Temporal dynamics and persistence of sponge assemblages in a Central Pacific atoll lagoon

Sponges are important components of coral reef fauna, although little is known of their temporal dynamics. Sponges dominate the lagoon system at Palmyra Atoll in the Central Pacific, which may not be its natural state. Here we examined the temporal variability and recruitment rates of these sponge assemblages to determine if they are stable and examined the evidence that a recent transition has occurred from a coral‐ to sponge‐dominated system. We found 24 sponge species in permanent quadrats in the lagoon between 2009 and 2011, and 11 species on our recruitment panels. The sponge assemblage composition and abundance did not vary significantly between years and appear stable. Many sponge recruits were found in both years that the panels were examined although higher rates were recorded in the second year of the study. While it seems very possible that a change to a sponge‐dominated lagoon is associated with declining environmental quality at Palmyra as a result of modifications over 70 years ago, without pre‐modification data on reef assemblage composition this remains speculative. Our observations of short‐term temporal stability in the sponge assemblages at Palmyra highlight the potential for sponge‐dominated reef states to be maintained in degraded reef environments that are seemingly unsuitable for coral survival.     

南沙群岛珊瑚礁海域黑边鳍真鲨的年龄与生长

利用脊椎骨鉴定 2004年5～7月于南沙群岛珊瑚礁海域捕获的黑边鳍真鲨的年龄,进一步推算其Von Bertalanffy生长方程.结果表明：南沙群岛珊瑚礁海域黑边鳍真鲨优势年龄组为雌性5～7a,雄性4～7a;v-b生长方程相关参数为：K=0.127,L∞=188cm,t0＝-1.442a;其重量生长的拐点年龄为8.22a.     

北太平洋西部和印度洋东部及其邻近海域表层水体中137Cs的分布

对北太平洋西部海域、苏禄海及印尼海、中国南海、印度洋东部海域、孟加拉湾及安达曼海等表层水体中放射性核素137Cs的活度进行了测定。结果表明,上述海域表层水体中137Cs活度显示了较大的变化范围,最低值出现在南极附近的南大洋(1.1Bqm-3),较高的活度值则出现在北太平洋西部海域及中国南海(3Bqm-3)。在所研究水域范围内,137Cs活度的纬度分布特征并没有完全有效地反映出137Cs的全球理论大气沉降趋势及其纬度效应。综合本研究及Miyake等人(1988)的测定结果,我们计算出137Cs自表层海水中的析出速率在苏禄海及印尼海约为0.016/a,在孟加拉湾及安达曼海约为0.033/a,在中国南海约为0.029/a,这一结果明显低于西北太平洋日本沿海表层水体中137Cs的析出速率。这可能是因为在这些海域,横向及纵向的水体混合过程相对都较慢,而且颗粒物对137Cs的吸附析出过程也比较弱所致。     

北太平洋秋刀鱼渔场形成与水温之间关系的初步研究

利用地理信息系统(GIS)技术对2004年7～9月在北太平洋秋刀鱼(Cololabissaira)资源调查中的渔业数据与水温之间的关系进行了初步分析。结果表明,各小渔场Ⅰ～Ⅳ的温跃层厚度及其平均值分别为23.21～45.23m(22.02m),9.26～26.16m(16.90m),19.03～27.60m(8.57m)和19.09～30.53m(11.44m)。各小渔场0～50m(50～100m)的温度梯度分别为0.46℃/m(0.40℃/m),0.36℃/m(0.14℃/m),0.49℃/m(0.24℃/m)和0.42℃/m(0.18℃/m)。50～100m水层时,各渔场最高单位捕捞努力量渔获量(CatchPerUnitEffort,CPUE)平均分布的各层温度范围较为接近,50m水层为3.00℃左右,75m水层约为2.00℃,100m水层为1.50℃左右。     

2016年秋季热带西太平洋网采浮游植物群落结构

作者于2016年9月27日～10月25日对热带西太平洋(0°～20°N, 120°～130°E)10个站位的网采浮游植物群落结构进行了采样调查。应用Uterm?hl方法对调查海域浮游植物的物种组成、细胞丰度、优势物种以及群落多样性等相关生态特征进行了分析。希望为热带西太平洋提供一些基础的背景资料,为以后的研究奠定基础。结果表明, 鉴定出浮游植物共计4门、66属、243种(包括变种、变型), 含硅藻门(Bacillariophyta)34属、103种, 甲藻门(Pyrrophyta)28属、133种, 金藻门(Chrysophyta)2属、4种,蓝藻门(Cyanophyta)2属、3种。浮游植物细胞丰度1 965.573×10³ 细胞/m³ , 其中蓝藻的细胞丰度为1 945.169×10³ 细胞/m³ , 决定了浮游植物的分布格局, 占总细胞丰度的98.96%, 高值区分布在0°N130°E-10°N130°E的4个站位(E130-13、E130-15、E130-17、E130-19); 硅藻丰度在20°N断面N20-4站位存在高值区; 甲藻丰度在130°E断面的3个站位(E130-10、E130-13、E130-15)存在高值区。本次调查的优势种依次为铁氏束毛藻(Trichodesmium thiebaultii)、扁形原甲藻(Prorocentrum compressum)、扁豆原甲藻(Prorocentrum leniculatum)、胞内植生藻(Richelia intracellularis)、菱形海线藻(Thalassionema nitzschioides)、细弱海链藻(Thalassiosira subtilis)、具边线形圆筛藻(Coscinodiscus marginato-lineatus)、科氏角藻(Ceratium kofoidii)、鲁比膝沟藻(Gonyaulax lurbynaii)、中华半管藻(Hemiaulus sinensis)、霍氏半管藻(Hemiaulus hauckii)、小等刺硅鞭藻(Dictyocha fibula)。Shannon-Weiner多样性指数的均值为2.440,Pielou 均匀度指数的均值为0.163。相关分析结果显示浮游植物空间分布主要受PO₄-P、NH₄-N的影响,且由蓝藻的相关性决定的。聚类分析得出群落结构分为大洋群聚和近岸群聚两种类型(其中大洋群聚的站位又划分为0°～10°N纬度范围聚集和10°～20°N纬度范围聚集)。     

中西太平洋紫魟渔业生物学初步研究

紫魟(Pteroplatytrygon violacea)作为金枪鱼延绳钓中最常见的副渔获物,对海洋生态系统的稳定和物种多样性起着重要的作用。根据2017年7月-2018年2月间我国远洋渔业科学观察员在中西太平洋作业中采集的紫魟生物学特征、渔获等数据,初步研究紫魟的生物学信息。结果发现:(1)紫魟的体盘宽范围在28～66cm间,优势体盘宽范围在35～45cm,雌性紫魟优势体盘宽(50cm)大于雄性紫魟(45cm),且紫魟雄性最大体盘宽比雌性短;(2)研究捕获紫魟基本已成年,雌雄比达到1︰2.7;(3)摄食等级以0级为主,达41.79%,胃含物中频率最高为沙丁鱼类和鱿鱼类等;(4)紫魟雌雄性体盘宽与体质量的关系式分别为:W_R=0.1447T_W~(3.3287)(n=482, R~2=0.8032)、W_R=0.1447T_W~(3.3287)(n=482, R~2=0.8032)。     

太平洋海气界面净热通量的季节、年际和年代际变化

根据 COADS资料 ,使用经验正交分解 (EOF)等分析方法 ,研究了北太平洋海气热通量的季节、年际和年代际变化特征。分析结果表明 :北太平洋海洋夏季净得热 ,冬季净失热 ,且黑潮及其延伸体区失热最大。净热通量年际变化较明显 ,北太平洋西部模态水形成区冬季净热通量和副热带失热区春季净热通量的年际变化都主要依赖于潜热和感热通量的年际变化。夏季净热通量的低频变化中心在热带 ,冬季低频变化中心在黑潮及其延伸体区。冬季赤道东、西太平洋净热通量异常的年际变化相反 ;在热带北太平洋中部年际变化达到最大。夏季热带太平洋是净热通量异常的年际变化最大的海域 ,沿赤道两侧在 16 5°E处呈偶极子型分布。     

中西太平洋镰状真鲨的生物学信息初步研究

镰状真鲨(Carcharhinus falciformis)是金枪鱼(Thunnus)延绳钓渔业中常见的兼捕鱼种之一,位于海洋食物链的顶端,对海洋物种多样性和生态系统的稳定性有重要意义,2017年10月1日作为濒危物种被正式列入濒危野生动植物种国际贸易公约附录Ⅱ中。作者根据中国金枪鱼渔业科学观察员在中西太平洋海域(7°S~9°N,149°E~150°W)采集的1 150尾镰状真鲨样本,对其叉长、体质量、繁殖和摄食等生物学信息进行初步研究与分析。结果表明:雌、雄镰状真鲨的优势叉长范围分别为80~180 cm和60~150 cm,雌性叉长均值显著大于雄性;雌、雄的叉长和体质量关系无显著性差异(ANCOVA,P0.05),叉长和体质量的幂函数关系为:W_R=9×10–6×L_F~(2.9712);雌、雄性比符合1︰1比例;镰状真鲨的鳍脚长度与叉长呈显著正相关性,其线性关系为L_C=0.1492×L_F–6.5;镰状真鲨的怀仔数为4~15尾,平均怀仔数为8尾,子宫内雌雄胚胎长度范围为24~56 cm;摄食等级以空胃率为主,其次为1级,分别为51.77%、35.07%。     

Sedimentary characteristics and the implications of cobalt-rich crusts resources at Caiwei Guyot in the Western Pacific Ocean

Abstract

Cobalt-rich crust has attracted increased attention due to their economic value. Studies have indicated that seamounts in the Western Pacific Ocean are rich in cobalt-rich crust resources. The Caiwei Guyot in Western Pacific Ocean is one of the cobalt-rich crust exploration areas contracted between China and the International Seabed Authority. A large volume of research has been conducted to elucidate the tectonic evolution, basement type, sediment type, gravity and magnetic anomaly characteristics, and geochemical characteristics of shallow surface sediments at Caiwei Guyot. However, a research gap exists on the sedimentary strata below the pelagic deposits and above the volcanic basement of the Caiwei Guyot. This paper summarizes that two main types of sediments existing on the top of Caiwei Guyot. The deposition thickness on the top of Caiwei Guyot is characterized by three sedimentary centers and exposed periphery. Pelagic sediments are difficult to form at the northeastern portion and edge area of Caiwei Guyot due to the strong bottom current environment, which makes these areas suitable for crust growth. This paper delineated three cobalt-rich crust prospective areas at the Caiwei Guyot with of significant implications for exploration and mining-lease-block selections at Caiwei Guyot.     

Distribution of Phyllosoma Larvae (Crustacea: Decapoda: Palinuridae,Scyllaridae and Synaxidae) in the Western North Pacific

Phyllosoma larvae were identified and their distribution was examined, based on the larvae in ichthyoplankton samples collected in the Japanese Eel Expedition to the spawning area of A. japonica in the western North Pacific from August 30 to September 13, 1986 (Leg. 1), and from September 22 to 25, 1986 (Leg. 2), on board the R/V Hakuho-maru. Phyllosoma larvae belonged to 3 families (Scyllaridae, Palinuridae and Synaxidae) representing 6 genera and 14 species. A total of 336 palinurid and synaxid phyllosoma larvae were collected, of which 233 larvae (about 70%) were identical with P. longipes s. l, while a total of 362 scyllarid phyllosoma larvae were collected, of which 274 larvae (about 76%) were identical with S. cultrifer. Phyllosoma larvae of P. longipes s. l and S. cultrifer showed a similar distribution to each other. The larvae were abundant in the water close to Mariana Islands, although late stage examples were abundant in waters of Luzon and eastern Taiwan. Distributions of these larvae may be related intimately with the North Equatorial Current existing along 15°N. The North Equatorial Current approaches the eastern coast of the Philippines and then separates into two branches of northward and southward flows. The northward flow contributes to generating the Kuroshio Current while the southward flow goes to generate the Mindanao Current. Judging from distributions of phyllosoma larvae in the present study, it is assumed that the larvae of the above two species may have been released in Mariana Islands and transported westward from there through the North Equatorial Current. These larvae may then be transported to eastern Taiwanese waters.     

东太平洋1787柱碎屑组分组合与沉积环境

对太平洋 １７８７ 柱沉积物样品进行了碎屑组分、分布、来源及组合的研究。结果表明,沉积物中的碎屑组分主要是生物来源、海洋自生来源和岩源。重组分以铁锰微结核、生物磷灰石、褐铁矿、磁铁矿、辉石类为主, 轻组分主要是生物蛋白石 （放射虫、海绵骨针等硅质生物壳体或骨骼）、粘土团集物和火山玻璃。根据各碎屑组分在整个柱芯的分布特点及其组合类型的不同, 把 １７８７ 柱分为 ６ 层, 并大致反映沉积环境的氧化还原条件、火山活动特点及底层流活动状况。研究结果能与磁性地层资料、地球化学资料和沉积物构造相互印证, 表明碎屑组分及其组合研究能为恢复沉积环境提供矿物学证据。     

涠洲岛珊瑚礁近千年的发育过程及其对气候变化的响应*

高纬度珊瑚栖息地能否成为气候变暖背景下热带珊瑚物种的“避难所”仍不明确, 南海北部的相关研究更是稀少。本文以取自涠洲岛的2根珊瑚礁沉积岩心为研究对象, 通过U-Th定年、沉积组分分析以及珊瑚种属鉴定等方法, 探讨近千年以来珊瑚礁的发育过程及其对气候变化的响应。研究结果发现, Core1(石螺口)岩心沉积的3个快速堆积阶段分别与罗马暖期、中世纪暖期和现代暖期大致对应; 而2个缓慢堆积阶段则分别与黑暗时代冷期和小冰期大致对应, 证实了温暖的气候对珊瑚礁发育有促进作用, 而寒冷的气候则不利于珊瑚礁的发育; 此外, 现代强烈的人为干扰可能也导致了涠洲岛珊瑚礁的迅速退化。Core2(南湾)中陆源沉积含量高, 珊瑚年龄主要集中在800AD—950AD和现代这两个时间段内, 其原因可能与环境变化、风暴作用及湾内现代珊瑚分布特征有关。通过对比这两个站位的珊瑚礁沉积特征, 本文进一步提出“完全避难所”和“非完全避难所”的概念, 揭示涠洲岛珊瑚可能同时具有低纬度热带珊瑚礁和高纬度珊瑚群落这两种发育特征和趋势。     

The structure of tuna access agreements in the Western and Central Pacific Ocean: Lessons for Vessel Day Scheme planning

The tuna industry in the Western and Central Pacific Ocean (WCPO) is one of the largest and most valuable fisheries in the world. Since the 1980s, Pacific island countries have used licensing agreements with foreign fishing interests—known as access agreements—to earn tuna-related revenue and control the environmental impacts of fishing, with only minimal success. To date, there has been little work detailing the structure of access agreements and assessing how this structure relates to economic and environmental outcomes in the sector. This article helps to fill this gap by providing an overview of various access structures and a detailed empirical assessment of how these structures are applied in access agreements between Pacific island countries and the major foreign fishing interests active in the WCPO. This analysis is placed in the context of evolving regional fisheries management structures. The study reveals that while there is no uniform formula for access agreements, each structure is subject to distinct political, economic and environmental considerations that influence outcomes for Pacific island countries. As Pacific island countries develop the mechanism to allocate fishing rights under the new Vessel Day Scheme, drawing on their long history with access agreements will assist efforts to use access to achieve policy objectives. Improved transparency will enable Pacific island countries to identify successes and problems and adapt the Vessel Day Scheme allocation mechanisms accordingly.     

晚新生代西太平洋古海洋环境演化过程与机制

晚新生代西太平洋通过水文循环和碳循环两类关键过程,对区域乃至全球气候变化产生深刻的影响。本文从上新世以来西太暖池及其主流系演化、晚第四纪北太平洋中层水演化和白令海峡开合、第四纪中国东部陆架环境演化以及新生代亚太沉积物源-汇过程与碳埋藏等方面,综述了西太平洋古海洋环境演化过程与机制。上新世以来西太暖池与印尼贯穿流的演化过程伴随构造运动而阶段性地发生,但其在轨道时间尺度上演化的细节过程并不清晰,尚未形成系统性认识。北太平洋中层水以及白令海峡开合等关键高纬过程在冰期旋回中发生了显著变化,并与低纬过程之间存在遥相关。第四纪中国东部陆架环境演化主要受控于海平面变化以及与低纬过程相关联的热量与物质传输,在此背景下,中国东部陆架形成了富有机碳的泥质沉积体系。构造隆升和亚洲季风驱动下的亚洲大陆与邻洋的沉积物源-汇过程具有显著的碳汇效应,可能在大气CO₂浓度（${p_{{\rm{C}}{{\rm{O}}_2}}} $）冰期旋回和新生代气候变冷中发挥重要作用。就西太平洋古海洋环境演化过程与机制中若干关键科学问题开展深入和系统研究,不仅可为建立气候变化的低纬驱动理论提供支撑,也可为更好认识我国陆架环境变化规律以及碳汇潜力提供科学依据。     

热带西太平洋浮力频率的垂直分布和经向变化

根据实测资料(1986-1990年),分析了热带西太平洋(165°E,10°N～10°S)浮力频率的垂直分布和经向变化,讨论了浮力频率与海水稳定度和海洋内波位能的关系。分析结果表明,赤道海域浮力频率的垂直分布和经向变化具有明显的年际变化。其垂直分布的特点是:浮力频率的垂直变化与位温梯度dθdz的垂直变化相似。在ENSO前期或初期,浮力频率在垂直方向上的极大值达到最大,此时跃层最强,但其厚度最薄;在LaNi na期间,垂直方向的极大值明显小于ENSO前期和初期,此时跃层较厚,跃层强度次之;在ENSO末期,垂直方向上的极值介于上述两者之间。此时跃层厚度最为深厚,跃层强度最弱。浮力频率的经向变化是:在ENSO前期和初期,赤道海域的垂向极大值明显高于赤道外海洋;在LaNi na期间,它明显低于赤道外海洋;而在ENSO末期,则与赤道外海洋无显著差异;在8°N,有一个近乎定常的浮力频率峰值,几乎与ENSO或LaNi na的年际变化无关。     

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.     

Rights-based management in the Western and Central Pacific Ocean tuna fishery: Economic and environmental change under the Vessel Day Scheme

Defining, strengthening and enforcing rights over fisheries resources is frequently identified as central to overcoming ‘the tragedy of the commons’ and associated environmental and economic challenges in fisheries systems. Though economic theory generally suggests that output control (e.g. quotas) creates the strongest incentives for efficiency and conservation, input controls (e.g. on effort) remain common. This paper explores the rationale for, and implications of, employing a transferable effort scheme in one of the largest and most valuable fisheries. In 2007, eight Pacific Island countries implemented the Vessel Day Scheme with the aims of strengthening their rights over tuna resources and control over economic and environmental trends. Four years since implementation, the scheme has significantly increased economic returns for the island states and generated improvements in data reporting. However, it has not generated a firm limit on fishing effort and its structure has made it difficult to directly target the biological concerns of individual species within the multi-species fishery. In the future, outcomes of the Vessel Day Scheme will continue to be tempered by the structural limitations of effort-based regulatory scheme, market conditions in the sector and the willingness of firms and island states to clarify, abide by and enforce the technical components of the scheme.     

基于世代分析法的西北太平洋柔鱼冬春生西部群体资源评估

根据1996-2006年7～11月中国大陆鱿钓船在西北太平洋38°N～46°N、150°E～165°E海域的生产统计、平均渔获个体等数据,基于Pope提出的世代分析法估算了不同自然死亡系数下(M＝0.03～0.1/10 d)柔鱼冬春生西部群体7月的初始资源量,以及该群体为对象的渔业管理参考点,包括最大可持续产量(MSY)和逃逸率,并且拟合了该群体补充量与亲体量的关系,推测了2006-2020年资源量和渔获量的变化.结果表明,M为0.06/10 d为1个临界点,若实际M＜0.06/10 d则该群体处于过度开发状态;若M=0.06/10 d则该群体处于充分利用状态;若M＞0.06/10 d则该群体还有进一步开发利用的空间.补充量亲体关系表明,Beverton-Holt模型拟合效果略优于Ricker模型.要持续利用该资源,逃逸率应设在40%左右,其相应的MSY为10万t左右.文章模拟了M=0.06/10 d时不同捕捞强度下资源量变化状况,认为维持目前的捕捞努力量下,到2020年该群体的资源量都将处在稳定状态,且能保持每年9～10万t的渔获量.     

Atmospheric input of trace elements to the western Pacific Ocean and the Kuroshio ocean area

ＡｔｍｏｓｐｈｅｒｉｃｉｎｐｕｔｏｆｔｒａｃｅｅｌｅｍｅｎｔｓｔｏｔｈｅｗｅｓｔｅｒｎＰａｃｉｆｉｃＯｃｅａｎａｎｄｔｈｅＫｕｒｏｓｈｉｏｏｃｅａｎａｒｅａ￥ＱｉａｎＦｅｎｌａｎ；ＹｕＨｏｎｇｊｉａｎ；ＬａｎＹｏｕｃｈａｎｇ；ＣｈｅｎＺｈｉ；Ｚｈｏｕ...     

Sponge Communities in Three Submarine Caves of the Balearic Islands (Western Mediterranean): Adaptations and Faunistic Composition

Abstract. The sponge fauna of three neighbouring submarine caves of the Island of Majorca (Balcaric Islands) is studied along a light gradient; 45 species have been recorded and systematic data are given for those showing morphological, pigmentary, or spicule differences. Adaptation to darkness and precarious trophic conditions is also discussed.