网上海洋

网上海洋[栏目主待爱春][栏目主持人语]海洋世界最新信息传递,银色浪花网际漫游撷趣,深海龙宫丰富宝藏探寻,海味英语原汁原味交流《网际热线》北京海洋馆向游人开放3月28日,被称为世界内陆最大的海洋馆——北京海洋馆正式向游人开放。这座总投资近1亿美元、建筑面积4.2万平方米的海洋馆,馆藏近2万尾各种鱼类及海狮、海豚和鲸等哺乳类海洋动物。它们分别被安置在“雨林奇观”、鲨鱼馆等6个不同内容的展示场馆内。馆内还装有近千块展示板牌和大量音像资料。游客在北京海洋馆不仅可立体地观赏各种海洋生物的生存状态,还可通过展板、讲座,深入了解有关海洋的各种知识。海洋剧院内的海豚     

海豚行为知多少

提起海豚，大多数人们眼前浮现出的会是，大海中不断跃动的身影，但在实际生活中，又有几人能够幸运地在野生环境中目睹这种“海洋精灵”的庐山真面目呢?北京海洋馆则为所有的普通人提供了这样一个亲自观察海豚的便利条件。     

蓝镜头

海豚是海洋哺乳动物的一种，因为格外“聪明”而备受喜爱。最近，科学家甚至认为它们是生活在海洋里的人类。瓶鼻海豚又叫宽吻海豚，是我们最容易见到的那种海豚，在海洋馆表演节目的就是它，     

解读瓶鼻海豚

提起瓶鼻海豚(以下简称海豚)，常听朋友们说：“这个我知道，不就是在海洋馆见到的那种最可爱、最聪明的鱼吗!”海豚的确是生活在大海中的，可如果你把它理解成鱼可就大错特错了。鱼的全身覆盖有鳞片、尾鳍是     

海洋资源瑰宝之 海豚传奇

<正>海洋馆里千奇百怪的海洋生物固然会让人目不暇给,但是最吸引人的,莫过于海洋剧院里面上演的海豚表演了。当驯兽师     

北京海洋馆与大连圣亚海洋世界签约成为“友好馆”

2004年6月6日,北京海洋馆和大连圣亚海洋世界签订了友好关系协议书,正式成为“姊妹”场馆。这标志着世界内陆最大海洋馆和国内第一家上市的海洋世界打开了全面交流的通道。今后,双方将在经营模式、动物驯养、科学研究等方面进行全面的交流与合作。     

图片新闻

北京海洋馆是世界内陆最大海洋馆，占地3.5万平方米，建筑面积4.2万平方米，绿化面积达8万多平方米。从空中俯瞰北京海洋馆，是别具一格的大海螺形状。     

海豚传奇

海洋馆里干奇百怪的海洋生物固然会让人目不暇给，但是最吸引人的，奠过于海洋剧院里面上演的海豚表演了。当驯兽师的一声哨响之后，几头海豚齐刷刷地跃出水面，然后同时在半空中做一个优雅的空翻动作，再齐刷刷地落入水中，溅起巨大的水花，这场景立刻就能引起全场观众的惊呼。有时候，驯兽师还会像海上滑板一样，半蹲在海豚的身体上，海豚便像箭一样快速地向前游去，场面十分惊险。     

纪念郑和下西洋600周年 2004年度“北京海洋馆杯”海洋知识竞赛颁奖典礼在北京举行

由国家海洋局、教育部和共青团中央联合主办的“纪念郑和下西洋600周年2004年度‘北京海洋馆杯’海洋知识竞赛”,11月20日在北京海洋馆举行了颁奖典礼。此次活动主办单位的领导、竞赛获奖者以及1000多位学     

海豚妊娠分娩哺育期间的观察及护理

野生海豚的妊娠、分娩及哺育过程很难进行科学、系统地观察监测，人工饲养海豚的繁殖情况却屡见报道。我馆于2003年3月20日从日本购进6头雌性太平洋瓶鼻海豚(Tursiops truncatus aduncus)，其中1头编号为“270”的海豚于2003年6月19日顺利产下1头雄性幼仔，作者对其母子进行每天24h看护达2周之久。此后的1年中，幼仔生长良好。本文就海豚“270”的妊娠、分娩及哺育过程进行详细描述，并将工作人员对“270”母子采取的护理措施作一具体说明。     

Occurrence of bottlenose dolphins Tursiops truncatus in natural gas fields of the northwestern Adriatic Sea

Common bottlenose dolphins, Tursiops truncatus, were surveyed in offshore gas fields off Ravenna, Italy, between Spring and Autumn, 2001–2005. These visual surveys provide the first density estimates of bottlenose dolphins in the Northwestern Adriatic Sea south of the Po River. Since no study has examined the distribution of bottlenose dolphins relative to gas platforms, when dolphins were encountered, their distance from the nearest gas platform was estimated and behaviour was assessed. Dolphins were sighted on ca. 36% of survey trips, which varied in duration from 1 to 6 h. Group size ranged from 1 to ~50 individuals, with no seasonal trend evident in the likelihood of encounter. Dolphin density was estimated to be approximately 80% higher within 750 m of gas platforms, relative to densities >750 m from platforms, although variability around the estimates was high. From a limited number of behavioural observations, slightly higher frequencies of feeding and milling behaviour were observed closer to gas platforms, whereas dolphins observed further away exhibited higher frequencies of socialising and travelling. Gas platforms are known to provide habitat for demersal fishes and act as aggregation points for pelagic fishes, and these data provide some support for the idea that bottlenose dolphins may utilise gas platforms opportunistically as feeding sites.     

Photo-identification of bottlenose dolphins in the far south of New Zealand indicates a ‘new’, previously unstudied population

Declines in the abundance of bottlenose dolphins in the Bay of Islands and in Doubtful Sound have contributed to the species being classified as Nationally Endangered in New Zealand waters. Updated information on distribution and abundance nationwide is therefore a high priority. This study presents data from the first photo-identification surveys of Paterson Inlet, Stewart Island, conducted to document bottlenose dolphin presence, abundance and residency. Open-population mark-recapture models indicate that 18 (95%CI = 15–20) dolphins regularly use Paterson Inlet. Photo-identification of dolphins from unknown populations during two chance encounters in Otago Harbour and Dusky Sound included 11 individuals previously identified at Stewart Island. These results indicate that dolphins found regularly at Stewart Island are part of a larger, wide ranging southern population with a minimum population abundance of 92 (95%CI = 80–111) individuals.     

Temporal variability in predator presence around a fin fish farm in the Northwestern Mediterranean Sea

Recently, aquaculture has generated worldwide interest as a result of the overexploitation of wild stocks combined with a growing international demand for fish and seafood products. Wild fish attracted to the marine fish farms, together with the presence of the farmed fish, are powerful attractants to predators that normally feed on similar or identical fish stocks in nature. This 9‐year study describes for the first time in Mediterranean waters the temporal variability of mammalian and avian predators in a coastal fin fish farm. In all, 99 months (1062 days during 36 consecutive seasons) were spent in the field. By examining the results of this study, it is clear that species as seagulls, shags, bottlenose dolphins and grey herons (considered to cause economic loss in aquaculture owing to direct predation) interact regularly with the fish farm. Although bottlenose dolphins and grey herons were not the most important of all predator species, predatory interactions with the fish farm occurred with what seems to be increasing regularity. Another result observed is the possible bottlenose dolphins’ attraction caused by the harvesting operations in the fish farm. The fish farm offers an alternative food source for predators; hunting at fish farms usually requires less effort on the part of the predator, and becomes a more attractive option than hunting wild fish over wide ranges. During the period of this study, individually identified dolphins feeding were regularly observed feeding on discarded fish from fish farm workers during harvesting operations, supporting the possibility that some individuals are habituated to this food supply. Based on the evidence presented in this paper, it is recommended that strategies for the management of both the aquaculture industry and marine mammal populations should take the results of this study into consideration.     

Bottlenose dolphin Tursiops truncatus group dynamics,site fidelity,residency and movement patterns in the Madeira Archipelago (North-East Atlantic)

The bottlenose dolphin Tursiops truncatus is one of the most frequently sighted cetacean species in the Madeira Archipelago (North-East Atlantic); however, little is known about its population ecology in these waters. Photo-identification undertaken during systematic, non-systematic and opportunistic surveys conducted between 2001 and 2012 was used to assess group dynamics, site fidelity, residency and movement patterns of bottlenose dolphins in the archipelago. Three different patterns of residency were assigned, based on individual sighting histories. Group size ranged between 2 and 90 individuals (median 12), with no significant monthly difference in group size. All resident dolphins formed a core, complex network with migrant and transient dolphins. In contrast, satellite clusters were formed exclusively by transient individuals. The lagged identification rate (LIR) model indicated that a dolphin remained in the area for an average of 90 days, whereas the average time an individual spent outside the study area was approximately 313 days. The Madeira Archipelago appears to be only a section of a much larger home range for this population, with the dolphins exhibiting three different patterns of occurrence that associate with each other. The information gained about this poorly studied population contributes to the overall knowledge of bottlenose dolphins in insular oceanic habitats.     

Detection distances of bottom-set gillnets by harbour porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus)

Many odontocetes die annually in gillnet fisheries. Why they become entangled is not yet clear. Maybe some species detect the nets too late to avoid collision. Therefore, the target strength of 11 types of bottom-set gillnets was measured under 0 and 45 degrees angles of incidence. From these target strengths and from knowledge on the echolocation abilities of two odontocete species (harbour porpoises, bottlenose dolphins), the detection ranges of the nets by these small cetaceans could be estimated. The 90% detection range by echolocating harbour porpoises, approaching the nets at right (perpendicular) angles under low noise level conditions, varied between 3 and 6 m depending on the net type. For bottlenose dolphins, under high noise conditions, the 90% detection range varied between 25 and 55 m. At other angles of approach, the estimated detection ranges are shorter. The study suggests that echolocating bottlenose dolphins can detect nets in time to avoid collision, whereas echolocating harbour porpoises cannot in most cases. Suggestions for future research to reduce small cetacean bycatch by improving the nets' detectability by echolocation are given.     

Bottlenose dolphin Tursiops truncatus at São Tomé Island (São Tomé and Príncipe) — relative abundance,site fidelity and social structure

Although the bottlenose dolphin Tursiops truncatus is one of the most common cetacean species around São Tomé Island, Gulf of Guinea, little research has focused on this species in this region. This study investigated the population of bottlenose dolphins around São Tomé Island by estimating the minimum population size, site fidelity and social structure. During a total of 226 surveys between 2002 and 2006, and in 2012, 51 sightings were recorded but only 33 had photographic data suitable for rigorous analysis. The minimum annual total population size, based on permanently marked dolphins, was 37 individuals, and the discovery curve indicated that a large part of the population remained undiscovered. The annual sighting rate for 76 highly distinctive adult animals ranged from 0.20 (seen in one year only) to 1.0 (seen every year of the study period). Resighted individuals demonstrated low association values; the dolphins seemed to form a single group with a fluid structure.     

Movement patterns of coastal bottlenose dolphins in the presence of a fast-flowing,prevailing current: shore-based observations at Cape Vidal,South Africa

The presence and movement of Indo-Pacific bottlenose dolphins Tursiops aduncus were investigated using shore-based observations made during a humpback whale Megaptera novaeangliae migration survey at Cape Vidal, South Africa, undertaken between June and October 1988–1991. Occurrence was analysed as counts of dolphin sightings per hour within a generalised estimating equation framework. Bottlenose dolphin sightings decreased throughout the daily survey period, and there was a small seasonal peak in sightings during August. Data on movement trajectory were collected using a theodolite for 60% of the groups of dolphins sighted. Most groups were observed travelling in a northerly direction, with few groups recorded moving south. A generalised linear model indicated that northward-travelling dolphins were located closer to shore, travelled at higher speeds, and occurred in bigger groups under low-tide conditions, than those seen moving in a southerly direction. The southward-flowing Agulhas Current is close to shore at Cape Vidal, where the continental shelf is particularly narrow. We suggest that bottlenose dolphins in this area have adopted a specific movement regime to cope with the consistent fast-flowing currents that dominate their environment at Cape Vidal.     

Spatiotemporal Dynamics of the Local Population of Black Sea Bottlenose Dolphins (Tursiops truncatus ponticus Barabash, 1940): Visual and Acoustic Description Methods

Oceanology - The local Sudak–Novyi Svet (Crimea) population of Black Sea bottlenose dolphins was studied. Observations and acoustic recordings were made throughout 2014 and 2015. This study...     

Abundance estimates of an isolated population of common bottlenose dolphins Tursiops truncatus in Walvis Bay,Namibia, 2008–2012

The coastal population of common bottlenose dolphins Tursiops truncatus found in Namibia is regionally isolated and unique. This population faces several potential anthropogenic threats, especially in Walvis Bay, including boat-based tourism, a commercial harbour undergoing expansion, and aquaculture for oysters and mussels. Between 2008 and 2012, 238 boat-based surveys were conducted, resulting in 170 encounters with bottlenose dolphins. Overall, group sizes varied from 1 to 45 individuals (mean 10.7). Encounter rates, group sizes and total numbers of animals identified were higher in winter than in summer field seasons. The number, and survival and immigration parameters, of bottlenose dolphins using Walvis Bay was investigated using robust design and Huggins closed-population mark-recapture models. The highest numbers estimated were in the first and last years of the study, with estimates of 74–82 in 2008 and 76–77 in 2012 (numbers identified and upper 95% confidence limits). The only previously available data, from an incomplete study in the early 1990s, suggested that the population was between 100 and 150 individuals at the time. Although no linear trend in population size was obvious during the current study, the clear evidence of isolation, small population size, low annual birth rate, and potential long-term decrease in numbers since the early 1990s is concerning. Further work to collect data on demographic parameters is urgently recommended with a view to obtaining increased protection for this species.     

A missing piece from a bigger puzzle: declining occurrence of a transient group of bottlenose dolphins off Southeastern Brazil

Bottlenose dolphins are widespread off South America with patchy distributions throughout coastal, nearshore and offshore waters. Only limited information on the connectivity between individuals from these different habitats exists, despite the importance of understanding the overall population structure. A group of bottlenose dolphins in an insular habitat off Brazil may help provide evidence of the structure of a larger pelagic population in Brazilian waters. It is unknown whether the dolphins that use this habitat seasonally are part of an open population, a closed population of transient animals, or even individuals from offshore or nearshore groups. To explore the nature of these seasonal visitors we combined two strategies. First, by assessing the population parameters, we described a small group of individuals (maximum of 38 individuals in 2004 and five individuals in 2010) characterized by wide‐ranging behavior, low survival probabilities (64%) and an apparent population decline. Secondly, by exploring their social organization at a fine scale, we observed that within a stable group, the dyadic associations are fluid and mostly of short duration, similar to well‐known coastal bottlenose dolphin societies. The evidence of a non‐structured social network seems to be coupled with apparent seasonal use of this insular protected area for calf rearing and/or reproductive strategies. Overall, our findings suggest that this group may not be an aggregation of individuals from different populations in a specific area, but a relatively stable group formed by the same animals. While continuing research efforts are necessary along the South America coast, the abandonment of the study area by this group may hamper the understanding of population structure and connectivity among pelagic and coastal populations of bottlenose dolphins, as well as the ecological and behavioral mechanisms driving their seasonal occurrence in oceanic habitats.