厦门水域中华白海豚出现于围头湾

厦门海域的中华白海豚是一个受威胁的种群。以往有关该种群的调查范围主要集中在厦门以及邻近的南部漳州海域。为了获得厦门岛东部海域（包括晋江围头湾、小嶝岛以及大嶝岛部分水域）白海豚的分布和数量等信息,本文于2013年6—8月对该水域进行了船基样线法调查和照相识别研究。调查期间共目击到白海豚26群,照相识别白海豚个体27头。所有照相识别的白海豚个体均与厦门中华白海豚个体识别数据库中的个体匹配,表明厦门中华白海豚的分布区至少向东延伸至围头湾。本文白海豚遇见率为5.8群/100km和24.8头/100km,均要高于以往在厦门水域的调查结果,表明大嶝岛—围头湾水域是厦门中华白海豚的重要栖息地之一,值得优先保护和管理。     

珠江西部河口中华白海豚分布与环境因子的关系

2012年采用船基截线法在珠江口西部河口进行了中华白海豚(Sousa chinensis)调查,并同步对渔业资源和渔业环境要素进行了现场采样测定,以分析该水域中华白海豚空间分布与环境因子的关系。利用广义加性模型(GAM)分析了中华白海豚目击率与海况、水深、底层水温、盐度、pH值、溶解氧、游泳生物密度、捕食种密度和离岸距离等的关系。GAM模型对中华白海豚目击率分布的总偏差解释率为64.7%,游泳生物密度、水深、捕食种密度、离岸距离、底层水温等对中华白海豚的栖息地选择有较大的影响。模型分析结果显示:中华白海豚的活动与捕食种密度密切相关,但当捕食种密度达到一定程度时对海豚目击率的影响减弱,推测可能与食物较多时海豚逗留捕食时间减少有关;中华白海豚较为喜欢的水深在10m左右,这一模拟结果与以前的统计结果基本一致;中华白海豚对底层水温似乎有一定的选择性,当底层水温大于19.5℃时目击率明显下降,推测底层水温可能影响了捕食种鱼类的分布,进而影响海豚的活动;离岸距离3km范围内是中华白海豚较为喜欢的水域,因此对这一水域范围应给予重点保护管理。     

厦门湾中华白海豚潜在生态廊道识别及人类活动干扰评估

生态廊道具有维持或恢复生态连通性的功能，对于连接生物栖息地、保护物种多样性具有重要意义。现有的生态廊道研究主要集中于陆地，而海洋生态系统具有水体广泛连通、缺乏直观的景观斑块等特点，导致海洋生态廊道的研究成为长期以来的科学难题。以栖息地位于厦门湾的国家一级保护动物中华白海豚（Sousa chinensis）为对象，尝试基于物种分布模型和最小成本路径分析法建立海洋生态廊道的识别方法。研究采用物种分布模型识别厦门湾内中华白海豚的适宜生境分布区和节点，并利用模型产出的生境适宜性结果生成海洋中的阻力表面，模拟计算节点与节点间在阻力表面上的最小成本路径，从而生成物种扩散网络。研究结果显示，厦门湾中华白海豚的分布主要受到航道距离、到岸线距离和叶绿素浓度三项因素的影响，主要适宜生境位于西海域至九龙江口和大嶝海域。潜在的核心生态廊道面积93.19km²，次级生态廊道面积170.41km²，九龙江口-鼓浪屿南侧-黄厝-大小嶝岛沿线可能是厦门湾中华白海豚的主要迁移路线。在此基础上，从用海空间重叠和桥梁影响两方面开展了人类活动对廊道的干扰评估。评估结果显示旅游活动和航运活动可能是中华白海豚生态廊道的主要影响来源，其中核心廊道受旅游活动影响更大，次级廊道受航运活动的影响更大。此外，厦门岛北部的桥梁亦可能会影响中华白海豚生态廊道的连通性。研究创新性地提出了海洋生态廊道的空间定量化识别方法并成功应用于厦门湾中华白海豚研究，研究结果可为我国海洋生物多样性保护、海洋保护区的空间规划等领域提供新的科学工具。     

有只海豚叫“三月”

正我要给你讲一个故事。故事的主人公是一只海豚,名叫三月。之所以叫这个名字,是因为它出生在农历的三月。三月降生在我国的珠江口海域。根据它的外形特点,科学家很容易就辨别出,它是一只雌性中华白海豚。三月很幸运,珠江口海域是全世界最大的中华白海豚栖息地,那里有不少它的同类。三月也很不幸,由于环境恶化,它一出生就要面对严峻的生存考验。     

北部湾儒艮现状的调查兼记印度洋白海豚

为了解北部湾中国水域儒艮的现状 ,于 2 0 0 0年 9月 15日至 11月 17日在广东、海南、广西三省区的沿岸海域进行了 36次舟船考察。调查结果表明 ,在北部湾的部分海域仍有儒艮存在 ,但数量比 2 0世纪 80年代已显著减少。建议把海南省西海岸近海的儒艮及其栖息地的保护作为最优先的海兽保护项目。另外在 11月 3日和 4日在广西壮族自治区北海市大风江口 (2 1°36′N ,10 8°5 4′E)的舟船考察中 ,还分别观察到约 7头和 4头印度洋白海豚的小群 ,它们属于在中国海域已知的唯一印度洋白海豚种群 ,建议广西合浦国家级儒艮自然保护区把印度洋白海豚也作为其重点保护对象之一。     

厦门水域中华白海豚栖息地选择的初步研究

中华白海豚（Sousa chinensis）在中国水域主要包括3个种群,分别分布在珠江口（包括香港）、九龙江口（厦门水域）和北部湾广西沿岸水域,近年来在台湾西海岸和广东的雷州又陆续发现了新的种群（Wang et al．,2004;周开亚等,待发表资料）。该物种主要以中小种群分布于近岸浅水水域,易受各种人类活动的影响,如渔业捕捞、船舶航运、港口建设和水体污染等,其保护状况引起了人们的广泛关注。在1988年颁布的《中华人民共和国野生动物保护法》中,已将该物种列为国家一级保护动物。     

珠江口伶仃洋海域底层游泳动物的季节变化

珠江口伶仃洋海域是渔业资源的重要栖息地,近年来由于人类活动的加剧导致生态环境质量下降。为进一步了解栖息环境恶化对渔业资源的影响,于2009年8月至2010年4月采用底拖网在珠江口伶仃洋海域进行了游泳动物4个季节的调查。共鉴定游泳动物92种,其中鱼类54种,甲壳类32种和头足类6种。游泳动物种数夏季最高,为52种,春季最低,仅35种,春、夏季和冬、春季种类季节更替显著。优势种组成较为稳定,以日本蟳(Charybdis japonica)、黑斑口虾蛄(Oratosquilla kempi)和棘头梅童鱼(Collichthys lucidus)为主要优势种,其中日本蟳为全年优势种,平均尾数密度占总密度的8.07%～26.22%。游泳动物资源密度和尾数密度季节变化趋势一致,均为夏季最高,秋季和春季次之,冬季最低。珠江口伶仃洋海域温度和盐度有明显的季节变化,夏季和秋季温度较高,盐度较低,冬季和春季温度较低,而盐度较高。温度是伶仃洋海域游泳动物种类和数量季节变化的主要因子。与历史资料比较,珠江口主要经济鱼、虾类出现小型化趋势。     

一头中华白海豚的病理解剖及死因分析

中华白海豚 (Sousachinesis)是生活于河口内湾的小型鲸类 ,我国香港、珠江口和厦门海域是其主要栖息地。根据黄宗国等调查 ,厦门海域约有60头中华白海豚[1] 。该海域 2 0 0 0年被定为海洋珍稀物种国家级保护区 ,其中中华白海豚是主要保护对象。 2 0 0 2年 2月 2日上午 ,在厦门海沧温厝村滩头上发现一具中华白海豚尸体 ,当时是退潮 ,水温14°C ,尸体放入冷库冰冻。 2 0 0 2年 2月 2 1日 ,对尸体进行了详细的解剖 ,随后在实验室进行了年龄鉴定和组织病理学检查 ,现报道如下。1　病理解剖结果1 1　外部检查测量身体浑圆饱满 ,体长 1 92m ,体重…     

中华白海豚生态学研究进展

中华白海豚(Sousachinensis)是国家一级重点保护水生野生动物,处于食物链的顶端,是近岸海洋生态系统健康状况的指示物种和海洋生物多样性保护的旗舰物种,具有重要的生态、科学和文化价值。自20世纪90年代开始,中华白海豚的研究逐渐兴起;近年来,随着3S技术、生态模型及分子生物学等技术方法的发展应用,在中华白海豚种群生态学、行为生态学、分子生态学等领域的研究取得了长足发展。国内外学者利用截线抽样法和标志重捕法,调查研究了全球范围内已知的中华白海豚种群的分布、数量等生态信息;在物种保护的背景下,开展了对中华白海豚栖息地的选择偏好、栖息地质量评价及潜在栖息地的预测研究;探究了中华白海豚的觅食行为和繁殖行为的规律和其他行为的生态意义;分子生物技术的应用,初步揭示了中华白海豚的遗传分化规律,以及该物种对气候变化表现出的脆弱性;涉海工程、水下噪声、水体污染、渔业活动等人类活动仍是目前中华白海豚面临的主要威胁。本文在总结已有研究的基础上,对未来该物种的生态学研究与保护提出了以下展望:(1)建立国家层面的动态基线数据库,以更好地追踪中华白海豚的种群动态及栖息地环境变化;(2)构建栖息地识别及保护...     

自组织特征映射神经网络识别珠江口夏季水质空间格局

通过建立珠江口2009 年夏季水质综合评价的自组织特征映射网络模型, 探索了珠江口不同河段水质状况。结果表明, 利用自组织特征映射网络人工神经网络可以直观清晰地对珠江口海域水质空间进行分类。珠江口海域水质可分为三大类, 第一类为受到人类活动影响显著的广州河段区域; 第二类为内伶仃洋海域, 该区域主要受到咸淡水混合的影响; 第三类为主要受到外海水交换影响的外伶仃洋海域。结果阐明人工神经网络模型能为珠江口环境保护与生物资源可持续利用提供科学的决策依据。     

Fine‐scale habitat use in Indo‐Pacific humpback dolphins,Sousa chinensis,may be more influenced by fish rather than vessels in the Pearl River Estuary,China

Shifts in habitat use and distribution patterns in dolphins are often concerns that can result from habitat degradation. We investigated how potential changes to a habitat from human activity may alter dolphin distributions within Lingding Bay in the Pearl River Estuary, China, by studying the relationship between fish choruses, vessel presence and Indo‐Pacific humpback dolphin (Sousa chinensis) detection rates. Analyses revealed temporal and spatial variation within fish choruses, vessel presence and dolphin detection rates. After accounting for any temporal autocorrelation, correlations between fish choruses and dolphin detection rates were also found; however, no relationship between fish choruses and vessel presence or dolphin detection rates and vessel presence were observed. Furthermore, fewer dolphins were detected at sites where fish activity was less intense. Thus fish activity, rather than vessels, may be a key factor influencing the distribution of the dolphins within the estuary. These findings emphasize the risk of potential shifts in habitat use for Indo‐Pacific humpback dolphins due to detrimental changes to prey availability and dolphin feeding grounds from human activity, such as overfishing and coastal developments, within the estuary. This is a critical conservation issue for this dolphin population that is facing intense anthropogenic pressure.     

Abundance and residency dynamics of the Indo-Pacific humpback dolphin,Sousa chinensis,in the Dafengjiang River Estuary,China

Robust population size estimates are essential for informing population conservation status. Residency dynamics show population habitat use through time. Population size of Indo-Pacific humpback dolphins (Sousa chinensis) has been extensively investigated in Chinese waters, but their residency dynamics are rarely known. Mark-recapture analysis based on photo-identification records was applied to humpback dolphins in the Dafengjiang River Estuary habitat, one of the key habitats in the northern Beibu Gulf, China. Movement analyses based on lagged identification rate indicated the humpback dolphins spent, on average, 78.5 days inside and 46.9 days outside the survey area. Within the study area, the humpback dolphin abundance was 83 identifiable dolphins. A total of 353–430 humpback dolphins, estimated by POPAN modeling, were involved in this fluid habitat-use dynamic. Robust Design analysis showed strong seasonality in humpback dolphin abundance and emigration probability, implying a movement- and habitat-use pattern likely associated with spatiotemporal distribution of oceanographic characteristics and prey occurrences. Population surveys and conservation measures currently conducted in Chinese waters seldom consider seasonality in movements between habitat patches, which can be addressed by genetic analyses across habitats and cross-matching photo-identification records among neighboring habitats.     

Distribution and abundance of Indo‐Pacific humpback dolphins in Leizhou Bay,China

Abstract

The Indo‐Pacific humpback dolphin (Sousa chinensis) is under severe threat in Chinese waters. Only four small populations of this dolphin are known to survive in the East China Sea and South China Sea. We conducted exploratory surveys from June to September 2005, and found a population of humpback dolphins in Leizhou Bay. Thirty‐eight individuals were identified and catalogued, of which 26 were photographed and re‐identified on more than one occasion, and nine were sighted on five or more occasions each. Our preliminary estimate of the size of the Leizhou population is about 237 individuals, second only to the Pearl River estuary population. We suggest that Leizhou Bay has the potential to serve as a “humpback dolphin sanctuary” in Chinese waters.     

A preliminary investigation on genetic diversity of Sousa chinensis in the Pearl River Estuary and Xiamen of Chinese waters

In this study, the mitochondrial DNA (mtDNA) control region and the mitochondrial cytochrome b gene of stranded Indo-Pacific humpback dolphin (Sousa chinensis) samples from the Pearl River Estuary and Xiamen waters were sequenced and analyzed. The result of mtDNA control region revealed 34 variable sites and four unique haplotypes (named as A, B, C and D) identified among the total samples from these two water areas, and the most common haplotype (A) was shared by 75% of the dolphins sampled from the two water areas. The haplotypic diversity (h) was 0.455 and the nucleotide diversity (π) was 0.0088. The phylogenetic analysis showed that the haplotype A, C, and D were closely related, but the haplotype B (unique for XM01 from Xiamen) was far from the other three. By scanning cytochrome b fragments, two haplotypes (A and B) were identified in these two water areas, and the most common haplotype (A) was shared by 91.67% individuals, while XM01 from Xiamen as the only exception. The date suggest that there is a possibility of gene exchange between the two populations in the Pearl River Estuary and Xiamen waters, and there possibly exists a unique maternal lineage in Xiamen waters.     

Whistle characteristics of a newly recorded Indo-Pacific humpback dolphin (Sousa chinensis) population in waters southwest of Hainan Island,China, differ from other humpback dolphin populations

Indo-Pacific humpback dolphins (Sousa chinensis) use whistles to communicate with their conspecifics. Little is known about the acoustic repertoire of Indo-Pacific humpback dolphins in waters southwest of Hainan Island, a newly recorded population in 2014. In this study, whistles of Hainan humpback dolphin population were collected by using autonomous acoustic recorders. The fundamental frequencies and durations of whistles were in ranges of 0.71–21.35 kHz and 0.06–2.22 s, respectively. Significant intraspecific differences in duration and frequency of whistles were found between the Hainan population and the other geographically neighboring populations (in Chinese waters) or the population in Malaysia waters. Compared with other Sousa species, significant interspecific differences were also observed. Based on clustering analysis, the whistle parameters of neighboring populations were likely similar to each other. Significant differences were found between humpback dolphins in waters southwest of Hainan Island and those dolphins in the neighboring areas, supporting the hypothesis that this population may be independent. Ambient noise measurements in waters of Hainan Island, Zhanjiang, and Sanniang Bay showed that humpback dolphin populations may use whistles with longer duration, lower frequency, and fewer inflection points for more effective communication to adapt to a noisier environment.     

Molecular phylogenetics and population structure of Sousa chinensis in Chinese waters inferred from mitochondrial control region sequences

Phylogenetic analyses of the genus Sousa were carried out across their geographic range and focused especially on the genetic variation patterns and population structure of Sousa chinensis in Chinese waters. The analyses were based on 287-bp of the mitochondrial control region from 122 Indo-Pacific humpback dolphins (Sousa chinensis) and two Atlantic humpback dolphins (Sousa teuszii). All specimens from China grouped together in a well-supported clade with high bootstrap (BS) and Bayesian posterior probability values (BPP), strongly suggesting that only one species of Sousa exists in China. Six haplotypes were identified in 65 individuals from Xiamen and Pearl River Estuary in China. The extremely low level of detected mtDNA genetic diversity strongly suggests a high priority in conservation of Sousa. The highly significant genetic differentiation between the two populations in Xiamen and Pearl River Estuary supports the designation of these two populations as separate management units (MUs) when designing management programs for this species.     

HABITAT USE AND PREFERENCES OF INDO-PACIFIC HUMPBACK DOLPHINS SOUSA CHINENSIS IN ALGOA BAY, SOUTH AFRICA

This paper examines environmental and behavioral determinants of the habitat use and preferences of Indo-Pacific humpback dolphins inhabiting the Algoa Bay region on the south Eastern Cape coast of South Africa. In order to quantify the habitat use and preference, two indices were used, the Coefficient of Area Use (AU) and the Activity Index (AI). The dolphins inhabit a narrow strip of shallow, inshore waters of Algoa Bay and remain mostly within 400 m of the shore, in water less than 15 m deep, with no apparent preference for clear or turbid water. Water depth is probably the main factor limiting their inshore distribution, and the 25-m isobath seems to represent the critical depth. Within this confined, inshore distribution, dolphin activities concentrate in the vicinity of rocky reefs-their primary feeding grounds. Dolphin dependence on these shallow-water habitats is evident throughout the year and, consequently, the inshore shallow reefs are identified as the "key habitat" which is of primary importance for humpback dolphins in Eastern Cape waters. The dolphins' dependence on this restricted type of habitat within an already restricted inshore distribution makes them particularly vulnerable to alteration or loss of this habitat.