Ecological Studies on the Nanoflagellates in Sanggou Bay

桑沟湾是我国北方重要的海水养殖海湾。从湾顶到湾口分别是贝类养殖区和藻类养殖区。本研究选择桑沟湾作为研究区域对养殖海区微型鞭毛虫的生态学进行研究。首先，于2011年春季，2011年夏季，2011年秋季和2012年冬季分别对桑沟湾微型鞭毛虫的时空分布、粒径结构和营养结构进行调查。而后，通过围隔实验研究贝、藻养殖对微型鞭毛虫的影响。根据围隔实验的结果设置营养盐添加实验和贝类摄食实验以探讨围隔实验中贝类增强微型鞭毛虫及其相关环节作用的原因。同时，本研究还探讨了微型鞭毛虫对微微型浮游生物的摄食。主要结果如下： （1）桑沟湾微型鞭毛虫以2-5μm微型鞭毛虫为主，微型鞭毛虫的总丰度的年变化范围从0.31×...Sanggou Bay in northern China is an important mariculture bay. The bay could be divided into the bivalves culture areas (B-area) and the macroalgae culture areas (M-area) from the bay head to the bay mouth. The ecological studies on the nanoflagellates (NF) in Sanggou Bay were conducted in the present study. Firstly, the spatial and temporal distributions, the size structure and the trophic struct...学位：理学博士院系专业：海洋与环境学院_海洋生物学学号：2242010015359

Simulated Study on the Nitrogen Nutrient Regeneration of Heterotrophic Nanoflagellates in Sanggou Bay

微型异养鞭毛虫（Heterotrophicnanoflagellates，HNF）是海洋异养细菌和聚球藻的主要捕食者，是海洋微食物环氮、磷营养盐再生过程的关键环节，同时也是海洋氮、磷元素生物地球化学循环过程中重要的环节。对其氮营养盐再生机制的深入研究和全面了解，是人们认识海洋微食物环乃至整个海洋生态系统的重要一步。然而，受到微型鞭毛虫研究方法的限制，目前对该领域的研究还不足。因此，通过室内模拟研究构建一套有效的估算模型，对人们更好地认识微型异养鞭毛虫在微食物环以及海洋生态系统中所扮演的角色具有重要意义。 本研究通过分子生物学技术结合显微观察法对一种微型异养鞭毛虫进行种类鉴定，并通过实验模拟研...Heterotrophic nanoflagellates (HNF) are major grazers of heterotrophic bacteria and Synechococcus,and also are the important conctributors to the regeneration of nutrient in the sea. To figure out the role of HNF in nitrogen regeneration would be helpful to understand the structure and function of the microbial food web and even the marine ecosystem. However, due to the limitation of research app...学位：理学硕士院系专业：海洋与地球学院_海洋生物学学号：2232012115132

L'aquaculture a-t-elle le potentiel pour devenir la « biotechnologie bleue » dans l'avenir?

L'aquaculture est passée d'une contribution insignifiante de moins de 10 % de la quantité de produits aquatiques destinés à la consommation humaine dans les années 1970 à environ 50 % à l'heure actuelle. Les attentes sont élevées pour couvrir d'autres besoins dans l'avenir alors que les captures de la pêche stagnent et que les besoins de l'homme augmentent. Cet article passe en revue l'état de l'aquaculture, son expansion d'une production destinée à satisfaire une demande locale à une demande commerciale mondialisée, et examine comment l'approche empirique des besoins du passé doit être complétée par la science et la technologie, non seulement pour répondre aux attentes mais aussi pour rendre la production aquacole plus écologique et durable. Ce document est établi à partir d'une évaluation des besoins pour le développement durable préparée pour la Conférence mondiale de la FAO sur l'aquaculture (septembre 2010, Phuket, Thaïlande)

A geochemical record of environmental changes in sediments from Sishili Bay, northern Yellow Sea, China: Anthropogenic influence on organic matter sources and composition over the last 100 years

Total organic carbon (TOC), total nitrogen (TN), delta C-13 and delta N-15 were measured in sediment cores at three sites in Sishili Bay, China, to track the impacts of anthropogenic activities on the coastal environment over the last 100 years. The increased TOC and TN in the upper section of sediment cores indicated a eutrophic process since 1975. In comparison, the TOC and TN in the sediment core near to a scallop aquaculture area displayed a much slower increase, indicating the contribution of scallop aquaculture in mitigating eutrophication. Combined information from delta C-13, delta N-15 and TOC:TN indicated an increased terrestrial signal, although organic matter sources in Sishili Bay featured a mixture of terrestrial and marine sources, with phytoplankton being dominant. Increased fertilizer use since 1970s contributed to the eutrophic process in Sishili Bay since 1975, and increased sewage discharge from 1990s has added to this process. (C) 2013 Elsevier Ltd. All rights reserved.Total organic carbon (TOC), total nitrogen (TN), delta C-13 and delta N-15 were measured in sediment cores at three sites in Sishili Bay, China, to track the impacts of anthropogenic activities on the coastal environment over the last 100 years. The increased TOC and TN in the upper section of sediment cores indicated a eutrophic process since 1975. In comparison, the TOC and TN in the sediment core near to a scallop aquaculture area displayed a much slower increase, indicating the contribution of scallop aquaculture in mitigating eutrophication. Combined information from delta C-13, delta N-15 and TOC:TN indicated an increased terrestrial signal, although organic matter sources in Sishili Bay featured a mixture of terrestrial and marine sources, with phytoplankton being dominant. Increased fertilizer use since 1970s contributed to the eutrophic process in Sishili Bay since 1975, and increased sewage discharge from 1990s has added to this process. (C) 2013 Elsevier Ltd. All rights reserved

Development of bivalve farming as a source of income generation for women’s self-help groups in coastal India

The existing technologies of mussel and oyster farming were converted into an income-generating activity for coastal fishers, particularly for women’s self-help groups. As a result of a concerted approach, coupled with novel extension techniques, commercial mussel and oyster farming became established in the States of India, Kerala and susequently in Karnataka. Production in 2009 was over 20 000 tonnes making India one of the top ten bivalve farming countries in Asia. Innovations in these bivalve farming technologies simplified them, which resulted in an increase in profitability and made them attractive to farmers. During this process, the entire gamut of bivalve farming operations such as site identification, seed and spatfall calendars, remote setting, mechanization in seeding and harvesting, quality and depuration protocols, ready-to-eat and ready-to-cook products, organic farming protocols and environmental impact assessments were worked out. The success in commercializing the technologies was mainly a result of a unique synergy that was actively pursued and developed by technology developers, promoters, and credit advancers. This development scenario can serve as a role model for other states and developing nations where a similar hydrological, social, and market environment exists

Global sensitivity analysis of an end-to-end marine ecosystem model of the North Sea : factors affecting the biomass of fish and benthos

Comprehensive analysis of parameter and driver sensitivity is key to establishing the credibility of models of complex systems. This is especially so for models of natural systems where experimental manipulation of the real-world to provide controlled validation data is not possible. Models of marine ecosystems fall into this category, but despite the interest in these models for evaluating the effects of climate change and fishing on nutrient fluxes and the abundances of flora and fauna, none have yet been subjected to global sensitivity analysis. Here we present results of both local ‘one-at-a-time’ (OAT), and variance based global sensitivity analyses (GSA) of the fish and fishery aspects of StrathE2E, an end-to-end (nutrients to birds and mammals) ecosystem model of the North Sea. The sensitivity of the model was examined with respect to internal biological parameters, and external drivers related to climate and human activity. The OAT Morris method was first used to screen for factors most influential on model outputs. The Sobol GSA method was then used to calculate quantitative sensitivity indices. The results indicated that the fish and shellfish components of the model (demersal and pelagic fish, filter/deposit and scavenge/carnivore feeding benthos) were influenced by different sets of factors. Harvesting rates were directly influential on demersal and pelagic fish biomasses. Suspension/deposit feeding benthos were directly sensitive to changes in temperature, while the temperature acted indirectly on pelagic fish through the connectivity between model components of the food web. Biomass conversion efficiency was the most important factor for scavenge/carnivorous feeding benthos. The results indicate the primacy of fishing as the most important process affecting total fish biomass, together with varying responses to environmental factors which may be relevant in the context of climate change. The non-linear responses and parameter interactions identified by the analysis also highlight the necessity to use global rather than local methods for the sensitivity analysis of ecosystem models

Numerical study on the hydrodynamic background in coastal aquaculture dominated regions and corresponding interactions in the Yellow Sea

The Yellow Sea is an important region for aquaculture in China as the main production area for shellfish and seaweed. The aquaculture organisms sometimes can be the major group in a local ecosystem. e.g., in the Sanggou bay where about 84,500 tonnes of kelp (dry weight) and 100,000 tonnes of shellfish (wet weight) are produced annually from a surface area of ~144 km2 (Zhang et al., 2009; Mao et al., 2018). To maintain the development of the aquaculture industry at such scales and to minimize the negative impact on the natural ecosystem, the knowledge of the biological processes at different scales is necessary for decision-makers in the formulation of policy and management strategies. However, a comprehensive description of the biogeochemical process in the aquaculture-affected regions can be highly complicated. Observations are often limited in time and space to fully describe the environmental variations in the aquaculture areas. Numerical models are capable of resolving the ecosystem processes at an often sufficient spatial and temporal scale, but with an increasing complexity from current models describing the physical environment to ecosystem models trying to describe complicated and often less known processes. In this thesis, we have implemented a hydrodynamic model based on the Regional Ocean Modelling system (ROMS) to provide the background physical information for aquaculture related applications, the Yellow Sea Model. We have collected various observations to validate the model, and the results do reproduce reasonably well the ambient environment in aquaculture areas. The tide is the dominating current component in the Yellow Sea, moving the water back and forth continuously. The tide also provides energy on the shallow shelves creating usually well mixed water masses. In the summer, a tidal mixing front is established around the 20-50 m isobaths bordering on the Yellow Sea bottom cold water mass below the seasonal thermocline in the central Yellow Sea. An associated frontal jet flows along the tidal mixed front, transporting water masses along the shelf breaks. The tidal current also make the tidal mixing front oscillate laterally creating temporal temperature variations in the farm regions of bottom cultured scallops. The assessment index derived from these temperature oscillations is correlated to a massive scallop mortality found in the past years. Our model results are also applied to study the baroclinic tides in the northern Yellow Sea, with a semi-diurnal internal tide being present in the stratified waters in the tidal mixing front region. The baroclinic flow associated with this internal tide contributes to enhance the total current in the bottom layer, thus potentially being important for material transportation to farmed scallops. The baroclinic signals are mostly coherent with the barotropic tides, indicating a local generation and a rapid dissipation. Finally, we have established an ecosystem model for the integrated culture of Pacific oyster Crassostrea gigas and kelp Saccharina japonica in Sanggou bay based on a box model concept. The growth of oysters and kelp is simulated at the individual level based on the dynamic energy budget theory. The hydrodynamic information is included as forcing data to compute volume transportation and nutrient exchange. The model is validated with individual growth data recorded in the aquaculture field and water quality data for nutrients from cruises and mooring devices. The model results show that the intensive aquaculture of these low-trophic species is dominant in the local ecosystem and dramatically impacts the phytoplankton population and nutrient flux. The bay acts as a nitrogen sink during the rapid growth stage of kelp from early spring until the harvest in May. The model enables a stocking density adjustment of the culture organisms, thus providing a tool to predict the dynamic process under different scenarios. The model results support that the actual aquaculture stock density, with 50 oyster ind./m2 and 4 kelp ind./m2, is a balanced choice of production and cost based on decades of practical experience.Doktorgradsavhandlin

The impacts of suspended mariculture on coastal zones in China and the scope for Integrated Multi-Trophic Aquaculture

Introduction: China is responsible for more than 60\% of global aquaculture production. As the frontiers of food production have expanded, the cultivation of marine organisms in coastal zones and the open ocean has grown rapidly. The dominant mariculture industry in China is suspended mariculture, which uses net cages, ropes, or other structures suspended in the water column to cultivate aquatic organisms. This systematic, quantitative review provides a clear and comprehensive account of research that has investigated the adverse impacts of suspended mariculture in China and reviews research that has applied Integrated Multi-Trophic Aquaculture (IMTA) systems for mitigating impacts. This work builds on 218 peer reviewed papers that have been published in English-language journals. Outcomes: Eighteen impacts were identified, including chemical, ecological, physical, and socioeconomic impacts. Eighteen measures for improving suspended mariculture were recommended consisting of government department, farm management, and ecological engineering measures. IMTA was the most frequently recommended measure. The capabilities of IMTA for bioremediation and increased farm production were the most frequently studied advantages. Seven other benefits have been explored but remain understudied. The current challenges facing the expansion of commercial IMTA include limited use of new technology, limited skills development, decreasing production of low trophic-level species, biogeographic and temporal barriers, and negative system feedbacks. Conclusion: Despite challenges, implementing commercial IMTA is a promising measure for reducing the impacts of suspended mariculture because it presents a range of secondary benefits that can improve the overall sustainability of aquaculture in the coastal zone

Transdisciplinary, co-designed and adaptive management for the sustainable development of rongcheng, a coastal city in China in the context of human activities and climate change

Half the population of China live in coastal zones where 70% of large cities are also located. Intensive human activities pose significant environmental and ecological hazards to these cities that are already vulnerable to natural hazards and climate change. The sustainable development of coastal cities is thus both a national and international issue. Rongcheng is a typical coastal city in east China. It is a national marine ranch demonstration area that is subjected to multi-stressors from human activities and climate change. The dominant economic sectors include aquaculture and fisheries, agriculture, shipping and tourism. A multitude of resulting pressures come mainly from intensified human activities, such as intensive aquaculture, overfishing, industrial pollutants, agricultural runoff, land reclamation and port expansion. In addition, Rongcheng is also facing exogenic pressures from extreme climate events such as intensified storms, storm surges, droughts and sea ice. A growing awareness of these problems brought together a trans-disciplinary group from local government, research institutions, local practitioners and coastal representatives to jointly explore and co-design adaptive coastal management options. In this transdisciplinary study, a social-ecological analysis based on a combination of the Systems Approach Framework and the Drivers-Pressures-States-Impacts-Responses framework was used to analyze and formulate an adaptive management plan for the sustainability of Rongcheng. More than 40 stakeholders including government, companies, civil society and institutions participated in the study through questionnaires and on-site meetings. A statistical analysis of the results identified urgent issues impeding the sustainable development of Rongcheng. The issues identified were poorly regulated aquaculture, loss of shoreline, and the decline of seagrass and cultural heritage.The study identified management options and measures, some of which were adopted by the local government in a co-designed management plan. The measures included upgrading of aquaculture industry, habitat conservation and restoration, and the development of cultural tourism. Another outcome was the increased knowledge exchange between stakeholders to inform management, policy, and decision making, as well as raised awareness of vulnerability to natural hazards and climate change. The success of this case study provides a reference for the adaptive management of other coastal cities and their sustainable development in a changing climate.info:eu-repo/semantics/publishedVersio

Identification of molecular and physiological responses to chronic environmental challenge in an invasive species: the Pacific oyster, Crassostrea gigas

Understanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. In this study, Crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed to the chronic environmental challenges of temperature (19 and 24°C) and pH (ambient seawater and a reduction of 0.4 pH units) in an extended 3-month laboratory-based study. Physiological parameters were measured (condition index, shell growth, respiration, excretion rates, O:N ratios, and ability to repair shell damage) alongside molecular analyses. Temperature was by far the most important stressor, as demonstrated by reduced condition indexes and shell growth at 24°C, with relatively little effect detected for pH. Transcriptional profiling using candidate genes and SOLiD sequencing of mantle tissue revealed that classical “stress” genes, previously reported to be upregulated under acute temperature challenges, were not significantly expressed in any of the treatments, emphasizing the different response between acute and longer term chronic stress. The transcriptional profiling also elaborated on the cellular responses underpinning the physiological results, including the identification of the PI3K/AKT/mTOR pathway as a potentially novel marker for chronic environmental challenge. This study represents a first attempt to understand the energetic consequences of cumulative thermal stress on the intertidal C. gigas which could significantly impact on coastal ecosystem biodiversity and function in the future