Estuarine and coastal ecosystems are often considered vulnerable due to the complex biogeochemical processes and the human disturbances through a variety of pollution. Among environmental contaminants, heavy metals in estuarine and coastal ecosystems have been of increasing concern in environmental conservation. Long-term exposure to heavy metal contamination, mainly through food and water, could be harmful to human health. It is therefore critical to understand the quantitative comparisons and combined effects of different heavy metals in common seafood species, such as oysters. This work studied the long-term spatiotemporal trends and health risk assessment of oyster arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) levels in the coastal waters of northern South China Sea. Cultured oysters (Crassostrea rivularis) from 23 estuaries and harbors in the coastal areas of northern South China Sea in 1989–2015 were analyzed for the spatiotemporal trends of the six heavy metal levels. Metal pollution index (MPI), target hazard quotient (THQ), and hazard index (HI) were used for quantifying the exposure of the six heavy metals to human health through oyster consumption. Principal component analysis (PCA) was used for assessing the relative importance of the six metals in oyster heavy metal distribution patterns in the northern South China Sea. Overall, the As, Cd, Cu, Hg, Pb, and Zn levels in oysters from the northern South China Sea generally declined from 1989 to 2015, stayed relatively high (MPI = 2.42–3.68) during 1989–2000, gradually decreased since 2000, and slightly increased after 2010. Oyster heavy metal levels were highest in the Pearl River Estuary (MPI = 1.20–5.52), followed by west Guangdong and east Guangdong, Guangxi, and Hainan coastal waters. This pattern is probably because economics and industry around the Pearl River Estuary have been growing faster than the other areas of this work in the recent two decades, and it should be taken as a hotspot for the monitoring of seafood safety in southern China. Principal component analysis indicated that Cu, Zn, and Cd were the most important metals in the long-term distributions of oyster heavy metal levels in the northern South China Sea. Health risk assessment suggested that the risk of the six heavy metals exposure through oyster consumption were relatively high during 1989–2005 (THQ = 1.01–5.82), significantly decreased since 2005 (THQ < 1), and slightly increased after 2010.

Abstract Estuarine and coastal ecosystems are often considered vulnerable due to the complex biogeochemical processes and the human disturbances through a variety of pollution. Among environmental contaminants, heavy metals in estuarine and coastal ecosystems have been of increasing concern in environmental conservation. Long-term exposure to heavy metal contamination, mainly through food and water, could be harmful to human health. It is therefore critical to understand the quantitative comparisons and interacting effects of different heavy metals in common seafood species, such as oysters. This work studied the long-term spatiotemporal trends and health risk assessment of oyster arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) levels in the coastal waters of northern South China Sea. Cultured oysters (Crassostrea rivularis) from 23 estuaries and harbors in the coastal areas of northern South China Sea in 1989–2015 were analyzed for the spatiotemporal trends of the six heavy metal levels. Metal pollution index (MPI), target hazard quotient (THQ) and hazard index (HI) were used for quantifying the exposure of the six heavy metals to human health through oyster consumption. Principal component analysis (PCA) was used for assessing the relative importance of the six metals in oyster heavy metal distribution patterns in the northern South China Sea. Overall, the As, Cd, Cu, Hg, Pb and Zn levels in oysters from the northern South China Sea generally declined from 1989 to 2015, stayed relatively high (MPI = 2.42–3.68) during 1989–2000, gradually decreased since 2000, and slightly increased after 2010. Oyster heavy metal levels were highest in the Pearl River Estuary (MPI = 1.20–5.52), followed by west Guangdong and east Guangdong, Guangxi, and Hainan coastal waters. This pattern is probably because economics and industry around the Pearl River Estuary have been growing faster than the other areas of this work in the recent two decades, and it should be taken as a hotspot for the monitoring of seafood safety in southern China. Principal component analysis indicated that Cu, Zn and Cd were the most important metals in the long-term distributions of oyster heavy metal levels in the northern South China Sea. Health risk assessment suggested that the risk of the six heavy metals exposure through oyster consumption were relatively high during 1989–2005 (THQ = 1.01–5.82), significantly decreased since 2005 (THQ < 1), and slightly increased after 2010.

鲎试验法作为国内外内毒素检测的一种标准方法,其地位短期内无可替代,中华鲎资源的重要性由此可见一斑.然而普通公众对于中华鲎属于渔业经济种类还是特殊保护物种,及其保护等级方面的认知盲点,导致公众参与的鲎资源保护行动无法满足鲎资源量变化的要求.中华鲎自然资源管理和利用方面缺乏明确的管理依据,鲎血采集尚未得到有效监管.近30年来中华鲎自然资源量快速下降,鲎试剂产业安全隐患迫在眉睫.建议相关监督和管理部门、研究单位和企业联合,组建国家级鲎资源保护与应用研究中心,对鲎试剂产业链进行系统化管理,同时探索中华鲎养殖利用新途径,通过适宜的管理方式实现中华鲎保护和利用之间良性互动及可持续发展.

鲎,英文别名马蹄蟹(Horseshoe crab),隶属节肢动物门、肢口纲、剑尾目、鲎科.目前全世界现存的鲎分为2亚科3属4种,美洲鲎亚科(Subfamily Limulinae)仅1属1种即美洲鲎(Limuluspoly phemus);鲎亚科(Subfamily Tachypleinae)分为蝎鲎属和鲎属,由3种亚洲鲎组成,分别为蝎鲎属的圆尾蝎鲎(Carcinoscorpius rotundicauda)和鲎属的中国鲎(Tachypleus tridentatus)与南方鲎(Tachypleus gigas).

A small No. 2 fuel oil spill contaminated a Mytilus edulis population in the Cape Cod Canal, Massachusetts, USA during a three day period in April 1983. Retention and release of the fuel oil compounds were assessed over several days and months. Compounds analyzed included n-alkanes, pristane, phytane, C-2 -, C-3 -naphthalenes, flourene, phenanthrene, C-1-,C-2-, C-3 - phenanthrenes. Biological half-lives were calculated for the release of the compounds up to day 29 and ranged from 1.5 days to 9.9 days. Results compared favorably with similar data from a small No. 2 fuel oil spill contaminating the same population of Mytilus edulis at the same time of year, April 1978. Gas chromatography-mass spectrometer analyses of C-2-, and C-3- phenanthrenes documented changes in relative abundance within the isomer groupings after day 29. This suggests a within isomer grouping molecular structural control on release or enzymatic catalyzed alteration of these compounds.

中华鲎是沿海居民耳熟能详的一个古老物种,众多文学作品中都有描述,也有一些有关的谚语俚语,这显示了其重要的历史文化价值.其血液还具有极大的经济价值.但是,中华鲎资源已快速下降至被IUCN列为“濒危”物种.中国颁布的《水生野生动物及其制品价值评估办法》,是判定是否构成破坏野生动物资源违法犯罪案件的重要依据.本文重点探讨根据该评估办法规定的计算方法对中华鲎进行经济价值评估的可行性,指出中华鲎这一物种的特殊性,探讨依据鲎试剂价值制定其价值评估方法.

Coastal heavy metal pollution has become an important topic for seafood safety and marine environmental protection. Unlike toxic heavy metals such as cadmium or chromium, copper is essential for oysters’ growth but can inhibit their immune response to exotic stress when going above normal levels. Oysters with high copper levels can easily accumulate and transfer abnormal amounts of copper to upper trophic levels, and generate health risks for humans. This study investigated the spatiotemporal variability and health risk of copper levels in cultured oysters (Crassostrea rivularis) sampled from 23 harbors, bays, or estuaries along the northern South China Sea during 1989–2015. Overall, oyster copper concentrations in the study area ranged from 0.9 to 1897.0 μg/g wet weight with a mean of 210.0 (± 143.6) μg/g and a median of 89.3 μg/g. Although oyster copper levels in the southern China provinces of Guangdong, Guangxi, and Hainan showed an overall decrease during 1989–2015, they stayed relatively low since 1996 and increased slightly after 2010. Oyster copper levels in Guangdong were significantly higher than in Hainan and Guangxi. In Guangdong, oyster copper levels were highest in the Pearl River Estuary, followed by west Guangdong and east Guangdong. The health risk of copper exposure through oyster consumption increased in 2011–2015 compared with in 2006–2010. It is recommended that the human daily intake of cultured oysters in the study area should be reduced by half to minimize copper exposure. This study suggested that copper is one of the most important heavy metal contaminants in coastal and estuarine ecosystems of the northern South China Sea.

一、中华鲎简介 中华鲎(hou)是具有重要经济、生态和科研价值的古老物种,是医疗检测鲎试剂的重要物质材料基础来源,曾经也是人们餐桌上的美味.目前国内的中华鲎资源已锐减至濒危,挽救其种质资源迫在眉睫.

为提高人工鱼礁建设选址和礁体设计的科学性,基于试验水槽对2种人工鱼礁在粉砂黏土上的局部冲淤情况进行了物理模型试验,通过地形测量和理论分析,研究了5组不同流速条件下2种人工鱼礁礁体结构的局部冲淤情况.结果表明,在粉砂黏土底质上,流速小于0.22 m·s-1时,泥沙扰动小,2种礁体的周围局部冲刷小,冲淤形态以礁体底板附近浮沙堆积为主,且随速度增大而增高;流速大于0.22 m·s-1时,洗掘现象较为明显,鱼礁周围冲刷坑范围及深度随流速的增大而增加,而礁体周围泥沙堆积高度随速度增大而减小.支撑结构较为复杂的A礁冲淤现象显著且复杂,冲刷坑深度最大值位于礁体中间底部,为-15 mm,且在礁后1倍礁高处出现长尾状泥沙堆积,其在0.27 m·s-1流速时达到最大值5 mm;而B礁冲淤现象不显著,仅在底板附近出现少量堆积与冲刷坑,但由于底板开口比较大导致B礁发生沉降.因此今后的研究应结合建设选址海域的底质及水文特征对礁体支撑结构和底板进行优化设计并进行模型试验及数值模拟,以避免礁体冲淤严重引起沉降、掩埋等现象,从而影响鱼礁建设效果.

Di-n-butyl phthalate, one of the most easily detected pollutants of phthalate esters in the environment, has been added to the priority list of hazardous substances by many countries. As one of low molecular weight phthalates, Di-n-butyl phthalate may have a great adverse potency on various aquatic organisms. In this study, the juvenile red snapper, Lutjanus argentimaculatus, was exposed to the concentrations of Di-n-butyl phthalate (20 μg L-1, 100 μg L-1 and 500 μg L-1) for 15 days. EROD activities and CYP1A levels were measured in liver and gill tissues. In gills, the similar effect has been found to inhibit or induce EROD activities and CYP1A levels, and there existed a good correlation between them. Whereas in the case of the liver, a moderate correlation was observed between EROD activities and CYP1A levels, which was mainly due to the inhibited EROD activities and the CYP1A levels with no significant difference by day 15. In conclusion, this study revealed the similar and different effects of cytochrome P450 enzymes on fish in the time-, concentration-, and tissue-dependent Di-n-butyl phthalate exposure. Furthermore, as the adverse effects indicated between CYP1A levels and EROD activities, metabolic mechanisms of phthalates in different tissues should be highly emphasized in future studies.

邻苯二甲酸二(2-乙基己基)酯(DEHP)作为生产量和使用量最多的一种邻苯二甲酸酯类化合物,其对水生生物具有多种毒性.本研究选用中国南方地区最重要的经济鱼类尼罗罗非鱼(Oreochromis niloticus)作为实验对象,研究DEHP(50mg/kg bw)作用下罗非鱼肝脏组织内转录组的响应特征.利用IlluminaTM HiSeq 4000测序平台对DEHP处理组和对照组尼罗罗非鱼肝脏RNA样品分别进行转录组测序.对照组和DEHP暴露组分别获得30.10Mb和30.16Mb待分析数据(clean reads),对转录组数据进行组装并去冗余后得到58,585个Unigene.将DEHP处理组和对照组的转录组数据进行比较一共获得5,008个差异表达基因,其中上调表达基因和下调表达基因分别为3,217个和1,791个.通过GO和KEGG功能分析后发现这些差异表达基因主要为机体免疫、生殖内分泌以及脂类代谢相关基因,这表明DEHP对尼罗罗非鱼肝脏毒性主要表现为免疫毒性、生殖毒性和脂类代谢紊乱.另外,实时荧光定量PCR验证结果发现转录组分析数据基本可靠.上述结果为在转录组水平筛选DEHP生物标志物,解析DEHP对罗非鱼毒性作用的分子机制提供了科学参考.

为探究人工鱼礁聚鱼效果,于2017年2月、4月、9月和11月主要通过声学探测技术,对防城港海域渔业资源密度、空间分布与大小组成进行了调查研究.结果显示,防城港人工鱼礁区及其临近海域4次调查共捕获各类游泳生物和底栖无脊椎动物201种,包括鱼类126种、蟹类32种、虾类20种、虾蛄类11种和头足类12种.双因素方差分析结果表明,调查海域渔业资源密度在时空层面上均存在显著性差异(P<0.001),且交互作用显著(P<0.001).2月调查海域人工鱼礁区渔业资源密度(547745 ind/n mile2)约为其周边海域(203990 ind/n mile2)的2.68倍,表现出明显的聚鱼效果.其中,二长棘鲷(Parargyrops edita)、多齿蛇鲻(Saurida tumbil)、花斑蛇鲻(Saurida undosquamis)等岩礁性底层鱼类为该季度主要优势种类.各航次人工鱼礁区小型个体所占比重较高,其平均目标强度(TS)分别为–55.6 dB(2月)、–54.5 dB(4月)、–53.6 dB(9月)和–52.2 dB(11月),随个体生长其平均TS呈稳步增大的变化趋势.在垂直方向上,2月和4月航次人工鱼礁区90％以上回波单体主要分布在9～16 m中下水层.上述研究结果表明,人工鱼礁建设对防城港海域小型岩礁性鱼类表现出明显的向底层诱集的效果,该结果能为海洋牧场生态效应系统评价提供重要支撑.

海底条件的变化可能会加剧人工鱼礁的局部冲刷甚至产生掏空,导致人工鱼礁倾覆或掩埋,最终影响人工鱼礁的生态修复功能.为更好地了解人工鱼礁的冲刷特性,明确冲刷地形的形成机制,本研究首先采用物理模型试验的方法,对放置在粉砂底质上的人工鱼礁在不同水流条件下的局部冲刷问题进行了研究,并通过对原型流场进行数值模拟,讨论分析了水流及礁体结构特征对局部冲刷形态的影响机制.模型试验结果显示,0.11 m/s流速对试验选取的模型沙的影响不显著,礁体模型背面冲刷坑的深度仅为0.5 mm,两侧无明显冲刷坑,当流速增加到0.22和0.27 m/s时,沙床表面形成了均匀分布的沙鳞,背面冲刷坑深度分别达到1.0和1.5 mm,两侧冲刷坑的最大深度为4.5 mm,宽度分别为4.0和7.5 cm;流场数值模拟的分析结果显示,原型条件下流场、沙床剪切力和涡量的高值区和模型试验中冲刷强区存在对应关系,礁体的开孔和多柱支撑设计增大了局部冲刷强度.该研究表明,在粉砂底质条件下人工鱼礁的局部冲刷程度随流速的增加而增强,但总体冲刷不严重,未出现掏空或掩埋现象;礁体结构对局部冲刷有较大影响,因此,礁体设计与布局时应综合考虑流场效应、稳定性和冲刷形态等因素.

浮游动物有明显的昼夜垂直移动现象,这种生态习性会导致摄食浮游动物的某些鱼类昼夜垂直移动.为分析人工鱼礁对中小型浮游动物昼夜变化的影响,于2018年11月在防城港人工鱼礁区及附近海域进行了1个昼夜的中小型浮游动物采样,获取了14份样品.结果显示:(1)礁区和非礁区浮游动物种类组成相似度高、更替率低,且主要优势种相同,属于同一生态类型;(2)在人工鱼礁流场效应的作用下,礁区浮游动物的数量和多样性高于非礁区;(3)非礁区浮游动物数量的昼夜变化明显,呈明显的正弦曲线,以16:00数量最高,8:00最低,其垂直运动规律明显,可分为4:00～20:00的运动期和20:00～次日4:00的稳定期;(4)在礁体上方流速较快的水平层的阻隔作用下,礁区浮游动物数量始终处于波动状态,没有明显的昼夜垂直变化规律,在礁区上层保持较高的数量,可提升集鱼效果、促进生产力转换;(5)聚类分析和排序表明,礁区浮游动物为一个群落类型.而非礁区中小型浮游动物可分2个群落类型,一个是白天随浮游植物而上浮的以植食性种类为主要特征种的群落类型,另一个是晚上植食性种类下沉后以肉食性种类为主要特征种的群落类型.

为了解人工鱼礁区鱼类的活动特点及使用超声波遥测方法进行人工鱼礁区鱼类研究的可行性,2017年7月7日至9月8日于防城港人工鱼礁区利用Vemco定位系统(Vemco position system,VPS)对5种北部湾沿海常见的野生恋礁性鱼类共9尾[体长(21.7±3.8)cm,体重(314±186)g]进行超声波标志遥测跟踪.结果表明,9尾鱼中的3尾定位效果较为理想(1749～9591个定位结果),活动范围较小,其中100％最小凸多边形(minimum convex polygon,MCPs)范围为12687.6～17123.2 m2.而50％和95％核心利用分布(Kernel utilization distribution,KUDs)范围为5788.1～8708.9 m2和10240.5～16463.7 m2.另6尾鱼未取得理想的定位效果(0～14个定位结果),接收机接收回的定位数据可以被检测,表明鱼依然在礁区附近活动.在游离检测范围28～51 d后又有信号返回,说明样本鱼对人工鱼礁环境有一定的偏好性,研究期间样本鱼表现出一定的活动深度变化规律,在15:00～22:00时段活动深度相对较浅,主要集中于人工鱼礁礁体上方(距水底5 m以上).研究表明,应用超声波遥测技术可以了解鱼类在自然生活状态下的活动特点,可作为鱼类研究的有效手段加以应用.

Phenanthrene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) found in continental shelf environment of China and is on the EPA’s Priority Pollutant list. In this study, the effects of phenanthrene on marine algal growth rate were determined after 96-h exposure at pH 6.0, 7.0, 8.0, 9.0, and 10.0 in seawater of salinity 35. Two measuring techniques to assess growth inhibition were also compared using prompt fluorescence and microscopic cell count. The results showed that the toxicity of phenanthrene increased significantly (p < 0.05) with decreasing pH, with the nominal concentration required to inhibit growth rate by 50%, EC50, decreasing from 1.893 to 0.237 mg L−1 as pH decreased from 9.0 to 6.0, with a decrease higher than 55% from 10.0 to 9.0. In addition, the nominal EC50 values calculated in this study were at the same range of some environmental concentrations of phenanthrene close to areas of crude oil exploration. Based on the two measuring techniques, the results showed that cell count and fluorescence measurement were significantly different (p < 0.05), and the nominal EC50 values calculated with cell count measurement were significantly higher than fluorescence measurement at pH 8.0, 9.0 and 10.0. In conclusion, the present studies confirmed that acidification of seawater could affect the toxicity of phenanthrene to this species of microalgae, and which encouraged further studies involving responses of marine organisms to ocean acidification.

In order to explore the effect of oil pollution on the food security of aquatic products in Guangdong coastal waters,a risk grade method of petroleum residue was first proposed,petroleum hydrocarbons (PH) in the oysters (Crassostrea rivularis) collected during 2001 ～2010 were determined by spectrofluorometry,and the PH level in fish and shrimp was speculated.The results indicated that PH contents in our oyster samples ranged from ＜ 0.2 × 10-6 to 36 × 10-6(wet weight),and might not make oil taste.The mean content of PH was 9.4 × 10-6 which was relatively lower in the oysters from coastal waters in China,but higher than the historical data (6.7 × 10-6) during 1989 ～ 1992.PH were detectable in 99.3 percents of our samples.16.7 percents of our samples contained more PH than the limit value (15 × 10-6,Chinese standard).The annual PH average and the over standard rate in our samples trended to decline during 2001 ～ 2006,but slightly rebounded after 2007,especially in the samples from the Pearl River Estuary and from industry-translation areas.Based on the data of this survey and other literature,wededuced that the PH contents in fish and shrimp in Guangdong coastal waters were probably lower than 15 × 10-6,seldom higher than 30 × 10-6,and also might be lower than above limit or oil taste threshold.

To study the feasibility of assessing artificial reef construction quality by side-scan sonar, we conducted a field survey of a one-year-old stock protection artificial reef area using side-scan sonar technology in April, 2017. We selected two types of artifi-cial reefs, AR1 and AR2, with 15 randomly selected reefs for each type. After software processing, the information of artificial reef height, settlement, structure and other data were obtained. The results show that the height of AR1 reef body was 3.74–4.76 m (average:4.44 m), and the settlement rate was 13.52%–32.20% (average: 19.20%). The height of AR2 reef body was 2.57–3.45 m (average:2.85 m), and the settlement rate was 13.67%–35.75% (average: 28.66%). By the time of investigation, two kinds of concrete reef structures were relatively complete, while individual reefs were dumped, and the actual reef layout had certain deviation from the preset layout. The results of single factor analysis of variance show that significant difference existed between the two types of reefs in anti-settling capacity, and AR1 had better reef-settling capacity than AR2.

Di-(2-ethylhexyl) phthalate (DEHP) is currently the most frequently detected phthalic acid esters (PAEs) compounds and can induce diverse toxicities on aquatic organisms. To understand the molecular responses of fish to DEHP, we performed transcriptomic profiles in liver of tilapia (Oreochromis niloticus) which were exposed to environmental concentration of DEHP. A total of 30.10 Mb and 30.16 Mb clean reads were retrieved from the control and DEHP treated libraries, respectively. De-novo assembly of all the clean reads obtained 58,585 unigenes. After comparing the two libraries, 2814 and 1790 genes were identified as significantly increased and depressed, respectively. Gene ontology (GO) classification system and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analysis demonstrated that DEHP significantly disturbed the expression level of genes associated with immunity, endocrine and reproductive system, lipid metabolism and so on. Quantitative realtime PCR was performed to validate the results of RNA-sequencing (RNA-seq) analysis. The resulting data provide new insights for exploring the molecular basis of tilapia response to DEHP exposure.

We studied the influence of triazophos on sex hormone levels, apoptosis, activity of related protease caspase and micro-structure of Perna viridis gonad,so as to discuss the endocrine disrupting mechanism and reproductive toxicity of triazophos on P.vi-ridis.The results show that triazophos reduced the contents of β-estradiol and testosterone in gonads of P.viridis(P>0.05),suggest-ing that triazophos can exert its endocrine-disrupting effects by reducing sex hormones levels. In addition, the response of caspase-3 and caspase-9 activities in the gonads of P.viridis to triazophos exposures were gender-specific.The activities of caspase-3 and cas-pase-9 in female and male mussels were depressed and induced significantly at different time intervals, respectively, which indicates that triazophos influences the enzyme activity of apoptosis in mussel gonads to affect the apoptosis process. Moreover, the number of reproductive cells decreased and the reproductive cells were more loosely arranged and deformed in P.virudis gonads after triazo-phos exposure.The results reveal that triazophos shows endocrine disrupting effects and has reproductive toxicity on P.viridis.