Viable aquaculture development in the U.S. affiliated islands‐lessons from giant clam and sponge farming

Abstract

The Center for Tropical and Subtropical Aquaculture (CTSA), which is funded by the U. S. Department of Agriculture as one of its Regional Aquaculture Centers, has assisted giant clam and sponge fanning technology development and technology transfer within the region since 1989. Six species of giant clam and one species of bath sponge can currently be commercially produced in the region. After over 12 years of intensive effort by CTSA to develop and transfer technology, the production of giant clam and bath sponges has yet to make any significant contribution to the local economy.

By self‐evaluation of our efforts and the continuing efforts of others, this paper provides possible solutions on aquaculture development related factors, which include biological, technological, environmental, and socioeconomic. Recommendations are made on viable aquaculture development in the region based on our experiences. Amongst other factors, the government's commitment to aquaculture and the resulting actions are vital. Farming technology for giant clams and sponges are also briefly reviewed.     

The effects of bioturbation by the Venus clam Cyclina sinensis on the fluxes of nutrients across the sediment–water interface in aquaculture ponds

A mesocosm experiment was conducted to study the effects of bioturbation by the marine bivalve Cyclina sinensis in an aquatic system and to examine how the bioactivities of this clam alter the rate at which nutrients are exchanged across the sediment–water interface. A dark incubation experiment was performed to determine the fluxes of inorganic nutrients (NH₄ ⁺, NO₃ ^? + NO₂ ^? and PO₄ ^3?), benthic chlorophyll a (Chl a), organic matter and sediment oxygen consumption (SOC) on days 1, 10, 20 and 30. C. sinensis destroyed the initial sediment surface and partially enhanced oxygen penetration into the sediment. The clam also increased the water content and volume of the oxic sediment. The analysis showed that increases in the clam density and time period produced higher fluxes of all the nutrients (NH₄ ⁺, NO₃ ^? + NO₂ ^? and PO₄ ^3?) in the bioturbated chambers compared with the control (non-bioturbated chambers). The concentration of Chl a in the sediment increased significantly at the end of the experiment (day 30) (p < 0.05). The SOC rate increased significantly with the increase in density and with the time period from day 10 to day 30 (p < 0.05). As a result, the fluxes of nutrients increased with increased SOC, producing oxygen-induced sediment mineralization. Our findings suggest that the activities of the clams could positively influence SOC and cause an increase in the fluxes of inorganic nutrients. These effects may substantially improve the primary productivity and water quality of earthen pond ecosystems.     

The expansion of the Atlantic–Mediterranean ghost crab Ocypode cursor (Linnaeus, 1758): Distribution,environmental niches and future perspectives

The tufted ghost crab Ocypode cursor (Linnaeus, 1758) found in the Mediterranean Sea and the Atlantic Ocean is currently a great example that elucidates concerns within scientific and conservation communities. This species, native to the subtropical Atlantic Ocean and the warmest southeastern Mediterranean Sea (Egypt), has been extending its distribution in both regions since the 1980s, likely due to the warming sea temperatures. These small nocturn crabs are typically found inhabiting sandy beaches and dune environments. This species is an opportunistic predator eating terrestrial and marine prey, especially on sea turtle eggs. Despite its status as a threatened species by two European conventions, there is a lack of knowledge of its ecology and biology. Sometimes considered as an indicator of good ecological status of beaches where it lives, this ghost crab could nevertheless benefit from climate change to extend its distribution range. This review aims to create a baseline on the current knowledge and gaps in the published scientific literature on the ghost crab. Additionally, through an analysis of the existing literature, we also offer insights into the potential risk of beach erosion associated with the expansion of this species.     

The financial feasibility of small‐scale grouper aquaculture in the Philippines

Abstract

This paper presents the results of an economic analysis of the aquaculture of two species of grouper E. coloides (orange‐spotted grouper, green grouper, red‐spotted grouper) and E. malabaricus (malabar grouper, black‐spotted grouper) for small producers in the Philippines. The findings of the analysis indicate that, based on the assumptions, grouper culture is financially feasible. However, the capital requirements for the broodstock, hatchery/nursery, and integrated system may be beyond the financial means of many small producers. These stages of grouper culture may need to be developed as a larger project by private investors or government. The capital investment requirement for grow‐out (not including purchase of transport boxes) is within the financial means of small producers. Loans or other incentives will need to be made available for the small producer, but the cash flow indicates that these loans can be repaid in the first year of production.     

The potential for aquaculture of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) in southern Croatia

To assess the potential of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) for aquaculture in southern Croatia, we analyzed their survival and growth rates under two experimental conditions—suspended culture and on-bottom culture. Furthermore, we investigated feeding on zooplankton by these two species in suspended culture conditions and compared them with previously published results of their feeding on zooplankton in the natural benthic environment. Experimental studies were conducted in Mali Ston Bay (Adriatic Sea) from December 2009 to December 2010. Differences were observed in terms of survival of tagged M. barbatus and A. noae—specimens of M. barbatus exhibited much better survival rates both in suspended culture and in on-bottom cages than did A. noae. Growth of A. noae under both culture conditions was essentially negligible, while M. barbatus grew several times faster in suspended culture than on the bottom. Values for the growth constant K and L _inf for M. barbatus in suspended culture were 0.45 year^?1 and 55.9 mm, while corresponding values for on-bottom culture were 0.09 year^?1 and 58.6 mm, respectively. Zooplankters were present in the stomachs of 86.3 % of M. barbatus and 86.4 % of A. noae. Most abundant taxa were bivalve larvae followed by tintinnids, copepods, unidentified eggs and gastropod larvae. In conclusion, this study clearly shows that M. barbatus is a promising candidate for suspended aquaculture in southern Croatia.     

Green grow the fishes‐oh? Environmental attributes in marketing aquaculture products

Abstract

The rise of aquaculture production in the last two decades has had a notable impact on many of the world's markets, sometimes supplementing or replacing existing capture fishery products, developing new market opportunities through improved availability, novel products and/or improved market chain efficiency. Meanwhile consumers have also become increasingly aware of environmental issues and associations with the products they consume; within this broader trend, the practices and possible impacts of aquaculture have justifiably or otherwise been subject to particular scrutiny and sometimes negative comment. Future opportunities and directions for growth and development of aquaculture may become increasingly driven by market perceptions of environmental attributes and, associated with this, the ways in which aquaculture processes and products are presented. This paper reviews the relevant issues of environmental attributes, explores the ways in which these may interact with future production and market trends and suggests critical emerging factors for the aquaculture sector.     

黄粉虫(Tenebrio molitor Linnaeus)工厂化规模养殖技术

本文从黄粉虫的形态、生物学特征、工厂化规模养殖及黄粉虫的活虫运输等方面对黄粉虫工厂化规模养殖技术进行了较详实论述.     

Intelligent fish farm—the future of aquaculture

Aquaculture International - With the continuous expansion of aquaculture scale and density, contemporary aquaculture methods have been forced to overproduce resulting in the accelerated imbalance...     

大菱鲆Scphthalmus maximus(Linnaeus)研究工作又获新进展

由我国著名海水鱼类养殖专家、中国水产科学研究院黄海水产研究所雷霁霖教授引进的大菱鲆,自1992年引进以来,相继完成了菌种培育和亲鱼养成全过程研究,现又获得新的进展。这批在我国培育成功的亲鱼,于今年4月份首次人工采卵成功,并培育出数千尾大菱鲆苗,至今这批鱼苗已达3cm以     

浅析太湖鲤鲫Cyprinus carpio Linnaeus & Carassius auratus (Linnaeus)鱼类种质(Genetical characterization)退化的成因及对策

在新世纪中，太湖渔业将进入一个新的发展时期，但也面临着各种新问题的挑战，本文作者结合太湖湖区的实际情况，在如何防止有些鱼类种质退化的新问题上作一些有益的分析与探讨。     

野生鲇(Silurus asotus Linnaeus)资源开发与养殖

本文总结了近10年来国内外关于鲇鱼(Silurus asotus)养殖的基础和应用技术研究的最新进展:生物学、育种、内分泌生理及其调控、人工繁殖技术、苗种培育和成鱼饲养。结果表明:该种鲇鱼具有很高的经济价值和人工养殖前景,已经成为日本和中国内陆水域新的养殖对象。解决苗种的规模化生产和成鱼饲养的产业化问题是目前的当务之急。     

大菱鲆Scophthalmus maximus (Linnaeus)引进我国10周年回顾

1992年8月，黄海水产研究所雷霁霖教授首次从英国将大菱鲆引进中国，进行增养殖实验。到今年8月份已经10周年了。目前大菱鲆养殖已成为我国北方海洋经济的一个新的亮点，成为海水养殖第四次浪潮的新兴产业。作者回顾了大菱鲆引进以来的研究和开发历程，坚信大菱鲆养殖业能够发展成为我国北方沿海地区的支柱产业。     

Risk in aquaculture: farmers’ perceptions and management strategies in Bangladesh

Abstract

This study examines Bangladesh fish farmers’ perception for risk sources, risk management strategies, and the relationship with socio-demographic variables. Data were collected from a sample of 350 farmers in Bangladesh. Exploratory factor analysis of a set of perception measurement items was used to assess farmers’ attitudes towards risk and their risk management strategies. The results reveal that fish-diseases, fish price variability, low quality of feed and fingerlings, flood and credit constraints were perceived as the most important sources of risk. For risk management, supply of good quality feed and fingerlings, diseases prevention, crop insurance, increasing personal savings, and assurance of bank loans were considered as the most important strategies to mitigate risks. Empirical evidence shows that farmers engage in multiple management strategies to reduce production risk.     

大西洋牙鲆Paralichthys dentatus(Linnaeus)工厂化养殖技术的研究

大西洋牙鲆是西北部大西洋所产的一种经济鱼类,于2003年引进我国试养。本文较详细概述大西洋牙鲆工厂化养殖技术的方法,取得了较好效果。     

欧鲶(Silurus glanis Linnaeus)池塘养殖在新疆获得成功

欧鲶(Stlurus glants Linnaeus)系凶猛肉食性鱼类,原分布于苏联和欧洲中东部等国家水域。新疆伊宁市水产养殖场从1990—1996年开展池塘养殖,进行驯化研究,经过短时间培育与驯化,该鱼适合池塘生