these studies will help provide further information to fine tune aquaculture systems throughout the world, and will result in considerable improvement in aquaculture practice as well as published literature to expand the impact beyond the boundaries of this region.

  • Impact of Introduction of Alien Species on the Fisheries and Biodiversity of Indigenous Species in Zhanghe Reservoir of China and Tri An Reservoir of Vietnam - 07MNE03UM (Final Report)
  • Assessing Effectiveness of Current Waste Management Practices for Intensive Freshwater and Marine Pond Aquaculture in China - 07MNE05UM (Final Report)
  • Determining the Ecological Footprint of Shrimp Aquaculture Through Life Cycle Analysis of Outdoor Pond Systems - 07MNE05UM (Final Report)
  • Monitoring and Reducing Microcystins in Tilapias and Channel Catfish Cultured in a Variety of Aquaculture Systems - 07HHI01UM (Final Report)
  • Polyculture of Sahar (Tor putitora) with Mixed-sex Nile Tilapia (Oreochromis niloticus) - 07BMA02UM (Final Report)
  • Workshop on Aquaculture, Human Health and Environment - 07MNE07UM (Final Report)

Project Summary

This project represents a collaboratively designed series of six investigations with host country counterparts in China, Nepal, and Vietnam. The host country scientists, in consultation with their university and government colleagues, were largely responsible for defining these experiments and studies as the most currently important research priorities. This project encompasses work on better aquaculture management practices, effects of effluents and invasive species on natural systems in the region, human health effects of aquaculture-related toxins, and methodology to quantitatively evaluate sustainability of different aquaculture systems in the study region and the world.

Investigation 1 evaluates effects of past introductions of exotic fish species (icefish in China; tilapia in Vietnam) on the local fishery and fish community in three reservoirs (Zhanghe and Huiting Reservoirs in China; Tri An Reservoir in Vietnam). This investigation focuses on existing natural systems with already introduced alien fishes and draws on comparative studies or historic data to determine changes in the fishery and indigenous fish community. The three study reservoirs are used for small-scale fisheries that provide economic benefits mainly to the regional rural poor. Changes in fish catch and fish communities will negatively affect, or already have affected, these poor fishers.

Investigation 2 evaluates effluent releases and pond water quality in a variety of intensive aquaculture systems used in freshwater, brackish water, and marine areas of China. The problem of surface water quality and the influence of aquaculture in degrading water quality is a primary concern of the Chinese government. However, the extent of this problem, as well as possible solutions, remains elusive. Tilapia production is important since China produces approximately 50% of the world’s tilapia. Most of the production is in extensive to intensive systems managed by small-scale farmers. Field surveys and tests will evaluate the influence of these farmers on local water quality.

Investigation 3, while occurring in China, is global in focus and is associated with another current study on indoor recirculating systems. This assessment study applies well-established quantitative methods—life cycle assessment (LCA), life cycle cost analysis (LCCA), and mass balance modeling—to outdoor shrimp culture. Our intent is to produce clear metrics of environmental impacts and to compare the ecological footprint of two very different aquaculture systems. While LCA has been applied sporadically to fishery and aquaculture systems, the methodology to combine LCA and LCCA with mass balance analysis, has not yet been developed. Application of all three methods is important for both quantifying impacts and for making fair comparisons between aquaculture and other food production systems.

Investigation 4 focuses on the health-related issue of algal blooms and cyanotoxins in the low trophic-level species culture of tilapia, using current, mostly semi-intensive systems as test cases. This experiment investigates the prevalence of microcystins (the most controversial cyanotoxin) in culture water from various types of tilapia aquaculture, how concentrated they are in fish flesh, and if they can be cleared by depuration. These studies will help determine if further action, beyond depuration, is needed and at the same time help small-scale farmers in their sale of fish.

Investigation 5 focuses on the interaction between fisheries and aquaculture in Nepal. Sahar is an important Nepalese game fish that is declining in abundance. It becomes piscivorous at larger sizes. Tilapia is commonly cultured in Nepal, but sex control is not practiced, resulting in a mixed-sex culture of stunted tilapia. Polyculture of sahar and tilapia may provide a tilapia reproduction and stunting control option. Tilapia consumption by sahar would provide a production control method while sahar production would offer a valuable pond-produced, alternative fish for sale, thus reducing demand for sahar from wild populations. This experiment is an attempt to initiate such a polyculture system, which could spur a whole new industry for small-scale culturists in Nepal.

Investigation 6 offers a concluding workshop that shares the project’s research results with a wider audience from the host institutions, government fisheries and public health agencies, private sectors, and NGOs. Local experts will also be invited to share their experiences on related topics.

All the project collaborators share in the dual mission of the AquaFish CRSP, which focuses on solving critical problems facing global aquaculture development and aquatic resource management in lower income countries. From a philosophical and methodological perspective, this mission provides a platform for collaborative research with the intent to develop host-country capacity for better problem solving. The project vision is for current and future work to focus both on solving important aquaculture problems in the region and developing the capacity for host-country investigators and their students to contribute to future research. This project continues a research interaction that was begun over 20 years ago with the goal to better understand regional resources and train the next generation of researchers to face the critical issues of aquaculture development.

Over its first five years, this project is designed for successful research outcomes to lead to future work. For example, additional experiments on sahar-tilapia polyculture will likely be undertaken to either refine best possible systems of production or to extend that technology to poor farmers. Following the previous research model, NGOs and government organizations will continue in their role of offering extension outreach of important components of this work. Future research developing from this project will focus on the next emerging issues.  Some outcomes may indirectly lead to further project progress such as additional life cycle assessments of aquaculture and fishery crops and the impacts of invasive species. In this regard, the near-term vision is to continue with this research focus, either in clear next steps or in following a similar research philosophy applied to different systems.

In the long term, aquaculture systems that deal with eutrophication of natural waters in China and the region will be developed. This work may encompass water quality issues in rivers and lakes, with or without cage culture, as well as the development of cage culture systems to better retain nutrients. With Investigation 2, the focus is on effluent levels and management practices. Reduction of conflicts between aquaculture and invasive species is another area of mutual research interest. The investigation of invasive species effects on indigenous fish communities and aquatic ecosystems fits the goals of the current CRSP program mission.