Sipunculus nudus is an important economic species because of its high nutritional and medicinal values. The exploitation and utilization of S. nudus primarily occur in the coastal regions of the Beibu Gulf. However, w...Sipunculus nudus is an important economic species because of its high nutritional and medicinal values. The exploitation and utilization of S. nudus primarily occur in the coastal regions of the Beibu Gulf. However, wild resource of S. nudus is rapidly decreasing because of the overexploitation, which has led to considerable developments of artificial breeding techniques. The cultivation scale of S. nudus has increased in response to successful artificial breeding; however, methods for culturing S. nudus in tidal flats or ponds require further study. Most studies have focused on the breeding, nutrition, medical value and ecological impact of these worms. Studies on the distribution, sediment requirements, nutrition characteristics, breeding techniques and aquaculture ecology of this species are summarized in this paper to promote the development of the aquaculture industry for S. nudus. The high biomass of S. nudus in the Beibu Gulf is positively correlated with the sediment characteristics and water quality of the region. The production of peanut worm has improved to some extent through culturing; however, the nutrient value and ecological environment problems have been observed, which reflect the over exploitation of trace elements and the sediment. These problems will worsen unless they are resolved, and the release of organic materials, nitrogen and phosphorus during harvesting impacts the coastal environment. Moreover, genetic erosion is a potential risk for larvae in artificial breeding programs in tidal flats. Therefore, culturing and collecting methods should be improved and the wild resource conservation should be implemented to promote the sustainable development of the peanut worm.展开更多
Understanding the attributes of traditional, location-specific land-use systems will provide insights for improvement of such systems and design of new ones for wider applicability. The integrated rice ＋ fish system ...Understanding the attributes of traditional, location-specific land-use systems will provide insights for improvement of such systems and design of new ones for wider applicability. The integrated rice ＋ fish system developed by the Apatani tribe of Ziro valley, Arunachal Pradesh, Northeastern India is such a unique system. Faced with shortages of their staple food items （rice and fish）, these subsistence farmers developed this ingenious system--in preference to the wide-spread shifting cultivation in the region--by capitalizing on the good water supply （from rainfall supplemented by natural flow from hills surrounding the valley）. Two rice crops are grown annually and fish is reared in paddy fields during the main rainy season. Crop residues and animal wastes are the sources of nutrients to crops, chemical fertilizers and insecticides are not used. Over the years, rice yield has been stable at about 3,700 kg.ha-1.year-1. Recently, UNESCO has tentatively added the valley as a ＂world heritage site＂ recognizing its ＂extremely high productivity＂ and ＂unique＂ ecological preservation. The resilience and the sustainability of the system could be attributed to efficient nutrient cycling and nutrient input through water seeping in from surrounding hills, which have not been, but deserve to be, quantified.展开更多
基金the National Natural Sci-ence Foundation of China (No. 41606137)Natural Science Foundation of Guangdong Province (No. 2015A030 310260)+2 种基金the Scientific Research Funds for Central Non-profit Institutes, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences (Nos. 2014ZD01, 2013ZD01)the Marine Fishery Science and Technology Industry Projects from Guangdong Province (Nos. B201601-01, B201500B 04)the Science and Technology Plan Projects from Guangdong Province (Nos. 2013B090500081 and 2013B 040500020)
文摘Sipunculus nudus is an important economic species because of its high nutritional and medicinal values. The exploitation and utilization of S. nudus primarily occur in the coastal regions of the Beibu Gulf. However, wild resource of S. nudus is rapidly decreasing because of the overexploitation, which has led to considerable developments of artificial breeding techniques. The cultivation scale of S. nudus has increased in response to successful artificial breeding; however, methods for culturing S. nudus in tidal flats or ponds require further study. Most studies have focused on the breeding, nutrition, medical value and ecological impact of these worms. Studies on the distribution, sediment requirements, nutrition characteristics, breeding techniques and aquaculture ecology of this species are summarized in this paper to promote the development of the aquaculture industry for S. nudus. The high biomass of S. nudus in the Beibu Gulf is positively correlated with the sediment characteristics and water quality of the region. The production of peanut worm has improved to some extent through culturing; however, the nutrient value and ecological environment problems have been observed, which reflect the over exploitation of trace elements and the sediment. These problems will worsen unless they are resolved, and the release of organic materials, nitrogen and phosphorus during harvesting impacts the coastal environment. Moreover, genetic erosion is a potential risk for larvae in artificial breeding programs in tidal flats. Therefore, culturing and collecting methods should be improved and the wild resource conservation should be implemented to promote the sustainable development of the peanut worm.
文摘Understanding the attributes of traditional, location-specific land-use systems will provide insights for improvement of such systems and design of new ones for wider applicability. The integrated rice ＋ fish system developed by the Apatani tribe of Ziro valley, Arunachal Pradesh, Northeastern India is such a unique system. Faced with shortages of their staple food items （rice and fish）, these subsistence farmers developed this ingenious system--in preference to the wide-spread shifting cultivation in the region--by capitalizing on the good water supply （from rainfall supplemented by natural flow from hills surrounding the valley）. Two rice crops are grown annually and fish is reared in paddy fields during the main rainy season. Crop residues and animal wastes are the sources of nutrients to crops, chemical fertilizers and insecticides are not used. Over the years, rice yield has been stable at about 3,700 kg.ha-1.year-1. Recently, UNESCO has tentatively added the valley as a ＂world heritage site＂ recognizing its ＂extremely high productivity＂ and ＂unique＂ ecological preservation. The resilience and the sustainability of the system could be attributed to efficient nutrient cycling and nutrient input through water seeping in from surrounding hills, which have not been, but deserve to be, quantified.
