The Diel Rhythms of Biosonar Behavior in the Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis) in the Port of the Yangtze River: The Correlation between Prey Availability and Boat Traffic

Information on the habitat use of the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is critical for its conservation. The diel biosonar behavior of the porpoise in the port areas of the Yangtze River was examined along with simultaneous observations of fish density and boat traffic. Biosonar pulses from the porpoises were detected for 1233 min (5.77%) over a 21,380 min duration of effective observations. In total, 190 (5.63%) buzzes (an indication of prey capture attempts) were recorded among the 3372 identified click trains. Of the 168 echolocation encounters (bouts of click trains less than eight min apart), 150 (89.3%) involved single animals, indicating that solitary porpoises were frequently present and feeding in the port areas. Significant diel patterns were evident involving the biosonar behavior of the porpoises (including click trains and buzzes), fish density and boat traffic. The frequencies of the click trains and buzzes were significantly lower during the day than in the evening and at night, which suggests that porpoises in this region are primarily engaged in crepuscular and nocturnal foraging. The lack of a significant diel pattern in the echolocation encounters indicates the importance of the port in porpoise conservation. A forced feeding schedule may be associated with the lack of a significant correlation between porpoise acoustics and boat traffic. Overall, prey availability appears to be the primary factor that attracts porpoises. Additionally, porpoises tend to migrate or remain downstream in the morning and migrate or remain upstream in the evening, most likely to follow their prey. The findings of this study can be used to improve the conservation of the Yangtze finless porpoise.     

固化河岸对长江江豚栖息活动的影响

长江江豚主要栖居在近岸浅水水域,喜好泥沙质类型的河岸。但在长江干流,有很多自然河岸被固化,河岸固化给长江江豚分布和栖息活动造的影响仍不甚清楚。2016年3月—2017年1月,对长江干流2个自然河段江豚的数量和分布做了12次考察,并收集了这2个河段岸型的相关数据,来分析固化河岸对江豚栖息活动的影响。12次考察累计发现江豚215头次,平均每次考察观察到江豚(17.92±7.09)头次。研究区域的固化河岸约占岸线总长的59%,分析发现,仅约13.9%的江豚分布在固化河岸水域,86.1%的江豚均分布在自然河岸水域。江豚在单位河岸长度的分布数量与该段固化河岸长度所占的比例呈显著负相关(r=-0.639,P0.01)。在自然河岸,分布在近岸50 m水域的江豚占31.8%,而在固化河岸,仅观察到2头江豚活动在近岸50 m水域内。由此可见,固化河岸对江豚的近岸分布有明显影响。调查还发现,安庆城区建设带约10 km江段12次考察均未发现江豚分布,城区建设带可能对江豚栖息已造成严重影响。长江干流的固化河岸所占比例非常高,研究结果提示这可能导致长江干流江豚栖息地的丧失和破碎化加剧,在制定长江江豚保护措施必需慎重考虑此因素的影响,并据此提出相应的栖息地保护和恢复方案。     

Detection of Helicobacter in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis

In animals, infection by the Epsilonproteobacteria Helicobacter spp. and H. cetorum is widespread. It has been suggested that H. cetorum may cause gastritis in cetaceans. The aim of our study was to investigate the presence of Helicobacter spp. in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. The fecal material of 12 porpoises living in the wild in Poyang Lake and 1 porpoise living in captivity at the Wuhan Baiji Dolphinarium were examined by PCR for the presence of Helicobacter spp. The fecal material of 8 of 12 wild porpoises and the captive porpoise were positive for Helicobacter spp. as determined by PCR using Helicobacter-specific primers, which target the 16S rRNA gene. A 16S rRNA clone library was then prepared from 1 sample isolated from a female porpoise living in the wild. DNA sequence analysis from 3 of the clones showed 98 to 99% identity to the H. cetorum 16S rRNA gene. These results demonstrate the prevalence of Helicobacter spp. and H. cetorum in endangered freshwater finless porpoises.     

Yangtze finless porpoises along the main channel of Poyang Lake,China: Implications for conservation

Poyang Lake is the largest freshwater lake in China and flows into the Yangtze River. It is a traditional habitat for the endangered Yangtze finless porpoise, which has not been well investigated. To reveal the distribution of the porpoise in Poyang Lake, 12 passive acoustic surveys were conducted along 123 km of the main channel of the lake during different seasons (spring transition season, wet season, autumn transition season, and dry season) from 2008 to 2012. We counted the number of phonating porpoises encountered and calculated the detection rate (encountered individuals detected per kilometer). The median porpoise detection rates ranged from 0 to 0.65 individuals per kilometer during the different surveys. The highest median detection rate of 0.50 was detected in the autumn transition season. The seasonal shrinking of the lake during the dry season may cause a concentration of porpoises in the narrow channels and a high incidence of collisions with cargo ships and fishing boats. Conservation actions should be focused on the main channel of the lake during the dry and transition seasons. In addition, the expansion of the existing reserve to include areas with high porpoise detection rates is necessary.     

长江湖口至荻港段江豚春季对生境选择的初步分析

研究表明鲸类的分布领域、集群规模、索食场所及迁移途径与栖息环境的地貌特征及生境因子密切相关（Watts and Gaskin,1986;Baumgartner,1997;Raum-Suryan et a1．,1998;Karczmarski et a1．,2000）。距离苏格兰较远的Moray Firth海域,生活的一群瓶鼻海豚（Tursiops truncatuz）,它们常聚集在岛屿附近的狭窄深槽入口处,那儿海床呈斜坡,     

长江安庆段江豚主要栖息地鱼类群落结构

长江皖河交汇处(皖河口)是安庆江段江豚主要的栖息地之一。为了解江豚主要栖息地鱼类群落结构,于2013年9月—2014年8月对皖河口及其附近4个断面逐月进行了鱼类调查。研究结果表明,共采集鱼类35种,与历史资料相比,鱼类物种多样性已经严重下降,并且小型化趋势明显。5个断面当中,皖河口鱼类种数最多,为27种,且以中上层鱼类餐和油餐为主要优势种;其余4个断面分别为16、20、19和14种,且多数断面以底层鱼类黄颡鱼和长须黄颡鱼为主要优势种。方差分析结果表明,皖河口渔获物的总数量和总重量与其他断面无显著差异,但总种数却显著高于断面1和5。对中上层、中下层和底层鱼类的进一步分析发现,5个断面的显著差异仅存在于中上层鱼类,且皖河口中上层渔获物的数量和重量均显著高于其他断面。由此推断,江豚选择皖河口作为主要栖息地可能主要由于其更加丰富的中上层鱼类资源。研究结果不仅有助于了解鱼类资源的变化,还对江豚的原地和迁地保护具有重要意义。     

Mitochondrial control region variability of baiji and the Yangtze finless porpoises,two sympatric small cetaceans in the Yangtze river

BaijiLipotes vexillifer (Miller, 1918) and the Yangtze finless porpoiseNeophocaena phocaenoides asiaeorientalis (Pilleri and Gihr, 1972) are two sympatric small cetaceans inhabiting the middle and lower reaches of the Yangtze River. In this study, a fragment (420–428 bp) of the mitochondrial control region was sequenced to provide the first comparative survey of genetic variability and population structure in these two endangered species, with samples of finless porpoises from the Yellow/Bohai Sea, East China Sea, and South China Sea also included. Low values of haplotype diversity and nucleotide diversity were found for both species, especially for the baiji and the Yangtze River and South China Sea populations of finless porpoises. The analysis of molecular variance (AMOVA) supported a high level of overall genetic structure among three porpoise populations in Chinese waters, with greatest differences found between either the Yangtze River population or the Yellow Sea population and the South China Sea population. The differentiation between the Yangtze and Yellow Sea populations was not significant, and the males have higher genetic differentiation than the females, suggesting a significant female-biased dispersal between these two populations. This study showed that the Yangtze finless porpoise, unlike the sympatric baiji, was not a genetically isolated population. The Yangtze and Yellow Sea porpoises should be included in the same management unit, but further studies using more samples and especially based on more molecular markers are urgently needed to confirm this.     

长江安庆段航道整治对长江江豚数量和分布的时空影响

栖息地丧失和破碎化是威胁长江江豚(Neophocaena asiaeorientalis)种群长期发展的主要因素之一。航道整治工程是导致江豚栖息地丧失和破碎化的一个主要原因,研究工程施工和运行对江豚数量和分布的影响可为江豚栖息地管护提供有益信息。通过对湖口-吉阳矶水域江豚数量和分布的持续调查,分析了安庆段航道整治工程施工和运行对江豚的影响。12次目视调查共在研究水域发现江豚258群次613头次,工程施工前、施工期和初步运行期单次考察分别平均观察到江豚(67.0±24.3)头次、(35.6±22.2)头次和(50.0±2.8)头次。在主要施工区共发现江豚79群次185头次,施工前、施工期和初步运行期单次考察分别平均观察到江豚(18.60±12.03)头次、(10.4±7.3)头次和(20.0±4.2)头次。工程不同时期主要施工区江豚的数量及占比在统计学上没有显著差异。主要施工区S2和S3工程段施工期江豚平均分布密度((0.18±0.17)头/km、(0.04±0.08)头/km)较施工前((0.62±0.16)头/km、(0.40±0.29)头/km)显著下降,S5和S6工程段施工期平均...     

长江江豚细菌性疾病的诊治

人工饲养或易地保护长江江豚(Neophocaena asiaeorientalis asiaeorientalis), 其水体中常含有病原菌且易引起江豚发病, 探讨长江江豚的细菌性疾病诊疗方法十分必要。文章利用细菌的分离培养与鉴定, 结合血液检测结果, 对安庆西江围网内一头患病江豚进行了病原确诊, 结果发现患病江豚的致病原为金黄色葡萄球菌(Staphylococcus aureus)和魔氏摩根菌(Morganella morganii)。依据致病菌的药敏试验结果, 综合患病江豚的整体状况制定了治疗方案并对其进行系统治疗, 结果预后良好。研究的成功开展为江豚、海豚等鲸类动物细菌性疾病的诊断与防治提供了良好借鉴。     

铜陵长江大桥对豚类栖息地的影响

根据1987-2001年在铜陵江段所进行的18次豚类生态考察,统计历年考察记录中,在成德洲-梅埂段（以下称大桥河段）工作的天数及观察到的白Ji豚和长江江豚数量,分别计算其SPUE值（Sightings per unit of effort,以头/d计）。并于1989,2001年,在长江水位8.5m左右（吴淞 高程）测定了大桥河段断面A,B,C,D的深度（m)及流速（m/s)。根据汉道最大河宽（B）,转折角（α）,曲折率（S/L）,以及汊道宽长比（B/S）的变化,分析河道与沙洲的变动对白Ji豚和长江江豚栖息地的影响。研究结果表明大桥建成后,河段平面变形小,汊道分流比稳定,滩槽很少变动,流态稳定,水势复杂多样,仍具备豚类栖息活动必要的水文条件,但铜陵大桥对其上下河道,沙洲也产生了一定的影响,主要表现为近期和悦洲与成德洲附近的滩槽冲淤明显,汇,分流区主流摆动不确定,不能形成稳定的水区,导致成德洲附近的白Ji豚和长江江豚活动次数明显减少,特别是白Ji豚的活动路线中（太阳洲→梅埂）的羊山矶,历次考察中未观察到白Ji豚,总而言之,白Ji豚在大桥河段的SPUE值降低与其种群急剧下降是一致的,但在梅埂活动的次数下降不明显;长江江豚在局部水域（梅埂,横港）的SPUE值有上升趋势,这些现象可能与近期的河床演变及桥墩挑流有关。     

天鹅洲迁地保护江豚群体的遗传评估与发展预测

文章以2008年春季遭受严重雪灾的天鹅洲白鱀豚国家级自然保护区迁地保护江豚群体为研究对象,利用物种特异性微卫星遗传标记对该群体的遗传多样性进行了评估,并通过软件对其发展趋势进行了模拟和预测。研究结果表明,虽然2008年春季雪灾并未导致该群体遗传多样性的严重损失,灾后群体依然表现出中等水平的微卫星遗传多样性(18个座位的平均等位基因数为4.780,平均观察杂合度和期望杂合度分别为0.748和0.674);但模拟结果显示,该迁地保护江豚群体的遗传多样性将快速下降,100年后仅能保留约79%的等位基因和约84%的遗传杂合度。此外,模拟结果表明,通过增加群体数量和调整群体性比可有效减缓该群体遗传多样性的下降速度。根据研究结果,并结合长江江豚自然种群快速下降的现状,作者提出天鹅洲迁地保护江豚群体当前最重要的保护策略应该是尽早补充一定数量的、合适的野生个体,在加强遗传多样性保护的同时使其群体数量快速增长并形成一个更大规模的有效繁殖群体。     

Auditory temporal resolution and evoked responses to pulsed sounds for the Yangtze finless porpoises (<Emphasis Type="Italic">Neophocaena phocaenoides asiaeorientalis</Emphasis>)

Temporal cues are important for some forms of auditory processing, such as echolocation. Among odontocetes (toothed whales, dolphins, and porpoises), it has been suggested that porpoises may have temporal processing abilities which differ from other odontocetes because of their relatively narrow auditory filters and longer duration echolocation signals. This study examined auditory temporal resolution in two Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) using auditory evoked potentials (AEPs) to measure: (a) rate following responses and modulation rate transfer function for 100 kHz centered pulse sounds and (b) hearing thresholds and response amplitudes generated by individual pulses of different durations. The animals followed pulses well at modulation rates up to 1,250 Hz, after which response amplitudes declined until extinguished beyond 2,500 Hz. The subjects had significantly better hearing thresholds for longer, narrower-band pulses similar to porpoise echolocation signals compared to brief, broadband sounds resembling dolphin clicks. Results indicate that the Yangtze finless porpoise follows individual acoustic signals at rates similar to other odontocetes tested. Relatively good sensitivity for longer duration, narrow-band signals suggests that finless porpoise hearing is well suited to detect their unique echolocation signals.     

长江江豚自然保护区建设管理存在的问题及调整建议

长江江豚(Neophocaena asiaeorientalis)是生活在中国长江的珍稀濒危鲸类动物, 自然栖息地破坏是造成其种群衰退的重要原因。目前中国已经在长江中下游流域建立了8个长江江豚自然保护区。然而, 早期保护区的功能区划随经济发展和生态保护的现实矛盾日渐突出, 按照现行法规对保护区难以实行有效管理, 迫切需要进行优化调整。文章基于国家政策、长江江豚生物学特点及分布规律, 兼顾航运等重大经济发展需求, 提出了长江豚类自然保护区调整的原则和建议: (1)将长江江豚喜好的近岸水域及一定范围的重要江滩和洲滩湿地, 及江心洲汊江一侧水域划入核心保护区; (2)将中间主航道水域以及长江大堤至核心区边界之间的水域划入一般控制区; (3)兼顾历史遗留问题, 细化不同区域的管控措施。该调整方案一方面使保护区功能区划更加符合长江江豚的分布特征和偏好生境, 有利于对其自然种群和重要栖息地的有效保护。另一方面也有助于理顺自然保护区管理上存在的法律障碍, 为长江江豚自然保护区建设、规划和管理提供新的思路和模式。     

渤海江豚种群现状初探

渤海是黄渤海江豚种群的重要分布区,但是有关该区域江豚的种群数量的资料极其匮乏。2015年至2016年,采用截线抽样法在渤海水域开展了6个航次的目视调查,收集了渤海江豚的分布数据,首次评估了区域内的江豚种群数量,为制定有效的渤海江豚种群生态保护策略提供了基础资料。调查结果显示,在2015年8月、2016年5~7月、9月和11月进行的6个调查航次共计8972 km的有效航程中,发现江豚87次、136头次。江豚在渤海各海湾和中部水域都可观察到;14:00-18:00时段、离岸15~35km范围内较易观察到江豚;黄河口外、秦皇岛东北侧老龙口和莱州外沿岸河口水域,江豚出现频次较多。各季节中,以5月在黄河口外20~40km范围内发现江豚的频次和数量最多。采用Distance 7.0软件估算渤海江豚种群数量,其中探测概率分别取值0.399、0.85和1时,渤海江豚种群数量估算值分别为7883头（CV=0.21）、3701头（CV=0.21）和3124头（CV=0.21）,对应的种群密度分别为1.441头/km2、0.066头/km²和0.056头/km²,均低于已报道的南黄海和日本海江豚种群相应值。受海上天气、调查条件和经验所限,本文估值可能存在偏差,但限于渤海江豚历史资料缺乏的现状,本文的结果对于认识渤海江豚的种群状况仍具有重要参考意义。     

Serum concentrations of gonadotropins and steroid hormones of Neophocaena phocaenoides asiaeorientalis in middle and lower regions of the Yangtze River

As a relatively isolated and unique freshwater population, the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) is the most endangered subpopulation of this species. The objective of this study was to improve our understanding of their reproductive endocrinology by measuring (radioimmunoassay) serum concentrations of FSH, LH, estradiol (E(2)), progesterone (P(4)) and testosterone (T(2)) in free-ranging animals. Blood samples were collected from 66 Yangtze finless porpoises (41 males and 25 females) captured in the middle and lower reaches of the Yangtze River. Based on significant variation of serum T(2) concentrations in males with body length (BL) >138 cm, we inferred that they were mature; in these animals, there were significant seasonal variations in serum T(2) concentrations, with the highest concentrations in March and April (502.0+/-319.8 ng/dL, mean+/-S.D.) and the lowest in December (79.4+/-83.2 ng/dL). Serum T(2) concentrations positively correlated with serum concentrations of LH and weakly correlated with serum concentrations of E(2), whereas there was a significant negative correlation between serum LH and FSH concentrations in males >138 cm. The smallest apparently pregnant female porpoise had a BL of 130 cm. Serum P(4) concentrations ranged from 13.2 to 112.4 ng/mL (43.9+/-28.3 ng/mL) in pregnant females, and fluctuated under 1.0 ng/mL in non-pregnant females with BL>130 cm. Serum LH concentrations were significantly higher in non-pregnant females >130 cm versus those females <130 cm. To our knowledge, this is the first study of endocrine-related maturity and seasonal breeding characteristics of the Yangtze finless porpoise.     

长江江豚脐带永生化成纤维细胞系建立及细胞生长特性研究

取长江江豚(Neophocaena phocaenoids asiaeorientalis)产后胎盘脐静脉,经组织块培养,差异贴壁法纯化,构建长江江豚的原代细胞系;经外源癌基因SV40 T antigens(猿猴病毒T抗原)转染构建稳定脐带细胞系,并对长江江豚的永生化后的成纤维细胞的细胞形态、转染效率、生长曲线和活率等...     

长江江豚微卫星DNA分离的初步研究

为了开发物种特异性微卫星标记,本文采用一种改良的快速微卫星分离法(FIASCO)从长江江豚(Neophocaena phocaenoides asiaeorientalis)的基因组中筛选得到72条微卫星DNA序列。根据重复单元的排列特点,完美型、非完美型及复合型序列所占的比例分别为58.3%、22.2%和19.5%。选择其中30条序列设计PCR扩增引物,并用12个随机选择的长江江豚样品进行多态性筛选。初步结果表明其中14对引物的扩增产物稳定并且具有多态性;在每个座位上获得2-13个等位基因,平均等位基因数为5.87个;14个微卫星座位的平均观察杂合度(Ho)和期望杂合度(He)分别为0.560和0.709。本研究获得了长江江豚的第一批物种特异性微卫星座位及其扩增引物,这些微卫星标记将在后续的保护遗传学研究中发挥重要作用。       

Post-mortem investigations on stranded dolphins and porpoises from Hong Kong waters

Stranded cetaceans reported from the territorial waters of Hong Kong during the period May 1993 to March 1998 were examined to establish factors that may have contributed to their death. During the current study, 28 Indo-Pacific hump-backed dolphins (Sousa chinensis), 32 finless porpoises (Neophocaena phocaenoides), and four bottlenose dolphins (Tursiops truncatus) were necropsied. Bacteria (15 species) were isolated from nine animals. Of these bacteria, 47% were of possible fecal origin reflecting the high level of sewage contamination in Hong Kong's waters. One finless porpoise displayed wounds caused by a shark attack, and two female finless porpoises presented prolapsed uteri. At least 10 finless porpoises showed evidence of moderate to heavy lungworm infections (Halocercus pingi), and this appears to have been a factor contributing to death in at least six animals. Evidence suggesting blunt traumatic injury (probably caused by boat collisions) was found in six cetaceans (three finless porpoises and three hump-backed dolphins). Signs of fishery-related mortality were detected in at least nine animals (six hump-backed dolphins, two finless porpoises, and one bottlenose dolphin). Of these two human-caused mortality types, pre-existing disease or bacterial infection were detected in 29% of cases. Results indicate that human factors may have played a significant role in the death of at least 15 animals (32% of hump-backed dolphins, 15% of finless porpoises, and 25% of bottlenose dolphins).     

Variations in independent areas of activity of captive Yangtze finless porpoises, <Emphasis Type="Italic">Neophocaena phocaenoides asiaeorientalis</Emphasis>, during the acclimation period after wild capture

The acclimation process of Yangtze finless porpoises to a limited holding pool after their introduction to this new captive environment is presented. One male (#1) and two female (#2, #3) finless porpoises, newly captured from two different sections of China’s Yangtze River, were observed in an indoor holding pool with an area of 155 m² from January 1997 to January 1998 (animal #3 was removed from the pool in mid-February 1997). Three separate areas in the pool were predefined. Time spent in each of the areas was individually monitored two or three sessions a week using the focal sampling method. In total, 71.3 h of observations (316 sessions) were recorded, with an average observation time each month of about 2.4 h (10 sessions) for each porpoise. The percentage of time spent in each area per month was calculated for each porpoise, and the variations in the percentage of time spent in each area was compared. Results indicated that independent areas of activity existed among porpoises during the early stages of captivity. However, over time, the frequent approaches of the female to the male caused these areas to fade away, resulting in almost equal use of the entire pool area by the newly formed group. The existence of the independent areas of activity during the early months of captivity indicates that newly introduced individuals from different wild subgroups may need separate areas for activities. However, further studies with more animals are needed to draw more general conclusions about the individual areas of activity of this subspecies when in captivity.     

Analysis of the bacterial diversity in the fecal material of the endangered Yangtze finless porpoise, <Emphasis Type="Italic">Neophocaena phocaenoides asiaeorientalis</Emphasis>

The aim of this study was to determine the bacteria present in the fecal material of the endangered Yangtze finless porpoise, Neophocaena phocaenoides asiaeorientalis. Fecal samples were collected from 12 Yangtze finless porpoises living in the wild at Poyang Lake, located in Jiangxi Province, China. To determine the bacterial diversity, a 16S rRNA gene clone library using the bacterial PCR primers fD1 and rP2, was prepared. A total of 138 near-full-length sequences were analyzed and 39 operational taxonomic units (OTUs) were identified. Sequences showing ≥97% similarity were grouped together as an OTU. Six different phyla were identified in which 38 OTUs were classified. Most of the OTUs contained sequences belonged to the phylum Firmicutes (51.3%), followed by Tenericutes (17.9%), Proteobacteria (15.4%), Actinobacteria (7.7%), Deinococcus-Thermus (2.6%) and Cyanobacteria (2.6%). A phylum could not be assigned for one clone within one OTU (2.6%). It appears that the Yangtze finless porpoise has a more diverse range of bacteria compared to other aquatic mammals, such as seals.