Understanding community perceptions of aquaculture: lessons from Australia

Aquaculture is a growing and high-value industry that depends on access to and wise use of shared inland, coastal and marine resources. Varied stakeholders and communities are very interested in these public resources, and there has been conflict about how the aquaculture industry uses them. Prior to the research discussed in this article, there have been few large-scale studies of community perceptions of aquaculture. Our research drew upon an extensive literature review, stakeholder interviews and a survey mailed to the public in two regional case studies in Australia: the Eyre Peninsula in the state of South Australia and Port Phillip Bay in the state of Victoria. The data revealed some public support for aquaculture’s socioeconomic benefits and strong interest in minimizing the risk of its environmental impacts. There were mixed opinions about the trustworthiness of governments’ aquaculture decisions and actions. Some industry sectors attracted greater trust and lower perceived environmental risks. The importance and credibility of different information sources varied. There was strong support for improved dialogue among governments, the aquaculture industry and communities. Key differences between the regions included levels of awareness of and knowledge about aquaculture. Our research is consistent with literature on risk communication and perception that suggests that conflict and subsequent costs to industry and the community can be overcome or mitigated if government and industry understand, acknowledge and respond to community perceptions of the industry.     

Assurance bonds: A tool for managing environmental costs in aquaculture

Abstract

The environmental costs associated with coastal aquaculture, though poorly understood, can in some cases be quite large. The presence of risk, uncertainty and insufficient monitoring can greatly reduce the power of traditional economic instruments such as environmental taxes and tradable permit systems to internalize these costs. Using the Texas shrimp farming industry as a specific example, this article explores the potential of environmental assurance bonds (EABs) as an alternative economic instrument to internalize environmental costs of aquaculture production under such conditions. Drawing from previous literature, an explicit distinction is made between two mechanisms simultaneously incorporated in the EAB: a deposit‐refund incentive and social insurance. The article discusses the role of each of these mechanisms in shifting the environmental costs of production back to firm. Practical application of EABs in the Texas coastal shrimp farming industry is then examined.     

Depth matters for bivalve culture in integrated multitrophic aquaculture (IMTA) and other polyculture strategies under non-eutrophic conditions

Bivalve cultivation, in single cultivation or in polyculture (including integrated multitrophic aquaculture; IMTA), is generally limited to eutrophic waters. We carried out a modeling study to test if, under meso- and oligotrophic conditions, depth could be a key factor for bivalve productivity associated to IMTA and other polyculture strategies. We applied the model Farm Aquaculture Resource Management (FARM) at three strata of the water column in two coastal fish farm areas in the Mediterranean Sea, using water column variables sampled seasonally to estimate the potential mussel production. According to FARM, mussel production was high in both areas and, in some cases, almost doubled when mussels were cultured below 25-m depth compared to shallower levels. Phytoplankton abundance is expected to notably influence mussel production compared to particulate organic matter. Thus, in meso- and oligotrophic stratified waters, where chlorophyll maximum is relatively deep, depth can be a key factor for the productivity of mussel cultivation. The obtained results could help to maximize the production of suspension-feeding bivalve cultivation and, therefore, the expansion and development of sustainable aquaculture in non-eutrophic marine waters.     

筏式和底播增养殖模式下魁蚶食物来源的比较研究

2014年5月和9月,运用稳定同位素技术和胃含物分析法,比较研究了不同增养殖模式下魁蚶(Anadara broughtonii)的饵料特征差异,以期探讨增养殖魁蚶可能的食物来源。结果显示,魁蚶的δ~(13)C值存在明显的季节差异,在5月,筏养区魁蚶的δ~(13)C值明显低于9月,底播区则表现出相反趋势。5月,两种增养殖模式下魁蚶的δ~(13)C和δ~(15)N值均无明显差异;9月,筏养区魁蚶的δ~(13)C、δ~(15)N值均显著高于底播区。以浮游植物为主的颗粒有机物是筏养区魁蚶的主要食物来源,其贡献率可达61.0%~62.9%,附着微藻是其重要的食物补充(37.2%~39.0%);而底栖微藻则是底播区魁蚶最主要的食物来源,其贡献率达到51.7%(5月)和72.5%(9月)。胃含物分析结果显示,魁蚶主要滤食圆筛藻属(Coscinodiscus)、曲舟藻属(Pleurosigma)、菱形藻属(Nitzschia)和舟形藻属(Navicula)种类。底播模式下魁蚶胃含物组成与底栖微藻群落的相似性系数可达85.30%(5月)和77.20%(9月),表明魁蚶对水体中的微藻具有一定的选择性,以浮游性较弱、且易于下沉的硅藻或底栖硅藻类为主。研究结果可为魁蚶筏式养殖和底播增殖的科学管理提供参考。     

THE FARMING PRACTICES AND ECONOMICS OF AQUACULTURE IN THAILAND

ABSTRACT

The paper reviews freshwater and coastal aquaculture practices in Thailand, and compares the productivity, costs, and benefits across various types of cultivation and various intensities of production. The paper is based on data that were collected in surveys conducted during 1998–2001 by the Department of Fisheries (DOF), Thailand and the WorldFish Center. More than 22% of Thailand's fish supply comes from aquaculture, with coastal aquaculture accounting for more than 88% of this in terms of value. Intensive culture of shrimp is the dominant form of coastal aquaculture, occupying 69% of the area under production. However, in some regions, the average net profit/kg of intensive shrimp culture is negative, and semi-intensive farming, with relatively lower fixed investment and operating costs, delivers the highest rate of return on investment. On the coast, grouper and sea bass are the most important cage-cultivated species, achieving an economic rate of return as high as 92%. In the same environment, culture of mollusks, such as green mussels, oysters, and blood cockles, is widespread. It can also be economically sustainable, with relatively low capital and operating costs. Although the relative share of freshwater aquaculture production is declining, the level of output has been increasing rapidly. While the average production from monoculture of carnivorous species is higher than that from polyculture, the average capital investment and operating costs associated with the former are also higher. The expansion of freshwater polyculture and of mollusk culture in coastal areas would greatly assist poor fish farmers.     

南海北部陆架水域多齿蛇鲻与花斑蛇鲻的年龄与生长

文章利用线粒体细胞色素b (cytochrome b, cytb)基因全序列作为分子标记,分析了中国近海和陆架的花斑蛇鲻(Saurida undosquamis)的遗传结构特征。从8个采样点266尾样本中共检测到142种单倍型,各采样点均表现出很高的单倍型多样性(0.925 1~0.992 9)和较低的核苷酸多样性(0.003 145~0.003 852)。单倍型的中间连接网络图呈现以4个优势共享单倍型为中心的星状发散结构,未发现与地理群体对应的谱系结构。分子方差分析表明花斑蛇鲻的遗传变异绝大部分(99.79%)来自种群内的个体之间,而群体之间几乎没有贡献遗传变异。成对遗传分化系数(F_ST)显示花斑蛇鲻群体间基因交流频繁,不存在明显的遗传差异,是一个随机交配群。中性检验表明种群历史动态显著偏离稳定种群模型,核苷酸错配分布表明花斑蛇鲻历史上曾经历过种群的快速扩张,扩张时间推算约在距今4万~10万年之前。研究结果表明,中国近海和陆架的花斑蛇鲻遗传分化不显著,在渔业上可以作为一个单元来管理。

     

The solution to pollution? The value and limitations of environmental economics in guiding aquaculture development

Abstract

The notable increase of aquaculture production in recent decades has in many instances been matched by growing concern for its impacts. Environmentalists, consumers and members of the general public are increasingly demanding to account for its resource use and to balance its proposed benefits with its environmental sustainability. Although conventional financial and economic analyses have demonstrated a broadly positive impact for many forms of aquaculture, including the more intensive resource‐demanding systems, the use of economic tools embracing wider measurements of social and environmental costs and benefits might provide different and possibly more critical perspectives. However, although these techniques hold promise for such analyses, their development and application in sectors such as aquaculture are as yet limited. This paper reviews the relevant issues, considers the tools and applications of environmental economics and proposes ways in which these may be more effectively be applied in strategic and local decision‐making for aquaculture development.     

Frequent monitoring of temperature: an essential requirement for site selection in bivalve aquaculture in tropical–temperate transition zones

Frequent monitoring of temperature (FMT) for over 1 year at two aquaculture sites in the western Baja California peninsula was analysed in terms of hourly, daily and monthly variability, and with this information, temperature‐change indices were calculated. These data were contrasted against a long‐term series from a global database (Extended Reconstruction of Sea Surface Temperature (ERSST)) to evaluate whether these could substitute for FMT. The compatibility of species requirements with the thermal conditions was evaluated by comparing the temperature frequency distributions from the two FMTs, with the optimum and lethal temperature information available on five bivalve species of aquacultural interest. We concluded that there was no correlation between ERSST and FMT because the former underestimates the amplitude of real temperature fluctuations and exhibits a different pattern of variation during the year. Therefore, FMT was needed for a correct selection of an aquaculture site for bivalves. The FMT indicated high temperature variability at both sites studied on different time scales, with the site located at lower latitude (Rancho Bueno) warmer and with a higher variability than Laguna Manuela. Contrasting these results with optimum and lethal temperature values of bivalve species, it was possible to find the ideal site, for temperature, for culturing the species, taking into account the variability associated with large‐scale phenomena.     

The use of physiological condition indices in marine bivalve aquaculture

The physiological condition indices most commonly used in bivalve aquaculture are reviewed and evaluated. Two general categories of indices may be distinguished: static and dynamic. Of the static indices reviewed, only one is recommended for use in the culture of early developmental stages — the dry ash weight: total dry weight ratio. In the case of juveniles and adults, the easily-measured dry tissue weight: dry shell weight is recommended for most routine work.The dynamic indices reviewed are based on production estimates, and hence reflect physiological changes over specified time intervals. Of these indices, only net growth efficiency is recommended for use in bivalve aquaculture, and it is applicable to all life stages. While this index gives the most information about the physiological state of the animals comprising a population, it is very difficult to evaluate and is thus most appropriate as a research tool.     

Evaluation of hemolymph biochemical properties,clearance rate,bacterial microbiota and expression of HSP genes of gulf pearl oyster Pinctada radiata in response to salinity changes

Fisheries Science - Hypo-salinity exposure is a serious concern for bivalve aquaculture, with profound effects on the animals’ physiological condition. The present study aimed to evaluate the...     

Economic Feasibility of Aquaculture of Spiny Lobsters Jasus edwardsii in Temperate Waters

Around the world there is strong interest in the aquaculture of spiny lobsters (family Palinuridae). However, there is little published information about the economic feasibility of spiny lobster aquaculture. For more than 20 yr there has been experimental grow out of the spiny lobster Jasus edwardsii in New Zealand in land-based systems using seed animals (puerulus) taken from the wild. These studies provide sufficient information on growth, mortality, food conversion, handling and capital costs to enable an assessment of the economic feasibility of the commercial culture of spiny lobsters in temperate waters. This assessment suggests that profitable spiny lobster aquaculture will rely on greatly reducing the infrastructure and operating costs of land-based farming operations, as well as lowering feed and labor costs. Financial simulations suggest that increasing productivity through faster growth rates and lowered culture mortalities will only have a minor effect on profitability unless infrastructure and operating costs can be reduced significantly. Seacage culture or sea ranching of spiny lobsters may offer a means of avoiding high infrastructure costs associated with land-based farming operations. The development of a cost-effective artificial feed would also appear to be a priority for improving the economic outlook for culturing spiny lobsters. The results of this study are relevant to the economics of spiny lobster culture developments in other temperate regions of the world.     

Introduction to the design of coastal aquaculture systems in Taiwan

The traditional culture of shellfish in the coastal waters of Taiwan has a long history. The culture area was limited to the sandy beaches of the south and southwest coast. In the past decade, due to the shortage of land resources and water pollution, coastal water aquaculture has been extended to intertidal rocky areas and the sublittoral zone. Concrete ponds have been constructed on the intertidal zone of the rocky coast specifically for culturing such species as small abalone, Haliotis diversicolor supertexta, grass shrimp, Penaeus monodon, grouper Epinephelus sp. etc. Fish culture in floating cages and oyster culture on floating long-lines and rafts are also practiced. This paper presents details of construction designs, with emphasis on utilizing water circulation, construction costs and wave resistance. Some examples are selected to illustrate the layouts used and the problems faced.     

ANTICIPATING THE GROWTH OF AN OCEAN AQUACULTURE INDUSTRY

In assessing the future expansion of aquaculture in coastal-ocean environments, most studies focus only on the constraint posed by the local environmental assimilative capacity. In open-ocean environments, however, the assimilative capacity is difficult to gauge. We develop an alternative economic approach for projecting the growth of the open-ocean aquaculture industry. We evaluate equilibria in the market for seafood, where the product may be supplied either by a wild-harvest fishery or open-ocean aquaculture or both. In our framework, the net demand for farmed fish determines the size of the aquaculture industry and, in turn, the levels of pollution discharges. We illustrate our approach with a case study of a groundfish fishery and the proposed open-ocean aquaculture of Atlantic cod in New England. We find that, for a range of competitive production costs for aquaculture, the optimal industry structure would comprise both a wild-harvest fishery and aquaculture.     

大型藻类在综合海水养殖系统中的生物修复作用

减少水产养殖自身对环境的负面影响是维持水产业持续健康发展的关键所在。大型藻类生物滤器可以有效地吸收、利用养殖环境中多余的营养物质，从而减轻养殖废水对环境的影响，并提高养殖系统的经济输出，被广泛应用于鱼、虾和贝类等的综合养殖系统中，是控制水体富营养化、增进食品安全和对污染水体进行生物修复的有效措施之一。本研究概述了大型藻类生物滤器用于养殖废水生物修复和环境控制的原理、依据、研究现状、修复效果以及应用大型藻类生物滤器产生的效益和存在的问题。     

Potential effect of aquaculture promotion on poverty reduction in Sub-Saharan Africa

There is a policy of increased support of aquaculture development in Sub-Saharan Africa. In the region, aquaculture expansion has the potential to create new jobs and improve food security among poor households. Three computable general equilibrium models were used to estimate the effects of aquaculture expansion and increased input productivity on poverty reduction in Ghana, Kenya, and Tanzania. The results suggest that there will be positive effects on per capita income for all households in Ghana and Kenya. In Tanzania some rich households will experience income loss, because of resource shift from other sectors to aquaculture. Because of reduction in poverty associated with price reductions, and increases in minimum income associated with income expansion, the poverty gap decreased in all household groups. Because of high sectoral linkages, aquaculture development is a potential candidate for sector-specific policy support to address poverty reduction in Sub-Saharan Africa.     

Analyzing Production Feasibility and Market Potential For Florida Aquaculture Catfish Products

A spatiotemporal linear programming model (GAMS) was constructed to simulate the catfish production and marketing system in the U.S. in order to study the economic feasibility of Florida entering the aquaculture catfish industry. Evaluation of base model results and sensitivity analysis were used to identify constraints to the potential expansion of the catfish industry in Florida. Results indicated production and processing costs were more important in determining the locus of production and processing than were processing capacity, storage costs and capacity, and transportation costs. Thus, existing industry geographic concentration is likely to continue, but small new processing plants could develop proximate markets for fresh product.     

Development of inland aquaculture in arid climates: water utilization strategies applied in Israel

Israel has a temperate climate with marked differences between the northern and southern regions. Rainfall ranges between 250 and 600 mm year⁻¹ in the former and between only 25 and 200 mm year⁻¹ in the latter. During the last 30 years, water consumption has increased markedly in all sectors. Although a water allocation for inland aquaculture is made, in most cases it is given the lowest priority, and aquaculturists have learned to contend with difficulties, and thrive on brackish water sources not fit for human consumption or agricultural crops. Since most water sources are already fully exploited, further development of all sectors will depend on their respective capacity to use recycled city water, desalinated brackish or sea water, or recycled pond water. In this respect, inland aquaculture is handicapped by public prejudices which will not allow the use of water from the first source and farms are still not able to cope with the cost of the second. Therefore, further development of inland aquaculture will depend on the capacity of farmers to use sea water, and to recycle pond water time and again to produce more fish with less (inland) water. Various strategies have already been developed in Israel and new ones are under study. These include water harvesting in dual-purpose reservoirs, recycling of pond water from one year to another, development of intensive flow-through systems based on recycled pond water and colleagues based on biofiltration.     

New Species for Coastal Aquaculture in the Tropical Pacific – Constraints, Prospects and Considerations

The proximity of many Pacific countries to seafood markets in Asia, the high value of species associated with coral reefs, and the increased demand for marine aquarium species, has prompted many nations in the region to investigate opportunities for coastal aquaculture. There are, however, several constraints to consider throughout much of the Pacific, including, transport problems, fragile ecosystems, lack of suitable sites, limited economies, and the effects of customary marine tenure on access to growout sites. To overcome these problems, coastal aquaculture in the Pacific will need to focus either on species of high value, or those that yield non-perishable products. Valuable industries have been established for pearl oysters, penaeid shrimps, and the microalgae, Spirulina, in tropical Australia, the French territories and Hawaii, whereas enterprises for cultured giant clams, milkfish (Chanos chanos) as tuna bait, the macroalgae, Eucheuma, and sponges are emerging in the small island developing states. Species demanded by the aquarium trade, groupers for live reef fish markets, tropical abalone (Haliotidae), mangrove crabs (Scylla spp.) and a variety of invertebrates as sources of bioactive compounds are promising new species for intensive farming. Aquaculture technology is being applied to the restocking and stock enhancement of valuable, sedentary species low in the food chain, and there are active programmes in several small island developing states to assess the scope for releasing cultured giant clams, trochus, green snail and sea cucumbers to replenish and enhance wild stocks. There is a growing awareness that the potential benefits of increased aquaculture, restocking and stock enhancement need to be balanced by the risks associated with culturing additional species, i.e. introduction of diseases, dilution of gene pools and increased biological interactions with other species, and that sustainable aquaculture, restocking and stock enhancement are most likely to be achieved with responsible application of technology and the use of indigenous species.     

Interactions and management for the future of marine aquaculture and capture fisheries

Aquaculture surpassed wild fisheries as the largest supplier of fish for human consumption in 2014 and is expected to supply the majority of seafood for future increases in demand. Marine and coastal aquaculture, collectively referred to as mariculture, currently represents just 36% of aquaculture production but is poised to expand in the decades ahead. One of the most commonly cited concerns regarding this likely expansion is ecological and socioeconomic interactions with wild‐capture fisheries. While attention has largely been drawn to high‐profile negative externalities from fed finfish and crustacean mariculture, not all marine‐based practices are equivalent. Empirical evidence for the different interactions between mariculture and wild fisheries is often sparse. While negative consequences can arise, positive synergies can also occur. By considering mariculture development in the context of fisheries interactions, we suggest that it is possible to minimize conflicts and maximize positive connections between the two sectors. We provide the first comprehensive synthesis of the interactions between mariculture and wild fisheries, characterizing the types of interactions, evaluating available empirical evidence and identifying where management (sector‐specific and cooperative) can play an important role. We highlight potential effects of mariculture on the efficiency, sustainability, and equity of seafood production and identify remaining knowledge gaps.     

Effects of seasonal variations in meteorology and oceanography on the Brazilian sardine fishery

Seasonal variations in meteorological and oceanographic processes in the South Brazil Bight were studied to assess their influence on the Brazilian sardine Sardinella brasiliensis fishery. According to its environmental characteristics, the South Brazil Bight was divided into three sectors. The northern and southern sectors were similar during the spring and summer, showing areas of coastal upwelling and low rainfall rates. The middle sector was characterized by the presence of low-salinity coastal waters in the inner shelf and by high rainfall. During autumn and winter, the middle and southern sectors were similar, both being under the influence of sub-Antarctic waters. Multiple regression analyses showed significant correlation between environmental data and catches, although at a lower level in the northern sector ( r ² = 0.57). In the middle and southern sectors, environmental data were highly correlated with the catches ( r ² = 0.90 and 0.84). The sardine landings in the middle sector are principally affected by meteorological parameters, and in the south by oceanographic ones. In the middle sector, an inverse correlation between landings and rainfall is shown, while in the south, landings are positively correlated with salinity and sea temperature. The conclusion is that the seasonal landings of the Brazilian sardine within the South Brazil Bight are influenced by the distribution of less saline waters, the coastal waters and sub-Antarctic waters.