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The temporal distribution of nesting and mating in green turtles Chelonia mydas at Ascension Island (7° 57 'S, 14° 22' W) in the South Atlantic is described. Mathematical description of the seasonal pattern of nesting showed extreme similarity between seasons, and evidence is pre- sented to support the hypothesis that observed patterns are driven by prevailing environmental tem- perature. Mating was observed to begin before nesting and follow a pattern consistent with a mod- elled seasonal influx of suitable females into the annual breeding population. When available data on male size are compared with that of females from the same population (n = 12 populations), a pro- nounced and consistent sexual dimorphism, with males being smaller than females, is highlighted in all populations. The possible mechanisms behind the evolution of such a pattern are discussed.

We examined the role played by temperature in the duration of incubation and sex ratio of green turtle hatchlings at Ascension Island, one of the most important green turtle rookeries in the Atlantic. Temperature at control sites at nest depth and in 39 green turtle nests was measured using small temperature recording devices. The sex ratio of hatchlings was ascertained in a sub-sample of monitored nests allowing the description of the relationship between intranest temperature and hatchling sex ratio, demonstrating a pivotal incubation temperature of 28.8°C. The seasonal profile in sex ratio of hatchlings produced on all nesting beaches at Ascension Island was estimated, showing that a female-biased sex ratio would be expected with a female:male ratio of the order of 3:1. The use of nest temperature, air temperature, sand temperature at control sites, and incubation duration as proxies to estimate hatchling sex ratio are discussed.

Marine Renewable Energy is developing fast, with hundreds of prototypes and operational devices worldwide. Two main challenges are assessing their environmental impacts (especially in near-shore, shallow environments) and ensuring efficient and effective maintenance (requiring specialised ships and fair weather windows), compounded by the lack of long-term measurements of full-scale devices. We present here broadband measurements (10 Hz to 32/48 kHz) acquired at the Falmouth Bay Test site (FaBTest, UK) from 2010 onwards, for a 16-m ring-shaped Wave Energy Converter, in waters up to 45 m deep. This period covers baseline measurements, including shipping from the neighbouring English Channel, one of the busiest shipping lanes in the world (ca. 45,000 ship transits annually) and the full period of installation and energy production, including maintenance episodes. Acoustic signatures are measured as Sound Pressure Levels (e.g. for impacts) and time/frequency variations (for condition-based monitoring via Acoustic Emissions). They change through time, depending on weather and modes of operation. Long-term measurements are compared with modelling of potential variations in this complex environment and with laboratory experiments. These are used to outline the varying acoustic contributions through the life cycle of a typical wave energy converter, yielding insights for other wave devices in other environments.

Growing concerns about climate change and energy security have fueled a rapid increase in the development of marine renewable energy installations (MREIs). The potential ecological consequences of increased use of these devices emphasizes the need for high quality environmental impact assessment (EIA). We demonstrate that these processes are hampered severely, primarily because ambiguities in the legislation and lack of clear implementation guidance are such that they do not ensure robust assessment of the significance of impacts and cumulative effects. We highlight why the regulatory framework leads to conceptual ambiguities and propose changes which, for the most part, do not require major adjustments to standard practice. We emphasize the importance of determining the degree of confidence in impacts to permit the likelihood as well as magnitude of impacts to be quantified and propose ways in which assessment of population-level impacts could be incorporated into the EIA process. Overall, however, we argue that, instead of trying to ascertain which particular developments are responsible for tipping an already heavily degraded marine environment into an undesirable state, emphasis should be placed on better strategic assessment. Publisher PDF

Temperature can have a profound effect on the phenotype of reptilian offspring, yet the bulk of current research considers the effects of constant incubation temperatures on offspring morphology, with few studies examining the natural thermal variance that occurs in the wild. Over two consecutive nesting seasons, we placed temperature data loggers in 57 naturally incubating clutches of loggerhead sea turtles Caretta caretta and found that greater diel thermal variance during incubation significantly reduced offspring mass, potentially reducing survival of hatchlings during their journey from the nest to offshore waters and beyond. With predicted scenarios of climate change, behavioral plasticity in nest site selection may be key for the survival of ectothermic species, particularly those with temperature-dependent sex determination.

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea , occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters.

SUMMARY Satellite telemetry was used to record the submergence duration of green turtles (Chelonia mydas) as they migrated from Ascension Island to Brazil (N=12 individuals) while time/depth recorders (TDRs) were used to examine the depth distribution and dive profiles of individuals returning to Ascension Island to nest after experimental displacement (N=5 individuals). Satellite telemetry revealed that most submergences were short (20 min), particularly at night. TDRs revealed that much of the time was spent conducting short (2–4 min), shallow (approximately 0.9–1.5 m) dives, consistent with predictions for optimisation of near-surface travelling, while long (typically 20–30 min), deep (typically 10–20 m) dives had a distinctive profile found in other marine reptiles. These results suggest that green turtles crossing the Atlantic do not behave invariantly, but instead alternate between periods of travelling just beneath the surface and diving deeper. These deep dives may have evolved to reduce silhouetting against the surface, which would make turtles more susceptible to visual predators such as large sharks.

Like many animals migrating through the oceans, sea turtles face difficult navigational tasks when they have to reach distant, specific sites. The paradigmatic case of Brazilian green turtles (Chelonia mydas), which nest on the tiny Ascension Island in the middle of the Atlantic Ocean, has often been the subject of hypotheses concerning their navigational mechanisms. To investigate their nature, we displaced 18 females from Ascension and tracked them by satellite after release from eight different points in the ocean, 60-450 km away from the island. Four turtles moved to Brazil soon after the release, 4 moved in various directions before heading to Brazil, and 10 reached the island. All the successful trips, bar 1, were winding but ended with a final straight segment of variable length, as if the turtles were searching for a sensory contact with the island which they obtained at various distances. The approach to Ascension mostly occurred from the direction opposite to the trade wind, suggesting a navigational role of wind-borne information originating from the island.

Albatrosses and sea turtles are known to perform extremely long-distance journeys between disparate feeding areas and breeding sites located on small, isolated, oceanic islands or at specific coastal sites. These oceanic journeys, performed mainly over or through apparently featureless mediums, indicate impressive navigational abilities, and the sensory mechanisms used are still largely unknown. This research used three different approaches to investigate whether bi-coordinate navigation based on magnetic field gradients is likely to explain the navigational performance of wandering albatrosses in the South Atlantic and Indian Oceans and of green turtles breeding on Ascension Island in the South Atlantic Ocean. The possibility that magnetic field parameters can potentially be used in a bi-coordinate magnetic map by wandering albatrosses in their foraging area was investigated by analysing satellite telemetry data published in the literature. The possibilities for using bi-coordinate magnetic navigation varied widely between different areas of the Southern Oceans, indicating that a common mechanism, based on a bi-coordinate geomagnetic map alone, was unlikely for navigation in these areas. In the second approach, satellite telemetry was used to investigate whether Ascension Island green turtles use magnetic information for navigation during migration from their breeding island to foraging areas in Brazilian coastal waters. Disturbing magnets were applied to the heads and carapaces of the turtles, but these appeared to have little effect on their ability to navigate. The only possible effect observed was that some of the turtles with magnets attached were heading for foraging areas slightly south of the control turtles along the Brazilian coast. In the third approach, breeding female green turtles were deliberately displaced in the waters around Ascension Island to investigate which cues these turtles might use to locate and return to the island; the results suggested that cues transported by wind might be involved in the final stages of navigation.

The depth and swim speed of a green turtle (Chelonia mydas) were measured during the internesting period in Cyprus. For dives to the seabed (U-dives) we used these data to determine dive angles. Typically the turtle initially descended at a steep angle (∼60°) but as the dive continued this angle lessened until the turtle approached the seabed at an average angle of ∼15°. This systematic change in descent angle is consistent with the prediction that the energetic implications of dive angle are most important at the start of the dive when the turtle is fighting to overcome its positive buoyancy. On leaving the seabed, the turtle often seemed to rise passively.

Ž. Temperature was recorded in 23 nests of the loggerhead turtle Caretta caretta and control Ž XX . sites of nest depth at Alagadi 35833 N, 33847 E , Northern Cyprus, eastern Mediterranean. Control site sand temperature was found to be highly correlated with mean daily air temperature and mean nest temperature. Mean temperature in nests ranged from 29.58C to 33.28C, with mean temperature in the middle third of incubation ranging from 29.38C to 33.78C. Hatching success was significantly correlated with incubation temperature, with nests experiencing very high temperatures exhibiting low hatching success. All nests demonstrated regular diel variation in temperature with mean daily fluctuations ranging from 0.38C to 1.48C. Increase in temperature above that of the prevailing sand temperature attributed to metabolic heating was clearly demonstrated in 14 of 15 clutches, with the mean level of metabolic heating of all nests being 0.48C. However, the level of metabolic heating varied markedly throughout the incubation period with levels being significantly higher in the final third of incubation. Incubation duration was found to be significantly correlated to both the mean temperature of nests throughout the incubation period and during the middle third of incubation. The relationship between incubation duration and mean incubation temperature was used to estimate mean incubation temperatures at

This paper reports the physical and biological nest parameters of loggerhead turtle (Caretta caretta) nests on northern Cyprus that predispose individual nests to infestation. All data were collected between June and September 1997, and data were analyzed using generalized linear models. The final model explained 66.5% of the total deviance, and the most significant factor was the depth to the egg chamber (deviance = 63.86, P < 0.0001). The implications of these results are discussed, and recommendations for future work are proposed.

Large annual fluctuations are seen in breeding numbers in many populations of non-annual breeders. We examined the interannual variation in nesting numbers of populations of green (Chelonia mydas) (n = 16 populations), loggerhead (Caretta caretta) (n = 10 populations), leatherback (Dermochelys coriacea) (n = 9 populations) and hawksbill turtles (Eretmochelys imbricata) (n = 10 populations). Interannual variation was greatest in the green turtle. When comparing green and loggerhead turtles nesting in Cyprus we found that green turtles were more likely to change the interval between laying seasons and showed greater variation in the number of clutches laid in a season. We suggest that these differences are driven by the varying trophic statuses of the different species. Green turtles are herbivorous, feeding on sea grasses and macro-algae, and this primary production will be more tightly coupled with prevailing environmental conditions than the carnivorous diet of the loggerhead turtle.

Large populations of marine turtles breeding in the Cayman Islands were drastically reduced in the early 1800s. However, marine turtle nesting still occurs in the islands. The present-day status of this nesting population provides insight into the conservation of marine turtles, a long-lived species. In 1998 and 1999, the first systematic survey of marine turtle nesting in the Cayman Islands found 38 nests on 22 beaches scattered through the three islands. Three species were found: the green Chelonia mydas, hawksbill Eretmochelys imbricata and loggerhead Caretta caretta turtles. Comparison with other rookeries suggests that the small number of sexually mature adults surviving Cayman's huge perturbations may be impeding population recovery. This shows the need to implement conservation measures prior to massive reductions in population size.

This paper describes dipteran infestation of loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle nests in northern Cyprus in 1996 and 1997. Insect larvae were collected from infested nests, reared to adulthood and identified to species. A minimum of 13.4% (1996) and 17.4% (1997) of loggerhead turtle nests and 3.3% and 20.7% of green turtle nests were infested in 1996 and 1997, respectively. Eleven dipteran species were found infesting turtle nests with one species (Sarcotachina aegyptiaca) being dominant. Gross estimates, utilizing the speeds of development for three species of sarcophagid showed that infestation was taking place differentially between the two turtle species. Various aspects of the effect of dipteran infestation on marine turtle nests in northern Cyprus and recommendations for future investigations are discussed.

A detailed survey of the nesting by green turtles ( Chelonia mydas ) on Ascension Island (7°57′ S, 14°22′ W) was conducted between 1 December 1998 and 1 October 1999. During this period there was a total estimate of 36,036 marine turtle nesting activities, resulting in the deposition of an estimated 13,881 clutches (95% confidence limits 13,092–14,660). These data suggest that 2–3 times more turtles nested than when previous detailed surveys were undertaken in the 1970′s. The peak of nesting was in March, with 95% of nesting activity being recorded between 4 January and 18 May. Possible reasons for the evolution of the seasonality of nesting are discussed. Individual beaches varied greatly in density of nesting activities (range=534–10,001 activities/km; mean=6204 activities/km), density of nests (range=213–5200 nests/km; mean=2390 nests/km) and the proportion of nesting activities resulting in nests (nesting success; range=0.13–0.52; mean=0.39).

We review some key resources freely or cheaply available to those involved with marine turtle research and conservation in the Mediterranean. These include: Marine Turtle Newsletter, Listservs, bibliographic databases, Mediterranean specific technical manuals, IUCN Marine Turtle Specialist Group publications, internet sources and books.

Incubation durations for loggerhead turtles Caretta caretta nesting at Alagadi, in North- ern Cyprus, were recorded over 6 full seasons (1993 to 1998). Because incubation duration depends on temperature, it was possible to convert data on durations to hatchling sex ratios, using extensive data from other areas on the relationship between these 2 variables. It was estimated that 89 to 99% of the hatchlings produced on Alagadi beach were females. These findings provide a further instance of highly female-skewed sex ratios in loggerhead turtles.

The status of the Green Turtle, Chelonia mydas, nesting population in the Mediterranean is reviewed on the basis of literature records and unpublished data. It is estimated that 350 to 1750 clutches are laid per year, from which an annual nesting population of 115 to 580 females can be estimated. 99% of all recorded nesting occurs in Cyprus and in Turkey, with the remainder being found in the Lebanon, Israel and Egypt. Interannual fluctuations in the number of nests follows a relatively synchronous pattern across the region. 78% of all nests are concentrated at five key sites, three of them in Turkey (Akyatan, Kazanli, Samandag) and two in northern Cyprus (North Karpaz, Alagadi). As well as making the nesting population vulnerable, this concentration allows the focussing of conservation efforts. The existing threats to the nesting sites are described in detail; they are multifold, and include destruction of nesting habitat for tourism and agriculture, beach erosion and pollution. By-catch of turt...

For six green turtles, Chelonia mydas, that had nested on Ascension Island in the South Atlantic, we used time-depth recorders to examine their diving behaviour during the subsequent internesting interval (10-12 days). All the turtles performed dives where they remained at a fixed depth for a long period, surfaced briefly and then dived to the same depth again. It is generally believed these dive profiles are caused by the turtles resting on the sea bed. The maximum depth that turtles routinely reached on these resting dives was between 18 and 20 m, with resting dives deeper than 20 m being extremely rare. Resting dive duration increased significantly with deeper dives. From this relationship, and assuming that turtles with fully inflated lungs at the surface need to dive to 19 m to achieve negative buoyancy, we estimated for two turtles that the oxygen consumption during resting dives was 0.016 and 0.020 litres O(2)/kg per h, respectively. This is similar to the value predicted from the allometric scaling relationship for the minimal oxygen consumption of turtles. We calculated that the energy conserved by resting during the internesting period may appreciably increase the reproductive output of females. Copyright 2000 The Association for the Study of Animal Behaviour.

Concentrations of heavy metals (Hg, Cd and Pb) were determined in internal organs and nest contents of green turtles Chelonia mydas and loggerhead turtles Caretta caretta from northern Cyprus, eastern Mediterranean Sea. Concentrations of mercury in liver tissue were higher in loggerhead turtles (median 2.41 μg g−1 dry weight) than in green turtles (0.55 μg g−1 dry weight). Preliminary data suggest cadmium concentrations to be highest in kidney tissue of loggerhead turtles (median 30.50 μg g−1 dry weight) but in liver tissue of green turtles (median 5.89 μg g−1 dry weight). Concentrations of lead in internal tissues were often below analytical detection limits in both species, but when measurable, tended to be higher in loggerhead turtles. Concentrations of mercury and cadmium in nest contents from both species were low, often below analytical detection limits, while those of lead were relatively high in loggerhead turtle hatchlings (up to 10.56 μg g−1 dry weight). When measurable, concentrations of all three metals tended to be higher in loggerhead turtle nest contents than in green turtle nest contents. Results presented here are consistent with inter-specific differences in diet and trophic status. Heavy metal burdens in loggerhead turtles and green turtles from the Mediterranean are similar or lower than corresponding concentrations in turtles from Japan and Hawaii, but some lead concentrations in Mediterranean loggerhead hatchlings are at levels known to cause subclinical toxic effects in other vertebrates.

Concentrations of individual chlorobiphenyls (CBs) and organochlorine pesticides (OCPs) in marine turtle tissues collected from the Mediterranean (Cyprus, Greece) and European Atlantic waters (Scotland) between 1994 and 1996 are described. CB concentrations were highest in adipose tissue and ranged from 775 to 893, 39 to 261 and 47 to 178 mg/kg wet wt in loggerhead (Caretta carretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) turtles, respectively. Omnivorous loggerhead turtles had the highest organochlorine contaminant (OC) concentrations in all tissues sampled. It is thought that dietary preferences were likely to be the main diAerentiating factor among species. Decreasing lipid contaminant burdens with turtle size were observed in green turtles, most likely attributable to a change in diet with age. Principal component analysis of data from loggerhead and green turtles indicated that there were also pattern diAerences between species, confirming bioaccumulation diAerences. Crown copyright # 1999 Published by Elsevier Science Ltd. All rights reserved.

Diving reptiles, unlike most diving birds and mammals, return infrequently to the surface to breathe. Spending the bulk of their lives underwater, they are likely to have developed a large variety of specific behavioural patterns different from those of their warm-blooded counterparts. However, for technical reasons, underwater behaviour of these aquatic reptiles remains poorly understood. In this study green turtles Chelonia mydas nesting on Cyprus (Eastern Mediterranean) were equipped with multi-channel data loggers monitoring diving behaviour and activity (via a logger-integrated 3-D compass which served as an activity sensor) during the inter-nesting interval. Data from 2 turtles for 2 consecutive inter-nesting intervals were available for detailed dive analysis. Both turtles showed highly variable dive patterns ranging from travelling subsurface dives to specific dive types such as U- (mainly resting and foraging dives), S- (a form of energy saving swimming) and V-dives. The green turtles stayed near the coast throughout the study, dived no deeper than ca 25 m, but remained underwater for up to ca 40 min. The recordings of the activity sensor revealed high activity levels (less than 20% resting d -1 ) during the whole inter-nesting period which was attributed to extensive foraging. The combination of both the activity data and the dive data showed that the turtles were engaged in travelling movements for 46 % of the inter-nesting time spent underwater, foraged for 34 % and rested for 12% of the time. We discuss the physiological, ecological and conservation implications of these results.

The IUCN Red List of Threatened Species (www.redlist.org) is a comprehensive list of relative extinction risk for species throughout the world, and it is commonly referenced in the scien- tific literature. Established in 1963, the IUCN Red List and its Criteria have been revised regularly to make them more scientific and objective. Nevertheless, the aim of the IUCN Red List to establish global standards across varied taxa has generated some controversy, particularly in terms of what is the most appropriate scale for both assessing the threat of extinction and setting conservation priori- ties for particular species. The papers included in this Theme Section of Endangered Species Research focus on the IUCN Red List and provide several recommendations for strengthening this conservation tool.

Based on an extensive sampling regime from both nesting populations and bycatch, frequency analyses of mitochondrial (mt) DNA control region haplotypes in the Mediterranean were used to assess the genetic structure and stock composition of the loggerhead sea turtle, Caretta caretta, in different marine fisheries. The analyses show the following. (i) In drifting longline fisheries working in Mediterranean pelagic habitats 53-55% of turtles caught originated from the Mediterranean stock; (ii) In bottom-trawl fisheries all turtle bycatch is derived from this regional stock; (iii) This regional stock contribution to fishery bycatch suggests that the population size of the Mediterranean loggerhead nesting population is significantly larger than previously thought. This is consistent with a recent holistic estimate based on the discovery of a large rookery in Libya. (iv) Present impact of fishery-related mortality on the Mediterranean nesting population is probably incompatible with its long-term conservation. Sea turtle conservation regulations are urgently needed for the Mediterranean fisheries. (v) The significant divergence of mtDNA haplotype frequencies of the Turkish loggerhead colonies define this nesting population as a particularly important management unit. Large immature and adult stages from this management unit seem to be harvested predominantly by Egyptian fisheries. (vi) Combined with other data, our findings suggest that all the nesting populations in the Mediterranean should be considered as management units sharing immature pelagic habitats throughout the Mediterranean (and possibly the eastern Atlantic), with distinct and more localized benthic feeding habitats in the eastern basin used by large immatures and adults. (vii) Between the strict oceanic pelagic and the benthic stages, immature turtles appear to live through an intermediate neritic stage, in which they switch between pelagic and benthic foods.

Mortality patterns of marine turtles entangled in fishing gear, found dead at sea or stranded dead on and around the coast of Britain in the period 1992–1996 are described. Of a total of 38 dead turtles identified, 35 were leatherback turtles (Dermochelys coriacea) and three were loggerhead turtles (Caretta caretta). All D. coriacea were considered adults or subadults nearing sexual maturity. Six individuals were assessed as females, ten were classified as males and 19 were not sexed. Dermochelys coriacea (N=20 measured) ranged from 120 to 210 cm in curved carapace length (mean, 152 cm). The three C. caretta were juveniles, and ranged from 15 to 30 cm curved carapace length. Possible origins, causes of mortality and interactions with fisheries are discussed. In addition, contaminant levels were determined in the tissues of three D. coriacea. Concentrations of organic contaminants determined were found to be low.

A survey of the levels of marine turtle bycatch in the small-boat based fisheries in northern Cyprus and the Turkish Mediterranean (Alanya to Mersin) was undertaken by questioning a sample of fishermen (n = 54) in all harbours in the survey region. Fishermen in Turkey caught an estimated 2.5 turtles/boat/year versus an estimated 4.0 turtles/boat/year in Cyprus. This yielded a likely minimum bycatch estimate of over 2,000 marine turtles per year in the region. An estimated 10% of turtles were thought to be dead at the point of capture. Turtles were caught in both nets and on long-lines and were perceived as detrimental to the livelihood of fishermen either by damaging nets, spoiling catch or removing bait. Although few fishermen admitted to deliberately killing turtles, a larger proportion thought others did so. Given the likelihood that a proportion of sea turtles caught will be Green Turtles (Chelonia mydas), and due to the highly endangered status of this species in this region, interaction wit...

Female green turtles (Chelonia mydas) were monitored for signs of throat movements/oscillations when attempting to nest at Ascension Island in the S5outh Atlantic. Throat oscillations occurred during all stages of the nesting process, with the mean frequency ranging from 10.9 to 36.1 oscillations/min, while the mean breathing rate for different stages during nesting activity ranged from 1.3 to 2.8 breaths/min.

The ecology and behaviour of a population of feral donkeys (Equus asinus) in the Karpas peninsula, northern Cyprus, was investigated. The population size in the area occupied by the donkeys was estimated by independent subjective assessment and by two mark and recapture techniques as being approximately 300 to 400 animals with a density of 8–10 animals/km2. It was concluded that subjective assessments after a period of familiarisation with the study area can provide estimates close to those obtained by other systematic sampling techniques. During daylight hours the donkeys were most frequently observed in groups of one to four animals although larger grazing associations were also formed. The animals exhibited features of social organisation typical of feral asses appropriate to the length of time the population had been established. In the Karpas, control measures should be implemented to prevent possible animal welfare problems.

Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix but connected with other Caribbean populations. Two distinct nesting populations of hawksbill turtles (Eremochelys imbricata) were detected in the Dominican Republic and exhibited interesting patterns of connectivity with other nesting sites and juvenile and adult male foraging aggregations. The green sea turtle (Chelonia mydas) has almost been extirpated from the Dominican Republic and limited inference could be made from our samples. Finally, results were compared with Lagrangian drifting buoys and published Lagrangian virtual particles that travelled through the Dominican Republic and Caribbean waters. Conservation implications of sink-source effects or genetic isolation derived from these complex inter-connections are discussed for each species and population.

The reproductive ecology of marine turtles in northern Cyprus, during the nesting seasons of 1992–1995, is described. Nesting was monitored on 88 beaches. Caretta caretta was found to be more widely distributed, nesting on 84 beaches, compared to the 56 on which Chelonia mydas nested. Up to 461 C. mydas and 519 C. caretta nests were recorded in any one season. These may constitute up to 30% and 10% of the estimated Mediterranean nesting populations of these species, respectively. Data are presented regarding spatial and temporal distribution of nesting, reproductive parameters, fate of nests and threats faced. The main threats to these populations were found to be: potential beach development for recreational use, sand extraction, incidental catch in fisheries, pollution and nest depredation by foxes and feral dogs.

For species of conservation concern, knowledge of key life-history and demographic components, such as the number and sex ratio of breeding adults, is essential for accurate assessments of population viability. Species with temperature-dependent sex determination can produce heavily biased primary sex ratios, and there is concern that adult sex ratios may be similarly skewed or will become so as a result of climate warming. Prediction and mitigation of such impacts are difficult when life-history information is lacking. In marine turtles, owing to the difficultly in observing males at sea, the breeding interval of males is unknown. It has been suggested that male breeding periodicity may be shorter than that of females, which could help to compensate for generally female-biased sex ratios. Here we outline how the use of molecular-based paternity analysis has allowed us, for the first time, to assess the breeding interval of male marine turtles across multiple breeding seasons. In our study rookery of green turtles (Chelonia mydas), 97% of males were assigned offspring in only one breeding season within the 3-year study period, strongly suggesting that male breeding intervals are frequently longer than 1year at this site. Our results also reveal a sex ratio of breeding adults of at least 1.3 males to each female. This study illustrates the utility of molecular-based parentage inference using reconstruction of parental genotypes as a method for monitoring the number and sex ratio of breeders in species where direct observations or capture are difficult.

Underwater noise from shipping is a growing presence throughout the world’s oceans, and may be subjecting marine fauna to chronic noise exposure with potentially severe long-term consequences. The coincidence of dense shipping activity and sensitive marine ecosystems in coastal environments is of particular concern, and noise assessment methodologies which describe the high temporal variability of sound exposure in these areas are needed. We present a method of characterising sound exposure from shipping using continuous passive acoustic monitoring combined with Automatic Identification System (AIS) shipping data. The method is applied to data recorded in Falmouth Bay, UK. Absolute and relative levels of intermittent ship noise contributions to the 24-h sound exposure level are determined using an adaptive threshold, and the spatial distribution of potential ship sources is then analysed using AIS data. This technique can be used to prioritise shipping noise mitigation strategies in coastal marine environments.

We describe the real-time movements of the last of the marine mega-vertebrate taxa to be satellite tracked – the giant manta ray (or devil fish, Manta birostris), the world's largest ray at over 6 m disc width. Almost nothing is known about manta ray movements and their environmental preferences, making them one of the least understood of the marine mega-vertebrates. Red listed by the International Union for the Conservation of Nature as ‘Vulnerable’ to extinction, manta rays are known to be subject to direct and incidental capture and some populations are declining. Satellite-tracked manta rays associated with seasonal upwelling events and thermal fronts off the Yucatan peninsula, Mexico, and made short-range shuttling movements, foraging along and between them. The majority of locations were received from waters shallower than 50 m deep, representing thermally dynamic and productive waters. Manta rays remained in the Mexican Exclusive Economic Zone for the duration of tracking but only 12% of tracking locations were received from within Marine Protected Areas (MPAs). Our results on the spatio-temporal distribution of these enigmatic rays highlight opportunities and challenges to management efforts.

Marine renewable energy installations harnessing energy from wind, wave and tidal resources are likely to become a large part of the future energy mix worldwide. The potential to gather energy from waves has recently seen increasing interest, with pilot developments in several nations. Although technology to harness wave energy lags behind that of wind and tidal generation, it has the potential to contribute significantly to energy production. As wave energy technology matures and becomes more widespread, it is likely to result in further transformation of our coastal seas. Such changes are accompanied by uncertainty regarding their impacts on biodiversity. To date, impacts have not been assessed, as wave energy converters have yet to be fully developed. Therefore, there is a pressing need to build a framework of understanding regarding the potential impacts of these technologies, underpinned by methodologies that are transferable and scalable across sites to facilitate formal meta-analysis. We first review the potential positive and negative effects of wave energy generation, and then, with specific reference to our work at the Wave Hub (a wave energy test site in southwest England, UK), we set out the methodological approaches needed to assess possible effects of wave energy on biodiversity. We highlight the need for national and international research clusters to accelerate the implementation of wave energy, within a coherent understanding of potential effects—both positive and negative.

1. The metabolic theory of ecology (MTE) predicts that, after correcting for body mass variation among organisms, the rates of most biological processes will vary as a universal function of temperature. However, empirical support for 'universal temperature dependence' (UTD) is currently equivocal and based on studies of a limited number of traits. 2. In many ectothermic animals, the rate at which females produce mature eggs is temperature dependent and may be an important factor in determining the costs of reproduction. 3. We tested whether the rate of egg maturation in marine turtles varies with environmental temperature as predicted by MTE, using the time separating successive clutches of individual females to estimate the rate at which eggs are formed. We also assessed the phenotypic contribution to this rate, by using radio telemetry to make repeated measurements of interclutch intervals for individual green turtles (Chelonia mydas). 4. Rates of egg maturation increased with seasonally increasing water temperatures in radio-tracked green turtles, but were not repeatable for individual females, and did not vary according to maternal body size or reproductive investment (number and size of eggs produced). 5. Using a collated data set from several different populations and species of marine turtles, we then show that a single relationship with water temperature explains most of the variation in egg maturation rates, with a slope that is statistically indistinguishable from the UTD predicted by MTE. However, several alternative statistical models also described the relationship between temperature and egg maturation rates equally parsimoniously. 6. Our results offer novel support for the MTE's predicted UTD of biological rates, although the underlying mechanisms require further study. The strong temperature dependence of egg maturation combined with the apparently weak phenotypic contribution to this rate has interesting behavioural implications in ectothermic animals. We suggest that maternal thermoregulatory behaviour in marine turtles, and many other reptiles, is consistent with a strategy of adaptively increasing body temperatures to accelerate egg maturation.

Despite extensive work carried out on leatherback turtles ( Dermochelys coriacea ) in the North Atlantic and Indo-Pacific, very little is known of the at-sea distribution of this species in the South Atlantic, where the world's largest population nests in Gabon (central Africa). This paucity of data is of marked concern given the pace of industrialization in fisheries with demonstrable marine turtle bycatch in African/Latin American waters. We tracked the movements of 25 adult female leatherback turtles obtaining a range of fundamental and applied insights, including indications for methodological advancement. Individuals could be assigned to one of three dispersal strategies, moving to (i) habitats of the equatorial Atlantic, (ii) temperate habitats off South America or (iii) temperate habitats off southern Africa. While occupying regions with high surface chlorophyll concentrations, these strategies exposed turtles to some of the world's highest levels of longline fishing effort, in addition to areas with coastal gillnet fisheries. Satellite tracking highlighted that at least 11 nations should be involved in the conservation of this species in addition to those with distant fishing fleets. The majority of tracking days were, however, spent in the high seas, where effective implementation of conservation efforts is complex to achieve.

Tractable conservation measures for long-lived species require the intersection between protection of biologically relevant life history stages and a socioeconomically feasible setting. To protect breeding adults, we require knowledge of animal movements, how movement relates to political boundaries, and our confidence in spatial analyses of movement. We used satellite tracking and a switching state-space model to determine the internesting movements of olive ridley sea turtles (Lepidochelys olivacea) (n = 18) in Central Africa during two breeding seasons (2007-08, 2008-09). These movements were analyzed in relation to current park boundaries and a proposed transboundary park between Gabon and the Republic of Congo, both created to reduce unintentional bycatch of sea turtles in marine fisheries. We additionally determined confidence intervals surrounding home range calculations. Turtles remained largely within a 30 km radius from the original nesting site before departing for distant foraging grounds. Only 44.6 percent of high-density areas were found within the current park but the proposed transboundary park would incorporate 97.6 percent of high-density areas. Though tagged individuals originated in Gabon, turtles were found in Congolese waters during greater than half of the internesting period (53.7 percent), highlighting the need for international cooperation and offering scientific support for a proposed transboundary park. This is the first comprehensive study on the internesting movements of solitary nesting olive ridley sea turtles, and it suggests the opportunity for tractable conservation measures for female nesting olive ridleys at this and other solitary nesting sites around the world. We draw from our results a framework for cost-effective protection of long-lived species using satellite telemetry as a primary tool.

Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human-turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. © Inter-Research 2010.

Long-distance migrations are among the wonders of the natural world, but this multi-taxon review shows that the characteristics of species that undertake such movements appear to make them particularly vulnerable to detrimental impacts of climate change. Migrants are key components of biological systems in high latitude regions, where the speed and magnitude of climate change impacts are greatest. They also rely on highly productive seasonal habitats, including wetlands and ocean upwellings that, with climate change, may become less food-rich and predictable in space and time. While migrants are adapted to adjust their behaviour with annual changes in the weather, the decoupling of climatic variables between geographically separate breeding and non-breeding grounds is beginning to result in mistimed migration. Furthermore, human land-use and activity patterns will constrain the ability of many species to modify their migratory routes and may increase the stress induced by climate change. Adapting conservation strategies for migrants in the light of climate change will require substantial shifts in site designation policies, flexibility of management strategies and the integration of forward planning for both people and wildlife. While adaptation to changes may be feasible for some terrestrial systems, wildlife in the marine ecosystem may be more dependent on the degree of climate change mitigation that is achievable.

On 2 of the major nesting beaches used by green turtles Chelonia mydas on Ascension Island, we measured the sand temperature at nest depths throughout the year. For both beaches, the sand temperature was strongly correlated (r 2 ≥0.94) with air temperature. We therefore used past records of air temperature to reconstruct sand temperatures on the different beaches throughout the nesting season between 1985 and 1998. This analysis showed that inter-annual differences in sand temperature were small and, while there were consistent thermal changes during the nesting season, over the 14 yr there was little overlap in the temperatures on the 2 beaches, with one being 2.6°C warmer, on average, than the other. This work suggests that inter-beach thermal variation is the major mechanism by which a range of incubation temperatures are realised on Ascension Island and hence is likely to facilitate the production of hatchlings of both sexes.

The globally distributed leatherback turtle Der- mochelys coriacea is subject to fisheries bycatch throughout its range. Protection from fisheries within pelagic foraging habitats is difficult to achieve but may be more tractable when populations are concentrated near neritic breeding and nesting grounds. We used satellite telemetry to de- scribe patterns of habitat utilization during the inter- nesting period for seven leatherback turtles nesting at Mayumba National Park in Gabon on the equatorial West African coast. The National Park includes critical nesting grounds and a marine protected area to 15 km offshore. Turtles dispersed widely from the nesting beach spending a mean of 62 - SD 26% of tracking time outside the confines of the National Park. This propensity to disperse is likely to increase the chance of deleterious interactions with fisheries in the region. Patterns of habitat utilization indicate the need for wider spatial scale planning on the West African continental shelf to enhance protection of leatherback turtles when they are seasonally occupying these habitats in great numbers for breeding and nesting.