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1.
Katsufumi Sato Wataru Sakamoto Yoshimasa Matsuzawa Hideji Tanaka Shingo Minamikawa Yoshimasa Naito 《Marine Biology》1995,123(2):197-205
Body temperatures, ambient water temperatures, light intensities and vertical positions (depth) of eight loggerhead turtles, Caretta caretta, were monitored by small recorders during internesting periods from 1991 through 1993 off Wakayama Prefecture, Japan. Body temperatures of eight loggerhead turtles were higher than ambient water temperatures through-out their internesting periods. Light intensities were compared with body temperatures and no evidence was obtained to suggest that the raised body temperatures were caused by the direct influence of solar radiation. Body temperatures were kept higher than water temperatures in cloudy weather or even at night. Mean thermal differences between body and water temperatures were significantly different among individuals, and larger turtles had a greater mean thermal difference. Elevations in body temperatures of adult loggerhead turtles can reasonably be assumed to result from the accumulation of metabolically produced heat. Surfacing times (spent at depths shallower than 2 m) of seven turtles were only 10.3 to 38.9% of their internesting periods, with the exception of one turtle who spent 66.3% of her time at the surface. Loggerhead turtles did not seem to bask positively at the sea surface to absorb radiative heat. 相似文献
2.
Dietary information obtained from stomach contents can provide a wealth of information on an animal’s ecology. Where animals
are cryptic, such as the post-hatchling life history stage of a sea turtle, the ecological insight that dietary analyses can
provide, may be otherwise unobtainable. Investigations into post-hatchling turtle stomach contents have found planktonic organisms,
dominated by pelagic molluscs and crustaceans, hydrozoans, Sargassum and fish eggs. The nature of these dietary organisms provides evidence for the widely accepted hypothesis that, with the
exception of the flatback turtle (Natator depressus), the post-hatchling stage of a sea turtle’s life history is pelagic and oceanic. As the majority of studies that have investigated
the stomach contents of post-hatchling sea turtles have been conducted on loggerhead turtles (Caretta caretta) in the northern Atlantic and Pacific Oceans, insight derived from dietary investigations into post-hatchling ecology is
biased. This study investigates the diet of post-hatchling green turtles (Chelonia mydas) and loggerhead turtles in the southwest Pacific Ocean. Stomach contents were obtained from 55 green and loggerhead post-hatchling
turtles that had stranded or been consumed by Coryphaena hippurus. Our findings demonstrate that loggerhead and green post-hatchlings in the southwest Pacific share similar feeding ecology
and feed on a variety of neustonic items that are indicative of an oceanic and pelagic existence. The dietary items consumed
by both species investigated belong to similar taxonomic groups as those found in previous studies with species level distinctions
occurring owing to the different geographical location. 相似文献
3.
Satellite tracking reveals a dichotomy in migration strategies among juvenile loggerhead turtles in the Northwest Atlantic 总被引:2,自引:2,他引:0
Katherine L. Mansfield Vincent S. Saba John A. Keinath John A. Musick 《Marine Biology》2009,156(12):2555-2570
Few data are available on the movements and behavior of immature Atlantic loggerhead sea turtles (Caretta caretta) from their seasonal neritic foraging grounds within the western north Atlantic. These waters provide developmental habitat
for loggerheads originating from several western Atlantic nesting stocks. We examined the long-term movements of 23 immature
loggerheads (16 wild-caught and seven headstart turtles) characterizing their seasonal distribution, habitat use, site fidelity,
and the oceanographic conditions encountered during their migrations. We identified two movement strategies: (1) a seasonal
shelf-constrained north–south migratory pattern; and (2) a year-round oceanic dispersal strategy where turtles travel in the
Gulf Stream to the North Atlantic and their northern dispersal is limited by the 10–15°C isotherm. When sea surface temperatures
dropped below 20°C, neritic turtles began a migration south of Cape Hatteras, North Carolina (USA) where they established
fidelity to the waters between North Carolina’s Outer Banks and the western edge of the Gulf Stream along outer continental
shelf. Two turtles traveled as far south as Florida. Several turtles returned to their seasonal foraging grounds during subsequent
summers. Northern movements were associated with both increased sea surface temperature (>21°C) and increased primary productivity.
Our results indicate strong seasonal and interannual philopatry to the waters of Virginia (summer foraging habitat) and North
Carolina (winter habitat). We suggest that the waters of Virginia and North Carolina provide important seasonal habitat and
serve as a seasonal migratory pathway for immature loggerhead sea turtles. North Carolina’s Cape Hatteras acts as a seasonal
“migratory bottleneck” for this species; special management consideration should be given to this region. Six turtles spent
time farther from the continental shelf. Three entered the Gulf Stream near Cape Hatteras, traveling in the current to the
northwest Atlantic. Two of these turtles remained within an oceanic habitat from 1 to 3 years and were associated with mesoscale
features and frontal systems. The ability of large benthic subadults to resume an oceanic lifestyle for extended periods indicates
plasticity in habitat use and migratory strategies. Therefore, traditional life history models for loggerhead sea turtles
should be reevaluated. 相似文献
4.
Junichi Okuyama Takashi Kitagawa Kei Zenimoto Shingo Kimura Nobuaki Arai Yoshikazu Sasai Hideharu Sasaki 《Marine Biology》2011,158(9):2055-2063
We used Lagrangian numerical simulations to examine the trans-Pacific dispersal processes of loggerhead turtle hatchlings.
Ten thousand simulated particles were released from each of the three nesting regions in Japan and tracked for 5 years. Results
showed many particles moving eastward, drifting in the Kuroshio Current followed by the Kuroshio Extension Current. However,
no particles reached Baja California, a known feeding area, through passive processes, indicating that trans-Pacific transportation
requires active swimming by turtles. The duration of the trans-Pacific dispersal was estimated to be at least 1.6–3.4 years,
with some turtles drifting in the Kuroshio Countercurrent and remaining in the western Pacific even after 5 years. This indicates
that as revealed by previous genetic studies, not all loggerheads always disperse along a trans-Pacific route. The findings
showed that survival and expected growth rates varied widely according to ambient temperatures during drifting, which in turn
depended on nesting location. 相似文献
5.
Carlos Carreras Sara Pont Fulvio Maffucci Marta Pascual Anna Barceló Flegra Bentivegna Luis Cardona Ferràn Alegre Manuel SanFélix Gloria Fernández Alex Aguilar 《Marine Biology》2006,149(5):1269-1279
The analysis of mitochondrial DNA in loggerhead sea turtles (Caretta caretta) from eight foraging grounds in the Mediterranean and the adjoining Atlantic revealed deep genetic structuring within the western Mediterranean. As a consequence, the foraging grounds off the North-African coast and the Gimnesies Islands are shown to be inhabited mainly by turtles of the Atlantic stocks, whereas the foraging grounds off the European shore of the western Mediterranean are shown to be inhabited mainly by turtles from the eastern Mediterranean rookeries. This structuring is explained by the pattern of sea surface currents and water masses and suggests that immature loggerhead sea turtles entering the western Mediterranean from the Atlantic and the eastern Mediterranean remain linked to particular water masses, with a limited exchange of turtles between water masses. As the north of the western Mediterranean comprises mostly individuals from the highly endangered eastern Mediterranean rookeries, conservation plans should make it a priority to reduce the mortality caused by incidental by-catch in these areas. 相似文献
6.
Resi Mencacci Elisabetta De Bernardi Alessandro Sale Johann R. E. Lutjeharms Paolo Luschi 《Marine Biology》2010,157(2):339-349
The routes of five satellite-tracked loggerhead turtles (Caretta caretta), subjected to an experimental translocation away from their usual migratory routes, have been analysed in relation to the
concurrent oceanographic conditions. Remote sensing data on sea surface temperature and height anomalies, as well as trajectories
of surface drifters were used, to get simultaneous information on the currents encountered by the turtles during their long-range
oceanic movements. Turtles mostly turned out to move in the same direction as the main currents, and their routes were often
influenced by circulation features they encountered. A comparison between turtle ground speeds with that of drifters shows
that in several instances, the turtles did not drift passively with the currents but contributed actively to the overall movement.
Two turtles embarked on an oceanic crossing, probably induced by seasonal changes in surface temperatures, a crossing that
was largely determined by the main currents existing in the area. 相似文献
7.
The species composition, catch and mortality rates of sea turtles captured incidentally by the tiger prawn fishery on Australia's northern coast in 1989 and 1990 were estimated by monitoring the fishery's catch. In 1990, the delayed rate of mortality from damage was estimated and the size composition was measured. Five species of turtles were captured: the flatback (Natator depressa, 59% of the total), loggerhead (Caretta caretta, 10%), olive ridley (Lepidochelys olivacea, 12%), green turtle (Chelonia mydas, 8%) and hawksbill (Eretmochelys imbricata, 5%). The turtle catches varied with water depth: the highest catch rates (0.068±0.006 turtles per trawl) were from trawls in water between 20 and 30 m deep, relatively few turtles (10%) were captured in water deeper than 40 m (25% of trawls). Catch rates varied with time of year: the highest catch rates were 0.098 (±0.013) turtles per trawl in winter. There was no significant difference in the overall catch rate (2= 0.047; p=0.8111; df=1) but a significant difference in mortality rate (2= 3.99; p<0.05; df=1) between the two years. The incidence of capture in the commercial fishery was 0.051 (±0.003) turtles per trawl towed for about 180 min, with 0.007 (±0.001) turtles per trawl drowning in the nets. There were no significant differences in the catch and mortality rates between the two years for any of the turtle species except the loggerhead, which had a significantly (2 = 11.029; p=0.0013; df=1) lower catch rate in 1990 (0.002±0.001 turtles per trawl) than in 1989 (0.008±0.002 turtles per trawl), and a significantly higher mortality in 1990 (33%) than in 1989 (19%). Catch rates and mortality varied between the species: the flatback had the highest catch rate (0.030±0.002 turtles per trawl) but the lowest mortality (10.9%); the loggerhead had a catch rate of 0.005±0.001 turtles per trawl, and high mortality (21.9%); the olive ridley had a catch rate of 0.006±0.001 turtles per trawl and a low mortality (12.5%); the green turtle's catch rate was 0.004±0.001 per trawl and mortality 12.0%; the hawksbill had the lowest catch rate (0.002±0.001 turtles per trawl) but highest mortality (26.4%). Based on the fishing effort (27 049 d for 1989 and 25 746 d for 1990), we estimate that 5 503 (±424) turtles were caught and returned to the sea in 1989 and 5 238 (±404) in 1990, of which 567±140 drowned in 1989 and 943±187 in 1990. In 1990, an estimated 25% of all captured turtles suffered some non-lethal damage; an estimated 21% of turltes were captured comatose and 4% were injured. We conclude that, considering other threats, trawl-induced drowning is not the major impact on turtle populations in northern Australia, but that measures to reduce drowning and delayed mortality would be desirable. 相似文献
8.
Interactions between large marine predators and their prey are difficult to observe and little is known about the risk of predation faced by sea turtles. The frequency of predator-inflicted injuries, however, has afforded insights into the predation risk faced by many taxa. We measured the frequency of shark-inflicted injuries on green (Chelonia mydas) and loggerhead (Caretta caretta) sea turtles in Shark Bay, Western Australia with a view to determining differences between species and sex-classes in the risk of predation from tiger sharks (Galeocerdo cuvier). Furthermore, we investigated how escape ability and habitat use might influence the probability of turtles being injured by sharks. Shark-inflicted injuries were more frequent on loggerhead than on green turtles, and most frequent on adult male loggerhead turtles. Species effects could not be attributed to differences in habitat use, since green turtles were found in habitats favored by tiger sharks more often than were loggerhead turtles. Green turtles, however, were faster and maneuvered better than loggerhead turtles, suggesting that escape ability is a factor in interspecific differences in injury frequency. The sex-class difference in injury frequency of loggerhead turtles suggests that males face greater predation risk than females and may take more risks. For green turtles, the lack of a sex difference in injury frequency might be due to greater escape ability lowering overall predation risk or to no differences between sexes in the benefits of risk-taking. 相似文献
9.
Aerial surveys were conducted to estimate the abundance and distribution of loggerhead turtles (Caretta caretta) in the Columbretes Islands Marine Reserve and surrounding waters (western Mediterranean). Four surveys were carried out during 2000 and 2001, following the line transect methodology. Loggerheads appeared to be present at high densities in the area throughout the whole year, although density varied between seasons, being more abundant during the spring. Mean density in the study area was 0.322 turtles/km2 (range 0.200–0.516) and the mean abundance was 1,324 turtles (range 825–2,124). The turtles were distributed homogeneously throughout the study area, we found no difference in loggerhead density between the water around the reserve and that in the rest of the study area. Current conservation measures planned by the local authorities, which include increasing the area of the reserve, would be very positive for the conservation of this stock.Communicated by S.A. Poulet, Roscoff 相似文献
10.
R. Lundheim 《Marine Biology》1997,128(2):267-271
The ice nucleation temperatures of different homogenised organs of the mussel Mytilus edulis L. were examined. The stomach and the hemolymph had the highest nucleation temperatures. In the homogenised stomach the nucleation
temperatures were fairly constant throughout the year, whereas the nucleation temperatures of the hemolymph increased in the
cold season. Bacterial growth experiments, microfiltration, and experiments using antibiotics indicated that the nucleators
were not of bacterial origin. The nucleation temperatures of natural seawater were approximately −9 °C, whereas seawater made
from distilled water and sea salt had nucleation temperatures of about −17 °C. The nucleation temperatures of the seawater
were reduced when the seawater was filtered by the mussels. However, no clear indication that the nucleators in the stomach
were obtained from the seawater was found. Stomach homogenates from mussels kept in nucleator-free water had the same supercooling
points as stomach homogenates from mussels kept in natural seawater. This indicates that the nucleators in the stomach are
not obtained from the seawater. The temperature and light conditions examined in the present study did not significantly influence
the hemolymph ice nucleation temperatures of mussels kept in the laboratory.
Received: 24 October 1996 / Accepted: 16 November 1996 相似文献
11.
Acoustic telemetry was used to track vertical and horizontal movement patterns and to monitor the stomach temperatures of seven juvenile shortfin mako sharks (Isurus oxyrinchus Rafinesque) in the Southern California Bight from July to November 2002. Makos (80–145 cm fork length, FL) were attracted to the tracking vessel, where they were fed a mackerel containing an acoustic transmitter that reported temperature and pressure. Tracks ranged from 6.8–45.4 h. Collectively, the mako sharks spent 80% of the track record at 0–12 m, 15% at 12–24 m, and 5% at depths >24 m. The average horizontal swimming speed was 2.3 km h–1 or 0.55 FLs s–1, and the greatest distance traveled was 145 km in 45.4 h. For the six tracks >21 h, there was a positive correlation between body size and maximum depth. Makos used more of the water column during daylight hours. Mean stomach temperature was 3.8±1.5°C above ambient, and body size was positively correlated with both maximum and average stomach temperature. Stomach content analyses of four makos captured at the end of tracking verified the occurrence of feeding events as indicated by changes in stomach temperature.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by J.P. Grassle, New Brunswick 相似文献
12.
The emergence patterns of both green (Chelonia mydas) and loggerhead (Caretta caretta) turtle hatchlings were observed in great detail over three seasons at Alagadi beach, northern Cyprus. In total, 38 green turtle and 50 loggerhead turtle nests were monitored, accounting for the emergence of 2,807 and 2,259 hatchlings, respectively. We quantified these emergences into 397 green turtle and 302 loggerhead turtle emergence groups. Overall, 85.0% of green turtle and 79.5% of loggerhead turtle groups emerged at night; these accounted for 85.5 and 90.8% of hatchlings, respectively. The remaining emergences were dispersed throughout the day for green turtle nests but confined to the morning in loggerhead turtle nests. Hatchling emergence from individual nests occurred over periods of between 1 and 7 nights, with most hatchlings typically emerging on the first night. Group sizes of green turtles emerging during the day were significantly smaller than those emerging at night. Hatchlings of both species that emerged from nests during the day had longer emergence durations than those that emerged from nests at night only.Communicated by R.J. Thompson, St. Johns 相似文献
13.
Nine post-nesting loggerhead turtles (Caretta caretta) were tracked using sonic and radio telemetry. Tracking began immediately after the turtles left the beach and continued until contact was either lost or terminated. As sonic tags transmit continuously underwater, they were much more effective than the radio tags in determining the paths of the turtles. Radio tags transmit only at the surface and were useful in ascertaining submergence durations. For nine of the ten turtles tracked with sonic signals, the gross movement was away from the beach in a westerly direction. The tracking periods ranged from 3.35 to 8.25 h, while the straight-line movements ranged from 3.05 to 12.88 km, respectively. Sixty-seven percent of the submergence durations recorded were <3 min. This respiratory behavior suggests continuous swimming, and the paths of the turtles suggested directed movement offshore immediately after nesting. The gradual littoral slope and lack of nearshore structure in this part of the Gulf of Mexico could be contributing factors to the patterns of dispersal observed, as benthic structures provide resting and foraging habitat for loggerheads. 相似文献
14.
N. R. Menon 《Marine Biology》1972,15(1):1-11
Three species of bryozoans—Membranipora membranacea (L.), Electra pilosa (L.) and Conopeum reticulum (L.) — are capable of acclimating to elevated temperatures, above the normal range experienced in nature, when exposed to a gradual increase in ambient temperature. Conspicuous differences in LD 50 values, as a consequence of acclimation, occur between representatives of the same species acclimated and grown at constant temperatures in the laboratory. The tolerance range of these species is influenced by their thermal history in the laboratory. While increased ambient temperatures accelerate growth rate, final colony size attained after prolonged exposure declines at higher temperatures. The size of zooecia attained is inversely proportional to the test temperature. Colonies of E. pilosa maintained at 22°C develop erect branches. Hence, it is probable that E. pilosa forma erecta is only a growth form of normally encrusting colonies of E. pilosa. Temperature affects rate of regeneration. 相似文献
15.
Susanna Piovano Marcel Clusa Carlos Carreras Cristina Giacoma Marta Pascual Luis Cardona 《Marine Biology》2011,158(11):2577-2587
We estimated for the first time the growth rates of loggerhead sea turtles of Mediterranean and of Atlantic origin found in
the Mediterranean Sea, combining both skeletochronological and genetic analyses. Our growth models suggested that the growth
rate of loggerhead sea turtles of Mediterranean origin was faster than that of their conspecifics with an Atlantic origin
exploiting the feeding grounds in the Mediterranean Sea. The age at maturity for Mediterranean origin loggerhead sea turtles,
estimated using our best fitting model, was 24 years, which suggests that loggerhead sea turtles nesting in the Mediterranean
are not only smaller than those nesting in the western North Atlantic but also younger. 相似文献
16.
Michael D. Arendt Albert L. Segars Julia I. Byrd Jessica Boynton Jeffrey A. Schwenter J. David Whitaker Lindsey Parker 《Marine Biology》2012,159(1):113-125
Sixteen satellite-tagged adult male loggerhead sea turtles (Caretta caretta) dispersed widely from an aggregation near Port Canaveral, Florida, USA (28°23′N, −80°32′W) after breeding. Northbound males
migrated further (990 ± 303 km) than southbound males (577 ± 168 km) and transited more rapidly (median initial dive duration = 6
(IQR = 4–16) versus 19 (IQR = 10–31) min, respectively).. Migration occurred along a depth corridor (20–40 m) except where
constricted by a narrow continental shelf width. Males foraged in areas 27 ± 41 km2 day−1 at locations <1–80 km from shore for 100.1 ± 60.6 days, with variability in foraging patterns not explained by turtle size
or geography. Post-breeding dispersal patterns were similar to patterns reported for adult female loggerhead sea turtles in
this region and adult male loggerhead sea turtles elsewhere in the northern hemisphere; however, foraging ground distributions
were most similar to adult female loggerhead sea turtles in this region. 相似文献
17.
Kathryn E. Gardner Robin L. Foster Sean O’Donnell 《Behavioral ecology and sociobiology》2007,61(5):783-792
Bumblebee colonies experience daily and seasonal fluctuations in ambient temperature, but proper brood development requires
a stable nest temperature. This study examined how adaptive colony responses to changing ambient temperature are achieved
through the in-nest workers’ behavioral plasticity. We studied three Bombus huntii colonies in the laboratory. In the first experiment, we manipulated ambient temperature and recorded brood cell incubation
and wing fanning by individually marked, known-age bees. The colonies maintained their nests closer to appropriate brood development
temperatures (28 to 32°C) when exposed to a range of ambient temperatures from 10.3 to 38.6°C. Incubation activity was greater
in cooler treatment conditions, whereas in the highest temperature treatment, some bees fanned and others moved off the brood.
As the ambient temperature dropped, workers increased the duration of their incubating bouts, but, except at the highest temperature,
the number of workers that incubated did not differ significantly among treatments. A subset of the bees incubated significantly
more than their nest mates, some of which never incubated. Worker body size, but not age, was a good predictor of incubation
rates, and smaller bees incubated at higher rates. In the second experiment, we removed the most actively incubating workers.
Immediately after removals, the total colony incubation effort was lower than pre-removal levels, but incubation effort rebounded
toward pre-removal levels after 24 h. The increased thermoregulatory demand after removals was met primarily by bees increasing
their rates of incubation rather than by bees switching from a different task to incubation. We conclude that some B. huntii workers specialize on nest thermoregulation, and that changes in work rates are more important than task switching in meeting
thermal challenges. 相似文献
18.
Luis Cardona Mónica Revelles Mari Luz Parga Jesús Tomás Alex Aguilar Ferran Alegre Antonio Raga Xavier Ferrer 《Marine Biology》2009,156(12):2621-2630
Previous studies of loggerhead sea turtles have concluded that drifting longlines were the main threat for immature specimens
in the western Mediterranean, because immature loggerhead sea turtles mainly inhabit oceanic waters. However, recent aerial
surveys have revealed large numbers of immature loggerhead sea turtles over the continental shelf of eastern mainland Spain,
where turtles are exposed to neritic fishing gears but not to drifting longlines. We satellite-tracked seven loggerhead sea
turtles (minimum straight carapace length (SCLmin) range: 36.5–55.0 cm) to assess whether the turtles in this region are vagrants
from the adjoining oceanic regions or whether these loggerheads mostly inhabit the continental shelf. Satellite-tracking revealed
that six of the tagged turtles avoided the oceanic realm and made extended use of the continental shelf, whereas only one
individual could be considered a true vagrant as it avoided the continental shelf and primarily used the oceanic habitat.
These results are in sharp contrast with those previously reported for immature loggerhead sea turtles of similar size from
the south-western Mediterranean and fit well a relaxed ontogenic model that was recently proposed for loggerhead sea turtles
in the central Mediterranean. Furthermore, these results demonstrate the vulnerability of loggerhead sea turtles of eastern
mainland Spain to neritic fishing gears, as three of the seven turtles died and one was bycaught incidentally while being
tracked over the continental shelf. 相似文献
19.
Paolo Casale Daniela Freggi Roberto Basso Carola Vallini Roberto Argano 《Marine Biology》2007,152(5):1039-1049
Sea turtle tagging carried out in Italy in the period 1981–2006 resulted in 125 re-encounters of loggerhead turtles (Caretta caretta) after a mean of 2.5 years, from different marine areas in the Mediterranean. At first finding, turtles ranged 25–83 cm of
curved carapace length. Data were analyzed according to size, area, habitat type, season, in order to provide indication of
movement patterns. When integrated with other information, results indicate that: (1) a part of turtles in the oceanic stage
show a nomad behavior with movements among different oceanic areas; (2) another part show fidelity to an oceanic area; (3)
turtles in the neritic stage show fidelity to neritic areas, and once settled to one area, change to other neritic areas is
unlikely; (4) nomad oceanic turtles are significantly larger than sedentary ones, and also larger than turtles found in neritic
areas; it is hypothesized that these could be Atlantic turtles that eventually leave the Mediterranean; (5) ecological transition
from oceanic to neritic habitats occurs at a wide range of sizes, and some turtles may have a very brief oceanic stage; (6)
turtles in the oceanic stage are more likely to recruit to neritic areas close to their oceanic areas than to distant ones;
(7) part of turtles from some Mediterranean nesting beaches might frequent a relatively limited area range, including both
oceanic and neritic areas; (8) in most of the Mediterranean, latitudinal seasonal migrations are unlikely. A general model
of movement patterns of loggerhead turtles in the Mediterranean is proposed. 相似文献
20.
Natal site and offshore swimming influence fitness and long-distance ocean transport in young sea turtles 总被引:1,自引:1,他引:0
Nathan F. Putman Rebecca Scott Philippe Verley Robert Marsh Graeme C. Hays 《Marine Biology》2012,159(10):2117-2126
Although long-distance transport of marine organisms is constrained by numerous oceanic and biological factors, some species have evolved life-histories reliant on such movements. We examine the factors that promote long-distance transport in a transoceanic migrant, young loggerhead sea turtles (Caretta caretta), from the southeastern U.S. Empirical data from near-surface buoys and simulations in two ocean circulation models indicated that passive drifters are often retained for long periods shoreward of oceanic fronts that delineate coastal and offshore waters. Further simulations revealed that offshore swimming aided newly hatched turtles in moving past fronts and increased turtles’ probability of survival, reaching distant foraging grounds, and encountering favorable temperatures. Swimming was most beneficial in regions that were more favorable under scenarios assuming passive drift. These results have broad implications for understanding the movement processes of many marine species, highlighting likely retention of more planktonic species and potential for dispersal in more nektonic species. 相似文献