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1.
A preliminary assessment of the marketability of saltwatercultured Florida red tilapia was conducted at a farm outlet store and at nine restaurants in Puerto Rico. Florida red tilapia were grown in six 0.2-ha ponds at 22.7 ± 1.2 (mean ± SE) ppt salinity by a commercial aquaculture enterprise in Dorado, northeastern Puerto Rico. Customers purchased 4,683kg of dressed-out fish (gilled, gutted and scaled) at $7.70/kg and 826kg of whole fish at $6.60/kg from a retail outlet store located at the aquaculture farm, and nine restaurants purchased 1,071kg of dressed-out fish at wholesale prices ranging from $4.96 to $5.18/kg. Farm outlet customers and restaurants preferred dressed-out fish between 454–567g and 567–580g, respectively. Prices paid per serving by restaurant customers for red tilapia ($7.00–$25.00) were similar to that paid for silk snapper Lutjanus vivanus , a popular marine food fish in Puerto Rico. Market surveys of customers at these outlets showed that 75–81% of the respondents were new consumers of red tilapia and that they rated red tilapia highly in taste, texture, freshness, and presentation and equal to or better than silk snapper. There was no effect ( P > 0.05) of age group or economic level on consumer responses. Survey participants stressed the need for product promotion, including a more markehriented name that emphasized the red color and that it was farm-raised in saltwater, to distinguish it from darkcolored, wild-caught freshwater tilapia. Local saltwater production of Florida red tilapia could help supply the market demand for fresh, marine fish in Puerto Rico if producers can meet the demand for quality, availability and price.  相似文献   

2.
Abstract

In order to assess whether gender differences affect uptake and participation in aquacultural activities, a study of a cage aquaculture development project managed by a non‐governmental organization (NGO) in Bangladesh was undertaken. CAGES project (Cage Aquaculture for Greater Economic Security) aims to promote the use of low input cage systems for the benefit of the rural resource poor, including women. Using a participatory approach involving semi‐structured questionnaires complemented by group discussions with mapping exercises to cross‐check information, the role of women was investigated. Distance of the household from the water body was revealed as a major constraint to the full participation of women, especially in the more conservative areas of the country. Time‐consuming activities such as the collection and preparation of feed were generally the responsibility of women as part of their ‘household’ tasks. The influence women held over post‐harvest decisions varied between region, villages and households, with women in the Jessore area appearing to become more empowered from cage aquaculture activities. The implications of these findings are discussed with reference to the CAGES project and gender goals in development.  相似文献   

3.
Abstract Population‐genetic structure and average long‐term effective size of yellowtail snapper, Ocyurus chrysurus (Bloch), sampled offshore from the Florida Keys and four localities in the US Caribbean, were investigated using nuclear‐encoded microsatellites and a fragment of the mitochondrially encoded ND‐4 gene. Analysis of spatial genetic variation revealed occurrence of up to four groupings (stocks) of yellowtail snapper: one in the Florida Keys, one along the west coast of Puerto Rico, one that includes the east coast of Puerto Rico and St. Thomas and one offshore of St. Croix. The observed genetic differences among localities are not strong, and additional sampling to examine whether the observed patterns of population structure are temporally stable is warranted. Levels of genetic variability and estimates of average, long‐term effective size (Ne) indicate that yellowtail snapper at all five localities have, at present, sufficient genetic variation to maintain long‐term integrity and sustainability.  相似文献   

4.
To calculate the potential for cage aquaculture to create economic opportunities for small-scale investors on the Volta Lake, Ghana, a local NGO with technical support from the Government of Ghana ran two trials (one of four and one of six units) of small-scale cage aquaculture in the town of Dzemeni. Cages were built locally from available materials at a cost of approximately US$1000 per 48 m3 cage. An indigenous line of Nile tilapia, Oreochromis niloticus, was stocked either as mixed sex (first trial) or all-males (second trial) at an average rate of 103 fish/m3 and grown on locally available pelleted feeds for approximately six months. Total costs averaged US$2038 per six-month production cycle. Gross yield ranged from 232 to 1176 kg/cage, averaging 460 kg/cage (9.6 kg/m3). Final average weight of mixed sex populations (253.05 ± 47.43g) was significantly less than of all-males (376.7 ± 72.30g). Likewise, percentage of fish over 300 g at harvest was significantly lower in mixed-sex (38.3%) compared to all-male (75.7%) populations. Mortality resulting primarily from poor handling during transport and stocking averaged 70% and was a major determinate of production and profitability. To break even, harvested biomass of fish needed to exceed 15 kg/m3. At 25 kg/m3, small-scale cage aquaculture generated a net income of US$717 per cage per six months (ROI = 30.2%) on revenues of US$3,500. Water quality in the area surrounding the cages was not negatively affected by aquaculture at the scale tested (5 tons of feed per six months).  相似文献   

5.
In aquaculture, the benefit of autotrophic production within land-based ponds for fish production has long been recognized. In cage culture, organisms growing on the cage net have so far only been considered as a problem. This study investigated the potential production of periphyton on cage nets used in a tropical mixed tilapia culture of Oreochromis mortimeri (Trewavas), Tilapia rendalli (Boulenger) and Oreochromis niloticus (Linnaeus) in Lake Kariba, Zimbabwe. The production of periphyton was assessed experimentally and compared with the energy demand of the caged fish. The tilapias were found to graze intensively on the net, and the primary production of periphyton on the cage net was ≈ 1% relative to the energy demands of the fish.  相似文献   

6.
中国深远海网箱的发展现状与展望   总被引：2，自引：0，他引：2       下载免费PDF全文
石建高  余雯雯  卢本才 《水产学报》2021,45(6):992-1005
深远海网箱养殖是一种新型水产养殖模式,具有技术先进、环境友好和成鱼品质高等优点,因此,它对推进水产养殖绿色发展战略意义重大。本文在介绍中国普通网箱和深水网箱、国外深远海网箱发展简况的基础上,重点概述2017年前后中国深远海网箱发展现状及其研究进展,并对今后的发展方向加以展望。2017年前,我国深远海网箱处于起步阶段,开发了特力夫~(TM)超大型深海养殖网箱等近10种深远海网箱。2017年后,我国深远海网箱进入快速发展期,开发应用了"深蓝1号"全潜式深海渔场等一系列深远海网箱,引领了深远海网箱的现代化建设。迄今为止,我国主要开展了深远海网箱的定义、专利、结构、绳网材料及其配套智能装备等研究,部分成果已得到应用。为适应水产养殖绿色发展要求,今后我国深远海网箱将朝着离岸化、大型化和智能化等方向发展。虽然我国深远海网箱养殖业取得了长足进展,但与挪威等国外先进技术相比,我们还存在巨大的差距。我国深远海网箱养殖业前景广阔,但相关工作任重道远。  相似文献   

7.
我国深远海网箱养殖工程与装备技术研究综述   总被引：1，自引：0，他引：1  
在远离大陆的深远海水域发展大型网箱养殖,已成为缓解近海养殖环境压力、突破资源受限和空间制约问题的重要举措。深远海网箱养殖产业的蓬勃发展,加速促进了养殖方式转型升级和海洋养殖空间大幅拓展,形成了海洋设施养殖新发展格局。本文立足我国网箱养殖产业发展现状,分析深远海网箱养殖产业发展需求、发展前景以及设施装备科技需求,详细介绍国内外深远海网箱养殖工程与有关装备技术的研究应用情况,分析我国深远海网箱养殖工程与装备发展面临的主要问题,并从科学规划、科技引领、规范建设和创新模式等方面,对深远海网箱养殖产业发展提出相关建议。  相似文献   

8.
桑沟湾不同养殖区大型底栖动物的群落结构特征   总被引：2，自引：0，他引：2  
于2016年9月和11月对我国北方典型筏式养殖海湾—桑沟湾的筏式贝藻养殖区和网箱养殖区的大型底栖动物进行调查,研究了桑沟湾不同养殖区大型底栖动物的种类组成、数量分布、群落结构及生物多样性等群落特征,分析了底栖动物与海洋环境因子的关系,以了解养殖活动对大型底栖动物的影响。结果显示,调查共鉴定出大型底栖动物67种,其中,环节动物多毛类36种,软体动物12种,节肢动物门甲壳类和全足类16种,棘皮动物3种。桑沟湾大型底栖动物的优势种主要为多毛类,贝藻区的绝对优势种为刚鳃虫和长叶索沙蚕,网箱区的绝对优势种为异足索沙蚕和多丝独毛虫。生物量和丰度的特性为9月网箱区11月网箱区9月贝藻区,多样性指数的趋势相反。研究表明,底栖动物群落特征与底质有机碳、总磷、硫化物和氧化还原电位等因素有关,桑沟湾大规模养殖活动对底栖动物群落组成和分布产生了一定的影响。  相似文献   

9.
A mass‐balance modelling approach combined with a sensitivity analysis was utilized to gain an improved understanding of the relative contributions of phosphorus (P) loading from various anthropogenic and non‐anthropogenic sources into Lake Wolsey (Manitoulin Island, Ontario, Canada), a Type 2 freshwater lake with a cage‐aquaculture facility. Total P loadings were estimated from eight sources (inlet exchange, non‐point sources, cage‐aquaculture facility, internal loading, groundwater seepage, atmospheric deposition, leaf litter and dwellings) and three sinks (outlet exchange, sedimentation and sportfishing). Results indicated that over the study period (May–November 2007) the non‐point sources were the leading contributor of total P to Lake Wolsey (1120 kg P) followed by the cage‐aquaculture facility loading (915 kg P), inlet exchange (539 kg P), groundwater inputs (305 kg P), dwellings (219 kg P), internal P recycling loads from the hypoxic hypolimnion (186 kg P), atmospheric deposition (79 kg P) and decomposing leaf litter (8.1 kg P). When comparing the loadings in this study, the sensitivity analysis showed that non‐point sources were the only significant input parameter of total P loading to the in‐lake concentrations of P in Lake Wolsey(P = 0.05). Information from this project will provide water quality managers with sound scientific information to make defencible decisions pertaining to policy and regulatory approaches for water quality risk assessment and management of cage‐aquaculture in Type 2 sites.  相似文献   

10.
Abstract

Bahrain, located in the Arabian Gulf, is composed of low‐lying islands made up primarily of sand covering limestone bedrock. The climate is extreme with seawater temperatures ranging between 8 and 38 °C. Seawater salinity ranges from about 40–60 p.p.t. Freshwater resources are limited with about half the freshwater consumed coming from desalinization plants. Total fish landings have increased over time with some fluctuations. Per caput consumption has dropped from a high of 27.2 kg/caput (1985) to 12.6 kg/caput (1997). Landings for certain preferred species have declined dramatically over the last 10 years. For example, total grouper landings have declined about 70% in 10 years. This has resulted in increased prices at the local market. Bahrain has no history or tradition of aquaculture. In 19 79, FAO conducted an initial assessment of aquaculture in Bahrain. This led to construction of basic laboratory facilities and some baseline aquaculture experiments. A second phase was started in the early 1990s that included establishing the National Mariculture Center (NaMaC). Initial work at NaMaC concentrated on small‐scale culture trials of orange‐spotted grouper, Epinephelus coioides, pearl‐spotted rabbitfish, Siganus canaliculatus and yellow‐finned black seabream, Acanthopagrus latus. Recently, NaMaC has been successful in mass culture of the sobaity bream, Sparidentex hasta. The initial 1979 FAO study recommended an economic assessment of aquaculture in Bahrain. An initial financial assessment was finally completed in 1994. At that time, hatchery and grow‐out production was not financially feasible. A subsequent grouper grow‐out production study indicated that if seed supplies could be assured, grow‐out operations might be financially feasible. Additional economic studies have been completed on feed and cage suppliers. In addition, local market surveys indicated good consumer acceptance of aquaculture products. Aquaculture management in Bahrain is under the Directorate of Fisheries. The goal of mariculture development in Bahrain is the establishment of a commercially viable private sector industry. This has yet to be achieved. Regulations for such an industry have been drafted, but have not yet been formalized. Bahrain has taken a long‐term perspective to aquaculture development. It has set up infrastructure and is developing technology to support commercial aquaculture. However, financial constraints have limited, but not stopped progress towards development of a commercially viable industry. As the economic conditions and the fisheries change, feasibility of such an industry should continue to improve.  相似文献   

11.
The tilapia fishery in a large Mexican reservoir has declined in recent years, promoting efforts to enhance stock quality in conjunction with feasibility studies for cage aquaculture. Spatial models to optimize cage location have been developed, incorporating aspects of topography, climate, hydrography, water quality and quantity, land use, infrastructure and socioeconomics. Three cage sizes were modelled, 5, 10 and 15 m diameter, for both high‐ and low‐water levels. When full the, reservoir has a total area of 312 km2 but a reduction in water level of 13 m was recorded between wet and dry seasons, significantly reducing the surface area available for cages to 265 km2. The results indicate a significant difference in the availability of sites between seasons. For the small, medium and large cages at high water level, the areas classified as highly suitable or suitable were 151, 184 and 146 km2, respectively, while at low‐water level these areas reduced to 113, 88 and 62 km2. Modelling this change in water level and the subsequent loss of available sites provide qualitative and quantitative guidelines for the development of aquaculture sites, their seasonal management and future monitoring, outcomes that can only be achieved using Geographical Information Systems and associated technologies.  相似文献   

12.
We investigated the usefulness of acceleration loggers in aquaculture by examining net-cage use and metabolic rates in red sea bream, Pagrus major. First, the fish’s metabolic rate (mg O2 kg−1 min−1) was measured with the logger in a swim tunnel at designated water velocities. We found that metabolic rate could be expressed by using a linear regression model of the activity rate index (unitless min−1) derived from acceleration data. Using this equation, the field metabolic rates of three fish in a net cage were monitored and were estimated at 14.1–15.0 kcal kg−1 day−1. The results suggested that 15–19% of energy from satiation feeding ration was consumed for metabolism and activity in the net cage. The loggers showed orderly net-cage use by the fish. Tagged individuals used the whole cage from surface to bottom, but individual fish that preferred the surface area rarely used the bottom, and vice versa. Metabolic rate increased significantly with distance of the fish from their preferred depths. The logger provided information on the physiological and behavioral responses of fish in a given breeding system, and its use should contribute to the design of practical aquaculture systems.  相似文献   

13.
Abstract

This paper examines recent advances in production economics with special reference to efficiency measurement using production frontiers and its implications for aquaculture management. Compared with agriculture and other industries, the use of production frontiers in aquaculture is still very limited. However, in recent years several frontier applications in aquaculture have appeared in the literature, suggesting potential applications of these techniques in aquaculture. A synopsis of stochastic frontier production function model and data envelopment analysis (DEA), the two most popular approaches to efficiency measurement, is presented, followed by a review of recent frontier studies in shrimp, carp and tilapia production. The paper concludes with a brief discussion of future development and prospects of frontier applications for aquaculture management.  相似文献   

14.
网箱养殖箱体内外的水质变化   总被引：2，自引：0，他引：2  
从网箱养殖过程中向水体输入废物的角度,对影响箱体内外水质变化的因子进行分析。探讨了网箱养殖箱体内外的水质变化及其影响,并为网箱养殖业的健康可持续发展提出一些对策。  相似文献   

15.
海水网箱养殖中,网衣污损附着物会影响网箱设施安全及其养殖鱼类的健康生长,因此,网衣防污是网箱养殖业备受关注的问题。本文在简述海水网箱网衣分类与特点的基础上,重点介绍了人工清除法、防污涂料法、机械清除法、金属合金网衣防污法、箱体转动防污法、生物防污法、网衣本征防污法等网衣防污技术最新研究进展;结合本课题组在网衣防污方面的研究成果,分析上述防污技术的特点,为网衣防污技术的深入研究以及水产养殖业的绿色发展提供参考。我国海水网箱养殖业大有可为,但网衣防污工作仍任重道远。  相似文献   

16.
Abstract

Although aquaculture in Egypt has the potential for satisfying the increased demand for protein and has been experiencing unprecedented growth during the last decade, questions remain regarding the sustainable development of the industry. It is thus the objective of this article to review the current status and practices of the aquaculture industry in Egypt, highlighting the major issues confronting the sustainable development of the aquaculture industry.

Several issues are identified as limitations to future sustainable development, namely, production technology, fry supply, a feed industry sufficient to meet the demands of a growing aquaculture industry, and marketing and distribution systems necessary to accommodate the strong seasonal supply pattern. The article then concludes with a discussion of recommendations for alleviating these limitations.  相似文献   

17.
为提高深水网箱养殖过程监控的准确性与实时性,设计了一种深水网箱养殖远程无线视频监控系统。该系统利用3G无线网络技术实现深水网箱养殖网络化的本地或远程的实时视频监控,采用3G＋VSaaS模式,通过网络摄像头采集深水网箱现场数据,通过无线网络传输、发布和共享,并同时实现执行机构的反馈控制。文章介绍了工作原理与系统总体构架,阐述了系统硬件部分的选取设计原则,并分析了系统工作的关键技术。构建起深水网箱全方位远程监控体系,可实现深水网箱养殖信息化管理,提高养殖生产效率及风险防范能力。  相似文献   

18.
Abstract.— The aquaculture performance of mutton snapper Lutjanus analis raised in floating net cages was assessed by measuring their growth, survival, and feed conversion rates during a growout trial conducted in a 3.2‐ha saltwater lake in the Florida Keys, Florida, USA. Approximately 10,500 hatchery‐reared finger‐lings were stocked in two circular, high‐density polyethylene (HDPE) net cages of 7‐m diameter × 7‐m deep (300 m2) and 10‐m diameter × 7‐m deep (600 m3) dimensions. Cages were stocked at 25 fish/m3 (3.2 kg/m3) and 5 fish/m3 (0.72 kg/m3), respectively. Fish grew from a mean of 16.5 g to 302.8 g (25.6 cm TL) in 246 days in the former cage and from a mean of 42.3 g to 245.6 g (23.8 cm TL) in 178 d in the latter cage. Growth rates in weight were best expressed by the following exponential equations: cage 1 (high stocking density): W = 20.716 e0.0112x (r2= 0.83); cage 2 (low stocking density): W = 38.848 e0.0118x (r2= 0.81). Length‐weight data indicate that hatcheryraised, cage‐cultured mutton snapper are heavier per unit length than their wild counterparts. There was no significant difference (P < 0.05) between the slopes of the two lines, indicating that fish in the two cages grew at the same rate. The length‐weight relationships for mutton snapper stocked in cages 1 and 2 are expressed, respectively, by the equations W = 0.000009 L 3.11 (r2= 0.99) and W = 0.000005 L 3.22 (r2= 0.97). Overall feed conversion rate for both cages combined was 1.4. Approximately 10% of the fish sampled exhibited some degree of deformity, particularly scoliosis. Overall survival rate was 70%. Results suggest that L. analis has potential for aquaculture development in net cage systems.  相似文献   

19.
深海网箱作为现代海洋渔业拓展外海养殖空间的重要养殖装备，其布设环境一般较近海更为复杂恶劣，对于保障其安全性和稳定性提出了更高的要求。本研究针对一种单点系泊潜浮式船型桁架网箱开展了模型比尺为1︰40的波浪流水池试验，重点围绕该网箱在不同吃水深度受波浪作用的系泊受力、升沉、纵摇和横摇等水动力学特性进行了比较分析。试验结果显示，波高为7.5~12.5 cm时(原型3~5 m)，网箱漂浮状态即可以满足养殖需求，其系泊力及运动响应均较小，具备较高的安全性和稳定性；恶劣海况时，即本试验中波高为15.0和17.5 cm (原型6 m和7 m)，通过整体下潜的方式网箱具有良好的避浪性能，其中，系泊力减幅达70%以上，升沉、纵摇和横摇等运动分量减幅也达20%~60%；波流试验中，海流对网箱避浪性能存在一定的影响，但总体上仍然具有较好的避浪效果。研究结果可为单点系泊潜浮式深海网箱的安全运行与日常管理提供理论依据和数据参考。  相似文献   

20.
Abstract

Social science can make important contributions to understanding the prospects for offshore marine aquaculture development because many of the potential barriers that may restrict its development are social and institutional rather than biological or technical. This study collects baseline data on attitudes towards offshore marine aquaculture held by a key stakeholder group. It also investigates the influence of information on attitudes towards marine aquaculture. Data reported in this study were collected from visitors to a seafood festival in coastal New Hampshire. The formal objectives of this research were to determine what effect, if any, two‐sided information on the potential advantages and disadvantages of marine aquaculture has on attitudes towards marine aquaculture and how prior familiarity with aquaculture moderates the effect of information. The findings from this study indicate that two‐sided information has a negative effect on attitudes, especially among individuals who are unsure of their level of familiarity with the issue.  相似文献   

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