热带西太平洋砂壳纤毛虫的多样性

为了探明热带西太平洋海区砂壳纤毛虫的多样性、垂直分布及纬向变化,我们于2012年11-12月在该海区四个断面采集了0-200 m的水样。共检出砂壳纤毛虫39属124种,多数种类喜好生活在表层和次表层。砂壳纤毛虫种丰富度、丰度以及多样性指数的高值主要出现在比叶绿素浓度最大值稍浅的位置,与温度和叶绿素浓度显著正相关,与盐度和采样深度显著负相关。多数优势种与环境因子间的相关性不显著。热带西太平洋海区砂壳纤毛虫多样性极高,各站种丰富度在25-52之间。在从表层至75 m处的多数采样点香农指数均大于3。该海区砂壳纤毛虫冗余种的比例很高,占砂壳纤毛虫总种类数的87.90%,贡献了砂壳纤毛虫60.38%的丰度,表明热带西太平洋海区砂壳纤毛虫群落对饵料组成和摄食压力改变的应对能力很强,稳定性很高。     

西北太平洋深海海山的一种蛇尾新记录

Ophioleila elegans是一种非常少见的蛇尾。2014年大洋35航次中利用“蛟龙”号载人潜器在西北太平洋麦哲伦海山链的采薇平定海山水深1660m处采集到2株该种标本。该种首次发现于夏威夷海山相似的生境当中,本次采集到的样品是继首次发现之后的再次公开报道。本文中对该种的形态学特征,如腕部骨骼等,进行了更加详细的研究,同时基于COI序列进行系统发育分析。形态和系统发育分析的结果都表明,Ophioleila属与辐蛇尾科更加接近。     

西太平洋暖池1990s中期的年代际扩张对夏季登陆中国台风的影响

应用美国联合预警中心(Joint Typhoon Warning Center,JTWC)的台风最佳路径资料、美国国家海洋大气局(National Oceanic and Atmospheric Administration,NOAA)的扩展海表面温度资料以及美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)和美国国家大气科学研究中心(National Center for Atmospheric Research,NCAR)的大气环流场资料,研究了20世纪90年代西太平洋暖池(简称暖池)年代际扩张对西北太平洋台风和登陆中国沿岸台风的影响。研究发现,相比于暖池扩张前期(1965—1992),后期(1993—2013)台风生成在西北太平洋中部区域(10°—20°N,135°—145°E)显著减弱,在10°—20°N,145°—160°E区域和南海北部区域则表现出增多的特点。台风移动路径变异特征呈现为移动进入南海和登陆中国东部沿岸的西行和西北行路径减少,登陆日本的转向型路径增多,同时登陆我国海南岛和东南部沿岸的台风增多。进一步探查这种影响的可能原因发现,与暖池扩张密切相关的太平洋年代际变化引起的纬向环流的变异是西北太平洋中部台风生成减少的主要原因;而南海北部台风生成增多则归因于南海区域局地环流特征的变异。同时,南海北部台风生成增多是登陆我国海南岛和东南沿岸台风增多的主要决定因素。     

中美两套西北太平洋热带气旋资料集的差异分析

利用中国气象局(CMA)和美国联合台风预警中心(JTWC)两套西北太平洋热带气旋(TC)资料集,对比分析了两者在1951—2005年TC定位和定强方面的差异。结果表明:两套资料定位差在20世纪50年代至60年代初及1988年至90年代差异较大;地理分布上主要是在TC登陆后所在的地区及高纬度洋面上差别较大。定强方面,CMA资料在20世纪50年代及60年代末至70年代初TC强度明显大于JTWC资料,JTWC资料则在80年代末以后的时段TC强度显著大于CMA资料;地理分布上定强差大的区域在80年代以前分布较零散,之后随着JTWC资料定强增大,其在西北太平洋洋面上强度显著偏强,CMA资料同期则在亚洲大陆沿岸部分地区强度较强。进一步分析显示,两套资料集之间的差异和TC观测技术的变化之间存在密切关系。在气象卫星使用以前(1951年至60年代初),以及美国空军飞机观测终止之后(1988年以后),两者无论是在定位还是定强上都存在很大差异;而两者定强差最小的时期(1973—1987年)则正好对应了飞机观测和Dvorak技术在TC观测上同时被使用的时段。两套西北太平洋TC资料集总体差异明显,却又各具特点,目前很难判断哪一套资料集更加可靠。但对于影响中国TC,CMA资料集具有明显优势。     

Coral assemblages and reef growth in the Commonwealth of the Northern Mariana Islands (Western Pacific Ocean)

Reef development varies considerably around the high, raised‐limestone islands of the Commonwealth of the Northern Mariana Islands (CNMI). Here we examine the modern assemblages at 30 sites for coral composition, colony density, colony size, and fidelity. We defined four reef types and hypothesize the presence of environmentally driven ecological stasis, whereby the environment continuously selects for coral species membership, defines colony sizes, and over time creates the noted reef types. Our results show that constructional spur‐and‐groove reefs supported significantly larger coral‐colony sizes and higher coral species richness compared with high‐relief interstitial framework, low‐relief incipient, and non‐constructional coral assemblages. Non‐constructional reefs supported much smaller coral colony sizes, despite similar population densities, and were consistently found in association with high wave exposure. The distinct coral assemblages found on interstitial framework and low‐relief incipient reefs were not affiliated with any wave exposure regime, but were located adjacent to large watersheds and on islands with unique geological history. These assemblages were nested within the spur‐and‐groove species pool. Overall, modern coral cover was well predicted by bathymetric slope and watershed size, while species richness was additively influenced by two proxies of pollution, suggesting the latter is better suited for establishing management targets. In contrast with previous studies that suggested modern assemblages were biologically controlled in the CNMI, we show reef assemblages and reef development are highly influenced by long‐term environmental forcing.     

A collective approach to Pacific islands fisheries management: Moving beyond regional agreements

The sustainable management and profitable development of the Pacific island tuna fisheries is the key ocean governance challenge for the Pacific islands region in the short and medium term. Resolving these challenges is fundamental to the long term future of the region and its ability to implement oceans governance across all resource and conservation concerns.     

Introducing a transferable fishing day management regime for Pacific Island countries

On 1 December 2007, eight ‘Small Island Developing States’ in the Western and Central Pacific Ocean implemented a management regime restricting the total number of days fished by tuna purse seine vessels within their waters, commonly referred to as the Vessel Day Scheme (VDS). The VDS is seen as one component of management arrangements to reduce fishing mortality on bigeye and yellowfin tuna, constrain fishing effort, and increase the rate of return from access fees by Distant Water Fishing Nations.     

Socio-economic drivers and indicators for artisanal coastal fisheries in Pacific island countries and territories and their use for fisheries management strategies

This is the first regional study of artisanal fisheries in Pacific Island countries and territories that demonstrated that the future of the region's artisanal fishery sector and the livelihood of coastal communities will be highly dependent on alternative subsistence and income sources, which are necessary to reduce fishing pressure to a sustainable level to maintain ecosystem services and food security. The overall objective of this study was to identify socio-economic indicators and drivers to improve the understanding of the dynamics between socio-economic conditions and current exploitation levels of finfish and invertebrates of coastal communities in 17 Pacific Island countries and territories. We showed that exploitation rates and thus possible overexploitation are not solely the consequence of a simple demographic growth process but are in fact a result of the choices people have. Our results confirmed a close relationship between resource exploitation rates and economic development at the national level and the availability of alternative income opportunities at the community level. Multivariate analysis results suggest that communities in countries with somewhat unfavourable conditions and limited access to alternatives and fishing households in communities with overall favourable economic conditions are at highest vulnerability as they have the highest dependence on coastal fisheries resources. Alternative economic opportunities at the national scale and availability of alternative income at the community level vary significantly between cultural groups. Based on our results, the development of management strategies with realistic expectations of ensuring livelihood of coastal communities and sustainable resource use in Pacific Island countries and territories requires a hierarchical and integral approach. Major drivers identified at the regional, cultural and local levels should be used to identify priorities, to assess overall advantages and limitations at the different levels as well as the vulnerability of communities targeted, and to develop strategies accordingly.     

基于形态法的西北太平洋柔鱼种群结构研究

西北太平洋柔鱼是我国鱿钓渔业重要捕捞对象,种群结构是渔业生物学研究的基础内容.文中根据2007年7~10月40°N~45°N,151°E~158°E海域连续采集的1 342尾柔鱼样本,测定其胴长(ML)、腕长等12项形态指标,利用正态线性转化、主成分分析和判别分析等方法研究雌雄个体的种群结构.结果表明,该海域雌、雄柔鱼均存在大小2个种群.均数差异显著性表明,雌性个体2个种群在MW/ML和FW/ML存在显著差异,雄性个体在MW/ML和AL_3/ML存在显著差异,但其形态差异仍属于种内差异.主成分分析和逐步判别分析的判别准确率(雌性60.3%,雄性60.1%),说明所划分的种群在部分形态比指标上差异明显.研究认为,形态学指标可初步区分西北太平洋柔鱼种群,但需结合其他生态学指标和耳石等硬组织进一步划分.