【作者】 陈斌；

【导师】 蔡明刚；

【作者基本信息】 厦门大学 ， 海洋事务， 2020， 博士

【摘要】 塑料作为重要基础材料,自20世纪中叶被广泛用于农工业生产与日常生活中,大量废弃塑料被排放入海,并逐渐破碎、分解为微小的塑料碎片。一般将直径小于5mm的塑料称为微塑料,后者已成为一类新型环境污染物,给生态环境安全构成了极大的威胁,并可能对海洋生物甚至人体健康产生危害。全球60%以上的人口生活在沿海地区,该地区也是塑料排放最密集的区域。作为全球最大的海水养殖国家之一,我国东南沿海典型海湾和工厂化海水养殖活动中,大量使用了各类塑料渔具设施,也已经成为微塑料的主要来源。但较之河口、海(潮)滩等其他沿海环境区域,沿海渔业养殖区域中微塑料的环境赋存状态和影响因素,则知之甚少。同时,应对海洋微塑料可能引发的各类环境与生态问题,全球尚缺乏全面、系统的沿海海洋塑料垃圾管控体系,我国也十分缺乏针对沿海渔业水域的海洋塑料管控与微塑料污染防治的政策和相应管理措施。因此,掌握典型沿海渔业水域和工厂化养殖海水环境中微塑料的赋存状态及其影响因素,在此基础上开展政策调研与分析,提出有效的管控对策,具有较重要的科学价值和现实意义。我国东南沿海渔业水域是最主要的养殖区域。广东省海洋经济发达,湛江湾是我国南部典型半封闭型海湾和重要水产养殖基地,是我国牡蛎养殖的主产区之一。福建省海洋生产总值居全国第三位,水产品出口额连续六年居全国第一。隆教湾位于台湾海峡西岸,近年来城镇化和工业化发展迅速,沿海养殖空间遭受挤压,工厂化海水养殖遂成为中小型海湾养殖模式的典型代表。本研究中,结合我国东南沿海渔业养殖特色和社会经济活动,选择较典型的南海北部渔业水域(广东湛江湾)和台湾海峡沿岸工厂化海水养殖体系(福建隆教湾),开展海水微塑料的污染特征、空间分布、季节变化和影响因素研究,可为我国全面开展沿海渔业水域环境微塑料监测提供重要的基础数据与科学研究依据。本研究于2017年9月,2018年1月和2018年5月,开展湛江湾微塑料的丰度组成、空间分布及季节变化(丰、平、枯水期)研究。结果表明:1)湛江湾表层海水中微塑料的检出范围为n.d.-2.65 n/m3(平均值0.37±0.57 n/m3),微塑料丰度在丰水期和平水期相对较高(丰水期范围为0.03-1.52 n/m3,9月的平均值为0.40 n/m3;平水期范围为0.05-2.65n/m3,5月平均值为0.50 n/m3),而枯水期丰度较低(n.d.-1.21 n/m3,1月平均值为0.28 n/m3)。2)小于3 mm的微塑料占优(81%),主要形态占比依次为碎片(47.0%)、薄膜(37.0%)、泡沫(10.6%)。泡沫、碎片分别是丰、枯水期占比最高的微塑料形态。3)聚乙烯(Polyethylene,PE)(20%)、橡胶(20%)和聚丙烯(Polypropylene,PP)(15%)为湛江湾微塑料的主要组分,其中PE(34%)、PP(31%)分别为丰、枯水期占比最高的微塑料形态。4)空间分布的季节性差异特征明显:丰水期,微塑料丰度高值出现在湾顶(1.14n/m3),并呈现向湾口(0.03 n/m3)逐渐下降的分布趋势。枯水期微塑料的分布特征与丰水期相反,微塑料丰度自湾顶(n.d.)向湾口(1.12 n/m3)逐渐升高。平水期,微塑料丰度则表现为湾顶与湾口高,湾内低的分布格局。5)源解析表明,海水养殖活动是湛江湾微塑料的主要来源;聚类分析表明,有别于工业活动带来的点源污染,养殖活动带来了面源污染,湾口站点微塑料的季节变化或与粤西附近的近岸海流有关。总之,不同季节和养殖类型差异可对微塑料的来源、形态、组分、丰度、分布等造成显著影响。本文于2018年4月至12月在隆教湾开展微塑料丰度等特征时间变化的研究。结果表明:1)隆教湾的工厂化海水养殖以流水式养殖模式为主,养殖水体中普遍可检出微塑料,其丰度范围在250-5 150n/m3,平均1 594.2±1 352.2n/m3。微塑料丰度的时间变化周期与养殖周期(100-120天)大致相符。2)与开阔体系不同,隆教湾工厂化养殖水体中微塑料的尺寸主要为大颗粒(0.3-5 mm:92.03%),主要由颗粒状(41.36%)和纤维状(34.93%)组成,颜色则以白色(45.42%)、黄色(32.13%)和黑色(19.55%)为主,组分以PE(34.40%)和聚对苯二甲酸乙二醇酯(Polyethylene terephthalate,PET)(30.18%)为主。由微塑料的形态、颜色、尺寸和组分特征,可以推断,微塑料主要来源于本地渔业养殖活动,即自身设备老化和投喂料活动。3)相关性分析表明,养殖水体中的微塑料丰度与当地海产品产量呈正相关关系,表明高丰度的微塑料势必增加养殖生物摄入风险,有可能对养殖生物的健康造成负面影响,因此有必要对工厂化海水养殖模式中生物体微塑料毒理进行研究。黑鲷(Acanthopagrus schlegelii)广泛分布于我国沿海地区,是典型的养殖经济鱼类。本文选取养殖工厂中黑鲷幼鱼,重点开展水溶性微塑料和传统微塑料对黑鲷生长的对比毒理实验。结果表明:1)微塑料对黑鲷生长率(体重增长率)、蛋白酶活性和饲料转化率等均有明显影响。养殖生物可能摄入微塑料,不仅影响养殖生物生长发育质量,更对渔业食品安全和人体健康产生重大潜在危害。2)PE和聚乙烯醇(polyvinylalcohol,PVA)影响程度不同。每天喂食30片微塑料的实验组经过8周后,增重率和饲料效率均明显小于对照组。在消化道、粪便及水中回收的微塑料中发现,PE组回收的碎片数量显著高于PVA组。3)胃蛋白酶活性随喂食微塑料数量的增加而增加,但肠道中的胰蛋白酶活性则相反。在测定的因子(蛋白酶活性)中均发现PE组对于黑鲷的影响显著高于PVA组。4)胰蛋白酶活性与增重率呈正相关关系,推测微塑料经摄食进入鱼体肠道后造成胰蛋白酶下降,进而对其生长造成影响。5)水溶性PVA对黑鲷的生长的影响显著低于非水溶性PE,表明PVA塑料较为环保,在海水养殖业有一定的应用推广前景,可在一定程度上缓解当前海水养殖中微塑料问题。基于开阔渔业水域及室内养殖环境中微塑料的广泛检出问题,本文进一步开展海洋渔业水域、海水养殖微塑料输入管控的政策法规和管理措施调研。具体而言,本文分析了全球海洋微塑料输入管控现状,系统地梳理了国际与国家(地区)两个层面涉及微塑料相关政策法规和管理措施,并从次生来源与原生来源角度分别对上述不同维度相关政策进行对比与分析。研究发现:1)我国现有海洋微塑料管控政策与措施不够全面。2)我国海域渔业水域相关微塑料政策法规和管理尚未得到重视。3)在塑料防控的政策和管理措施方面,还缺乏长效激励的治理机制。4)建议我国应在现有法规基础上,率先提出相应的政策或行动方案,努力争取起到全球引领之作用。在上述对比研究基础上,开展了我国沿海渔业水域微塑料管控挑战、政策建议和防治措施等方面的梳理分析。具体如下:1)梳理了我国沿海渔业生产微塑料管控面临的诸多问题与挑战:微塑料危害形成机理复杂、管控情景多元;迁移路径广泛、治理主体权责不清;面临经济快速发展和生态环境承受力的矛盾;国际环境压力。2)提出了沿海渔业水域的微塑料管控之政策建议,主要包括:建立渔业水域塑料垃圾分类和回收体系;建立渔业水域生产者责任延伸制度;建立“海陆统筹”的综合治理模式;提高民众环保意识;提升水处理技术;建立全生命周期的管控制度等。3)针对海水养殖的微塑料危害,提出海水养殖微塑料防治的政策和管理建议,具体包括:改进渔具管理政策;建立海水养殖微塑料风险评估体系;将微塑料纳入海水养殖水质监控指标;建议微塑料严重污染海域限制或禁止海水养殖;建议将微塑料特征指标纳入海产品食品安全管控体系;建立海水养殖污染企业责任制和市场调控机制。更多还原

【Abstract】 As an important basic material,plastic has been widely used in agricultural and industrial production and daily life since the mid-20th century.A lot of waste plastics have been discharged into the sea and gradually decomposed into tiny plastic fragments.Generally,plastics with a diameter less than 5 mm are called microplastics.It has become a new class of environmental pollutants that pose a great threat to ecological safety and may be harmful to marine life and even human health.More than 60%of the world’s population lives in coastal areas,which also have the highest concentration of plastic emissions.As one of the largest mariculture countries in the world,various kinds of plastic fishing gear facilities are widely used in the typical bays and factory mariculture activities along the southeast coast of China.These have become one of main source of microplastics.However,compared with estuaries,tidal flats and other coastal environments,the environmental status and influencing factors of microplastics in coastal fish culture areas are less well known.At the same time,to deal with various environmental and ecological problems that may be caused by marine microplastics,there is still a global lack of a comprehensive and systematic control system for coastal marine plastic garbage.China also lacks policies and corresponding management measures for marine plastic control and microplastic pollution prevention and control in coastal fishery waters.Therefore,it is of great scientific value and practical significance to grasp the occurrence state and influencing factors of microplastics in typical coastal fishery waters and factory farming seawater,and to carry out policy research and analysis on this basis,and propose effective control countermeasures.The fishery waters in the southeast coast of China are the most important aquaculture areas.Zhanjiang Bay is a typical semi-enclosed bay and an important aquaculture base in southern China.It is also one of the main oyster farming areas in China.Longjiao Bay is located on the west coast of the Taiwan Strait,in Fujian province,whose gross Marine product ranks the third in China and its aquatic product export ranks the first in China for six consecutive years.In recent years,urbanization and industrialization have been developing rapidly,and the space for coastal aquaculture has been squeezed.Therefore,factory mariculture has become a typical representative of small and medium-sized Gulf aquaculture models.In this study,combined with the characteristics of fish farming and socio-economic activities in the southeast coast of China,we choose a typical fishing areas(Zhanjiang Bay)in northern South China Sea and the coast of Taiwan strait factory mariculture system(Longjiao Bay),to carry out the seawater pollution characteristics of the microplastic,spatial distribution,seasonal change and influence factors of research.These will provide important basic data and scientific basis for the monitoring of environmental microplastics pollution in coastal fishery waters in China.This study was conducted in September 2017,January 2018 and May 2018 to study the abundance composition,spatial distribution and seasonal variation(highwater period,level-water period and dry season)of microplastics in Zhanjiang Bay.The results showed that:1)the detection range of microplastics in surface seawater of Zhanjiang Bay was n.d.-2.65 n/m3(mean value 0.37±0.57 n/m3),and the microplastic abundance was relatively high in the high-water and level-water periods(the range was 0.03-1.52 n/m3 in high-water period,and the mean value was 0.40 n/m3 in September;the range was 0.05-2.65 n/m3 in level-water period,and the mean value was 0.50 n/m3 in May),while the abundance was lower during the dry season(n.d.-1.21 n/m3,mean 0.28 n/m3).2)Microplastics smaller than 3 mm predominated(81%),with the major forms being fragments(47.0%),films(37.0%),and foams(10.6%).3)Polyethylene(PE)(20%),rubber(20%),and polypropylene(PP)(15%)were the most abundant(n.d.-1.21 n/m3,the mean value was 0.28 n/m3 in January).Foam and fragment were the most important forms of microplastics in abundant and dry water period,respectively.3)Polyethylene(PE)(20%),rubber(20%)and polypropylene(PP)(15%)were the main components of microplastics in Zhanjiang Bay,of which PE(34%)and PP(31%)were the most important forms of microplastics in abundant and dry water period,respectively,and PE(34%)and PP(31%)were the most important forms of microplastics in abundant and dry water period,respectively.4)The seasonal differences in spatial distribution were obvious:during the high-water period,the high abundance of microplastics appeared at the top of the bay(1.14 n/m3)and showed a decreasing trend toward the mouth of bay(0.03 n/m3).The distribution of microplastics during the dry period was opposite to that during the high-water period,with the microplastic abundance gradually increasing from the top of the bay(n.d.)to the mouth of the bay(1.12 n/m3).During the level-water period,the microplastic abundance showed a high distribution pattern in the bay top and bay mouth,and a low distribution pattern in the central of bay.5)Source analysis showed that mariculture activities were the main source of microplastics in Zhanjiang Bay.The cluster analysis showed that,the non-point source pollution caused by farming activities,different from the point source pollution caused by industrial activities,and the seasonal changes of microplastics at the bay mouth site might be related to the coastal currents near the west of Guangdong.In a word,different seasons and differences in farming types can have a significantly influence on the source,morphology,composition,abundance anddistribution of microplastics.In this study,we carried out a study on the temporal changes of microplastic abundance and other characteristics in Longjiao Bay from April to December 2018.The results showed that:1)The factory mariculture in Longjiao Bay was mainly in the flowing water aquaculture model,and microplastics could be detected in the water.The abundance range was 250-5 150 n/m3,with an average of 1594.2±1352.2 n/m3.The temporal variation of microplastic abundance was roughly consistent with the aquaculture cycle(100-120 days).2)Unlike the open system,there was a higher abundance of microplastics in the Longjiao Bay.The size of microplastics in factoryfarmed water was mainly large(0.3-5 mm:92.03%),consisting mainly of granular(41.36%)and fibrous(34.93%),with white(45.42%),yellow(32.13%)and black(19.55%)colors,PE(34.40%)and with polyethylene terephthalate(PET,30.18%)as the main components.Based on the morphology,color,size and component characteristics of microplastics,it can be inferred that microplastics mainly originated from the local fish farming activities,i.e.,aging of their own equipment and feeding activities.3)The correlation analysis showed that the tiny plastic in the aquaculture water abundance was positively correlated with the local seafood production relations.This indicated that high abundance of microplastics would increase the risk of intake of farmed organisms and might cause health problems to farmed organisms.So it was necessary to study the toxicology of microplastics in organisms in the factory mariculture model.Black seabream(Acanthopagrus schlegelii)is widely distributed in the coastal areas of China and is a typical cultured economic fish.In this study,we selected black seabream juvenile fish from aquaculture plants and focused on the comparative toxicological experiments of water-soluble microplastics and traditional microplastics on the growth of black seabream.The results showed that:1)microplastics had a significant effect on the growth rate(body weight growth rate)of black seabream,protease activity and feed conversion ratio.Microplastics might be ingested by farmed organisms,which not only affected the growth and development quality of farmed organisms,but also caused significant potential harm to fishery food safety and human health.2)The influences of PE and polyvinyl alcohol(PVA)were different.After 8 weeks,the weight gain rate and feed efficiency of the experimental group fed 30 pieces of microplastics a day were significantly lower than those of the control group.n the microplastics recovered from digestive tract,feces and water,it was found that the amount of debris recovered from PE group was significantly higher than that from PVA group.3)Pepsin activity increased with the amount of microplastics fed,but trypsin activity in the intestine was opposite.The effect of PE group on black seabream was found to be significantly higher than that of PVA group.4)There was a positive correlation between trypsin activity and weight gain rate.It was assumed that microplastics would decrease trypsin after ingestion into the intestinal tract of fish,thus affecting the growth of the microplastics.5)The effect of water-soluble PVA on the growth of black seabream was significantly lower than that of water-insoluble PE,indicating that PVA plastic was more environmentally friendly and had a certain application and promotion prospect in mariculture,which could alleviate the current microplastic pollution problem in mariculture to a certain extent.Based on the widespread detection of microplastics in open fishery waters and indoor aquaculture environment,this study further carried out research on the policies,regulations and management measures for microplastics pollution control in marine fishery waters and mariculture.Specifically,we analyzes the current status of global marine microplastic pollution control,systematically combs international and national(regional)policies,regulations and management measures related to microplastics,and compares and analyzes relevant policies in different dimensions from the perspectives of secondary and primary sources.It is found that:1)China’s existing marine microplastics control policies and measures were not comprehensive enough;2)China’s fisheries-related microplastics policies,regulations and management had not received much attention;3)There was still a lack of long-term incentive governance mechanism for plastic prevention and control policies and management measures;4)It was suggested that China should take the lead in proposing corresponding policies or action plans on the basis of existing laws and regulations,and strive to play a leading role in the world.Based on the above comparative studies,we carried out a combing and analysis of the challenges,policy recommendations and prevention measures for microplastics control in China’s coastal fishery waters.The details were as follows:1)Sorted out the problems and challenges of microplastics control in China’s coastal fishery production:complicated formation mechanism of microplastics hazards,multiple control scenarios,wide migration paths,unclear authority and responsibility of governance entities,international environmental pressure,and how to balance rapid economic development and ecological environment carrying capacity,and.2)Put forward policy recommendations for microplastics control in coastal fishery waters,mainly including:establishing a fishery waters Plastic garbage classification and recycling system,the establishment of fishery waters extended producer responsibility system,the establishment of "integrated land and sea" comprehensive management mode,improving public awareness of environmental protection,improving water treatment technology,and the establishment of the whole life cycle of the control system.3)In view of the hazards of microplastics in marine aquaculture,put forward the microplastics in marine aquaculture prevention and control policy and Management recommendations,including improving fishing gear management policies,establishing a risk assessment system for marine aquaculture microplastics,incorporating microplastics into marine aquaculture water quality monitoring indicators,suggesting that microplastics seriously pollute sea areas to limit or prohibit marine aquaculture,suggesting that microplastic characteristics of indicators into seafood food safety control system,and establishing a marine aquaculture pollution enterprise responsibility system and market control mechanism.更多还原