Modeling impact of culture facilities on hydrodynamics and solute transport in marine aquaculture waters of North Yellow Sea

An increasing number of marine aquaculture facilities have been placed in shallow bays and open sea,which might significantly affect hydrodynamic and solute transport processes in marine aquaculture waters.In this study,a coupled hydrodynamic and solute transport model was developed with high-resolution schemes in marine aquaculture waters based on depth-averaged shallow water equations.A new expression of drag force was incorporated into the momentum equations to express the resistance of suspended culture cages.The coupled model was used to simulate the effect of suspended structures on tidal currents and the movement of a contaminant cloud in the marine aquaculture of the North Yellow Sea,China.The simulation results showed a low-velocity area appearing inside the aquaculture cage area,with a maximum reduction rate of velocity close to 45%under high-density culture.The results also showed that tidal currents were sensitive to the density of suspended cages,the length of cages,and the drag coefficients of cages.The transport processes of pollutants inside aquaculture facilities were inhibited away from the vicinity of the culture cage area because of the diminished tidal currents.Therefore,the suspended cages significantly affected the transport processes of pollutants in the coastal aquaculture waters.Furthermore,the reduced horizontal velocity significantly decreased the food supply for the aquaculture areas from the surrounding sea.

The Impact of Marine Aquaculture on the Environment;the Importance of Site Selection and Carrying Capacity

A growing increase in the world’s population and a gradual decline in poverty necessitate a search for new sources of protein in order to guarantee food security. Aquaculture has been identified as a potential sector capable of meeting the requirements for increased protein production without making excessive demands on the ecosystem. Although water makes up 70% of the earth’s surface, aquaculture cannot feasibly be practised everywhere;it requires a unique set of natural, social and economic resources to be managed in an environmentally responsible way. Finding suitable sites for aquaculture is becoming an ever increasing problem in the development of the sector as precautions need to be taken in setting up sites to ensure appropriate environmental characteristics exist and that good water quality can be maintained. Additionally, the effects of aquaculture on coastal and inland resources must be clearly determined to implement policies and regulatory frameworks to control its impact. Marine cage farming is gaining momentum, specifically in the Mediterranean and Black Sea coastal regions. For these sites to be further developed there is a need to minimize the effects on the environment and conflicts with other coastal users. To this aim the concept of allocated zones for aquaculture (AZA) is being adopted to provide specific areas for marine aquaculture to avoid environmental degradation. When choosing an (AZA) suitable site, it is vital to calculate ‘carrying capacity’ to reduce the risks and to protect the marine ecosystems. In this study the MERAMOD model was used to investigate the carrying capacity of marine fish farms. Modelling offers the possibility to simulate and predict the environmental impact of fish farms.

Training Mode of Aquaculture Professionals in Local Applied Marine Colleges and Universities

In the training of aquaculture professionals,there are problems such as unreasonable structure of teachers,unclear understanding of aquaculture by parents and students,poor practical ability of students,lack of grass-roots aquaculture talents,and imperfect multi-party cooperation training mechanism.In view of the above situation,the training mode of applied talents in aquaculture needs to be reformed and innovated.In this paper,some measures to establish the training mode of aquaculture professionals were proposed,including strengthening students’correct understanding of the major,improving the curriculum system for cultivating applied talents,establishing a training model for practical teaching,improving the practical ability of teachers,increasing the provision of high-quality educational resources,and adopting school-enterprise cooperation,so as to cultivate high-quality and high-tech aquatic talents under the training mechanism of applied talents.

Current Situation and Problems of Marine Fishery in China

Marine fishery plays an essential role in promoting the employment of labor force,ensuring food safety,promoting the construction of ecological civilization and safeguarding the maritime rights and interests. The development of marine fishery is of great significance. This paper analyzed the current situation and existing problems of marine fishery in China and came up with some pertinent recommendations and measures. The area of marine fishery with authentic right is increasing year by year,and pelagic fishery constantly grows and the industrial structure is becoming more and more reasonable. However,there are still problems such as serious pollution of marine environment,frequent occurrence of marine disasters,shrinking space of fishery development,which seriously affect healthy development of the marine fishery. In this situation,it came up with recommendations including strengthening monitoring of marine fishery resources and protection of marine environment,optimizing the industrial structure,and raising the scientific and technological level of marine fisheries,to protect the sustainable development of marine fishery. It is expected to provide references for the development of marine fishery in China.

Potentiality of Bioconverted Leafy Vegetable Waste as Aquaculture Feed Supplement

Purple non-sulfur bacteria (PNSB) are well known for their ability in transforming organic substrates for their own source of nutrients. The nutritional values of leafy vegetable waste could be improved through bioconversion with PNSB. This study was conducted to access nutritional status of leafy vegetable waste bio-converted product and efficacy of derived product as aquaculture feed supplement. Proximate compositions of bio-converted leafy vegetable wastes were improved after 6 days with 30% inoculums of Afifella marina strain ME (KC205142). The crude proteins (%) and ashes (%) in derived product was increased to 51.7% and 19.6% respectively. On the other hand, the fiber (%) in the bio-converted derived product was decreased by 21%. During feeding trial in Tilapia (Oreochromis niloticus), no significant differences were observed in the feed intake (g/fish/day), but significant differences were observed in the value of feed conversion ratio and weight gain (%) among the used diets. However, lower ingestion rate (g/d/fish) and better feed conversion ratio were obtained while fishes were fed with diet composed of commercial feed mixed with 5% of the bio-converted product. The higher ingestion rate (g/d/fish) and lower feed conversion ratio were observed with only commercial diet. There observed no significant differences in the ingestion rate (g/d/fish) and FCR values among the diet composed of commercial feed with 5% (D5) and 10% (D10) of the bio-converted product. The derived bio-converted product can be a promising approach to open new market segment in aquafeed industry.

Evaluation of the impacts of aquaculture and freshwater habitat on the status of Atlantic salmon stocks in Ireland

Atlantic salmon (Salmo salar) returns to rivers in Ireland have fallen in the last decade resulting in the dramatic closure or curtailment of traditional fisheries. Concerns that stocks were slow to recover prompted further investigation of all factors believed to impact on salmon. In examining geographic and temporal trends in Atlantic salmon stock abundance at a River Basin District level, the effect of salmon aquaculture sites and freshwater habitat quality as potential drivers of stock abundance are evaluated. This study found no correlation between the presence of aquaculture and the performance of adjacent wild salmon stocks. Freshwater habitat quality was found to have a highly significant correlation with stock status, suggesting that it may be a key driver, implicated in the survival of individual stocks.

我国深远海养殖产业发展现状、弱质性分析及高质量发展路径

伴随着我国对海产品需求的持续增长和近海养殖产生问题的日益增多,深远海养殖产业应运而生,成为我国海水养殖产业结构调整和产业升级进程中的新业态,加速促进了水产养殖方式转型升级,形成了海洋养殖模式新发展格局。当前我国深远海养殖产业具有对先进技术的依赖程度高、产业链间相互关联性强、以独特产品定位占据市场份额的产业特征。文章立足深远海产业养殖规模、养殖设备、养殖模式的发展现状,介绍深远海养殖的定义,对比国外发展模式,详细对我国深远海养殖产业展开弱质性分析,并从完善风险预警机制、拓宽养殖产业链、攻克关键技术难题、出台优惠政策和提升科学化繁育水平等方面提出建议,为我国深远海养殖模式的高质量发展提供参考。

基于Sentinel-2A和GF-1B遥感数据的海岸带水产养殖识别方法比较

近海水产养殖为人类提供优质的动物蛋白,对海洋经济高质量发展具有重要意义。卫星遥感技术已被广泛用于海岸带水产养殖的监测,但目前相关的研究聚焦基于单一传感器卫星数据并使用单一信息提取算法而忽略与不同卫星传感器以及处理方法之间的比较。本研究以北莉岛东北部为研究区,基于多光谱Sentinel-2A卫星和高分一号B(GF-1B)卫星数据,分别使用自适应阈值法、支持向量机监督分类法以及多尺度分割面向对象分类法,开展海岸带人工水产养殖区的识别。研究表明,更高空间分辨率的GF-1B卫星对人工水产养殖水网密集区的提取正确率远优于Sentinel-2A卫星;基于高空间分辨率GF-1B卫星,多尺度分割面向对象分类法的正确率最高,为94.65%,优于支持向量机监督分类法的94.45%和自适应阈值法的84.62%;自适应阈值法更适用于中等空间分辨率卫星数据的水产养殖信息提取,其提取的水产养殖水面的面积与目视解译提取的面积差异小于4%。针对单个养殖池使用情况的业务化监测需使用高空间分辨率卫星数据,而大范围水产养殖面积的变化分析则可应用中等空间分辨率卫星数据。

基于浮式风机的海洋清洁能源融合发展

介绍浮式风机在深远海风能资源开发中的优势及国内外研发现状,简述波浪能发电的原理并综述在浮式风机上集成波浪能转换器的最新研究进展,归纳海水制氢的几种途经并梳理海上风电联合海水制氢相关概念设计及发展潜力,分析浮式风机整合海洋养殖笼的水动力特点并例举海上风电联合海洋养殖的试点项目,为基于浮式风机的海洋清洁能源融合发展提供参考。

海水养殖网箱防污损生物技术的研究进展

海水养殖网箱上的污损生物过多时,会影响网箱内外水体的交换、缩短网衣的使用寿命,甚至危害养殖生物的健康。如何解决网箱污损生物的附着成为了海水养殖网箱使用的一个难题。本文简述了国内外海水养殖网箱防污损生物技术的现状,重点介绍了机械清除法、涂料防污法、金属合金网衣防污法等海水养殖网箱防污损生物技术的研究进展,同时指出了当前海水养殖网箱防污损生物技术所面临的问题并给予了建议,旨在为海水养殖网箱的防污损生物技术以及海水养殖业的可持续性健康发展提供参考。

深远海养殖多主体协同创新价值链构建机制研究

深远海养殖是我国发展海洋经济、建设海洋强国的重要手段。我国深远海养殖是以科技创新为基础的新兴技术产业,通过协同创新提升深远海养殖新质生产力是现阶段我国亟须解决的问题。文章运用三级编码的方法,对与深远海养殖相关新闻报道资料进行编码及理论饱和度检验,探索深远海养殖多主体协同创新价值链机制,结果表明:在政府多方位战略布局的支持与指导下,企业通过多主体协同创新获得创新知识,并多方向转化为新产品/服务、新流程、新业态,本质上实现了价值链创新,最终可以获得经济、社会与生态创新效益。

东山湾海带养殖区沉积物中细菌群落结构变化

漳州市东山湾是福建省海带养殖的重要基地之一,对其中一处海带养殖区沉积物中的细菌群落进行了考察,了解在海带不同生长阶段该沉积物中细菌群落的结构组成。调查发现在海区未挂养海带前,该处沉积物中的优势细菌为芽孢杆菌属细菌。在海带生长的凹凸期、薄嫩期、厚成期、成熟期,沉积物中的优势细菌类群分别为类芽孢八叠球菌属、盐芽孢杆菌属、亚硫酸杆菌属、亚硫酸杆菌属细菌。

基于谷歌地球引擎平台的海上养殖信息提取方法研究——以福建省平潭县为例

海上养殖业对粮食安全有着至关重要的作用。然而,海上养殖的无序扩张和开发,阻碍了海上交通,同时也造成了海洋环境问题。为及时、准确地获取海上养殖信息,满足海岸带调查以及推进海上养殖规范化、科学化,提出一种基于谷歌地球引擎(Google Earth Engine, GEE)平台实现长时间序列下海上养殖区信息快速提取的方法。本研究构建了一个基于随机森林分类的海上养殖区信息提取模型,该模型综合利用了Sentinel-1卫星SAR影像数据的VV和VH极化波段,以及Sentinel-2卫星的多光谱影像数据。此外,模型还融合了4个用于增强养殖区特征的指数,以提高养殖区域信息提取的准确性和效率。这种方法的应用旨在优化海上养殖区的识别过程,通过精确分析和利用不同数据源的互补优势,展现了遥感技术在海洋养殖监测领域的巨大潜力。本研究对2017—2021年平潭县海上养殖区域进行判定与提取,实验结果表明,以养殖密度较低,养殖特征不明显为特征的海上养殖区,基于GEE平台的海上养殖区信息提取方法精度在90%以上,表明在复杂水体背景下对养殖区快速识别取得较好的效果,可为海上养殖科学规划与规范化管理提供有效的参考依据。

我国海洋自然保护区养殖活动的生态环境影响及对策建议

我国海洋自然保护区内普遍存在养殖活动,如何促进海洋自然保护区建设与养殖活动协同发展,一直是保护区管理部门与相关利益群体密切关注的问题。结合我国国家级海洋自然保护区的保护目标及养殖活动现状,从保护对象和养殖方式两个方面分析了养殖活动对海洋自然保护区生态环境的可能影响。通过梳理我国海洋自然保护区的养殖活动管理及用海政策,发现海洋自然保护区的养殖活动管理政策不一致、养殖活动管理和海域使用政策缺乏与海洋自然保护区管控相衔接等问题,进而结合新时期自然保护区相关的管控政策要求,提出了细化海洋自然保护区内养殖活动的管控要求、尽快开展海洋自然保护区养殖活动管理试点、加强海洋自然保护区管理、海域管理和渔业管理间协调、加强对海洋自然保护区管理的能力建设等建议,以期为我国海洋自然保护区内的养殖活动管理提供参考,促进海洋自然保护区建设和周边渔业社区的协同发展。

我国水产业高质量发展战略研究

我国是世界第一大水产养殖国,水产业在提供优质和健康食物来源方面发挥了重要作用;在保障国家食物安全的新形势下,践行大食物观、建立食物多元化供给体系对水产业高质量发展提出了重大需求。本文以渔业资源与捕捞、水产养殖与海洋牧场、水产品加工与流通等水产业三大方向为研究划分,通过深入的行业调研、广泛的交流研讨,把握了水产业的发展现状及趋势、存在的主要问题,进而提出了行业发展目标与重点举措。调研发现,近海渔业捕捞压力过大,对远洋与极地资源认知不强、技术与装备能力薄弱,养殖机械化、自动化、智能化水平低,优质饲料原料依赖进口,智慧渔业的基础软硬件能力存在短板,水产品加工能力滞后;建议实施近海渔业资源养护和修复、远洋渔业资源开发与科学利用、水产健康养殖新技术体系构建与应用、深远海养殖平台技术研发与应用、水产养殖新模式构建与推广、水产品绿色加工与高值利用等重点举措。通过水产业高质量发展,力争2035年迈入水产科技强国行列并生产水产品8.1×107 t,2050年全面实现智慧渔业并生产水产品1×108 t。

Marine aquaculture regulates dissimilatory nitrate reduction processes in a typical semi-enclosed bay of southeastern China

Marine aquaculture in semi-enclosed bays can significantly influence nutrient cycling in coastal ecosystems.However,the impact of marine aquaculture on the dynamics of dissimilatory nitrate reduction processes(DNRPs)and the fate of reactive nitrogen remain poorly understood.In this study,the rates of DNRPs and the abundances of related functional genes were investigated in aquaculture and non-aquaculture areas.The results showed that marine aquaculture significantly increased the denitrification(DNF)and dissimilatory nitrate reduction to ammonium(DNRA)rates and decreased the rate of anaerobic ammonium oxidation(ANA),as compared with non-aquaculture sites.DNF was the dominant pathway contributing to the total nitrate reduction,and its contribution to the total nitrate reduction significantly increased from 66.72%at non-aquaculture sites to 78.50%at aquaculture sites.Marine aquaculture can significantly affect the physicochemical characteristics of sediment and the abundances of related functional genes,leading to variations in the nitrate reduction rates.Although nitrate removal rates increased in the marine aquaculture area,ammonification rates and the nitrogen retention index in the aquaculture areas were 2.19 and 1.24 times,respectively,higher than those at non-aquaculture sites.Net reactive nitrogen retention exceeded nitrogen removal in the aquaculture area,and the retained reactive nitrogen could diffuse with the tidal current to the entire bay,thereby aggravating N pollution in the entire study area.These results show that marine aquaculture is the dominant source of nitrogen pollution in semi-enclosed bays.This study can provide insights into nitrogen pollution control in semi-enclosed bays with well-developed marine aquaculture.

多营养层次养殖的海水池塘水体理化因子变化与富营养状况评价

2020年10月至2021年4月,在漳浦县佛昙湾垦区对“鱼-虾-贝”多营养层次养殖的海水池塘水体进行采样分析。研究结果显示,养殖过程中,各池塘水温变动范围为17.8~25.5℃;盐度变动范围为33.1~35.2,偏高且较为稳定;pH值变动范围为7.94~9.46,先下降后趋稳;溶解氧变动范围为7.46~10.43 mg/L,水体溶解氧充足;化学需氧量变动范围为0.57~4.57 mg/L,总体呈上升趋势。无机氮含量变动范围为0.03~0.18 mg/L,均处于低值;活性磷酸盐含量变动范围为0.009~0.208 mg/L,在养殖后期剧增;氮磷比变动范围为0.68~17.22,呈先升后剧降趋势。养殖水体营养状况从初期的贫营养状态演变为后期的氮限制潜在性富营养化。

基于U 2-Net深度学习模型的沿海水产养殖塘遥感信息提取

针对近海沿岸复杂地理环境中“同谱异物”效应导致传统方法提取水产养殖塘边界模糊、精度较低的问题,提出了基于U 2-Net深度学习模型的沿海水产养殖塘遥感信息提取方法。首先,对遥感影像进行预处理,选择合适的波段组合方式以区分养殖塘和其他地物;其次,通过目视解译进行样本制作;然后,利用U 2-Net深度学习模型训练并提取沿岸养殖塘;最后,利用局部最佳法确定养殖塘范围。实验结果表明,该方法平均总体精度达到95.50%,平均Kappa系数、召回率和F值分别为0.91,91.45%和91.01%;在养殖塘个数及面积评价方面,提取出养殖塘区19块,共计9.79 km^(2),区块数和面积的平均准确度分别为94.06%和93.18%。本研究能够快速、准确地开展海岸带区域养殖塘制图,能够为海洋资源管理和可持续发展提供技术支持。

中国海水养殖业绿色发展评价与时空演化特征

基于海水养殖业绿色发展的理论内涵,从环境友好、经济高效、绿色技术创新、空间拓展4个维度构建综合评价指标体系,对2004—2020年中国沿海9省(区)海水养殖业绿色发展水平进行测度。运用变异系数法、障碍度模型,深入分析中国海水养殖业绿色发展的区域差异和主要障碍因素。结果表明:(1)研究期内中国海水养殖业绿色发展整体水平呈波动上升趋势,在空间上逐渐形成了以山东、江苏、海南为核心的北部、东部、南部沿海地区三足鼎立的海水养殖业绿色发展格局。(2)研究期内中国海水养殖业绿色发展水平的区域差异正在逐步扩大,其差异主要来源于经济高效维度。(3)中国海水养殖业绿色发展的主要障碍因素来自经济高效和空间拓展维度,并且空间拓展维度上的障碍度仍有增大趋势。

小竹山岛海洋牧场区营养盐分布特征及增养殖适宜性探究

营养盐作为海水生物的基本生源要素,其含量与分布显著影响渔业资源分布与渔业活动。为了探究海洋牧场生态环境分布状况,并为海洋牧场的开发管理提供科学指导,于2017年12月—2018年9月对小竹山岛海洋牧场区进行4个航次的季度调查,分析并讨论了该海区营养盐分布特征,并针对虾夷扇贝(Patinopecten yessoensis)和深水网箱增养殖活动,选取海水营养水平指数、叶绿素a浓度、温度、盐度、水深和底质类型等指标,对增养殖适宜性进行了探究。结果显示,活性磷酸盐(DIP)浓度为冬季>夏季>秋季>春季,浓度值分别为0.032、0.021、0.017和0.015 mg/L。无机氮(DIN)浓度为秋季>冬季>夏季>春季,浓度值分别为0.26、0.21、0.20和0.18mg/L。DIP和DIN浓度在4个季节间差异明显,但季节内分布均匀。受到地形坡度和人工鱼礁投放的影响,在人工鱼礁投放区域的中下层水体有较高的营养盐浓度。增养殖适宜性结果显示,虾夷扇贝增养殖适宜性指数在冬季和夏季较高,适宜在海洋牧场西部区域进行增养殖活动。深水网箱增养殖适宜性指数在夏季和秋季较高,也适宜在西北区域进行增养殖活动。由于人工鱼礁投放改善了生态环境,除西北海域外,在人工鱼礁投放区域附近出现较高的增养殖适宜性指数。海水营养盐分布与增养殖活动适宜性评价可为提高海洋牧场增殖效率、促进可持续发展及开发提供科学依据与参考。