Integrating the Concept of Resilience into an Ecosystem Approach to Bivalve Aquaculture Management

Bivalve aquaculture has become increasingly important for marine protein production and is an alternative to exploiting natural resources. Its further and sustainable development should follow an ecosystem approach, to maintain both biodiversity and ecosystem functioning. The identification of critical thresholds to development remains difficult. The present work aims at combining the calculation of the system’s ecological carrying capacity (ECC) with the ecosystem view of resilience for a bay system exposed to bivalve (scallop) aquaculture. Using a trophic food-web model, a stepwise further expansion of culture activities was simulated, and the impact on the system was evaluated twofold: First, a recently developed approach to estimating ECC was used, and second, a resilience indicator was calculated, which is based on the distribution of consumption flows within the trophic network (sensu Arreguín-Sanchez in Ecol Model 272: 27–276, 2014). Results suggest that a culture expansion beyond present-day scale would (a) cause a shift in community composition towards a system dominated by secondary consumers, (b) lead to the loss of system compartments, affecting ecosystem functioning, and (c) result in a decrease in resilience, emphasizing the need to regulate aquaculture activities. The applicability and potential of this presented method in the context of an ecosystem-based approach to aquaculture is discussed. This work aims at adding to the ongoing discussion on sustainable bivalve aquaculture and is expected to help guide aquaculture management.     

Characterization of Methanosarcina mazei N2M9705 Isolated from an Aquaculture Fishpond

A new methanogenic isolate, designated as strain N2M9705 (=OCM 668), was isolated from an aquaculture fishpond near Wang-gong, Taiwan. This strain grew on trimethylamine and methanol, but it did not catabolize H₂-CO₂, acetate, or formate. The cells were stained Gram-negative, nonmotile, irregular coccus 0.6–0.8 μm in diameter. Gas vacuoles were observed and cell aggregated to form various sizes of granules. Cells grew optimally at 32°–37°C with 1% NaCl. The pH range of growth was 6.2–7.4, and higher pH inhibited the cell growth. The cells grew well in minimal medium, but growth was greatly stimulated by yeast extract and peptone. A comparison of 16S rDNA sequences of this organism phylogenetically related to Methanosarcina mazei. This is the first report of methyltrophic methanogenic isolated from an aquaculture fishpond. Received: 16 March 1999 / Accepted: 16 April 1999     

Assessing the Risk of an Aquaculture Development on Shorebirds Using a Bayesian Belief Model

One of the largest Ramsar-designated wetlands in New Zealand is located at Miranda, in the Hauraki Gulf, at the head of a large sheltered embayment (the Firth of Thames). The habitat is particularly significant in that it supports large populations of nationally important, and Arctic migratory, shorebirds. At present regulatory authorities are processing applications for a new marine farming region in the Firth and both regulators and stakeholders have expressed a desire to investigate possible interactions between the possible marine farms and the Ramsar wetland. The specific objective of this study was therefore to use existing information to investigate the risks of the possible aquaculture activities on the ability of the southern Firth habitats to support shorebirds. The study involved the development of a hazard assessment, and then investigating risk pathways through the use of a Bayesian network model, and a complex systems model. The hazard assessment identified multiple pathways through which the farms may interact with the wetland habitat; including through changes to primary productivity, detrital pathways and sediment dynamics. Furthermore, both the Bayesian network model and complex systems model suggested that the ability of the habitat to support shorebirds is nonlinearly dependent on both the habitat size, and quality; both of which could potentially be influenced by the establishment of the farms.     

Aquaculture: global status and trends

Aquaculture contributed 43 per cent of aquatic animal food for human consumption in 2007 (e.g. fish, crustaceans and molluscs, but excluding mammals, reptiles and aquatic plants) and is expected to grow further to meet the future demand. It is very diverse and, contrary to many perceptions, dominated by shellfish and herbivorous and omnivorous pond fish either entirely or partly utilizing natural productivity. The rapid growth in the production of carnivorous species such as salmon, shrimp and catfish has been driven by globalizing trade and favourable economics of larger scale intensive farming. Most aquaculture systems rely on low/uncosted environmental goods and services, so a critical issue for the future is whether these are brought into company accounts and the consequent effects this would have on production economics. Failing that, increased competition for natural resources will force governments to allocate strategically or leave the market to determine their use depending on activities that can extract the highest value. Further uncertainties include the impact of climate change, future fisheries supplies (for competition and feed supply), practical limits in terms of scale and in the economics of integration and the development and acceptability of new bio-engineering technologies.In the medium term, increased output is likely to require expansion in new environments, further intensification and efficiency gains for more sustainable and cost-effective production. The trend towards enhanced intensive systems with key monocultures remains strong and, at least for the foreseeable future, will be a significant contributor to future supplies. Dependence on external feeds (including fish), water and energy are key issues. Some new species will enter production and policies that support the reduction of resource footprints and improve integration could lead to new developments as well as reversing decline in some more traditional systems.     

Design and Application of a Solar Mobile Pond Aquaculture Water Quality-Regulation Machine Based in Bream Pond Aquaculture

Bream pond aquaculture plays a very important role in China’s aquaculture industry and is the main source of aquatic products. To regulate and control pond water quality and sediment, a movable solar pond aquaculture water quality regulation machine (SMWM) was designed and used. This machine is solar-powered and moves on water, and its primary components are a solar power supply device, a sediment lifting device, a mechanism for walking on the water’s surface and a control system. The solar power supply device provides power for the machine, and the water walking mechanism drives the machine’s motion on the water. The sediment lifting device orbits the main section of the machine and affects a large area of the pond. Tests of the machine’s mechanical properties revealed that the minimum illumination necessary for the SMWM to function is 13,000 Lx and that its stable speed on the water is 0.02–0.03 m/s. For an illumination of 13,000–52,500 Lx, the sediment lifting device runs at 0.13–0.35 m/s, and its water delivery capacity is 110–208 m³/h. The sediment lifting device is able to fold away, and the angle of the suction chamber can be adjusted, making the machine work well in ponds at different water depths from 0.5 m to 2 m. The optimal distance from the sediment lifting device to the bottom of the pond is 10–15 cm. In addition, adjusting the length of the connecting rod and the direction of the traction rope allows the SMWM to work in a pond water area greater than 80%. The analysis of water quality in Wuchang bream (Parabramis pekinensis) and silver carp (Hypophthalmichthys molitrix) culture ponds using the SMWM resulted in decreased NH₃⁺–N and available phosphorus concentrations and increased TP concentrations. The TN content and the amount of available phosphorus in the sediment were reduced. In addition, the fish production showed that the SMWM enhanced the yields of Wuchang bream and silver carp by more than 30% and 24%, respectively. These results indicate that the SMWM may be suitable for Wuchang bream pond aquaculture in China and that it can be used in pond aquaculture for regulating and controlling water quality.     

International Journal of Aquaculture(IJA)

<正>International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for practice in aquaculture;information about the entire area of applied aquaculture,     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for practice in aquaculture;information about the entire area of applied aquaculture,     

水产养殖饲用微生态制剂研究进展

微生态制剂作为新型饲料添加剂,能够有效调节水产动物营养保健和微生态平衡,减少抗生素使用,是理想的抗生素替代品,对保障高效种养殖、食品安全及环境可持续发展意义重大。我国饲用微生态制剂应用起步较晚且发展较慢,仍面临着难点和挑战。本文介绍了微生态制剂及饲用益生菌在鱼、虾及海参养殖中的应用,基于优良益生菌选育、培养条件优化及混合菌株发酵与制剂应用等生物技术研究现状,总结了近年来水产养殖饲用微生态制剂的研究进展,并对未来微生态制剂研究重点和发展前景进行了展望。     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by BioPublisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for     

International Journal of Aquaculture (IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for     

International Journal of Aquaculture(IJA)

正International Journal of Aquaculture(ISSN 1927-5773)is an open access,peer reviewed journal published online by Bio Publisher.The journal publishes all the latest and outstanding research articles,letters and reviews in all working and studying within the many varied areas of aquaculture,containing the latest developments and techniques for practice in aquaculture;information about the entire area of applied aquaculture,