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。     

厦门海域两头中华白海豚体内铁的含量

铁是动物体的必需元素,是血红蛋白和肌红蛋白中氧的携带者。动物体内的含铁化合物主要为血红蛋白、肌红蛋白（Mb）、转铁蛋白、含铁血黄素和含铁酶（王夔,1992）。铁与水生哺乳动物的潜水能力密切相关。Wright和Davis（2006）对威德尔海豹（Leptonychotes weddellii）的研究表明,Mb是水生哺乳动物最重要的储氧部位,在胃肠吸收后状态下Mb从正常水平降低7％时,有氧潜水限度（Aerobic Dive Limit,ADL）下降39％;Mb增加两倍时,ADL则增加30％。     

厦门中华白海豚体内微量元素的初步分析

对5头中华白海豚(Sousa chinensis)9种器官组织中的Cu、Zn、Cd、Pb、Hg、Ni、Se、As、Mg、Mn、Al等微量元素的含量进行了测定。结果表明,在少年个体中,Cu(P<0·05)和Mn(P<0·01)在肝中的含量及Zn在肝(P<0·01)、肠(P<0·05)、胃(P<0·05)和心(P<0·05)中的含量明显高于肌肉中相应微量元素的含量,其余微量元素在各种组织中变化不大;在成年个体中,Pb在肺中的含量明显高于肝(P<0·001)、肌肉(P<0·01)、胃(P<0·01)和心(P<0·05)中的含量,Hg在肝中的含量明显高于胰(P<0·05)。整体上来说,大多数微量元素在成体中的含量高于少年个体,表明微量元素是随年龄的增长而逐渐累积的。有毒重金属如Hg、Cd和Pb在肾、肝以及卵巢中累积较多,提示这些器官承受了较大的毒性压力。     

基于广义可加模型的珠江口中华白海豚栖息地偏向性研究

基于2013年12月—2014年9月珠江口水域20个站位的10类海水水质因子数据(p H、深度、表层水温、盐度、溶解氧、叶绿素a、化学需氧量、活性磷酸盐、无机氮、活性硅酸盐),结合珠江口水域中华白海豚Sousa chinensis的密度分布,首次利用广义可加模型(GAM)分析了珠江口中华白海豚密度分布与海水水质因子的关系。结果表明:建立的模型运行良好,GAM对中华白海豚密度分布的总偏差解释率达86.3%。影响中华白海豚密度分布的主要水质因子为深度、化学需氧量、活性磷酸盐以及盐度。中华白海豚主要栖息于水深15 m以内,盐度10‰~30‰之间的水域。化学需氧量和活性磷酸盐与其密度分布的相关性提示环境污染因子对其密度分布造成了一定的影响。     

贵州草海越冬黑颈鹤觅食栖息地选择的初步研究

本文报道了利用Friedman非参数统计方法,研究越冬黑颈鹤(Grus nigricollis)在贵州草海对其觅食栖息地选择的结果。在草海的黑颈鹤越冬觅食栖息地可分为5种——莎草草甸、浅水沼泽、草地、玉米地和蔬菜地。黑颈鹤对莎草草甸的选择性最高,对玉米地的选择性最差,对其余类型栖息地的选择随地点的不同而不同。草海的人为活动很多,是影响黑颈鹤利用和选择栖息地的一个重要因素。本文也对改善黑颈鹤越冬栖息地的管理和保护提出了一些建议。     

珠江口伶仃洋中华白海豚栖息地利用对海岸线等变迁的响应

沿岸鲸豚类栖息地易受人类活动的干扰，导致其分布和核心栖息地发生变化。珠江口-漠阳江口中华白海豚种群是目前所知全球范围内最大的种群，其中伶仃洋水域是其重要的栖息地。近年来，珠江口伶仃洋周边城市发展带来的人类活动增加，白海豚的生存压力日益增大，分析伶仃洋中华白海豚对栖息地环境变化的响应，研究对应的保护策略显得非常迫切。以多源陆地资源卫星Landsat为数据源，通过影像分析近43年珠江口伶仃洋围填海造成的海域流失，结合近20年来采用截线抽样法收集的海豚观测数据，运用含障碍核插值（Kernel interpolation with barriers）方法，分析白海豚的分布及核心栖息地的变化。结果显示：1986-2015年期间，研究区域内流失的海域面积为344.08km²；目击分布离人工海岸线的平均距离大于自然海岸线的平均距离，目击分布到自然海岸线和人工海岸线的平均距离均在减小，表明过去20年白海豚的栖息地使用选择发生了一些变化，被迫适应人类活动的干扰；1997-2016年白海豚的分布范围呈现先增加后减小，白海豚栖息地使用的重心偏向伶仃洋东部水域，核心栖息地趋向主航道和无人海岛附近水域萎缩，可能是海豚因海域食物资源减少而迫不得已的选择。不同时期，珠江口中华白海豚国家级自然保护区所覆盖的核心栖息地比例呈递减趋势，占比由79.9%下降到49.4%，当前有必要对保护区范围和功能区作出一些优化调整，以适应栖息地使用的变化格局。     

栖息地选择的理论与模型

栖息地选择理论和模型的发展经历了两个主要阶段:理想自由分布模型和空间直观的栖息地选择模型。随着对理论模型假设的放宽,近年来产生了越来越多的新模型。通过对栖息地选择过程的分析,提出了栖息地选择的几个关键环节:栖息地偏好、信息获取、行为决策及选择行为。在建立栖息地选择模型的各个关键环节上均存在大量有待解决的问题。目前对栖息地偏好的研究主要为相关分析,栖息地信息获取的过程仍然是一黑箱;对动物在栖息地选择过程中的行为决策以及对其生理状态的影响尚不了解,而解决这些问题需要生态学、生态学及认知学等多个领域的研究结果支持,也有待新的理论及方法加以充实,甚至还需要其他学科的介入。     

厦门海域两头中华白海豚体内微量元素的积累

对2004年4月在厦门海域搁浅死亡的两头中华白海豚（Sousa chinensis）进行了肝脏、胰、胃、肾、肠、肺、肌肉、心脏等多组织微量元素锌（Zn）、铜（Cu）、汞（Hg）、铅（Pb）、镉（Cd）和砷（As）浓度的测定。两豚各组织总体上必需元素Zn、Cu浓度高于有毒元素Hg、Pb、Cd和As。XM20040430体内特别高的Zn、Hg、Pb、Cd浓度分别出现于皮肤（500μg/g干重）、肝脏（255μg/g干重）、肺（13.0μg/g干重）和肾（2.82μg/g干重）中,而Cu和As在各组织中的浓度较为相似。XM20040429体内仅肝脏中Zn（448μg/g干重）和Cu（52.0μg/g干重）的浓度远高于其他组织。虽然两海豚微量元素的总体积累多低于急性毒性水平,但有毒元素Hg、Pb、Cd、As的明显检出和XM20040429肝脏中异常高的Zn浓度均显示出进一步研究微量元素慢性胁迫效应的必要性。结果还显示厦门港海域近年来Hg、Cd、Pb污染未见减轻,As也明显检出,必须引起高度重视。今后有关水生哺乳动物中As积累的研究也有待加强。     

中国大陆鸟类栖息地选择研究十年

栖息地选择研究一直是鸟类生态学研究的重要内容之一。通过对2001年1月至2010年12月10年期间中国大陆鸟类学家在国内外期刊上发表的鸟类栖息地选择研究的论文进行分析,对我国鸟类栖息地选择研究提出展望。10年间,我国鸟类学家共发表有关鸟类栖息地选择或利用的论文170篇,共涉及到鸟类10目31科73种。在这10年里,中国大陆有关鸟类栖息地选择或利用的文章持续增长。然而,我国鸟类栖息地选择的研究也存在着如下问题:(1)存在栖息地选择和栖息地利用误用的现象,这种现象在10年内并无明显改善;(2)在选择研究方法时,很少考虑个体的可获得性、种群密度及抽样尺度对栖息地选择的影响;(3)大多数的栖息地选择的论文没有对鸟类的栖息地选择行为进行研究,也缺乏对其选择的适合度背景去进行研究。根据这些问题,对我国未来的鸟类栖息地选择研究提出了建议。     

中华白海豚雄性生殖系统组织学初步研究

采用组织学和形态学方法研究了中华白海豚(Sousa chinensis)的雄性生殖系统。以睾丸和附睾中是否存在精母细胞及精子细胞等作为判断雄性中华白海豚性成熟的标准,通过比较不同个体睾丸和附睾的组织结构特征,发现成熟个体的生精小管和附睾的组织学结构与未成熟个体间存在显著差异。通过测量样本睾丸的2个形态参数:生精小管直径和生精小管的相对面积,得到性成熟个体的生精小管直径为(118.3±12.8)μm,生精小管相对面积为0.52;未成熟个体的生精小管直径(47.4±3.5)～(60.3±6.0)μm,生精小管相对面积为0.27～0.40。     

中华白海豚3 个MHC 基因座位遗传变异的初步分析

主要组织相容性复合体(Major histocompatibility complex,MHC) 基因是由一组紧密连锁的基因组成,是哺乳动物免疫系统中最重要的组成部分。本文选择3 个MHC 基因座位的第二外元,即:MHC-I 类基因和II 类基因的DRA 和DQB 座位,初步调查濒危物种中华白海豚的遗传变异。共鉴定了2 个DRA、2 个DQB 和7 MHC-I等位基因。DRA 座位遗传变异非常低,而DQB 和MHC-I 座位具有相对较高水平的遗传变异。并且,在DQB 和MHC-I 基因座位的假定的抗原结合位点(Antigen binding sites,ABS),非同义替代明显大于同义替代,提示平衡选择(Balancing selection)维持这两个座位的多态性,而在DRA 座位上,并没有检测到平衡选择。系统发生分析表明中华白海豚的MHC 等位基因没有聚在一起,而是和其他的物种聚在一起,符合MHC 跨种进化(Transspecies evolution)的模式。     

Daylight occurrence of humpback dolphins Sousa chinensis in Algoa Bay, South Africa

This paper describes the pattern of daylight occurrence of humpback dolphins Sousa chinensis in Algoa Bay, the Eastern Cape, South Africa, between May 1991 and May 1994. Two indices, the Sighting Index (SI) and the Total Recorded Dolphin Presence (TRDP), were used to quantify the dolphins' daylight occurrence. Humpback dolphins display a clear pattern of daylight occurrence in Algoa Bay and can be seen mostly in the morning, and, to a lesser extent, in the evening. This pattern varies little between seasons (with possible exception for the evening hours), follows the time of the solar day, is not related to the tidal cycle and is probably governed by the diurnal cycles of dolphins' prey.     

Record of an Indo-Pacific humpback dolphin (Sousa chinensis) without its upper rostrum in Xiamen Bay,Fujian Province,China

Many cetaceans are killed as a result of intensive anthropogenic impacts, and those that survive often endure wounds or scars. This study is the first report of an Indo-Pacific humpback dolphin (Sousa chinensis) that is missing its upper rostrum. This individual has inhabited Xiamen Bay, Fujian Province, China, for more than 3 years. Since the lower jaw and the other part around the upper jaw are intact, it is likely that the upper jaw was entangled in fishing nets or pipelines and subsequently broke off. Without the upper rostrum, this dolphin cannot snap prey, but it may use other feeding strategies – and the fact that this individual has survived for more than 3 years without its upper rostrum provides a novel insight into the ability of this species to persist in the wild.     

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.     

海南三亚一头死亡中华白海豚的形态学记录

On February 2,2015, a dead female Indo-Pacific humpback dolphin (Sousa chinensis) was found in the coastal water of Meilian Village, Yacheng Town, Sanya City, Hainan Province, China. It was the first Indo-Pacific humpback dolphin death case ever found in waters southwest of Hainan Island. In the present study, data about external morphology and skeleton system of the dead dolphin were documented, Body length and body mass of the animal were 235.0 cm and ca. 150 kg, respectively, with completely white body color. The cranium of this dolphin wa 189 mm in zygomatic width, and 415 mm in skull length. Its vertebra formula was C6+T12+L10+Ca20=48. It had 12 pairs of ribs and 11 V-bones. According to previous reports, our skeleton sample may have one cervical vertebra missing, and one or more caudal vertebras and V bones missing. More new skeleton samples from the same population are needed to confirm this presumption.     

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.     

中国中华白海豚的研究和保护现状

本文对中国中华白海豚的形态、分类、种群数量及分布、濒危状况及原因和保护现状进行了综述分析,指出中国境内的中华白海豚的保护形势依然严峻,仍需要加强保护措施.