海洋江豚的研究概述

近年来随着国家政策的重视,人们环保意识的提高,针对珍稀濒危水生野生动物,尤其是鲸类动物的保护工作受到越来越多的关注。截至目前,国内相关研究单位针对鲸类动物开展了大量研究,但研究对象主要局限在中华白海豚(Sousa chinensis)和长江江豚(Neophocaena asiaeorientalis asiaeorientalis)。相比较而言,在我国分布范围更广的海洋江豚得到的研究和保护远远不够,亟需开展系统深入的研究工作。鉴于此,本文对江豚的记载、分类和海洋江豚的研究进行了回顾,重点总结了海洋江豚的生态学、生物学、遗传学、声学以及摄食和繁殖等方面的研究进展,对今后的研究和保护重点提出了建议,包括注重基础研究、强化保护区建设、注重保护技术研发和加强宣传教育,以期对未来的工作提供借鉴。     

长江天鹅洲故道长江江豚饵料鱼类状况与管理建议

<正>饵料鱼资源是影响长江江豚个体营养状况、生长和繁育的关键因素。调查发现,贝氏鰲、鰲、短颌鲚等1 1种优势种是天鹅洲故道长江江豚的主要饵料鱼类;放流长江干流鱼类早期资源对保护区长江江豚饵料鱼增殖具有关键作用;丰富和稳定饵料鱼供给是天鹅洲保护区长江江豚种群稳步增长的重要原因。长江江膝(Neophocaena phocaenoides asiaeorientalis)是仅分布于长江及附属通江湖泊的濒危保护动物;2017年考察结果显示,当前长江     

不同模拟情景下长江江豚种群生存力分析

为了探讨长江江豚(Neophocaena asiaeorientalis asiaeorientalis)种群的生存动态和管护对策，本研究利用漩涡模型(Vortex 10.3.7.0)对长江江豚种群生存力进行了回顾和现状分析。结果发现，以1999年作为回顾分析起点，长江江豚的灭绝概率最可能为0.0754，且不高于0.5629。平均灭绝时间最可能为93.5年，且不少于87.9年。以2017年作为现状分析起点，长江江豚种群灭绝概率为0.3551~0.6985，平均灭绝时间为83.5~88.0年。在特定情景下，设定新生幼豚雄性所占比例分别为0.55、0.50和0.45，经模拟计算得出，雄性化让灭绝概率由0.6985增加到0.9157，雌性化使其下降到0.3664。同时，数据比较发现，新生幼豚雄性所占比例下降10%，成年雌豚生殖率提高10%，二者最终效果相当。上述研究结果表明，长江江豚种群生存风险较大，需重点保护，修复其生境，尤其是母子豚相关生境有利于长江江豚的保护。     

长江安庆段长江江豚种群数量和分布特征分析

<正>自从白鳍豚被宣布功能性灭绝以来，长江江豚是长江中仅存的淡水鲸类(TURVEY S T,2007)。从20世纪80年代初开始，长江江豚数量持续下降，针对长江干流的调查显示，长江江豚从1991年的2 546头下降至2006年的1 225头；长江湖口以下的安庆段是长江干流中江豚密度最高的江段之一(Zhao X,2008;Huang J,2020)。目前，该江段已成立安庆江豚省级自然保护区，对江豚野生种群进行全面保护。然而至目前为止，     

江豚

1988年2月，我们在长江江阴江段搜集到一只体重23公斤，体长1．05米的江豚(见照片)，并剥制成标本陈列于中国水产科研究院淡水渔业研究中心水族实验室。江豚俗名江猪、海猪、海豚、海和尚。在分类学上属脊索动物门，哺乳纲、鲸目，鼠海豚科，是世界上最小的温水性齿鲸类，被列为我国第二类保护动物。     

南京长江江豚省级自然保护区鱼类重金属含量与风险评价

为评价长江江豚(Neophocaena asiaeorientalis)保护区内鱼体质量金属富集现状及重金属污染对江豚的潜在影响,2018年6月、9月和12月分别在保护区江段采集了鳊、鳜、■、鲢和鲫5种鱼类,测定鱼体肌肉中的Pb、Cd、As、Cu和Zn等5种重金属元素的含量,评价保护区鱼类受重金属污染的程度。结果显示,鲫肌肉Cd的单项污染指数(Pi)均大于0.5,夏季捕捞的肌肉As的Pi略高于0.5,其余鱼类的Pb、Cd和As的Pi均小于0.5。研究结果表明,保护区鱼类重金属污染总体风险较小,但部分江豚饵料鱼类存在轻度污染,对江豚有潜在影响,需要引起注意。     

驼背鲸偏爱“丰满女士”

在海洋世界里,丰满的女士是驼背鲸追捧的巨星。一项最新研究显示,雄性驼背鲸总是寻求体型肥大的雌性作为自己的伴侣。这一研究对于我们了解鲸的交配习惯以及开展鲸类保护工作开辟了新的方向。     

驼背鲸偏爱“丰满女士”

在海洋世界里,＂丰满的女士＂是驼背鲸追捧的＂巨星＂。一项最新研究显示,雄性驼背鲸总是寻求体型肥大的雌性作为自己的伴侣。这一研究对于我们了解鲸的交配习惯以及开展鲸类保护工作开辟了新的方向。     

浅谈江西省鄱阳湖长江江豚保护

概述了近年来国内外关于江西省鄱阳湖长江江豚研究现状及保护进展,主要从长江江豚面临的主要威胁因子、保护工作进展等方面进行总结阐述,并对其中一些具体措施和问题进行了梳理分析。针对性提出了鄱阳湖长江江豚保护保护措施与建议,探讨了以后研究与保护应注意的重点问题,旨在为江西鄱阳湖长江江豚的保护指明方向,为合理科学保护鄱阳湖长江江豚奠定基础。     

长江中的微笑天使

正长江江豚(Neophocaena asiaeorientalis)是我国特有的淡水水生哺乳动物,属哺乳纲、鲸目、鼠海豚科江豚属,俗称"江猪"。长江江豚曾经是窄脊江豚的指名亚种,2018年4月11日被升级为独立物种。长江江豚体型较小,体长一般在1.2m左右,最长的可达1.9m,全身呈铅灰色或灰白色,头部钝圆,其额部隆起前凸,吻部短而阔,且带有一定弧度,正面看上去就像一个笑脸,被人们称为"微笑天使"。     

Population abundance and habitat preference of the Yangtze finless porpoise in the highest density section of the Yangtze River

1. Habitat loss and degradation together represent one of the five major factors contributing to the rapid decline of the Yangtze finless porpoise in the Yangtze River. Protecting key habitat patches and maintaining migration corridors between habitat patches are major conservation objectives to ensure the in situ viability of the Yangtze finless porpoise. Baseline information essential for addressing these two objectives includes that pertaining to distribution and habitat preference.
2. To investigate the distribution and habitat preferences of the Yangtze finless porpoise, five transect surveys were conducted in the Anqing section of the Yangtze River, which has the highest porpoise density among all sections of the river. Porpoise abundance estimates were calculated, and preferences for different habitat types were evaluated.
3. The calculated porpoise abundance in the Anqing section was 181 (95% CI 125–239) animals on average. The inter‐annual and inter‐seasonal differences in porpoise abundance estimates were not significant. The natural river banks and sandbar shores were the most preferred habitats, representing 46.3 and 29.8% of the porpoise observations, respectively. In contrast, 8.1% of the porpoises were observed in habitats along reinforced river banks, which account for 38.7% of the total coastline. In subsections with natural habitat patches, porpoises were observed in almost every survey, while porpoise occurrence became highly stochastic in subsections with long reinforced river banks. These results indicate a significant tendency of the Yangtze finless porpoise to prefer natural habitats with natural river bank or sandbars but to keep away from reinforced river‐bank habitats.
4. According to porpoise density in different subsections, free migration may be impeded or only one migration corridor remains in some subsections.
5. Although protecting finless porpoise habitats has become a primary conservation objective, this study highlights the need to protect frequently used habitat patches and migration corridors, particularly those near natural river banks and sandbars, and to restore ecological environments along reinforced river banks.

     

Evidence of nighttime movement of finless porpoises through Kanmon Strait monitored using a stationary acoustic recording device

From March 2005 to March 2006, the presence of the finless porpoise Neophocaena phocaenoides in the Kanmon Strait, Japan was monitored using a stationary acoustic event recording device. A stereo acoustic event recorder (A-tag) recorded biosonar signals as well as sound source directions, which can be used to count the number of echolocating porpoises within a distance of 126m. During 75 days of effective observation, 37 porpoises were detected acoustically. On average, one individual was detected every two days. Most of the finless porpoises appeared at night, and no porpoises were observed from 12:00 to 18:00 hours. Shipping traffic observed using the same acoustic system showed trends opposite to that of finless porpoise during the daytime. The tidal current did not affect the presence of the animals. (up to 5.2 knots). However, porpoises were suggested to swim along the current direction. Finless porpoise appeared to be isolated and used relatively long-range sonar during the observations, suggesting that the porpoises passed through the Kanmon Strait rather than searched for prey.     

The impact of fisheries management practices on the survival of the Yangtze finless porpoise in China

1. The Critically Endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is facing a significant threat from illegal fishing in Poyang Lake and Dongting Lake, and current fisheries management has proved insufficient to eliminate illegal fishing.
2. A survey of local communities around the two lakes was conducted to investigate fishing activities and their potential impacts. Using a series of six scenarios derived from our data, we suggest that enhanced daytime patrols may have driven fishers to conduct compensatory night‐time fishing when the patrols are absent. Night‐time fishing activities overlap temporally with the main period of Yangtze finless porpoise foraging, so the potential intensification of night‐time fishing with the use of illegal gears could pose an increased threat to porpoises.
3. In addition to increasing law enforcement management efforts, helping fishers to secure alternative livelihoods may provide a more practical and sustainable long‐term method for reducing illegal fishing and its impacts on porpoises. This study also provides important lessons for conservation policy‐making and implementation for other cetacean species threatened by illegal fishing.

     

铜陵淡水豚自然保护区江豚迁地保护现状与对策

铜陵江段是长江下游长江江豚(Neophocaena phocaenoides asaeorientalis)种群数量最集中、密度最大的江段之一。但随着人类活动的影响,长江江豚的资源保护也凸现出诸多问题。综合已有的研究资料和最新的调研结果,对其存在的问题进行了分析。认为植被人为演替、肆意采挖江砂、大型水利工程建设和江湖通道阻隔等是其面临的主要问题。同时,针对性地提出加强部门协同管理、协调经济发展和生态保护的关系、恢复江湖连通等措施和建议。     

Far‐reaching effects of a seal scarer on harbour porpoises,Phocoena phocoena

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长江江豚的饲养和观察

本文报道了对饲养下的长江江豚的行为、食物数量的观察和疾病治疗实验结果。在饲养状态下,江豚除正常的游泳姿势外,也表现侧游、跳跃、直立、滚游和滑行等姿态。呼吸间隔大多在10～20秒之间,最短为3秒,最长为43秒。每日3～8时的呼吸间隔均值略大于其它时间。一般游泳速度为1.3米/秒。日投喂量可达其体重的10％左右。对鱼类没有选择性。对疾病治疗可参考家畜的用药种类和剂量。     

Abundance estimates of three cetacean species in the coastal waters of Matang,Perak, Peninsular Malaysia

1. The paucity of baseline data on coastal cetaceans due to a lack of research in developing countries frequently precludes assessment of their status and informed management actions for conservation.
2. This study provides the first abundance estimates of Indo-Pacific humpback dolphins, Irrawaddy dolphins, and Indo-Pacific finless porpoises in the coastal waters of Matang, Peninsular Malaysia.
3. Boat-based surveys covering 1,152 km² of coastal waters with 4,108 km of survey effort were conducted between 2013 and 2016 to collect data for line transect analysis of Irrawaddy dolphins and finless porpoises. Photo-identification data of humpback dolphins were concurrently collected for mark–recapture analysis.
4. Estimates of abundance from four sampling strata totalled 763 Irrawaddy dolphins (CV = 13%, 95% confidence interval (CI) [588, 990]) and 600 Indo-Pacific finless porpoises (CV = 27%, 95% CI [354, 1,016]).
5. The annual abundance estimates of humpback dolphins ranged between 171 (95% CI [148, 208]) in 2014–2015 and 81 (95% CI [67, 98]) in 2015–2016, likely due to the presence of offshore individuals that moved in and out of the study area. The estuarine strata were inhabited by 68 (95% CI [63, 73]) inshore humpback dolphins in 2013–2014 to 87 (95% CI [78, 97]) dolphins in 2014–2015.
6. As an International Union for Conservation of Nature important marine mammal area, the productive coastal waters of Matang are shown to support a high density of small coastal cetaceans, and the results serve as an important baseline for future studies to identify population trends for conservation management plans.

     

Differential population dynamics of a coastal porpoise correspond to the fishing effort in a large estuarine system

1. The finless porpoise (genus Neophocaena) is susceptible to fishery‐caused mortality, and its numbers are thought to be in decline across its entire range. However, population demographics have rarely been quantified for this genus, with a few exceptions of the narrow‐ridged form (Neophocaena asiaeorientalis) in waters off Japan, Korea, and in the Yangtze River of China, all of which show a drastic decline in recent decades. Similar analyses have not been performed for the Indo‐Pacific (known also as the wide‐ridged) finless porpoise (Neophocaena phocaenoides) that inhabits (sub‐)tropical waters; thus, reliable risk assessments are lacking.
2. The demographic dynamics of the Indo‐Pacific finless porpoise in the Pearl River Delta (PRD) region were investigated by analysing 307 cases of beached carcasses that were recovered between 1996 and 2014. The mean instantaneous rate of increase r indicated a declining trend of 3.6% loss per annum during 1996–2005, and a subsequent recovering trend with 0.76% increase per annum during 2006–2014. The individual‐based Leslie matrix model constructed with the most up‐to‐date demographic parameters suggests that the conservation status of the finless porpoise in the PRD region corresponds to Near Threatened (NT) according to the International Union for the Conservation of Nature criterion A3.
3. This temporal demographic change may be due to changes in fishing effort, which has been declining locally since the late 1990s. Although more quantitative evidence is needed, it is shown that regulated management of coastal fisheries can serve as an effective tool in securing the long‐term persistence of Indo‐Pacific finless porpoise in the PRD region, which likely applies also elsewhere in the genus/species' range where coastal fisheries overlap with the porpoise habitat. Results provide baseline ecological indicators that can facilitate further monitoring of the population status and trend.

     

Distribution and habitat characteristics of three sympatric cetacean species in the coastal waters of Matang,Perak, Peninsular Malaysia

1. Coastal cetaceans in Southeast Asia are poorly studied and are particularly vulnerable to anthropogenic threats, especially in intensive fishing grounds.
2. To investigate the distribution and habitat characteristics of cetaceans in the productive coastal waters of Matang, Perak, Malaysia, boat‐based line transect surveys were conducted between 2013 and 2016.
3. The Irrawaddy dolphin (Orcaella brevirostris) was most frequently encountered at 3.87 sightings per 100 km, followed by the Indo‐Pacific finless porpoise (Neophocaena phocaenoides) at 1.72 sightings per 100 km, and the Indo‐Pacific humpback dolphin (Sousa chinensis) at 0.66 sightings per 100 km.
4. The mean group size was largest for humpback dolphins (8.4 individuals), followed by Irrawaddy dolphins (6.4 individuals), and finless porpoises (2.8 individuals).
5. Humpback dolphins exhibited a clustered distribution concentrated mainly in shallow estuarine waters (<10 m deep and <5 km from river mouths), whereas Irrawaddy dolphins were more widely distributed in farther coastal waters (<15 m deep and <15 km from river mouths), and finless porpoises were mostly found farthest from the shore in coastal waters (10–25 m deep and >15 km from river mouths).
6. The spatial distribution of the three cetaceans overlapped minimally, and this is likely to reflect the distribution of preferred prey resources, species interactions, and their differential responses to anthropogenic activities and species dominance.
7. The results from our study serve as baseline information for future research, conservation, and habitat management of these vulnerable and endangered coastal cetaceans. Conservation actions are recommended for the Matang area.

     

Harbour porpoises exhibit localized evasion of a tidal turbine

1. Tidal energy generators have the potential to injure or kill marine animals, including small cetaceans, through collisions with moving turbine parts. Information on the fine scale behaviour of animals close to operational turbines is required to inform regulators of the likely impact of these new technologies.
2. Harbour porpoise movements were monitored in three dimensions around a tidal turbine for 451 days between October 2017 and April 2019 with a 12-channel hydrophone array.
3. Echolocation clicks from 344 porpoise events were localized close to the turbine. The data show that porpoises effectively avoid the turbine rotors, with only a single animal clearly passing through the rotor swept area while the rotors were stationary, and none passing through while rotating.
4. The results indicate that the risk of collisions between the tidal turbine and porpoises is low; this has important implications for the potential effects and the sustainable development of the tidal energy industry.