海豚组织中多氯联苯（PCBs）气相色谱测定的改良方法研究

研究和建立了一种测定海豚体内不同组织中多氯联苯(PCBs)前处理的改良方法,即将海豚组织分为低脂样品和高脂样品,分别经萃取、净化、浓缩等处理后,用Agilent6890N型气相色谱仪、63Ni放射源ECD检测器测定,采用保留时间定性和峰面积外标法定量。结果显示,加标回收率为75.8%~119.2%,精密度为5.6%~11.2%,方法检出限为0.126~0.642ng.g-1,说明该方法的准确性、可重复性符合海洋生物体痕量有机污染物分析要求。海豚组织样品的实际测定结果表明,该方法适合海豚体内PCBs含量的分析测定。     

广东大鹏湾海域糙齿海豚体内多氯联苯的分布特征与毒性评价

以广东大鹏湾海域糙齿海豚(Steno bredanensisLesson)为研究对象,采用气相色谱法分析了海豚8种组织中多氯联苯(PCBs)的含量。将海豚8种组织分别经皂化、萃取、净化、浓缩等处理后,用Agilent 6890N型气相色谱仪、DB-XLB型毛细管气相色谱柱(30 m×0.32 mm×0.50μm)、ECD检测器测定。共检测出43种PCBs同系物。结果表明,PCBs在海豚8种不同组织中的含量范围为19.6~1 326.3 ng/g组织,皮肤中比其余7种组织的PCBs含量(19.6~90.4 ng.g-1)高2个数量级,各组织中含量由大到小依次为皮肤、心脏、肌肉、肝脏、睾丸、胃、肾脏、肺。PCBs同系物和同族物在海豚不同组织中的分布特征相似,同系物中以PCB153所占总量的百分比最大,在18.7%~21.1%之间,其次分别为PCB180、PCB187,分别占9.65%~12.02%和4.08~9.26%,PCB138、PCB157、PCB151、PCB110和PCB145等5种同系物所占百分比相对较低,范围为0.87%~5.80%;在同族物中以含6个氯原子的PCBs百分比最大,为48.2%~58.2%,其次分别是含7个和5个氯原子的,所占百分比分别为18.76%~24.81%和12.10%~18.10%。应用二英毒性当量(TEQ)评价了糙齿海豚不同组织中PCBs的毒性,其TEQs范围为45.04~2 896.67 pg/g,其中皮肤的毒性当量最高,比肺的高2个数量级,比心脏、睾丸、肌肉、肝脏、胃和肾脏的高1个数量级。TEQs主要来自非邻位取代的PCBs,占总量的98.5%~99.3%,其中来自PCB126的占86.3%~93.7%,是海豚体中TEQs的主体。与世界其他海域海豚的PCBs污染水平相比,大鹏湾海域糙齿海豚的PCBs污染处于相对严重水平。     

鲸类体内持久性有机氯残留研究的进展

文章综述了20世纪70年代以来有关鲸类体内持久性有机氯（persistent organochlorines，POs）的研究进展和概况，包括鲸类体内POs残留水平的分析方法；POs进入鲸体内的方式及消除途径；鲸类体内POs的残留水平；POs对鲸的有害影响；鲸类体内POs污染的毒性评价。通过分析表明，POs对海洋生态系统的影响还将持续很长时间，中国应进一步研究近岸海域哺乳动物POs的长期污染效应，进而更深入地研究其环境行为、归宿和影响效应。     

福建省东山湾生态环境中多氯联苯的残留特征

对福建省东山湾海域的水质、沉积物和养殖贝类中的多氯联苯（polychlorinated biphenyls,PCBs）残留进行气相色谱法检测,并对其在水域环境及贝类中的残留水平、生态风险及食用安全进行了探讨。结果表明： 1）海水中PCBs浓度底层高于表层;夏季（8月）高于春季（5月）。总体上,东山湾海水中PCBs浓度的平面分布从湾内到湾外呈递减趋势。底层海水中PCBs与悬浮物浓度之间具有极显著的相关性。2）表层沉积物中PCBs浓度平面分布呈近岸高、湾中部和湾外低的格局;PCBs与总有机碳（TOC）之间呈极显著正相关。PCBs残留量产生的生物有害效应的风险低。3）养殖贝类体中PCBs的残留量种间差异明显,对PCBs富集能力的大小,僧帽牡蛎、缢蛏和波纹巴非蛤最高,泥蚶和华贵栉孔扇贝次之,菲律宾蛤仔和杂色鲍最低。养殖贝类致癌风险指数在可接受风险范围内,贝类体中的PCBs残留水平居福建省沿海养殖贝类中等水平。     

浙江沿海海洋水产动物的多氯联苯检测分析

对浙江沿海5个地区的贝类、虾类和鱼类等水产动物体内的多氯联苯进行GC-MS检测分析,研究多氯联苯各单体在不同生物体内的分布特征、影响因素和积累分布规律。结果表明：浙江沿海海域生物多氯联苯检出率为100%,ω(PCBs)为0.12～9.40μg/kg,低于国家标准限量。其中,贝类中ω(PCBs)为0.83 ~10.52 ng/g,平均值为4.20ng/g;虾类ω(PCBs)为0.43~2.18ng/g,平均值为1.27ng/g;鱼类中ω(PCBs)为0.50～2.63ng/g。平均值为1.61ng/g。总体看不同种类海洋生物PCBs含量贝类>鱼类>虾类。从地区分布来看三门地区海产品中PCBs含量最高,玉环、椒江次之,宁海最低。甲壳类样品的PCBs检出以六氯联苯(PCB138)为主,鱼类样品的PCBs检出以五氯联苯(PCB118)为主,表现出水生生物对高氯联苯富集量高于低氯联苯富集量的共同点。而在各类动物中PCBs检出量最高的样品,如缢蛏、僧帽牡蛎和菲律宾蛤仔,都表现出了对于四氯联苯（PCB52）的强富集能力。     

吕四渔场近岸海域水质和沉积物中多氯联苯(PCBs)的分布特征

采用气相色谱测定了吕四渔场水质和沉积物样品中的多氯联苯(PCBs),并分析了其分布特征。结果显示,吕四渔场水质和沉积物中的PCBs平面分布特征为南部近岸高,而北部近岸较外海低,调查海域PCBs含量有逐年升高的趋势。水质中以低氯代PCBs同族体为主,沉积物中以高氯代PCBs同族体为主,含6个氯原子的PCBs在水中和沉积物中含量都比较高。为了削减PCBs对环境和人类的危害,我们要加强控制、管理、研究和合作。     

福建沿海中北部主要贝类养殖区沉积物、贝类质量的初步分析和评价

2009年8至9月对福建沿海中北部主要贝类养殖区沉积物及贝类质量状况进行了全面的调查。结果表明,沉积物中有机碳、石油类、Hg、Cd、Pb、As、HCHs、PCBs含量均符合海洋沉积物质量第一类标准,部分海域硫化物、DDTs含量超标,整体上贝类养殖环境质量良好。贝类体内Hg、As、Pb、HCHs、PCBs、DDTs含量均符合无公害水产品质量安全要求,仅有小部分站点贝类体内镉含量超标,但贝类受石油烃污染较严重。     

海水养殖贝类体中TPH和PCBs的分布和积累研究

根据2005年4月和10月对厦门海域贝类养殖区养殖贝类体中有毒有害物质含量的调查资料,对4种养殖贝类(僧帽牡蛎、菲律宾蛤仔、泥蚶和缢蛏)体中石油类(TPH)和多氯联苯(PCBs)含量的分布和积累特征进行了研究。结果表明,厦门海域4种养殖贝类体中TPH和PCBs含量范围分别为(2·89~34·6)mg/kg,湿重和(5·06~45·7)μg/kg,湿重,总平均值分别为12·3mg/kg,湿重和15·5μg/kg,湿重。总体上,养殖贝类体TPH和PCBs含量的区域分布,潮间带养殖贝类>浅海养殖贝类>虾池养殖贝类,呈西海域和同安湾内较高,大嶝海域较低的格局。养殖贝类体TPH和PCBs含量季节变化呈春季(4月)高于秋季(10月)之势。养殖贝类体内组织对TPH和PCBs吸收和积累能力的高低为胃(包括胃含物)>肌肉组织>外套腔液。缢蛏体对TPH的吸收和积累能力较强,泥蚶对PCBs吸收和积累能力较强。这与其自身对TPH和PCBs的吸收和排泄能力有密切的关系。厦门海域养殖贝类受到PCBs轻度污染,一些养殖区的缢蛏、泥蚶和僧帽牡蛎受到TPH的不同程度污染。     

广东沿海养殖牡蛎中多氯联苯残留水平及人体饮食暴露风险评估

文章利用气相色谱质谱法测定了广东沿海主要养殖区(汕头、汕尾、深圳、珠海、江门、阳江、湛江)养殖牡蛎体内30种多氯联苯(Polychlorinated biphenys,PCBs)的含量,评价了其污染水平和致癌风险。结果表明,广东养殖牡蛎中普遍检出PCBs,检出率为97.6%,其质量分数为nd~8.62 ng·g^-1(湿质量,下同),平均值为(0.57±1.23)ng·g^-1,其中以深圳水域养殖牡蛎体内的PCBs含量最高,珠海次之,汕头、阳江、江门、湛江及汕尾较低。不同地区养殖牡蛎中PCBs的组成模式类似,均以五氯代和六氯代PCBs为主。与国内外部分沿海海域贝类相比,广东省养殖牡蛎中PCBs含量处于较低水平。广东省养殖牡蛎中PCBs残留量低于中国《食品安全国家标准食品中污染物限量》及欧盟国家的贝类卫生标准,食用牡蛎的致癌风险及危害商数均小于美国环保局(EPA)推荐的可接受风险水平,致癌风险处于可接受风险水平。     

海水污染物对对虾毒性研究的进展 Ⅰ.对虾的重金属毒性研究

本文从重金属对对虾的毒性效应;重金属在对虾体内的积累、分布和排出规律,重金属在对虾体内的致毒和解毒机理等三个方面的研究展开述评。认为重金属对对虾的毒性研究须区分其存在形态及其形式,进行毒性实验的同时亦须重视重金属在对虾体内的生长效应的研究。有关重金属在对虾体内的积累、分布和排出规律的研究较多,但食物链的迁移和生物学放大作用尚未引起足够的注意;重金属在对虾体内的致毒和解毒机制也少见文献报道,尚待深入探讨,并需加强对虾体内不同重金属之间的协同和拮抗机理研究。     

Seasonal distribution of the Indo-Pacific humpback dolphins: Implications for coastal habitat management

1. Organisms utilize suitable habitat patches wherein they optimize fitness. For marine megafauna such as cetaceans, foraging is generally the explanation for their utilization distribution. However, an explicit link between cetaceans' distribution and spatio-temporal pattern of food resource is usually lacking.
2. The Indo-Pacific humpback dolphin (Sousa chinensis; VU listed in the IUCN Red List) inhabits the coastal waters from south-east China to eastern India. Seasonal distribution of the humpback dolphin was explored in the northern Beibu Gulf, China. Sightings of the humpback dolphin were systematically collected at monthly intervals from 2012 winter till 2018 spring and used to derive distribution patterns from kernel density estimates. Satellite remotely sensed net primary productivity (NPP) and bathymetry were used to present oceanographic characteristics in the study region.
3. Seasonal variations were observed in oceanographic characteristics and spatial distribution of the humpback dolphin. Although the core distribution area of the humpback dolphin showed seasonal expansion and contraction, it had consistently higher NPP and shallower depth than the survey range throughout the seasons.
4. Our findings indicate a clear profile of these two oceanographic characteristics (i.e. NPP and bathymetry) in the humpback dolphin's core distribution area. Food resource utilization could play an important role in the humpback dolphin's distribution within the study site. The seasonal dynamics imply that not only food abundance, but also efficiency in accessing/capturing the prey may affect distribution of the humpback dolphin.
5. In the study site, human activities that can change regional topography and productivity of the coastal water through land reclamation, dredging, sand mining and bottom trawling, should be mitigated, regulated or avoided. Proactive conservation should incorporate catchment management of the main rivers to address potential sediment and nutrient load into the estuary to protect local habitat configuration in terms of NPP and bathymetry.

     

Dusky dolphin foraging habitat: overlap with aquaculture in New Zealand

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Abundance,distribution and diet of the common dolphin,Delphinus delphis,in the northern Aegean Sea (Greece)

1. The abundance, distribution and diet of the short-beaked common dolphin were investigated as part of the first detailed study on cetacean populations in the North Aegean Sea. Since 2004, the area has been proposed by national and international entities as a marine protected area for common dolphins and other cetacean species owing to its high biodiversity.
2. Abundance and distribution were investigated between 2005 and 2013 through dedicated scientific marine transect surveys, covering 14,701 km, in sea conditions of Beaufort sea state 3 and below. The line-transect sampling method was used to estimate relative abundance, using Distance 6.0 software. Encounter rate for this species in the study area was estimated to be 0.24 groups/100 km (1.5 dolphins/100 km), with a mean group size of 6.88 (SE = 1.90).
3. Common dolphin sightings were analysed for correlations with eight environmental variables (distance from the coast, depth, slope, median salinity, gradient of salinity, median temperature, gradient of temperature and mean current) using generalized additive modelling. Common dolphin sightings were significantly correlated to depth, temperature and salinity.
4. Stomach-content analyses were performed on eight suitable samples from common dolphins stranded in the study area. The trophic level of the species was calculated, indicating that this species is a top predator.
5. This research provides the first estimates for abundance and distribution and the first diet analysis for this Mediterranean Endangered dolphin species in the study area based on a year-round long-term study.

     

Species‐specific distribution model may be not enough: The case study of bottlenose dolphin (Tursiops truncatus) habitat distribution in Pelagos Sanctuary

1. Geospatial models are used to predict the distribution of terrestrial and marine species, according to their ecological and ethological habits. The bottlenose dolphin is a cosmopolitan marine top predator, inhabiting most of the ocean, with the exception of polar and subpolar waters. This wide distribution is associated with a remarkable plasticity in ecological and behavioural habits, which makes it difficult to model and predict its distribution.
2. This study proposes a ‘multi‐type approach’ to predict the presence and distribution of the bottlenose dolphin in the Pelagos Sanctuary, a Specially Protected Area of Mediterranean Importance located in the north‐west Mediterranean Sea. A multi‐type model based on random forest regression was developed, analysing the distribution habits of two geographical units living in the Pelagos area.
3. When compared with a classical single‐type model, the multi‐type model performed much better in a prediction test (true skill statistics, TSS = 85% vs. 52%), confirming the value of this experimental approach. This work suggests that wild species should not be considered as one single‐type entity, as local specialization may change and shape their distribution habits.

     

Influence of seasonality on cetacean diversity,abundance, distribution and habitat use in the western Mediterranean Sea: Implications for conservation

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Habitat configuration for an obligate shallow‐water delphinid: The Indo‐Pacific humpback dolphin,Sousa chinensis,in the Beibu Gulf (Gulf of Tonkin)

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Beware of changes: Conservation of Indo‐Pacific humpback dolphins in disturbed habitats

1. Protecting critical habitats of the Indo‐Pacific humpback dolphin, Sousa chinensis, is a hot topic of discussion for marine biodiversity conservation in China and many Southeast Asian countries. In practice, sound habitat protection action (HPA) planning often suffers from information gaps in macroscopic habitat configurations and changes in the habitat conditions of humpback dolphins.
2. Recent publications in the journal Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) have served to advance humpback dolphin conservation in Chinese waters by resolving such habitat configurations and indicating significant changes in distribution patterns and habitat characteristics under intense coastal anthropogenic activity.
3. We highlight an integrative research framework to investigate habitat configuration and long‐term habitat changes when planning a holistic HPA programme for humpback dolphins. When constructing habitat configuration baselines, field surveys should be designed and conducted in a systematic manner to ensure survey efforts cover diverse environments equally, in either a spatially stratified or gridded pattern, to minimize potential spatial sampling biases. Long‐term habitat changes can be revealed by comparing satellite images from different decades. Changes in habitat preferences and habitat characteristics can be explored through questionnaire surveys on local ecological knowledge, associating historical occurrences with coastline features and projecting historical habitat configuration by species distribution modelling exercises.
4. A lack of good communication and sharing of information between research and management sectors can still be an obstacle to the implementation of sound conservation practices, however, even though there is robust scientific evidence to fill knowledge gaps in distribution and habitat baselines. We have addressed the need to establish a mechanism to improve and streamline information sharing between research teams, management sectors, and stakeholder groups.

     

Barriers to biodiversity conservation in marine fishery certification

Two global certification and ecolabelling systems – the generic global dolphin‐safe ecolabel and the global Marine Stewardship Council (MSC) ecolabel – are assessed for their present and potential contributions to improving biodiversity conservation in marine capture fisheries. The dolphin‐safe ecolabel appears to have played a minor role in a reduction of dolphin mortality in tuna fisheries, but dolphin populations in the worst‐affected area have not recovered, and it appears that the current level of dolphin by‐catch sanctioned by present‐day fishery management and the ecolabel is not effective enough to achieve population recovery. The MSC ecolabel has established a poorly expressed environmental standard that has resulted in variable interpretations by certifiers, creating an apparently systematic bias in application of the standard to the certified fisheries. Without substantial revision of both these systems, it seems unlikely that they will be able to make major contributions to marine biodiversity conservation because of barriers created by limitations in programme design, lack of robust linkages between the certification standard and biodiversity conservation outcomes, and unclear standards and their inconsistent application in the certification of fisheries.     

Parental Contributions in a Japanese Flounder Hatchery Inferred from Mitochondrial DNA Haplotypes

We analyzed a portion of the mitochondrial genome of hatchery Japanese flounder Paralichthys olivaceus to compare the genetic characteristics between maternal parents and their offspring. The maternal parents consisted of 11 subcultured fish (broodstock taken from hatchery-raised fish) and 41 wild fish. A 1098 base pair region extending from the 3'half of the cytochrome b gene to the central domain of the control region of mtDNA was amplified by PCR and analyzed using 11 restriction endonucleases. We also analyzed the number of copies of tandem repeats in the control region from the sizes of the PCR products. Each female parent had a unique haplotype, but only 31 of them were observed among the 66 offspring examined. From these results, we estimated that about 60% of the maternal parents in the hatchery contributed to the offspring we surveyed. The distribution of the family sizes of the wild fish was Poisson, which is consistent with expectation from a randomly mating population. In contrast, the distribution of family sizes of the subcultured fish deviated from a Poisson distribution. One of the sources of the deviation was that none of the six oldest fishes contributed to offspring production, which is consistent with observation that the spawning peaks later in the spawning season for older fish in flounder hatcheries. Uneven contribution of the female flounders in the hatchery has the potential to reduce substantially the genetic diversity in the offspring. Our results suggest that the misuse of subcultured fish as broodstock is an important cause of reduced genetic diversity in hatchery-raised flounder juvenile.     

Bottlenose dolphins (Tursiops truncatus) in the north-western Adriatic Sea: Spatial distribution and effects of trawling

1. Many species and populations of odontocetes have modified their behaviour to take advantage of feeding opportunities provided by fishing activities, with depredation of fishing gear being the most common type of adaptation.
2. The northern Adriatic Sea has been identified as an important marine mammal area because of a regular occurrence of common bottlenose dolphins. Boat surveys were conducted within a 3,000 km² sector of the Adriatic Sea off the coast of Veneto, Italy, between April and October 2018–2019. Based on 76 days at sea, 10,711 km of navigation, and 81 h 26 min of dolphin tracking, this study contributes novel quantitative information on dolphin spatial distribution, and on their occurrence in the wake of beam trawlers, otter trawlers, and midwater pair trawlers.
3. A combined generalized additive model and generalized estimation equation framework indicated that trawling—along with other physiographic, biological and anthropogenic variables—influenced dolphin distribution. In days of trawling, the chance of encountering dolphins increased by ~4.5 times (95% confidence interval 1.8–11.0) near active beam trawlers, by ~16.0 times (7.1–36.0) near otter trawlers, and by ~28.9 times (12.0–69.6) near midwater pair trawlers.
4. Spatial modelling was used to create maps of predicted distribution, suggesting differences in habitat use between trawling and no-trawling days. Spatial modelling for all days identified a dolphin distribution hotspot of 832 km², situated off the Po river delta.
5. Evidence contributed by this study can be used to inform management action within one of the world's areas most heavily impacted by fishing and other human encroachment. Such management action would help enforce the European Union's Habitats Directive and Marine Strategy Framework Directive, while also informing EU's Maritime Spatial Planning.