Genetic composition of the Ascension Island green turtle rookery based on mitochondrial DNA : implications for sampling and diversity

In species of conservation concern it is often difficult to be certain that population diversity and structure have been adequately characterised by genetic sampling. Since practical and financial constraints tend to be associated with increasing sample sizes in many conservation genetic studies, it is important to consider the potential for sampling error and bias due to inadequate samples or spatio-temporal structure within populations. We analysed sequence data from the mitochondrial DNA control region in a large sample (n = 245) of green sea turtles Chelonia mydas collected at the globally important rookery of Ascension Island, South Atlantic. We examined genetic diversity and structure among 10 sampling sites, 4 beach clusters and 4 nesting seasons, and evaluated the genetic composition of Ascension against other Atlantic nesting populations, including the well-studied rookery at Tortuguero (Costa Rica). Finally, we used rarefaction and GENESAMP analyses to assess the ability of different sample sizes to provide acceptable genetic representations of a population, using Ascension and Tortuguero as models. On Ascension, we found 13 haplotypes, of which only 3 had been previously observed in the rookery, and 5 previously undescribed. We detected no differentiation among beach clusters or sampling seasons, and only weak differentiation among the 3 primary nesting sites. The increased sample size for Ascension provided higher resolution and statistical power in describing genetic structure among all other known Atlantic rookeries. Our extrapolations showed that a maximum of 18 and 6 haplotypes are expected to occur in Ascension and Tortuguero, respectively, and that current sample sizes are sufficient to describe most of the variation. We recommend using rarefaction and GENESAMP analyses on a rookery-by-rookery basis to evaluate whether a sample set adequately describes mitochondrial DNA diversity, thus strengthening subsequent phylogeographic and mixed stock analyses, and management recommendations for conservation.

Flipper beat frequency and amplitude changes in diving green turtles, Chelonia mydas

Using a turtle-borne camera system, changing flipper beat frequency and amplitude were measured in five diving green turtles (Chelonia mydas Linnaeus 1758) in the Bahía de los Angeles, Mexico (28°58′N, 113°33′W). These observations were made between June and August 2002. Turtles worked hardest (i.e., had the highest flipper beat frequency and amplitude) at the start of descents when positive buoyancy is predicted to oppose their forward motion. During the later part of descents, turtles worked less hard in line with opposing buoyancy forces being reduced. For example, flipper beat frequency declined from about 60–80 beats min−1 at the start of descent to around 25–40 beats min−1 after 30 s of the descent. At the start of ascents the flipper beat frequency was around 30 beats min−1, lower than on descent, and declined as the ascent progressed with often passive gliding for the final few meters to the surface. This pattern of effort during diving appears to apply across a range of marine reptiles, birds and mammals suggesting that graded effort during descent and ascent is an optimum solution to minimising the cost of transport during diving.

Are green turtles globally endangered?

Aim  To examine the exploitation, recovery and current status of green turtles (Chelonia mydas) nesting at Ascension Island. Location  Ascension Island (UK) (7°57′ S, 14°22′ W), South Atlantic Ocean. Methods  We analysed records of the harvest of green turtles nesting at Ascension Island between 1822 and 1935, illustrating the decline in numbers over this period. Using a deterministic age-class structured model we predict the initial number of breeding females present in the population prior to the recorded harvest and compare this to our estimate of the current population based upon our recent annual surveys (1999–2004). Results  Prior to 1822 we estimate the nesting population of green turtles to have been at least 19,000–22,000 individuals in order for the population to have survived the level of harvest recorded. From recent data (1999–2004), we estimate the current breeding population of green turtles at this site to be 11,000–15,000 females. Our results illustrate a dramatic recovery of the population, which is still increasing exponentially and shows no evidence of slowing, suggesting it has not reached 50% of its carrying capacity. Main conclusions  We estimate that, since the 1970s, the Ascension Island population of green turtles has increased by 285% and question the recent listing of this species as endangered by the IUCN (World Conservation Union), in particular in the Atlantic Ocean, where 75% of the populations assessed by the IUCN are increasing. Indeed, we estimate the global population of this species to be in excess of 2.2 million individuals. We suggest that the IUCN's global listing process detracts attention from those populations that are truly threatened with extinction and should not, in its present form, be applied to globally distributed long-lived species such as marine turtles.

Patterns in the emergence of green (Chelonia mydas) and loggerhead (Caretta caretta) turtle hatchlings from their nests

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.

Rhythmic throat oscillations in nesting green turtles (Chelonia mydas)

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.

Representation of multiculturalism in urban green spaces : a review of immigrants' experiences in Australia

Rapid population influx due to migration in Australia has produced diverse cultural landscapes, which become visible in cities as physical forms, settings and symbols produced by different ethnic communities. Scholars have argued that people moving away from the country of their birth, whether this be a necessary migration, labour mobility or voluntary migration, results in a difficult process of resettlement for families and individuals. To provide a cohesive multicultural society for all citizens, it is essential to understand how immigrants perceive their new environments and how they make connections in a new land in the process of cultural renewal. While the policy of ‘multiculturalism’ has had a rocky road since the optimistic 1970s, a drive through many suburbs in Australian cities shows buildings, festivals and communal gatherings of people that express and refer to diverse cultural backgrounds. Urban green spaces, ranging from private home gardens to public parks and botanical gardens, play an important role in the life of immigrants. Besides psychological and the restorative effects of urban green spaces, these spaces are public places that provide opportunities for recreation, social gatherings, and the celebration of collective cultural values and events such as festivals for many communities. This study aims to raise awareness of ethnicity as an important issue in park settings and spaces. It investigates the interrelationship between these cultural practices in the urban park environment, in relation to ethnic and cultural identity and physical settings. The concept of transculturalism – reinventing a new common culture as a result of migration to a new place – can help the analysis of the affects and the perception of urban green spaces. The paper will review different experiences of immigrants in relation to the use and perception of urban green spaces, developing alternative perspectives about the Australian landscapes.

The contribution of Building Information Modelling (BIM) to Green Building Design and Assessment in Abu Dhabi "ESTIDAMA"

Estidama is a mandatory Green Building code in Abu Dhabi by which the compliance of building design is being assessed. This paper examines the current design and assessment approaches for Green Buildings to identify the reasons that lead to delay defects and it investigates a new approach for improvement. The available literature provides a realistic understanding to the problems and shows the road to some potential solutions. The identified problems were mainly attributed to the manual assessment with too much human interference. The piled documents with limited resources left the assessment system too slow to handle the whole projects within the greater Abu Dhabi engendering high risk of the commitment to review mistakes. Therefore, this paper investigates the potentiality of automating several stages via the use of Building Information Modeling (BIM) into the assessment process. Different experienced participants from all aspects within the construction industry were interviewed to contribute to the research. Also, a close question questionnaire was distributed to examine the current practice in Abu Dhabi to compare it with the initial findings. The findings point out significant requirements to adopt BIM in the assessment process, such as the availability of proper contracts form to shape the relationship between BIM parties and the readiness of the current system. Hence, the authors suggest a new model that integrates BIM capabilities within the system to accelerate the process and reduce human involvement.