Towards environmentally sustainable aquaculture: Comparison between two trout farming systems using Life Cycle Assessment

Life Cycle Assessment (LCA) was applied to evaluate the global environmental impact of two scenarios of trout production systems based on the operational information from an operational farm using a flow through system (FTF) and an experimental pilot low head recirculating system (RSF) located on the same site. The main differences between the environmental balances of the two systems were relative to water use, eutrophication potential and energy use. Independently of the system used, feed is the key indicator in determining the environmental balance (notwithstanding eutrophication potential and water dependence) monitored by fish production, chemical products, buildings and energy consumption.Consequently, when considering the RSF with a lower feed conversion ratio (0.8 versus 1.1 for FTF), the environmental balance of the RSF is more favourable at both global and regional levels, except with regards to energy use. RSF water dependence is 93% lower than the FTF and its eutrophication potential is 26–38% lower due to reduced waste release. On the other hand, at 57,659 MJ per ton of fish produced (16 kWh per kg), the RSF consumes 24–40% more energy than the FTF, especially for aeration and water treatment. Nevertheless, the RSF has significant potential for energy reduction through improvements to airlift and biofilter designs which would reduce RSF energy use to a level similar to that of the FTF (34,869–43,841 MJ per ton of fish produced, corresponding to 10 and 12 kWh respectively). LCA is therefore a powerful tool which can be used on fish farms to define and prioritise the most promising potential improvements to the system.     

水产养殖业可持续发展及管理的研究进展

全球水产养殖业在过去的几十年内得到了迅速发展,但同时也带来了诸多的环境、经济和社会问题,因此可持续发展水产养殖理念的提出得到了国内外众多学者的认可。本文简单介绍了全球水产养殖业近年的发展情况及可持续发展水产养殖业的理念发展进程,重点分析了可持续发展水产养殖管理涉及的六大步骤,介绍了水产养殖指标体系构建及评估的研究成果,以期为我国水产养殖可持续发展提供借鉴。     

健康养虾模式在可持续发展中的作用

我国的对虾养殖业在经历了1982-1992年的快速发展阶段和1993-1994年的急剧衰退阶段之后,在各级政府和有关科研、生产部门的协同努力下,近年来开始复苏.这一发展--衰退--复苏的过程,体现了人类在改造自然中不断认识不断实践不断提高的过程,这将有助于对虾养殖业在今后的发展中更好地遵循自然规律,在谋求生产发展的同时,通过各种途径解决矛盾,减少病害,达到持续发展的目的.本文旨在通过对我国对虾养殖模式演变规律的回顾,探讨其在健康养殖中的作用.     

白洋淀水产养殖污染分析及可持续发展建议

阐述了白洋淀水产养殖对水体造成的污染。其中,饵料的投放、添加剂和药剂的使用、鱼类的排泄以及底质释放等是造成水体中氮、磷含量偏高及水体富营养化的主要原因。本文就水产养殖对水体及周边生态环境的影响和渔业生产存在的问题作了综述,从发展健康养殖和改善管理水平方面,提出了白洋淀水产养殖可持续发展的对策。     

辽宁海水养殖业发展现状及可持续发展对策

辽宁海水养殖业在全国具有重要地位.随着城市化、工业化进程推进,多元用海矛盾问题凸显,养殖空间萎缩,受技术、管理等因素制约海域资源利用效率不高,养殖生产方式传统粗放,近岸环境监控压力增大,水产品质量存在安全隐患.解决这些问题需要合理规划布局,优化海域空间资源配置,加强技术创新,改变传统生产方式,提高病害防控能力,保护海域生态环境,提高养殖产品质量.     

Towards sustainable freshwater prawn aquaculture – lessons from shrimp farming, with special reference to India

The annual increase in farmed freshwater prawn production in the world during the decade ending 2001 has been estimated as 29% and that during 1999–2001 as 48%, the production in 2001 being about 300 000 mt (all Macrobrachium species). Between 1999 and 2003 the annual increase in farmed Macrobrachium rosenbergii production in India was about 80%, production reaching 30 450 mt in 2002–2003. This log phase of production followed the rise and fall of shrimp farming in the country. Several shrimp farming ventures collapsed in the 1990s, owing to degraded environment and diseases, abetted by lack of awareness and inadequacy of information on the culture systems and their interactions with other human endeavours. This shrimp farming experience has made the aquafarmer and other stakeholders aware that while aquaculture has a high potential in ensuring food and nutritional security and livelihood, besides profit to the farmer and socio‐economic benefits to local communities, it is likely to slip from sustainable development pathways if adequate understanding, improved management practices, governmental policies and plans for implementation and regulation to ensure sustainability are not in place. The lessons learned from shrimp farming can help in steering the development of sustainable freshwater prawn aquaculture in India and elsewhere.     

Safety issues and sustainable development of European aquaculture: new tools for environmentally sound aquaculture

Sustainable and long-term growth of the aquaculture industry should involve both ecologically sound practices and appropriate resource management. The increasing economic dimension of Mediterranean aquaculture is opening new economic niches and may be a valid support to reduce the pressure of traditional fisheries. Aquaculture practices can also lead to modifications of coastal habitats through the impact of wastes of land-based and open-sea mariculture facilities. In addition to these aspects which place a direct pressure on aquatic ecosystems and wild fishery resources, a wide range of environmental contaminants, such as chemicals used in farming operations, can accumulate in farmed organisms and put fish health and quality at risk. Thus, as aquaculture makes its transition to a major food-producing sector, proper assessment and control of environmental impacts and food safety awareness are becoming increasingly important. The development of simple tools able to monitor the extent of environmental and biological impacts associated with farming operations at various levels of biological complexity from the ecosystem to the organism level is required. Although a number of techniques for assessing the environmental and biological impact of pollutants in natural ecosystems are available, the development of practical and validated tools is sorely needed in aquaculture.     

The economics of sutchi catfish (Pangasianodon hypophthalmus) aquaculture under three different farming systems in rural Bangladesh

This paper examines production costs and returns of sutchi catfish (Pangasianodon hypophthalmus) aquaculture under three different farming systems in Bangladesh. Based on the production technology, sutchi catfish farming is classified as extensive, semi‐intensive and intensive. Results showed that sutchi catfish farming is profitable irrespective of the level of intensification and in all three instances the cost of feed dominated the variable costs of production. The average annual production costs were estimated at US$5217 ha^?1 in intensive farming, while US$2694 ha^?1 in semi‐intensive and US$981 ha^?1 in extensive farming. Despite the higher production costs per hectare, the average annual net return was higher in intensive farming (US$3364), compared with semi‐intensive (US$2048) and extensive (US$1099) farming. The average annual production per hectare under intensive farming conditions (13 945 kg) was higher than semi‐intensive (7705 kg) and extensive (3380 kg) farming mainly due to higher levels of inputs, including seed, feed, fertilizer and labour. However, the Cobb–Douglas production function model suggests that inputs are inefficiently used in the intensive farming system. Conversely, there is enough scope to increase the production and income from the semi‐intensive and extensive farming systems by using more inputs.     

Cage culture development and its role in aquaculture in China

Abstract. This paper is divided into four parts. First, history: cage culture has long been practised. The origin of cage culture world-wide should be regarded as the middle reaches of the Yangtze River, China, in the Sung Dynasty. Second, characteristics of cage culture in China. Third, influence: development of open-water fisheries is actively promoted in lakes, reservoirs and rivers. More kinds of water bodies have been employed for this purpose. Marine cages have also rapidly developed. Finally, discussion and conclusions. Cage culture is a modern development of aquaculture which has changed the long-established, fish-farming structures and, to a great extent, pushed forward fisheries development in China. Cage culture is typically characterized by intensive farming, running-water culture, high yield and great efficiency. It is generally accepted that cage culture will actively play an increasingly important role in international aquaculture.     

云纹石斑鱼工厂化循环水养殖技术

本试验率先采用循环水系统开展了云纹石斑鱼的养殖试验并取得了成功.结果显示,在莱州明波养殖基地选用的平均体重50 g/尾规格的云纹石斑鱼苗种10万尾,在水温22～ 25℃、盐度28～31、pH7.8～ 8.2的水环境条件下,经12个月培育,长成平均体重为0.65 kg/尾的商品鱼,平均单尾月增重50 g,成活率93.5％;共收获成鱼9.35万尾,单产49.9 kg/m3.本研究为云纹石斑鱼工厂化循环水养殖提供一个成功的范例.     

DMTIOLA: decision making tool for identification of optimal location for aquaculture farming development

Decision making tool called Decision Making Tool for Identification of Optimal Location in Aqua farming development was developed using Visual Basic programming language for identification of optimal location for aquaculture farming development. Twenty-four input criteria to the tool were categorized into six broad heads of main-criteria namely: water (10 sub-criteria), soil (5 sub-criteria), support (2 sub-criteria), infrastructure (3 sub-criteria), input (1 sub-criterion), and risk factor (3 sub-criteria). In this tool, the optimal location was identified based on the objective function, which was derived from the combination of rank sum, pair-wise comparison, and Technique for Order Preference by Similarity to the Ideal Solution methods. Based on the objective function values, alternatives (or aqua farms) were ranked in descending order in a table. In order to validate the developed tool, the same alternatives were ranked in descending order according to the observed average yield value per hectare (ha) for the last three crops. Spearman’s rank correlation was used to assess the correlation between ranks obtained by the tool and ranks obtained based on average yield. It showed with 99% confidence that a significant correlation exists between ranks obtained by the tool and ranks obtained based on average yield. Developed tool appeared to be confident and robust in proof-of-concept application for aquaculture farming development in Kalla mandal with reference to shrimp farms, West Godavari district, Andhra Pradesh, India.     

Developing native fish species for aquaculture: the interacting demands of biodiversity, sustainable aquaculture and livelihoods

Aquaculture continues to be the fastest growing animal production industry and this rate of expansion must continue if aquaculture is to satisfy global demand for fish products in the face of dwindling capture fisheries. The relationship between aquaculture and biodiversity is complex, with examples of positive and negative impacts having been reported. To enable this expansion while avoiding negative impacts from introductions of exotic species, the investigation of indigenous species becomes important and worthwhile.This paper establishes the background to development of new species for culture and describes the example of the Mexican silverside Menidia estor, which has for centuries been the principal species in an artesanal fishery in Lake Pátzcuaro, Mexico. The species is geographically isolated and is unique but is now endangered because of a range of factors including overfishing, environmental degradation and introduction of exotic species. Considerable advances have been made recently in developing a closed reproductive cycle, understanding feeding and small‐scale on‐growing technology for the species. Based on this, a Darwin Initiative programme was developed focused on technology transfer to implement small‐scale pilot on‐growing thus helping to conserve the species and to improve livelihoods. This has allowed successful pilot scale development of aquaculture for the species while at the same time addressing the objectives of the international Convention on Biodiversity.     

Assessing the feasibility of sponge aquaculture as a sustainable industry in The Bahamas

Sponge harvesting was a significant part of the Bahamian economy until the late 1930s when disease, hurricanes, and unsustainable harvesting practices reduced the viability of the sponge industry. Current international demands for natural products, increasing regional needs for economic diversification, and the historical foundation of sponging in The Bahamas makes sponge aquaculture a desirable candidate as a sustainable industry. To determine the feasibility of sponge aquaculture in The Bahamas, we deployed growout arrays between February 2006 and September 2009 at two sites off South Eleuthera to examine the survival and growth rates of grass sponge (Spongia tubulifera) and hardhead sponge (Spongia pertusa) cuttings. Complete skin regeneration occurred for both species by the second week following deployment. Following 43 months of growout, both grass and hardhead sponges showed significant positive growth, with cuttings of both species exhibiting faster growth trajectories at the more protected site (Site A) when compared with the site further from shore (Site B). The proportion of sponge cuttings lost during the course of the study was also considerably less for both species at Site A, as was the amount of required maintenance for the arrays. The initial deployment of larger sponge cuttings could help reduce the overall growout period, as would the selection of sites that offered more protection for growout. Based on these results, sponge aquaculture could prove to be a sustainable low-cost industry in The Bahamas; however, further research on site selection, regulations, and market acceptability remains to be done.     

The aquaculture of freshwater prawn, Macrobrachium malcolmsonii (Milne Edwards), at farmers'level in Pakistan

Abstract. Artisanal culture of Macrobrachium malcolmsonii (Milne Edwards) was studied on two sites in Pakistan. The juvenile prawns of M. malcolmsonii were collected randomly from the lower belt of the river Indus, transported and stocked in ponds at Mirpur Sakro and Chilya, Thatta, Sindh, Pakistan after acclimation. They were fed on supplementary feed containing 15% protein once daily. The stocked prawns grew from a mean weight of 0·5–2·0g to 47·5–83·5g in ponds under the conditions described herein, so a total production of 216·5–1037·5kg/ha was achieved.     

循环流水水产养殖可持续发展特性探讨

水产养殖是农业生产的重要组成部分 ,在过去的五十年中得到了迅猛发展。在现代科技的支持下 ,水产养殖有望成为继种植业之后的第二大食物产业。但传统的养殖方式由于技术和管理问题 ,已越来越暴露出不可持续生产的局限性 ,不但自身受到暴发性流行病的困扰 ,生产效益的持续性得不到保证 ,而且还存在破坏生态环境和浪费资源 (水、饵料等 )等弊端。如何对旧的生产方式进行改革 ,在有限的资源条件下 ,进一步提高水产养殖生产水平 ,同时又保护和改善生态环境 ,实现可持续发展 ,是现代水产养殖所面临的最严峻的挑战。可持续发展是社会、经济发展和…     

Assessment of the aquaculture subsystem in integrated agriculture–aquaculture systems in Northeast Thailand

A survey of integrated agriculture–aquaculture systems (IAAS) was carried out in four different agroecologies, an irrigated and three rainfed agroecologies (drought‐prone, rainfed lowland and rolling land), in Northeast region of Thailand, of tropical wet:dry climate. Fish culture system of IAAS varied with agroecology but not with the length of farmers' experience in IAAS farming. The size of pond holdings in the rainfed lowland agroecology was estimated to be significantly smaller (P≤0.05) than in the three other agroecologies. The highest average extrapolated gross fish yield of 2.3 tonnes ha^?1 was recorded in the irrigated agroecology and this was significantly higher (P≤0.01) than in the three rainfed agroecologies: drought‐prone (1.1 tonnes ha^?1), rainfed lowland (0.5 tonnes ha^?1) and rolling land (0.4 tonnes ha^?1). Higher fish yield in the irrigated agroecology was associated with longer stocking period and higher amount of pond inputs. Average income of IAAS households from fish also varied across agroecology in a fashion that was noted for yields. However, the farm pond played a pivotal role in the diversification of the farming system in rainfed agroecologies, as it was essentially the only source of water supply for fruit and vegetables production. While fish culture in all agroecologies was a low‐input system, intensification through fertilization of ponds with chemical fertilizers can be envisaged to increase fish production in IAAS in Northeast Thailand.     

An assessment of the economic contribution of EU aquaculture production and the influence of policies for its sustainable development

This review paper examines the structure of the EU aquaculture sector, the contribution it makes to the EU economy and the policy environment for past and future development. The primary analysis uses statistical data from the Food and Agriculture Organization of the United Nations which has been re-categorized according to species groups established by the European Aquaculture Technology and Innovation Platform (EATiP) and by culture system type using expert knowledge. Additional data sources for the analysis include the European Market Observatory for Fisheries and Aquaculture Products (EUMOFA) and the European Commission Scientific, Technical and Economic Committee for Fisheries. EU aquaculture production was 1.34 million tonnes in 2012 with a first sale value of €4.76 billion. Shellfish comprised 45 % by volume and 28 % by value; marine fish 30 % by volume and 53 % by value; and freshwater fish 25 % by volume and 19 % by value. The total production volume has actually fallen slightly from 1.4 million tonnes in 2000, whilst the value has increased significantly from 2.79 billion in 2000, mainly due to a growth in Atlantic salmon production. Five countries accounted for around 78 % of the direct output value of EU aquaculture in 2012, the UK, France, Greece, Italy and Spain. Around 50 % of the direct output value was generated using marine cage systems (28 % by volume), whilst less than 3 % of value was generated in recirculated aquaculture systems (<1.5 % by volume). Around 5 % of value was contributed by extensive to semi-intensive inland and coastal pond systems. STECF (2014) estimates there are between 14,000 and 15,000 aquaculture enterprises in the EU employing around 80,000 people, approximately 40,000 full-time equivalent (FTE). The greatest number of jobs (FTE) is provided by the freshwater pond and suspended shellfish sectors due to much lower productivity figures. This could be seen as a social benefit in rural and coastal regions, but corresponding low wages could also discourage young entrants to the industry and lead to dependency on migrant workers. Where efficiencies can be improved through capital investment there is likely to be significant scope for consolidation of ownership as can be observed in the marine fish sector. The output from aquaculture has to find a place within the wider fish and seafood market where volumes are generally inversely related to price. The potential growth of the sector is therefore constrained both in relation to the overall market and with respect to competition from substitute products. These include product from EU capture fisheries as well as imports from third countries (sourced from aquaculture and capture fisheries). Whilst interactions between individual products can be hard to demonstrate, any increase in production costs is likely to lead to lower output volumes, whilst improvements in production efficiency can lead to increased output volumes. With around 60 % of EU fish and seafood supply obtained through imports, and little prospect of increasing outputs from capture fisheries, EU policy is generally supportive of sustainable aquaculture development for reasons of food security and economic development. The underlying basis for this is maximizing the quality and health benefits of farmed products, whilst improving resource efficiency and minimizing impacts. This is expressed through funding support for research and technological development and structural funds to the fisheries and aquaculture industries. However, constraints to growth also exist in the form of regulatory barriers and costs that reduce industry competitiveness. Changing market requirements are also a factor. Prospects for growth have been assessed using the results of EATiP stakeholder workshops combined with the analysis of the sector by system type. These suggest an overall increase in production by 55 % is possible by 2030 based mainly on expansion of marine cage-based farming using larger systems in more exposed sites and similarly shellfish farming using larger-scale suspended systems. Expansion of recirculated aquaculture systems appears likely based on entrepreneurial and European policy for research and technological development activity, although constrained by currently low competitiveness.     

欧洲循环水养殖系统研究进展

欧洲循环水养殖系统技术随着欧盟和欧洲各国环保法规的加强而不断创新和发展。本文对欧洲正在使用生命周期法对循环水养殖进行环境影响评估的状况,以及欧洲应用独特的循环水养殖系统技术增加了养殖的品种进行了介绍和分析。并着重介绍了欧洲循环水养殖系统新技术的应用及其发展状况,特别阐述了脱硝反应技术、淤泥浓缩技术和臭氧技术等新技术在循环水养殖系统的应用情况。在此基础上,指出了循环水养殖可能面临的新挑战。     

我国工厂化循环水养殖发展研究报告

报告回顾、总结了我国水产工厂化循环水养殖发展的主要历程和现阶段的主要特点,分析了我国工厂化循环水养殖的主要问题,着重从技术角度剖析了不足和努力方向.然后,又从促进我国水产养殖业可持续发展的角度阐述了对循环水养殖技术的需求,并对现阶段工厂化循环水养殖产业的发展提出了政策建议.