Aleuts, sea otters, and alternate stable-state communities

Reexamination of stratified faunal components of a prehistoric Aleut midden excavated on Amchitka Island, Alaska, indicates that Aleut prey items changed dramatically during 2500 years of aboriginal occupation. Recent ecological studies in the Aleutian Islands have shown the concurrent existence of two alternate stable nearshore communities, one dominated by macroalgae, the other by epibenthic herbivores, which are respectively maintained by the presence or absence of dense sea otter populations. Thus, rather than cultural shifts in food preference, the changes in Aleut prey were probably the result of local overexploitation of sea otters by aboriginal Aleuts.     

Lumber spill in central california waters: implications for oil spills and sea otters

A large quantity of lumber was spilled in the ocean off central California during the winter of 1978, and it spread through most of the range of the threatened California sea otter population within 4 weeks. The movement rates of lumber were similar to those of oil slicks observed elsewhere. These observations indicate that a major oil spill could expose significant numbers of California sea otters to oil contamination.     

Killer whale predation on sea otters linking oceanic and nearshore ecosystems

After nearly a century of recovery from overhunting, sea otter populations are in abrupt decline over large areas of western Alaska. Increased killer whale predation is the likely cause of these declines. Elevated sea urchin density and the consequent deforestation of kelp beds in the nearshore community demonstrate that the otter's keystone role has been reduced or eliminated. This chain of interactions was probably initiated by anthropogenic changes in the offshore oceanic ecosystem.     

南方鲍藻混养技术研究及其效益分析

在福建省莆田市南日东岱海区,利用现有海藻养殖设施,进行海藻与皱纹盘鲍混养周年试验.结果表明：海区筏式单养、混养生长率无显著差异,但混养的成活率、肥满度比单养分别高8%、2.24%;2种养殖模式的投入产出比分别为1∶1.62、1∶1.9.同时,鲍和海藻处在海洋生态系统的不同生态位,互利共生,促进海洋生态系统物质良性循环.     

Fossil evidence for the origin of aquatic locomotion in archaeocete whales

Recent members of the order Cetacea (whales, dolphins, and porpoises) move in the water by vertical tail beats and cannot locomote on land. Their hindlimbs are not visible externally and the bones are reduced to one or a few splints that commonly lack joints. However, cetaceans originated from four-legged land mammals that used their limbs for locomotion and were probably apt runners. Because there are no relatively complete limbs for archaic archaeocete cetaceans, it is not known how the transition in locomotory organs from land to water occurred. Recovery of a skeleton of an early fossil cetacean from the Kuldana Formation, Pakistan, documents transitional modes of locomotion, and allows hypotheses concerning swimming in early cetaceans to be tested. The fossil indicates that archaic whales swam by undulating their vertebral column, thus forcing their feet up and down in a way similar to modern otters. Their movements on land probably resembled those of sea lions to some degree, and involved protraction and retraction of the abducted limbs.     

不同底泥处理对软叶丁香蓼去除水体中氮素的影响

选用沉水植物软叶丁香蓼(Ludwigia hyssopifoliaExell)为材料,结合不同的底泥处理,在人工模拟条件下研究了水体中几种氮形态变化的影响.结果表明,开始阶段因裸露底泥处理会向水体中释放出不同形态的氮素,使水体总氮含量有所增加.但试验的后期因软叶丁香蓼对铵态氮,尤其是对硝态氮的吸收作用,以及底泥中大量硝化和反硝化菌参与的硝化反硝化作用,会使软叶丁香蓼配合裸土的处理加快水体中氮的去除.在处理50 d后,软叶丁香蓼 裸露底泥(植物裸土)的处理和软叶丁香蓼 包裹底泥(植物包土)的处理对氮素的去除已经没有显著差异,说明在一定条件下底泥对水质的影响并非总是负作用,尤其在与一些高等水生植物组成的生态系统中能起到营养物质"库"的作用.     

基于微卫星标记的刺参群体遗传结构分析及与经济性状的相关性研究

采用微卫星分子标记技术对7个刺参Apostichopus japonicus(Selenka)群体:辽宁葫芦岛养殖群体、山东烟台野生群体、山东莱州养殖群体、大连旅顺底播群体、丹东东港养殖群体、大连广鹿岛底播群体、大连黑石礁野生群体的遗传多样性进行分析,并随机抽取7个群体中的180头刺参进行体长、体宽、体积、体质量和总棘数与17个微卫星标记之间的相关性研究。结果表明:用12个微卫星标记共扩增获得83个等位基因,每个位点的等位基因数为3～12个,长度为102～368 bp。刺参群体位点多样性分析显示,各刺参群体等位基因数为5.083 3～5.416 7,平均值为5.261 9;有效等位基因数为3.205 0～3.701 1,平均值为3.446 8;观测杂合度为0.547 5～0.686 9,平均值为0.614 9;期望杂合度为0.649 1～0.697 1,平均值为0.674 1;多态性信息含量为0.598 9～0.638 6,平均值为0.620 0。对各群体的Hardy-Weinber平衡检测显示,7个刺参群体均存在不同程度的平衡偏离。刺参群体遗传分化与基因流分析显示,刺参群体间遗传分化系数平均值为0.078 2,变异主要来源于群体内;基因流平均值为5.301 9,刺参群体间存在一定程度的基因交流。刺参群体间遗传相似性系数为0.731 8～0.886 0,UPGMA聚类显示,7个群体中山东烟台野生群体单独为一类,其他6个群体聚为一类。刺参微卫星标记与经济性状相关性分析显示,HC312、EAJ07位点与刺参体长、体积、体质量显著相关(P<0.05);IS45、EAJ03、EAJ04位点与刺参体长、体积、体宽、体质显著相关(P<0.05);SJ04位点仅与刺参总棘数显著相关(P<0.05);SJ09位点与刺参体积、体宽、体质量显著相关(P<0.05);SJ18位点仅与刺参体宽显著相关(P<0.05);SJ19位点与刺参体积、体宽、体质量、总棘数显著相关(P<0.05);SP072位点与刺参体积、体质量显著相关(P<0.05)。本研究结果可为刺参群体结构优化、经济性状的QTL定位、养殖和选育提供参考。     

国外海参渔业及增养殖概况

对日本、印度尼西亚、马来西亚、菲律宾等国的海参渔业现状进行了介绍,阐明了过度开发海参资源是各国普遍存在的问题,提出对海参资源进行保护势在必行。另外,还对印度尼西亚、马来西亚、菲律宾等国的海参养殖及日本的海参增殖的放流情况进行介绍,认为进行海参增养殖是保持海参自然资源和渔业可持续发展的关键所在。     

北方海区经济海胆性腺脂肪酸组成与β-胡萝卜素含量的比较研究

海胆性腺中脂肪酸含量丰富,β-胡萝卜素含量高,是一种营养价值较高的食物来源,不同种、不同群体间、不同性别海胆性腺中二者的组成与含量存在差异。对我国北方海区4种经济海胆(虾夷马粪海胆、光棘球海胆、马粪海胆和海刺猬)以及大连黑石礁、旅顺、獐子岛3个群体的光棘球海胆性腺中的脂肪酸组成及β-胡萝卜素含量进行了测量和分析。结果显示:不同种海胆、同种海胆的不同群体及不同性别海胆性腺中脂肪酸、β-胡萝卜组成与含量均存在差异。不同种海胆间,光棘球海胆性腺中脂肪酸种类最多为31种,虾夷马粪海胆性腺中种类最少为24种;不同群体的光棘球海胆间,黑石礁群体性腺中脂肪酸种类最多为29种,旅顺群体最少为26种。雄性、雌性马粪海胆性腺中β-胡萝卜素含量均显著高于其他3种雌性海胆(P<0.01)。3个群体的光棘球海胆性腺中,黑石礁群体雄性性腺β-胡萝卜素含量显著低于其他2个群体(P<0.05);獐子岛群体雌性性腺中β-胡萝卜素高于其他2个群体,差异极显著(P<0.01)。上述结果为进一步开展海胆杂交及海胆优良品种的选育奠定了基础。     

蓝狐、水貂和獭兔的毛纤维显微结构观察

[目的]区分成型的毛皮产品,避免假毛皮以假乱真。[方法]用哈氏切片法快速制取高清晰度毛纤维横切片,采用生物显微镜和扫描电镜观察蓝狐、水貂、獭免3种动物的毛纤维结构。[结果]獭兔毛鳞片排列紧密,髓质发达,横切面呈花生豆状;黑貂绒很细,有髓,且鳞片翘角非常大;蓝狐针毛从根部到梢部由连续状髓过渡为断续状髓到毛尖时无髓,横切面呈椭圆形,其绒毛基本呈圆形,有髓。[结论]蓝狐、水貂、獭兔3种动物的毛纤维的结构不同,可用于毛皮的鉴别.     

伊乐藻和固定化细菌对富营养化水体中氮循环菌的影响

本试验研究了沉水植物伊乐藻(Elodea nuttallii)和固定化微生物两者相结合对富营养化水体和底泥中4种菌群的氮循环微生物(氨化细菌、亚硝化细菌、硝化细菌、反硝化细菌)分布的影响。试验结果表明:种植沉水植物和接种固定化微生物无论对水体还是底泥都有利于4种微生物数量的增加,而且两者相结合的处理效果最为明显。与对照组相比,除氨化细菌外,其余菌群都有10~100倍的增长。虽然不同时期受环境因素的影响,各种群微生物变化并不一致,但总体上底泥中氮循环微生物的分布多于水体。研究结果显示:优化种植水生植物和固定化微生物的镶嵌技术或许是促进氮循环微生物增长,加速富营养化水体中氮素转化的有效手段。     

Aleuts: Ecosystem, Holocene Historys, and Siberian Origin: Soviet and U.S. scientists join in a study of the origins of the first Americans

An original objective of these multidisciplinary studies was to determine the position of the Aleuts in the Aleutian ecosystem with time depth. This has been done in a variety of ways (7, 14, 20, 21). One of the most useful approaches is the construction of life expectancy tables. The greater longevity of Aleuts compared with Eskimos represents an effective biological and cultural human adaptation within this ecosystem. The Aleuts defined their ecosystem by expanding to the limits of the area they could effectively exploit with their complex technology, population structure, and population deployment system. Their intellectual achievements played a tangible role in their longevity in the pre-Russian period, and their sophisticated knowledge of human anatomy is both a causal and a consequential correlate of their longevity. From the Aleut point of view, the food resources were diverse, abundant, and accessible, and they also provided fabricational materials necessary for their complex material culture. The Aleuts successfully hunted the world's largest range of sea mammals, from the sea otter to the whales. At the same time, extensive use of invertebrates easily available on the ice-free strandflats enabled disadvantaged sectors of the population to make important contributions to their own food supply and thus improve life expectancy. The rich food and fabricational materials antedate the Holocene history of Nikolski Bay and the arrival of the ancestral Aleuts. The natural resources of this area are fundamentally related to the former peninsular extension of Beringia and the permanent upwelling system in Samalga Pass (22). Sea otters, seals, and sea lions were present when the first Aleuts came to the area. Nikolski Bay has been an ideal place to obtain samples representing the entire Holocene Epoch. The earliest Asiatic migrants came from Siberia and traversed the southern coastline of Beringia. They established a large and permanent village on the northern arm of Nikolski Bay and remained there while expanding to the far ends of the Aleutian domain in the sixth millennium of their residence. The record of cultural change spans a lithic revolution. It begins with a conservative unifacial core and blade industry that preserves several Asiatic traits but includes stone lamps, dishes, an image of the deity, and the use of red ochre. Between 7000 and 6000 years ago bifacially flaked and stemmed points appear, with some continuing elements of the old unifacial industry. This transition culture continues to about 4500 years ago, when the standard sequence seen in the old midden of Chaluka takes form. This culture continues, adding and subtracting various elements but always maintaining a distinctive configuration through time, to the present Aleuts, whose connection with the first Anangula settlement includes having remembered an older Aleut designation, "the place of the blades," and collecting eggs on its flanks. The dating of events inside Nikolski Bay and the identification of the Asiatic elements do throw light on human migration from Siberia into Alaska. The Aleuts and Eskimos may well have been a part of a single population system of Bering Sea Mongoloids who expanded along the Siberian coasts and across the southern Beringian coasts. The population that reached Nikolski Bay became Aleuts. Those closer to the old mouth of the Kuskokwim River and further north became Eskimos. The rise of sea level presented no problems to marine-adapted people. Instead it presented more opportunities in the form of more coastline to exploit. The ancestors of the American Indians migrated earlier through the interior of Beringia. The double-thumb hypothesis of Hrdlicka (23) is useful now for interpreting human migration into the New World. He suggested that if the Eskimos were physically related to the Indians as the thumb of one hand is to the fingers, then a second thumb is necessary to represent the Aleuts, who are also distinctive. The Bering Sea Mongoloids as a group (Aleuts, Eskimos, Chukchi, Koryaks, and probably Kamchadals) are distinguished from the Indians by both genetic traits such as the presence of blood group B, which is absent in the Indians, and morphological configurations such as the unusually broad, low ascending portions of the mandible. This magnitude of difference fits very well with a geographic difference in point of origin, separate route of entry into the New World across Beringia, and the maintenance of separation by many geographic, economic, and cultural barriers. Earlier investigators in the Aleutians compiled invaluable bodies of information. The Russian W. J. Jochelson worked in the Aleutians and the American A. Hrdlicka in Siberia. The problems common to both sides of the Bering Sea have now been studied by Soviet and American scholars at the same time, in the same place, and with the same specimens. It has been pleasant and informative to work directly with the Siberian authorities on Siberia in the Aleutians. In summary, I submit the following eight conclusions: 1) Increased longevity, rather than rapid population turnover, served as a major form of population adaptation and resource management among the Aleuts. Because people lived longer, genetic and cultural wastage was minimized. 2) Cranial vault change, from narrow to broad, has been the result of evolution within the population. 3) The Aleuts have continuously occupied Nikolski Bay, Umnak Island, for 8700 years. During this time sea level has risen and the coastline configuration has changed. 4) Siberian characteristics of the Anangula core and blade industry have been identified, and a transition culture, which links the earliest Anangula tool tradition with the later Aleut culture of Chaluka, has been discovered. 5) Organic remains of human occupation have been used to precisely date geological events of the Holocene Epoch for 8700 of its 10,000 years. Major volcanic eruptions occurred, at exponentially increasing intervals, 10,000, 9000, 7000 and 3000 years ago. 6) The earliest Aleut culture has preserved its Asiatic template because of the coastal entry route from Siberia and subsequent isolation of the population. The abundant lithic remains indicate a complex and diverse material culture. 7) The known similarity of Aleuts to Asiatic populations plus our Holocene time scale suggest a slower rate of human evolution than was assumed when a later date of entry into the Aleutians was accepted. 8) In the broadest perspective, these findings are relevant to understanding the entry of man (Aleuts, Eskimos, and Indians) into the New World in that other migrant populations originating in Siberia may also have entered the New World with a sophisticated and complex culture.     

人工湿地植物生理生态及其去污机理研究

阐述了国内外有关人工湿地植物生理生态及其去污机理的研究成果,提出了人工湿地系统植物有待进一步研究的问题。     

Observations on the Behavior of the Porpoise Delphinus delphis

Common porpoises have been observed in January, in the area of the Hudson Canyon, feeding on fish that escaped an otter trawl. An echo-sounder alsorecorded, in one instance, a descent of a porpoise to a depth of 200 feet in less than 2 minutes.     

中间球海胆性别性状的微卫星分析

针对中间球海胆Strongylocentrotus interm edius育苗生产中很难进行活体性别鉴定这一特点,采用组织切片法和微卫星标记分析法对海胆进行观察分析。试验用样品由大连太平洋海珍品有限公司提供,共31只。采用组织切片法鉴别雌、雄个体,发现17只个体为雌性,14只个体为雄性。同时,将31只个体分为雌、雄两个群体,提取性腺组织基因组DNA,利用已经筛选好的11对引物对雌、雄两个群体进行微卫星分析。结果表明,两个群体的遗传多样性没有显著差异;发现INST09-A,INST10-A,INST10-B三个等位基因的频率在两个群体间存在极显著差异(P<0.01),位点INST10在雌、雄两个群体中的基因型频率存在极显著差异(P<0.01)。初步说明这些位点及相应等位基因可能与性别决定位点存在一定的连锁关系。     

Olfactory-based orientation in artificially imprinted sea turtles

Sea turtles (Lepidochelys kempi) are being artificially imprinted to Padre Island, Texas, in an effort to establish a new nesting population. These turtles spent more time per exposure in solutions made of Padre Island sand and seawater than in control solutions in a multiple-choice test. This is evidence that sea turtles may detect differences in natural water samples and remember olfactory cues to which they were exposed neonatally and that these differences may affect their orientation behavior. This suggests that imprinting could be used as a conservation technique for establishing new breeding populations of endangered sea turtles.     

太湖沉水植物附生藻类群落对水盾草入侵能力的影响

为探究冬季乡土沉水植物表面附生藻类群落对水盾草的入侵是否存在抵抗力,在冬季采用透析袋对接种有来自乡土种、入侵种沉水植物及二者混合的附生藻类群落的水盾草断枝进行为期4周的培养,收获后分析不同附生藻类群落对水盾草附生藻类群落密度、组成情况和生长、拓殖再生能力的影响。结果表明,不同处理下,水盾草的附生藻类群落密度与组成有显著区别。入侵沉水植物附生藻类群落处理组中的水盾草断枝生长速率与再生拓殖能力均高于乡土和混合附生藻类群落处理;相较于水盾草表面原生附生藻类群落,乡土附生藻类群落短期内可显著抑制水盾草的生长和拓殖,表现出抵抗作用。但在冬季,随着太湖中乡土沉水植物相继死亡,其附生藻类群落随之消亡,无法继续抵抗水盾草的入侵。这在一定程度上解释了水盾草在冬季太湖入侵并形成单一优势群落的原因,为沉水植物生物入侵的治理提供了理论依据。     

乌梁素海氮循环转化过程的初探

氮是湖泊生态系统的主要营养元素之一，对不同形态氮的循环转化规律的分析是研究湖泊生态系统稳定结构及其演化进程的基础，针对乌梁素海的生态现状，建立了不同形态的氮的循环转化概念图，分析了有机碎屑氮、氨态氮(NH3-N)、亚硝态氮(NO2-N)、硝态氮(Nq-N)间的转化关系，描述了芦苇、水草、浮游植物、浮游动物、鱼、底栖动物组成的食物链中氮的循环规律。注意到乌梁素海大型水生植物(芦苇、水草)生长期间主要是吸收湖泊水体中的硝酸盐氮(NO3-N)和氨态氮(NH3-N)，腐败沉落后则以有机氮的形态存在于底泥中，这一结论为以机械化方式收割大型水生植物治理湖泊富营养化提供了理论基础。     

Coiling Direction of Globigerina pachyderma as a Climatic Index

An interdependence between the geographical distribution of dextral and sinistral populations of the planktonic foraminifer, Globigerina pachyderma, and sea surface-temperatures is demonstrated. It is inferred that changes in dominant coiling direction at lower levels in sediment cores from the North Atlantic record southward shifts of isotherms during the last ice age.     

油松遗传结构与地理阻隔因素的相关性

油松(Pinus tabulaeformis)是我国特有广布树种。秦岭是我国亚热带和暖温带气候的重要分界线,贺兰山是我国西北干旱区与半干旱区的分界线。旨在以分布于秦岭、贺兰山和晋陕两省的10个天然油松种群为研究对象,通过对其线粒体DNA(nad1和matR内含子)的序列,探讨地理阻隔对油松遗传结构的影响。结果表明,10个天然油松种群的100个个体中共检测到27个单倍型,多态位点172个,简约信息位点35个,单一多态性位点137个。其中1个单倍型为全部种群共有,4个单倍型为2-5个种群共有,其余22个单倍型为各个种群所独有。在这10个种群中,有8个种群分别具有1-4个独有单倍型。尽管秦岭南侧种群和北侧种群分别具有两个和一个独有单倍型; 贺兰山东侧种群和西侧种群均具有3个独有单倍型;但是与晋陕种群(即油松分布区中心种群)相比,其种群独有单倍型平均数目则明显较少。与此同时,不仅秦岭南北两侧或贺兰山东西两侧种群的独有单倍型的进化关系往往较近,而且秦岭北侧或贺兰山东侧种群的独有单倍型与油松分布区中心种群的某些独有单倍型的关系亦较近。从而导致秦岭南北两侧或贺兰山东西两侧种群与油松分布区中心种群之间表现出比较复杂的聚类关系。由此可见,油松的遗传结构与山脉屏障的存在没有明显关系。