中国水产养殖产业演化影响因素研究

水产养殖业在我国渔业产业结构中占据重要地位,在促进我国渔业经济发展中发挥着重要作用。当前渔业正处于由要素驱动向创新驱动转型的新旧动能转换时期,这也对水产养殖业的转型升级提出了更高要求。文章根据产业演化路径及其运行机理,从资源、技术、市场、制度4个方面构建指标体系,采用1998—2019年的指标数据,通过灰色关联分析和岭回归分析,探索影响产业演化的因素,探讨不同影响因素对水产养殖业演化发展的影响程度,以期为促进中国水产养殖产业的发展,增强水产养殖业的竞争力提供理论支撑。结果表明,城镇居民人均水产品消费量对中国水产养殖产业演化影响程度最大,GDP及单位面积产量的影响显著,水产技术推广经费支出影响最小。基于此,为促进我国水产养殖业的转型升级提出做好水产品消费需求引领与管理、拓展国内国际消费市场;增加科技投入,发展养殖技术;加大资源保护力度,推进绿色发展;着力解决养殖水产品质量安全问题等相应对策建议。     

UK macroalgae aquaculture: What are the key environmental and licensing considerations?

Macroalgae has numerous commercial uses and the potential to create large carbon sinks. The study reviewed the legal context, including environmental and social aspects, for the setting up of a seaweed farm in the UK. A lease is required to use the seabed and a Marine Licence is required from the national regulator. There is no need for new legislation, however, the existing guidance should be updated. There is a major need to clarify what level of assessment is required as part of the marine licensing process. The environmental and social considerations to licensing were also reviewed. Changes to the hydrodynamics and sediment transport are expected in and around the farm. These may lead to changes in seabed siltation and light levels. The addition of hard substrate (from the anchors) and a macroalgae canopy lead to attraction of benthic animals, fish, marine mammals and birds. These, in addition to potential changes in organic matter and nutrients reaching the seabed from exudate and detritus, could create changes in existing benthic communities on the seafloor. No reason for major population-level impacts were seen. However, numerous knowledge gaps where identified. Scale appears to be an important consideration. A small farm on its own is unlikely to have a large effect on the marine environment. However, a very large farm, or multiple small farms next to each other could have a more notable effect. Knowledge gaps were identified and recommendations were provided that can assist the development of the UK macroalgae farming industry.     

Energy prices and seafood security

Fish resources are critical to the food security of many nations. Similar to most contemporary food systems, many fisheries and aquaculture resource supply chains are heavily dependent on fossil fuels. Energy price increases and volatility may hence undermine food security in some contexts. Here, we explore the relationships between energy price changes, fish resource supply chain viability, seafood availability and food security outcomes – both for producers and consumers of fish resources. We begin by characterizing the energy intensities of fish resource supply chains, which are shown to be highly variable. We subsequently assess the comparative magnitude and distribution of potential food security impacts of energy price increases for nation states by scoring and ranking countries against a set of vulnerability criteria including metrics of national exposure, sensitivity and adaptive capacity. Considerable variability in the vulnerability of populations and high levels of exposure for already food-insecure populations are apparent. Developed countries are likely to be most exposed to the effects of energy price increases due to their high rates of fleet motorization and preference for energy-intensive seafood products. However, heavy reliance on seafood as a source of food and income, as well as limited national adaptive capacity, translates into greater overall vulnerability in developing countries. At the level of individual producers, a variety of adaptation options are available that may serve to reduce vulnerability to energy price changes and hence contribute to increased food security for producers and consumers, but uptake capacity depends on numerous situational factors.     

Invasion genetics of Pacific oyster Crassostrea gigas shaped by aquaculture stocking practices

As a result of aquaculture activities Pacific oysters Crassostrea gigas (Thunberg, 1793) have invaded the European Wadden Sea. Using a variable noncoding mitochondrial marker, we show that the invaded range is the result of two independent invasions. Haplotype frequencies point towards two separate groups, one in the southern and the other in the northern Wadden Sea. We found virtually no genetic differentiation throughout the southern range and the putative source from British Columbia, Canada, suggesting that the Southern region can be considered as a closed population. In the North, mismatch distributions, haplotype ordination and isolation-by-distance analysis suggest a stronger, persistent impact of aquaculture on invasive populations. Due to the ongoing supply of new genetic material from hatchery production the northern invasive populations can therefore be considered as an open population highlighting the importance of aquaculture practice on the genetics of this keystone invader in the Wadden Sea.     

Work segmentation in the Norwegian salmon industry: The application of segmented labor market theory to work migrants on the island community of Frøya,Norway

Work migration is increasing in Norway, particularly in the production sector of the aquaculture industry. This sector is growing rapidly and manual labor needed in the industry is consistently being sought through Eastern European networks and temp-agencies. This article looks at the island community of Frøya, in Sør Trøndelag in Norway, where around 20% of the population is of foreign descent, and where stakeholders in the production line experience a lack of upward mobility due to their lack of Norwegian language skills, and the insecure nature of their employment status. The capacity of the island community to adapt to a 3-fold increase in aquaculture production will depend on this segment of society as well being able to adjust, and on their inclusiveness in society. Based on a stakeholder driven workshop looking at the perceptions of a set of foreign workers in the aquaculture industry,segmented labor market theory was applied to the experience of the workers. The priority issues of the migrant population of Frøya involved in the aquaculture industry was also explained, and their wish for upward mobility and job security, as well as inclusiveness in society elaborated upon. This upward mobility, however, would lead to the bottom segment of the labor market on Frøya – the aquaculture production line – to have to be filled with another lower segment group of workers.     

混合溶液浓度线性图解法及其在水产养殖中的应用

提出一种关于同质溶液混合的浓度或溶液量任意项求解的线性图解法，并阐明其在水产养殖的换水水质控制和盐度调节方面的应用。     

Effect of sea cucumber (Australostichopus mollis) grazing on coastal sediments impacted by mussel farm deposition

Deposit-feeding holothurians are important processors of surface sediments in many coastal marine systems. The present study examined the effect of grazing by the sea cucumber Australostichopus mollis on sediment impacted by green-lipped mussel biodeposits (faeces and pseudofaeces) from coastal aquaculture activities. Grazing effects were investigated in a series of tank-based feeding experiments conducted over 1, 2, 4 and 8 week periods. Sediment quality indicators routinely applied to determine the impacts of coastal aquaculture were used to evaluate sediment health from grazed and ungrazed sediments. Sea cucumber grazing resulted in reductions in total organic carbon, chlorophyll a and phaeopigment, as well as chlorophyll a/phaeopigment ratio of impacted sediments. These results demonstrate that sea cucumber grazing significantly reduces the accumulation of both organic carbon and phytopigments associated with biodeposition from mussel farms. Sea cucumber grazing offers a means of constraining or reversing the pollutive impacts of coastal bivalve aquaculture.     

间歇施肥对龙须菜的生长和化学组成的影响

于１９８４年５－７月在青岛麦岛氮营养盐贫瘠的海区,对人工养殖的龙须菜进行间歇施肥现场实验。结果表明,龙须菜可以在短时间里快速吸睡氮盐并累积在藻体内以用于生长;经间歇施肥的藻体生长较快,产量较对照组的高８８％;藻化学组成分析结果显示,龙须菜体内含氮化合物和碳水化合物组成呈现负相关变化,存在氮低糖高,糖低氮高的现象。以上结果提示对氮盐贫瘠海区人工养殖的龙须菜间歇施肥,可以促进藻体生长,提高产量;在养殖     

Norwegian salmon-farming industry in transition: dislocation of decision control

There are three milestones in the organization of the Norwegian salmon-farming industry (NSFI). In 1969 the net-pen production technology was established, and formed the basis for all further organization. In 1978, the Fish-Farmers Sales Organization (FSO) was established, and the organizational and institutional apparatus were thus complete. In 1991 the FSO went bankrupt and major amendments in the aquaculture legislation - such as the removal of the ownership regulation - were made. This three-step development is analyzed along two dimensions: the effect of dislocation of decision control from the local level to remote actors, and the changes in the government's aquaculture policy. During the last 20 years the NSFI has changed from a single farm locally-owned industry to a structure of large corporations, while the governments' policy has changed from support to neutral tasks such as control and surveillance. In sum the local residents use rights of coastal areas is severely reduced.     

Distribution patterns of macrobenthic species in relation to organic enrichment within aquaculture earthen ponds

The relationship between organic enrichment and macrobenthic colonization patterns was investigated during an 8-month period in Diplodus sargus (white seabream) production ponds. A stratified sampling design was applied and each pond was divided into three zones: water entrance (WE); central (C); and automatic feeder zones (AF). Generally, the number of species and Shannon–Wiener diversity increased from the WE to the AF zone. Abundance did not present a clear trend. The recently developed marine biotic index (AMBI) was applied and showed to be sufficiently robust to discriminate, within a relatively small area, differences in macrobenthic communities due to organic enrichment. Nevertheless, caution is advised when applying this index or others based on ecological group’s assignment, as the classification of a certain area may differ when allocating a certain species to an unsuitable group. This is particularly evident when common species are involved.