雷州半岛海龟洄游的通道

<正>经过研究人员十多年的"卫星追踪海龟洄游路线"研究证明,广东粤西沿海和海南沿海海域都是海龟洄游的必经之地之一。我国的琼州海峡和北部湾之间,不但是海龟洄游的主要通道,同时也是海龟的重要栖息觅食场所。徐闻珊瑚礁自然保护区、雷州珍稀海洋生物自然保护区,雷州乌石海洋公园这二区一园的生态系统和生物多样性几乎是相同的,其珊瑚礁生态系统、     

人工培育幼年绿海龟的卫星追踪试验

2011年6月—2012年2月期间,在3只人工培育的幼年绿海龟背甲上安装微型卫星追踪器,通过全球Argos系统开展追踪监测,旨在研究海龟洄游路线以及海流、海水叶绿素浓度等因子对洄游的影响。结果表明,试验幼龟洄游方向与同期海流趋同,洄游路线与历年产卵后母龟大体相似;洄游平均速度为0.2~1.8 km·h~(-1),洄游距离68~949 km;觅食场海水叶绿素浓度为1~2 mg·m~(-3)。揭示南海台湾至海南近岸海域间可能存在绿海龟洄游通道,绿海龟的洄游可能与食性及海流有关,开展增殖放流应充分考虑季节、海流等因子的影响。     

中国海龟标志方法纵览

广东惠东港口海龟湾是我国目前唯一的海龟国家级自然保护区,在1985—2005年的21年间,共保护绿海龟安全上岸产卵1184头次,标志放流成年雌海龟125头,近几年又开展了海龟卫星追踪试验,并获得了丰富的研究数据。海龟个体标志为开展科学研究活动提供了极大的方便,有利于建立龟口管理档案,完善海龟标识溯源信息系统。有关海龟生物学生态学的许多问题,例如母龟每季产卵次数、巢间期、产后洄游路线、母龟生殖周期、每一族群产卵地和觅食地分布。     

海龟的福音——2006国际海龟年中国保护行动

海龟是我国重点保护野生动物。我国政府高度重视对海龟的保护。1992年在广东省惠东市港口镇的海龟湾建立了国家级海龟自然保护区。保护区搭建了科学研究、驯养繁殖、增殖放流、科普宣传、社区共管平台,先后对7只成年雌性海龟进行了卫星跟踪,探明了在海龟湾产卵的海龟的洄游路线,并孵化养殖了约六万小海龟,放归大海五万余只。联合国环境规划署与印度洋及东南亚地区23个国家和地区在泰国联合发起保护海龟活动,并将2006年定为“国际海龟年”。2006年保护区管理局紧密围绕国际海龟年的主题,开展了丰富多彩的海龟保护活动。     

惠东幼年绿海龟的洄游规律及觅食地选择

绿海龟(Chelonia mydas)为全球性濒危物种、我国Ⅰ级重点保护野生动物。栖息地保护是野生绿海龟保护的一种极为重要和有效的保护策略,但我国幼年绿海龟的生活习性及其栖息地分布尚不明确,故开展相关洄游行为及栖息地分布研究意义重大。2011至2015年间,将6只来自广东惠东海龟国家级自然保护区人工培育2～14 a的幼年绿海龟,分为夏季组(n=3)及冬季组(n=3),在其背甲上安装追踪器。其中,2只个体分别安装了美国Wildlife Computers公司生产的追踪器SPOT5-AM-S181C和SPOT5-AM-S244A,另外4只个体安装美国Telonics公司生产的TAM-2639追踪器,然后在出生地放归。利用全球ARGOS系统实施全天候的追踪监测,地理坐标数据的筛选及分析在卫星追踪分析工具软件(STAT)上完成。6只个体4年共获得有效位点397个,其中,包括前期研究获得的有效位点62个。相关有效位点输入免费软件Maptool,通过GIS图层叠加、汇总生成洄游路线图。研究结果用以揭示我国幼年绿海龟的洄游规律。使用SPSS软件t-检验统计冬夏两组海龟间的个体大小及洄游速度是否存在统计学差异。冬季组、夏季组绿海龟的背甲曲线长(CCL)分别为(48.9±8.65)cm和(59.07±7.64)cm,组间无显著性差异(t=1.527,df=4,P=0.202)。追踪期平均(66±47)d,追踪路程(1 653±1 585)km(n=6)。平均最小洄游速度,夏季组为(1.63±0.22)km/h(n=3),冬季组为(0.67±0.12)km/h(n=3),夏季组明显较冬季组高(t=6.726,df=4,P=0.003);夏季及冬季分别游往台湾和海南两个方向,主要沿大陆架140 m等深线以内海域洄游,所有个体的洄游路线及方向均与同期海流大致相同,活动范围与近海渔场及开发区域高度重叠,与早期野外调查结果一致。仅冬季组观察到定居及归巢行为,越冬场分布在越南昏果岛及我国海南岛东部;越夏场则分布在福建至浙江一带,主要分布在近岸或近岛20 m等深线以内浅海,为底栖大型海藻、海草床或珊瑚礁的集中分布区。研究结果揭示,惠东人工培育幼年绿海龟放归后可正常洄游、觅食和适应野外环境,在东海、南海之间作季节性定向洄游的趋势十分明显,觅食地沿我国大陆架沿岸及附属海岛分布,进一步印证了我国近海绿海龟洄游廊道的存在。建议把北部湾、琼州海峡、海南东部、广东、福建、浙江及台湾沿岸及附属岛屿的海洋保护地整合优化,制订国家海龟栖息地名录,组建海洋类型国家公园保护网络,同时深入开展国际及地区间的保护合作,加强绿海龟及其觅食地和洄游廊道这些重要栖息地保护,使海龟整个生命周期得到有效和完整的保护。     

海龟的饲养初报

海龟科Cheloniidae中的蠵龟Caretta caretta、海龟Chelonia mydas、玳瑁 Eretmochelys imbricata在青岛海产博物馆的水族馆里均有饲养。且长年饲养的海龟科动物共五只,计有:蠵龟二只、海龟一只、玳瑁二只。二只蠵龟分别为1953年、1957年来馆;海龟由1964年来馆;二只玳瑁分别由1955年、1965年来馆。上述五只动物,自来馆后,至今在水族馆中生活得极好。这就为研究它们的食性提供了非常方便的条件。 在此也顺便说明一下,我馆每年夏、秋两季,都可     

豆雁在中国的春季迁徙路线及迁徙停歇地

掌握禽流感病毒携带者豆雁(Anser fabalis)的迁徙路线对于全面理解候鸟在禽流感疫情传播与扩散中的作用具有重要意义。2013年3月至4月在江西省鄱阳湖南矶山保护区,利用卫星跟踪法对3只豆雁个体的迁徙路线进行研究,仅有1只个体成功传输数据。数据经Google Earth和Excel软件处理后,结果显示:该只豆雁由江西鄱阳湖出发,途经安徽、江苏、山东、天津等省市到达河北秦皇岛,5月被发现死于山海关,迁徙总距离约1 500 km,有5个停歇地;两相邻停歇地之间最短距离为20 km,最长为700 km;停留时间最短为1 d,最长为14 d;约68%的停歇位点地物类型为农田;飞行高度平均值为15 m,最大值为407 m。     

海龟是怎样回到故乡的?

海龟是珍贵的海洋动物,属于一类大型海生爬行类。海龟自破壳而出之日起,便开始过着旅行洄游的生涯,是著名的海洋旅行家。它生活在热带海洋里,有时偶而随着暖流游到温带海域,但不在温带产卵繁殖。我国黄、渤、东海有它的踪迹,这可算是随暖流北上的“游客”。当生殖季节到来之时,在大洋中旅游的海龟即使在千里之外,也要三、五成群从四面八方回到故乡交配产卵。繁殖后代重返故乡南海诸岛气候炎热,岛上的热带林木终年郁郁葱葱,岛的四周有沙带环绕,因而这里是大海龟繁殖的优良场所。每年4月到7月是海龟繁殖的旺季。那些尾巴长长的雄     

基于卫星信标跟踪的斑海豹放流效果研究

利用卫星标记跟踪方法对斑海豹的野外释放效果进行了研究。2010 年和2011 年6 月分别释放了4 头和3头人工繁殖的2 龄未成年斑海豹,2011 年同时释放了3 头野外出生的救助个体。标记斑海豹在释放后,7 头人工繁殖斑海豹中的5 头信标信号持续时间较长,在信号消失前,1 头斑海豹一直在渤海海域活动,另4 头沿辽宁沿岸、朝鲜西海岸到达辽东湾斑海豹的主要度夏海域韩国白翎岛附近。研究期间,1 头人工繁殖的斑海豹在59 d内运动的距离超过1 250 km。救助斑海豹中,2 头个体的信标信号持续较长,并分别在山东半岛沿海和黄渤海活动。研究结果表明,人工繁殖的斑海豹在经过野化训练后,放归自然海域后可以正常生活洄游。     

中国海龟的保护问题

在中国,共有5种海龟会在东侧的大陆棚沿岸海域及南中国海出现,它们分别是绿海龟（Cheloniamyds）,龟（Carettacaretta）,玳瑁（Eretmochelysimbricata）,丽龟（Lepidochelysolivacea）,及棱皮龟（Dermochelyscoriacea）。在这5种海龟中,以绿海龟的数量为最多。此外在5种海龟中,仅有绿海龟、龟及玳瑁会在我国领土沿海的沙滩上产卵。和其他的沿海民族一样,数千年来,沿海省份的居民,不但捕食海龟及龟蛋,而且利用其部分的身体做为中药材来治疗高血压等疾病,或将其皮甲制成标本出售,稚龟亦被当成水族宠物加以出售图利。根据估计…     

Post-nesting movements and submergence patterns of loggerhead marine turtles in the Mediterranean assessed by satellite tracking

Two female loggerhead turtles (Caretta caretta) were tracked, following nesting at Alagadi Beach (35°33′N, 33°47′E), Northern Cyprus, eastern Mediterranean for 60 and 82 days, respectively. The two individuals showed marked differences in their behaviour. Individual A was tracked to Syrian coastal waters, whereas individual B travelled around the coast of Northern Cyprus to a foraging site in the waters off the east coast of Northern Cyprus. Submergence durations varied markedly during different phases of the migration, suggesting coastal foraging/resting at certain stages en route with sustained directed travelling movements during initial coastal movements and open ocean crossing. Both turtles showed fidelity to foraging grounds for the duration of transmissions (Turtle A: 36 days; Turtle B: 58 days). In both cases, locations were centred in inshore waters although the two individuals exhibited quite different submergence patterns. Individual A carried out very short dives of typical duration <10 min, whereas Individual B carried out longer dives with typical duration >20 min. Diel differences in submergence duration at the foraging grounds suggested longer dives at night/early morning for both turtles. For Turtle A, there was a general reduction in submergence duration as the period of residence increased; a pattern that may have been related to increasing temperature experienced. The total distance travelled by the two turtles (320 and 227 km) was relatively short when compared to satellite tracking studies of conspecifics following nesting in South Africa and USA and tagging studies of nesting loggerhead turtles in Greece and Australia. It is hypothesized that short migratory distance may be correlated with both the small body size and the relatively high frequency of remigration in this population.     

Fidelity and over-wintering of sea turtles

While fidelity to breeding sites is well demonstrated in marine turtles, emerging knowledge of migratory routes and key foraging sites is of limited conservation value unless levels of fidelity can be established. We tracked green (Chelonia mydas, n=10) and loggerhead (Caretta caretta, n=10) turtles during their post-nesting migration from the island of Cyprus to their foraging grounds. After intervals of 2-5 years, five of these females were recaptured at the nesting beach and tracked for a second migration. All five used highly similar migratory routes to return to the same foraging and over-wintering areas. None of the females visited other foraging habitats over the study period (units lasted on average 305 days; maximum, 1356 days), moving only to deeper waters during the winter months where they demonstrated extremely long resting dives of up to 10.2h (the longest breath-holding dive recorded for a marine vertebrate). High levels of fidelity and the relatively discrete nature of the home ranges demonstrate that protection of key migratory pathways, foraging and over-wintering sites can serve as an important tool for the future conservation of marine turtles.     

Post-nesting migrations patterns of Green Turtles (Chelonia mydas) from the Egyptian Red Sea

In order to identify the migratory pathways and foraging grounds of post-nesting Green Turtles (Chelonia mydas) in the Red Sea, we attached satellite transmitters to four females immediately after egg deposition and tracked them between 207 and 647 days. We identified four geographically distinct post-nesting habitat areas and migration paths from Zabargad Island, Egypt which was remarkable given our small sample size. Our shortest migration was 140?km and the longest 940?km, with the migrations and post-nesting habitat encompassing the boundaries of four of the seven Red Sea countries (Egypt, Sudan, Eritrea, and Saudi Arabia). The post-nesting habitats were located in shallow coastal habitat and three consisted of near-shore archipelagos. Two turtles moved past areas of suitable post-nesting habitat that was occupied by other turtles, which suggests that these turtles may be exhibiting fidelity to certain feeding and nesting sites. Our results suggest that regional and multi-national cooperation will be needed to protect sea turtles that nest on Zabargad Island, a nesting site that is important for Egypt and other Red Sea nations.     

Behaviour of leatherback sea turtles, Dermochelys coriacea, during the migratory cycle

Leatherback sea turtles, Dermochelys coriacea, undertake broad oceanic movements. While satellite telemetry has been used to investigate the post-nesting behaviour of female turtles tagged on tropical nesting beaches, long-term behavioural patterns of turtles of different sexes and sizes have not been described. Here we investigate behaviour for 25 subadult and adult male and female turtles satellite-tagged in temperate waters off Nova Scotia, Canada. Although sex and reproductive condition contributed to variation in migratory patterns, the migratory cycle of all turtles included movement between temperate and tropical waters. Marked changes in rates of travel, and diving and surfacing behaviour, accompanied southward movement away from northern foraging areas. As turtles approached higher latitudes the following spring and summer, they assumed behaviours consistent with regular foraging activity and eventually settled in coastal areas off Canada and the northeastern USA. Behavioural patterns corresponding to various phases of the migratory cycle were consistent across multiple animals and were repeated within individuals that completed return movements to northern waters. We consider the potential biological significance of these patterns, including how turtle behaviour relates to predator avoidance, thermoregulation and prey distribution.     

Multinational Tagging Efforts Illustrate Regional Scale of Distribution and Threats for East Pacific Green Turtles (Chelonia mydas agassizii)

To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale.     

Home on the range: spatial ecology of loggerhead turtles in Atlantic waters of the USA

Aim Although satellite tracking has yielded much information regarding the migrations and habitat use of threatened marine species, relatively little has been published about the environmental niche for loggerhead sea turtles Caretta caretta in north‐west Atlantic waters. Location North Carolina, South Carolina and Georgia, USA. Methods We tracked 68 adult female turtles between 1998 and 2008, one of the largest sample sizes to date, for 372.2 ± 210.4 days (mean ± SD). Results We identified two strategies: (1) ‘seasonal’ migrations between summer and winter coastal areas (n = 47), although some turtles made oceanic excursions (n = 4) and (2) occupation of more southerly ‘year‐round’ ranges (n = 18). Seasonal turtles occupied summer home ranges of 645.1 km² (median, n = 42; using α‐hulls) predominantly north of 35 ° latitude and winter home ranges of 339.0 km² (n = 24) in a relatively small area on the narrow shelf off North Carolina. We tracked some of these turtles through successive summer (n = 8) and winter (n = 3) seasons, showing inter‐annual home range repeatability to within 14.5 km of summer areas and 10.3 km of winter areas. For year‐round turtles, home ranges were 1889.9 km². Turtles should be tracked for at least 80 days to reliably estimate the home range size in seasonal habitats. The equivalent minimum duration for ‘year‐round’ turtles is more complex to derive. We define an environmental envelope of the distribution of North American loggerhead turtles: warm waters (between 18.2 and 29.2 °C) on the coastal shelf (in depths of 3.0–89.0 m). Main conclusions Our findings show that adult female loggerhead turtles show predictable, repeatable home range behaviour and do not generally leave waters of the USA, nor the continental shelf (< 200m depth). These data offer insights for future marine management, particularly if they were combined with those from the other management units in the USA.     

Long-distance migration and homing after displacement in the green turtle (Chelonia mydas): a satellite tracking study

Four green turtle females were tracked by satellite during their post-reproductive migration in the South China Sea. Three of them reached their feeding grounds 923–1551 km distant. During nesting activity, a female was displaced twice, and her return trips to the nesting beach from 11 and 284 km were tracked by a direction-recording data-logger and by satellite, respectively. Part of the journeys occurred coastwise, indicating that leading geographical features had been utilised. The straightness of the turtles' tracks in open seas, both over shallow and deep waters, and their ability to pinpoint distant targets and home after displacement off their usual routes, provides circumstantial evidence for a true navigation mechanism.Abbreviation PTT platform transmitter terminal     

Navigation by green turtles: which strategy do displaced adults use to find Ascension Island?

Sea turtles are known to perform long-distance, oceanic migrations between disparate feeding areas and breeding sites, some of them located on isolated oceanic islands. These migrations demonstrate impressive navigational abilities, but the sensory mechanisms used are still largely unknown. Green turtles breeding at Ascension Island perform long oceanic migrations (>2200 km) between foraging areas along the Brazilian coast and the isolated island. By performing displacement experiments of female green turtles tracked by satellite telemetry in the waters around Ascension Island we investigated which strategies most probably are used by the turtles in locating the island. In the present paper we analysed the search trajectories in relation to alternative navigation strategies including the use of global geomagnetic cues, ocean currents, celestial cues and wind. The results suggest that the turtles did not use chemical information transported with ocean currents. Neither did the results indicate that the turtles use true bi-coordinate geomagnetic navigation nor did they use indirect navigation with respect to any of the available magnetic gradients (total field intensity, horizontal field intensity, vertical field intensity, inclination and declination) or celestial cues. The female green turtles successfully locating Ascension Island seemed to use a combination of searching followed by beaconing, since they searched for sensory contact with the island until they reached positions NW and N of the Island and from there presumably used cues transported by wind to locate the island during the final stages of the search.     

First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche

Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads (Caretta caretta) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms.     

Individual variation in feeding habitat use by adult female green sea turtles (Chelonia mydas): are they obligately neritic herbivores?

Satellite telemetry and stable isotope analysis were used to confirm that oceanic areas (where water depths are >200 m) are alternative feeding habitats for adult female green sea turtles (Chelonia mydas), which have been thought to be obligate herbivores in neritic areas (where depths are <200 m). Four females were tagged with satellite transmitters and tracked during post-nesting periods from Ogasawara Islands, Japan. Three females migrated to neritic habitats, while transmissions from another female ceased in an oceanic habitat. The overall mean nighttime dive depths during oceanic swimming periods in two females were <20 m, implying that the main function of their nighttime dives were resting with neutral buoyancy, whereas the means in two other females were >20 m, implying that they not only rested, but also foraged on macroplankton that exhibit diel vertical migration. Comparisons of stable carbon and nitrogen isotope ratios between 89 females and the prey items in a three-source mixing model estimated that 69% of the females nesting on Ogasawara Islands mainly used neritic habitats and 31% mainly used oceanic habitats. Out of four females tracked by satellite, two females were inferred from isotope ratios to be neritic herbivores and the two others oceanic planktivores. Although post-nesting movements for four females were not completely consistent with the inferences from isotope ratios, possibly due to short tracking periods (28–42 days), their diving behaviors were consistent with the inferences. There were no relationships between body size and the two isotope ratios, indicating a lack of size-related differences in feeding habitat use by adult female green turtles, which was in contrast with loggerhead sea turtles (Caretta caretta). These results and previous findings suggest that ontogenetic habitat shifts by sea turtles are facultative, and consequently, their life histories are polymorphic.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.