Responses of humpback whales to a changing climate in the Southern Hemisphere: Priorities for research efforts

Globally, baleen whales were severely depleted by historic whaling. Recovering populations have been observed to alter their behaviour. These changes have been attributed to climate change in some cases and raise concerns over the successful recovery of baleen whale populations. Current data-driven statistical habitat and behavioural models have proven useful for addressing questions of whale distribution changes within their limitations. Given observed changes in oceanic conditions, a new approach to managing baleen whale population recovery is necessary. Model predictions of future whale movements and distributions under climate change scenarios are vital to enable adequate conservation management. This paper presents a new perspective on understanding the impacts of climate change on humpback whales, arguing the need for a system-based multidisciplinary research approach. Our approach includes coupled, mechanistic models based upon robust ecological principles, and integrates key physical, biogeochemical, biological and ecological modules to address long-term changes associated with climate change. To illustrate the need for this system-based multidisciplinary approach, we focus on Southern Hemisphere humpback whales, the recovery of which may be impacted by rapid changes in habitat conditions brought about by anthropogenic climate change.     

Changes in the Quantitative Characteristics of Macro- and Meiobenthos in the Blagopoluchiya Bay from 2013 to 2020 (Novaya Zemlya,the Kara Sea)

Oceanology - Macro- and meiobenthos of the Blagopoluchiya Bay (Novaya Zemlya, Kara Sea) have undergone significant changes in their quantitative distribution from 2013 to 2020. During this period,...     

The end of shark finning? Impacts of declining catches and fin demand on coastal community livelihoods

For several decades, fishing sharks for their fins has provided important livelihoods for eastern Indonesian coastal communities that fish the Halmahera, Arafura and Timor Seas. Fishery and interview data collected in 2012-13 from three case studies on the islands of Seram, Aru and Rote were used to examine changes in shark fishers’ livelihoods over the preceding 20 years. While recent declines in catches and shark fin prices have had a substantial impact on fishers’ livelihoods, the fishery's low visibility in some areas of its geographic range and its political complexity in general have meant that government and international development agencies have largely been unaware of this impact. Many respondents remembered the Asian Financial Crisis in 1997-98 and the turn of the millennium as a time when sharks were still abundant and shark fin prices high, but were concerned about the on-going fall of shark fin prices since March 2012. High-value species, particularly guitarfish, hammerhead and sandbar sharks were most affected, losing up to 40% of their pre-2012 value. These changes, combined with the loss of fishing grounds, few attractive options for alternative income and restrictive debt relationships with shark fin bosses, have led some fishers to resort to high-risk activities such as blast fishing, illegal transboundary fishing, and people smuggling. This paper examines the multi-layered causes and consequences of fishers’ decision-making in response to adverse changes in their fishery, and explores options and obstacles to pursuing livelihoods that carry lower environmental, financial and personal risks.     

亚洲季风区石笋氧同位素环境机理研究进展

洞穴石笋作为古气候研究重要载体之一,其氧同位素指标运用极为广泛,逐渐成为低纬甚至全球古气候变化的参比标准。然而,已有研究对洞穴碳酸盐沉积δ18 O气候意义的解译存在很大差异,包括洞穴温度、降雨量、降雨过程、大气环流模式等,亚洲季风区相关研究的分歧尤其突出,至今仍未统一。因此,洞穴古气候学界必须加强现代观测等机理研究,探明石笋δ18 O各种控制因子及其相互关系,充分发挥其气候地层学方面的优势,进一步促进区域间和全球气候对比。     

日本海、鄂霍次克海和白令海的古海洋学研究进展

边缘海的存在使大陆和大洋之间的物质和能量交换变得相当复杂。在构造运动和海平面升降的控制下,边缘海和大洋之间时而连通时而隔绝,各种古气候变化信号都在一定程度上被放大。基于近期有关西北太平洋边缘海的古海洋学研究成果,简要概述了日本海、鄂霍次克海、白令海以及北太平洋地区自中新世以来的古气候和古海洋环境演化特征,并认为它们与全球其它地区一样也受控于因地球轨道参数变化引起的太阳辐射率的变化,大尺度的气候变化具有与地球轨道偏心率周期相对应的100ka周期,而41ka的小尺度周期则受地球自转轴斜率变化的控制。一些突发性的气候变化则是由气候不稳定性、海峡的关闭与开启和其它一些地球气候系统的非线性活动所驱动。但同时作为中高纬度边缘海,它们的古海平面、古海水温度、古洋流等古海洋环境因子的变化特征还受到冰盖扩张和退缩、构造运动、冰川性地壳均衡补偿、东亚季风等因素的影响,具有一定的区域特点。     

九龙江口海域中磷的化学形态分布

根据１９８７年３月至１９８８年１２月笔者在九龙江口、厦门西海域的调查研究资料，着重讨论颗粒态磷（ＰＰ）、溶解态无机磷（ＤＩＰ）、溶解态有机磷（ＤＯＰ）、总磷（ＴＰ）等各种形态磷的含量分布、季节变化，及其与叶绿素（Ｃｈｌ．ａ）、总悬浮物量（ＴＳＭ）等其他要素的关系。     

粤东后江湾涨落潮下的碎波带波能与滩面地形时空变化分析

利用涌浪和处于陡滩面、滩面下陡坎和深槽海滩地形条件下的海滩碎波带压力波和滩面地形资料,对碎波带中的入射总波能、长重力波能及两者比值随潮位涨落的变化关系,碎波带动力因子与滩面地形之间的作用关系及典型相关和多维偏交叉谱关系等作了初步分析。结果表明,碎波带中的入射总波能与潮位涨落呈现出一致的变化规律;而碎波带中的长重力波能变化与潮位涨落变化趋势相反;碎波带各动力因子、滩面潜水位和碎波带波浪、潮位及滩面地形引起的滩面陡坎处破波点位置变动等因素的耦合作用,对滩面向海发育和滩面地形变化有重要影响。     

细菌和藻类表面疏水性及其生态学意义研究概况

有关细菌和藻类表面疏水性及其生态学意义的研究近年来发展较快。本文对表面疏水性的研究方法,细菌和藻类表面疏水性的物质基础、特性及其随环境条件的变化,生态学意义等进行介绍和概括。     

南海潮汐主要分潮振幅变化趋势研究

潮汐变化研究对于海洋工程、沿海地区洪涝灾害预防、海上交通等各个方面都有着重要的意义.由于验潮站都集中在近海,所以之前潮汐变化研究主要集中在近海海域.相比之下,深海地区由于长期高频水位观测的缺乏导致相关的潮汐变化研究非常少.基于近海验潮站数据和深海卫星高度计数据,本文首次用非平稳潮汐调和分析工具包S_TIDE提取了南海4...     

The impact of natural mortality variations on the performance of management procedures for Spanish mackerel(Scomberomorus niphonius) in the Yellow Sea,China

Natural mortality rate(M) is one of the essential parameters in fishery stock assessment, however, the estimation of M is commonly rough and the changes of M due to natural and anthropogenic impacts have long been ignored.The simplification of M estimation and the influence of M variations on the assessment and management of fisheries stocks have been less well understood. This study evaluated the impacts of the changes in natural mortality of Spanish mackerel(Scomberomorus niphonius) on their management strategies with data-limited methods. We tested the performances of a variety of management procedures(MPs) with the variations of M in mackerel stock using diverse estimation methods. The results of management strategies evaluation showed that four management procedures DCAC, SPMSY, cur E75 and minlen Lopt1 were more robust to the changes of M than others; however, their performance were substantially influenced by the significant decrease of M from the 1970s to 2017. Relative population biomass(measure as the probability of B0.5 BMSY) increased significantly with the decrease of M, whereas the possibility of overfishing showed remarkable variations across MPs. The decrease of M had minor effects on the long-term yield of cur E75 and minlen Lopt1, and reduced the fluctuation of yield(measure as the probability of AAVY15%) for DCAC, SPMSY. In general, the different methods for M estimation showed minor effects on the performance of MPs, whereas the temporal changes of M showed substantial influences. Considering the fishery status of Spanish mackerel in China, we recommended that cur E75 has the best trade-off between fishery resources exploitation and conservation, and we also proposed the potentials and issues in their implementations.     

Review on North Pacific Subtropical Countercurrents and Subtropical Fronts: role of mode waters in ocean circulation and climate

A Subtropical Countercurrent (STCC) is a narrow eastward jet on the equator side of a subtropical gyre, flowing against the broad westward Sverdrup flow. Together with theories, recent enhanced observations and model simulations have revealed the importance of mode waters in the formation and variability of North Pacific STCCs. There are three distinct STCCs in the North Pacific, maintained by low potential vorticity (PV) that mode waters carry from the north. Model simulations show that changes in mode water ventilation result in interannual to interdecadal variations and long-term changes of STCCs. STCCs affect the atmosphere through their surface thermal effects, inducing anomalous cyclonic wind curl and precipitation along them. Thus, mode waters are not merely passive water masses but have dynamical and climatic effects. For temporal variability, atmospheric forcings are also suggested to be important in addition to the variability of mode waters. STCCs exist in other oceans and they are also flanked by mode waters on their poleward sides, suggesting that they are maintained by similar dynamics.     

牛山湖浮游生物群落DNA指纹结构与物种组成的关系

利用RAPD及DGGE指纹技术揭示牛山湖5个采样点浮游生物群落的DNA多态性,并定性地探讨其与物种组成的关系.结果如下:(1)从40条随机引物中筛选出9条引物,共获得93条谱带,多态率为58%;各采样点所得谱带平均为67条,其中Ⅰ站最少,为61条,Ⅴ站最多,为74条;(2)PCR-DGGE指纹图谱共含102条谱带,其中原核生物56条,真核生物46条,谱带总数以Ⅲ站、Ⅳ站和Ⅴ站较多.Ⅰ站和Ⅱ站较少;(3)5个采样点共观察到62种/类浮游生物,其中Ⅰ站和Ⅱ站种类较少.Ⅲ站、Ⅳ站和Ⅴ站种类较多,分布概率在100%的种类达19种.多维尺度(MDS)分析表明:基于RAPD指纹和DGGE指纹,Ⅰ站和Ⅱ站最相似,Ⅲ站、Ⅳ站和Ⅴ站最相似;基于物种组成.Ⅳ站和Ⅴ站相似性最高,Ⅲ站和Ⅳ站次之,相对RAPD指纹和DGGE指纹,Ⅰ站和Ⅱ站相似性较低.研究表明:浮游生物群落DNA指纹结构与物种组成有一定的相关性,可能因部分物种信息的缺失导致些许偏差.     

Geological and Geotechnical Characteristics of Marine Clays at the Busan New Port

Despite a number of geotechnical investigations that have been carried out in the Busan new port area of South Korea, the local practicing engineers have been unable to deduce successfully the geotechnical properties of the clays due to their spatial variation. In the area, clay deposits, so-called Pusan clays, are unusually thick, varying from 20 m to 70 m in thickness. For this study, comprehensive geological and geotechnical investigations were carried out with sophisticated sampling techniques, in situ and laboratory tests as well as geological analyses at an additional three locations. As a result of the investigations, it was found that depositional environments are closely related to the relative changes in sea level and have different features depending on location and depth. The clays consist of soft and stiff clays in the upper and the lower layers, respectively, which are classified as normally consolidated and cemented clay. Moreover, most of the geotechnical properties undergo small changes due to their depositional environment. Information about these effects would be quite helpful to understand the spatial variation of geotechnical properties as well as the effect of sample disturbance. Some correlations which reflect the geological history of the deposts were conducted for physical indexes and mechanical properties.     

Does the Port 2000 harbour construction have an effect on the Seine estuary suprabenthic community?

Using a Before/During/After protocol, the effects of Port 2000 (the Le Havre harbour extension) on the suprabenthic communities in the Northern Channel of the Seine estuary (English Channel) were examined from March 2001 to March 2009. Since the beginning of Port 2000 construction in 2002, there have been several changes in the hydrological and sedimentary characteristics in the North Channel, including changes in current velocity, bottoms salinity and sand accumulation, as well as in the benthic communities themselves, moving from mud to medium and coarse sand communities. For the suprabenthos, changes were moderate, corresponding to an increase in species richness in the upper-part of the North Channel and a decrease in species density in the dominant mysids species (i.e., mainly Mesopodospsis slabberi) over time. Due to hydrological changes since the beginning of the Port 2000 project (several years of low freshwater input) it has been difficult to attribute the biological changes to Port 2000 construction only. In the future, the results obtained for the suprabenthos will have to be compared to those obtained for the macrobenthos. Similarly, since the suprabenthos is known to play an important role in the estuarine trophic chain, it will also be essential to estimate the fish distribution in the North Channel and to examine their stomach contents to evaluate the probable changes since the Port 2000 project began.     

Cloning and characterization of proliferating cell nuclear antigen gene of Alexandrium catenella (Dinoflagellate) with respect to cell growth

Harmful algal blooms (HABs) have been affecting negatively the shellfish and aquaculture industries around the world. Though a lot of efforts have been made to disclose the changes of environmental factors involved and their effects on the HABs events, the molecular mechanism of this process remains unclear. To address this problem, proliferating cell nuclear antigen gene (pcna) was isolated and characterized from Alexandrium catenella. It showed high homology to those of other dinoflagellates (89% and 91% homology to Pfiesteria piscicid and Pyrocystis lunula, respectively), and also 42%–43% homology to those of plant and animals. The expression level of pcna revealed by quantitative real time PCR was the lowest at the late lagging cell growth phase, increased to the highest at the late exponential phase, and then decreased at the stationary phase. Though the cell growth rate was also changing, no positive correlation between pcna expression level and cell growth rate was displayed throughout the whole cell growth stages (r 2 =0.024 6). However, the pcna expression level had the similar trend with the change of cell growth rate throughout the whole growing process, e.g., from increasing at the earlier cell growth stage to decreasing at the following stages, though slightly lagging to the latter.     

Sequence surfaces and paleobathymetric trends in Albian to Maastrichtian sediments of Ariyalur area, Cauvery Basin, India

Exposed Late Cretaceous (Albian-Maastrichtian) marine rocks of the Ariyalur area in the Cauvery Basin have been extensively studied based on biostratigraphy and paleobathymetry with paleobathymetric interpretation carried out using vertical and lateral relationships of rock facies, macro- and microfossil assemblages, textural characteristics and diagenetic changes of the lithologic units. The integration of these data reveals four Transgressive-Regressive (T-R) cycles, viz. Dalmiapuram, Garudamangalam, Sillakkudi and Kallankurichchi (in stratigraphic order). These T-R cycles have been compared with global published relative sea level curves of the study area. The major sea level changes during the Late Turonian and Late Maastrichtian in the study area correlate well with global sea level changes of [Vail et?al., 1977] and [Haq et?al., 1987] and Miller et al. (2005). Based on biostratigraphy, stratal patterns and their relationship, the Late Cretaceous succession of the Ariyalur area is thus subdivided into four 2nd/3rd order sequences.     

Geological and Geotechnical Characteristics of Marine Clays at the Busan New Port

ABSTRACT

Despite a number of geotechnical investigations that have been carried out in the Busan new port area of South Korea, the local practicing engineers have been unable to deduce successfully the geotechnical properties of the clays due to their spatial variation. In the area, clay deposits, so-called Pusan clays, are unusually thick, varying from 20 m to 70 m in thickness. For this study, comprehensive geological and geotechnical investigations were carried out with sophisticated sampling techniques, in situ and laboratory tests as well as geological analyses at an additional three locations. As a result of the investigations, it was found that depositional environments are closely related to the relative changes in sea level and have different features depending on location and depth. The clays consist of soft and stiff clays in the upper and the lower layers, respectively, which are classified as normally consolidated and cemented clay. Moreover, most of the geotechnical properties undergo small changes due to their depositional environment. Information about these effects would be quite helpful to understand the spatial variation of geotechnical properties as well as the effect of sample disturbance. Some correlations which reflect the geological history of the deposts were conducted for physical indexes and mechanical properties.     

清水沟流路期间黄河三角洲区潮波运动的模拟和预测

为了探讨黄河三角洲附近潮波运动的变化特征，乐肯堂等(1995)用二维数值模式模拟了1855-1984年该海区的潮汐和潮流的分布变化，并着重考察了M2和S2分潮的无潮点，以及规则全日潮区的位置变化。乐肯堂等(1995)的研究表明，黄河尾闾的摆动以及由此而造成的黄河三角洲之进退，是该海区潮波特征发生变化的主要外因。自从1976年黄河尾闾改道清水沟以来，该流路已稳定运行了20多年，由此造成了河口附近沙嘴不断向莱州湾内延伸，因而对该区的潮波分布特征产生了显著影响。从黄河三角洲区的经济可持续发展和海洋生态环境的可持续发展的目的出发来规划今后黄河尾闾的走向，就必须对以下两个问题进行深入研究：(1)清水沟流路是否还能长期稳定下去；(2)如果清水沟流路长期稳定不变，并且按照清水沟流路期间黄河三角洲向莱州湾推进的方式来推演10a后黄河三角洲的形势，那么到2010年该区的潮波运动将会发生什么变化。为此，在本文中我们仍然采用乐肯堂等(1995)已经过验证的数值模式和数值预的方法对上述问题作初步探讨。     

Length variation of the oceanic coasts as a cause of eustatic sea-level changes

The volume of the continental and continent-derived matter in oceanic basins can be inferred from their bathygraphic curve: coeteris paribus, this volume depends upon the length of the corresponding coasts. Although the present-day order of magnitude of its equivalent sea-level rise per kilometre of coast is no more than some millimetres, large-scale variations of the length of oceanic coasts — like those which may have taken place following upon continental drifting — may have been a cause of important eustatic sea-level changes both positive and negative.     

Isozyme changes during larval development of Penaeus chinensis

Isozyme changes during early development of Penaeus chinensis are described for six enzymes (EST, AMY MDH, GDH, Gd and LDH) by means of polyacrylamide gel vertical plate electrophoresis. The results show that the number of isozymes varies considerably and the enzyme activity also rises gradually with development. The band number of EST increases from 1 in nauplius stage to 6 in postlarval stage. There are three types of AMY, α-AMY, R-AMY and Q-AMY. The phenotype of LDH changes slightly, showing the same pattern except nauplius in all the stages. The remaining three enzymes (MDH, Gd and GDH) have more bands and their isozyme number also increases with development.