Anatomy and variability of "Cuvierichelys parisiensis", a geoemydid turtle that crosses the Eocene-Oligocene boundary in Belgium

Abundant material of turtles from the early Oligocene site of Boutersem-TGV (Boutersem, Belgium), is presented here. No information on the turtles found there was so far available. All the turtle specimens presented here are attributable to a single freshwater taxon that is identified as a member of Geoemydidae, Cuvierichelys. It is the first representative of the ‘Palaeochelys s. l.–Mauremys’ group recognized in the Belgian Paleogene record. This material, which allows to know all the elements of both the carapace and the plastron of the taxon, cannot be attributed to the only species of the genus Cuvierichelys so far identified in the Oligocene, the Spanish form Cuvierichelys iberica. The taxon from Boutersem is recognized as Cuvierichelys parisiensis. Thus, both the paleobiogeographic and the biostratigraphic distributions of Cuvierichelys parisiensis are extended, its presence being confirmed for the first time outside the French Eocene record. The validity of some European forms is refuted, and several characters previously proposed as different between Cuvierichelys iberica and Cuvierichelys parisiensis are recognized as subjected to intraspecific variability.

Postdoktoral karriär vid Stockholms universitet ur ett jämställdhetsperspektiv

Several previous studies indicate that among newly graduated PhDs, women tend to continue with a postdoctoral academic career to a lesser extent than men do. The Central PhD Student Council (CDR) has investigated to what degree this is also the case for Stockholm University. Using various sources, the relative change of the gender balance of PhD students compared to researchers at a postdoctoral level has been assessed at the four faculties of Stockholm University. For the Faculty of Science, the four different sections have been analysed as well. CDR finds that it is first and foremost at this faculty that a clear change in the gender balance between PhD students and postdoctoral researchers is discerned. Even though the variations between the individual departments and sections at the faculty are large, as a whole the relative decrease of the proportion of women is between 11 % and 21 %, depending on what metric is used. The dropoff of female researchers takes place primarily in already male-dominated areas of research. Unlike at the other faculties, we also find that the proportion of female senior lecturers at the Faculty of Science is lower than what could be expected. The proportion of female professors, even among new recruits, is still lower than the population of hypothetical recruits at all faculties – except at the Faculty of Humanities. We do, however, note that the proportion of female professors at the Faculty of Science is currently increasing and approaching that of the population of hypothetical recruits. At the Faculty of Social Sciences we see that, compared to the rest of the faculty, the proportion of women within the educational sciences is considerably higher and when excluding these subjects the trend towards more female professors disappears. CDR concludes that it is important to increase the directed efforts to encourage support to newly graduated female PhDs within male-dominated areas to stay in academia. Furthermore, it is crucial to study the reasons for a larger female drop-off within certain areas of research in the transition from PhD studies to a postdoctoral level. We further consider it important to ensure that women are given the same possibilities as men to qualify themselves scientifically and not be burdened with teaching and administrative duties to a larger extent than men are.

Population structure and conservation implications for the loggerhead sea turtle of the Cape Verde Islands

[EN] The Cape Verde Islands harbour the second largest nesting aggregation of the globally endangered loggerhead sea turtle in the Atlantic. To characterize the unknown genetic structure, connectivity, and demographic history of this population, we sequenced a segment of the mitochondrial (mt) DNA control region (380 bp, n = 186) and genotyped 12 microsatellite loci (n = 128) in females nesting at three islands of Cape Verde. No genetic differentiation in either haplotype or allele frequencies was found among the islands (mtDNA FST = 0. 001, P > 0. 02; nDNA FST = 0. 001, P > 0. 126). However, population pairwise comparisons of the mtDNA data revealed significant differences between Cape Verde and all previously sequenced Atlantic and Mediterranean rookeries (FST = 0. 745; P < 0. 000).

Variation in spatial distribution of juvenile loggerhead turtles in the eastern Atlantic and western Mediterranean Sea

[EN] Loggerhead sea turtles (Caretta caretta) originating from the Western Atlantic carry out one of the largest marine migrations, reaching the eastern Atlantic and Mediterranean Sea. It has been proposed that this transatlantic journey is simply a consequence of drifting, with the lack of a target destination and a passive dispersal with oceanic currents. This predicts that the size of the source populations and geographic distance to the feeding grounds should play important roles in defining stock composition in the eastern Atlantic and Mediterranean Sea.

Potential adverse health effects of persistent organic pollutants on sea turtles: Evidences from a cross-sectional study on Cape Verde loggerhead sea turtles

[EN] The Cape Verde nesting population of loggerhead sea turtles (Caretta caretta) is the third largest population of this species in the world. For conservation purposes, it is essential to determine how these reptiles respond to different types of anthropogenic contaminants. We evaluated the presence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in the plasma of adult nesting loggerheads from Boa Vista Island, Cape Verde, and studied the effects of the contaminants on the health status of the turtles using hematological and biochemical parameters. All turtles had detectable levels of non-dioxin like PCBs, whereas dioxin-like congeners (DL-PCBs) were detected in only 30% of the turtles.

Satellite tracking derived insights into migration and foraging strategies of male loggerhead turtles in the eastern Atlantic

[EN] In recent years, information about the movements and timing of migration by male sea turtles has begun to be unraveled. Here, we present the first satellite tracking of male loggerhead sea turtles (Caretta caretta) in the eastern Atlantic. Satellite linked transmitters were attached to five adult males, captured in the near shore waters off Boavista, Republic of Cape Verde. This archipelago hosts the single most important breeding site of loggerhead turtles in the eastern Atlantic.

Natural colonization of loggerhead turtle eggs by the pathogenic fungus Fusarium oxysporum

[EN] Sea turtle nests are exposed to different environmental risks that may affect their hatching success. Human exploitation, predation by wild or domestic animals, nest flooding or severe beach erosion or accession are common causes of egg mortality. However, there is very little information about the impact of microorganisms on turtle eggs. We analyzed loggerhead turtle eggs from Boavista Island (Republic of Cabo Verde) which were incubated under different environmental conditions in order to evaluate the presence and impact of fungus. We have isolated Fusarium oxysporum from dead and live eggs after three days of incubation.

The eastern Atlantic juveniles of loggerhead sea turtles: Where do they come from and how do they distribute?

[EN] After hatching, loggerhead sea turtles (Caretta caretta) enter in the sea and start the ocean phase of their lives, where juveniles inhabit pelagic feeding areas during 6-12 years. In the Atlantic Ocean, the central and the eastern feeding grounds harbor loggerhead juveniles from different nesting populations, constituting the designated mixed stocks. We studied the distribution of juveniles in the Eastern Atlantic comparing mtDNA sequences from canarian individuals with samples from Azores, Madeira and the Atlantic coast of Andalusia.

New records of the olive ridley sea turtle Lepidochelys olivacea (Eschscholtz, 1829) from the Cape Verde Islands

[ES] The olive ridley sea turtle Lepidochelys olivacea has been recorded in the Cape Verde Islands, but the most recent published data (1998-2000) are of stranded ndividuals and remains only. This article presents new data on olive ridleys recorded during the years 2001-2011 on Boavista and Sal islands. The presence of his species does not appear to be related to nesting activity. The possible geographical origin of these turtles is discussed. In addition, we propose some studies that could help to reinforce the conservation of sea turtles in West Africa.

Urban hazards : spatial ecology and survivorship of a turtle in an expanding suburban environment

Evaluating the Effects of Sea Level Rise on Sea Turtle Nesting Sites: A Case Study of the Archie Carr National Wildlife Refuge

The purpose of this thesis was to determine the extent of sea level rise (SLR) impact on sea turtle nesting beach habitat on Archie Carr National Wildlife Refuge (NWR) as well as impacts on management strategies. The Archie Carr NWR is of exceptional importance due to the high density of Loggerhead, Leatherback, and Green sea turtles that nest there in the summer months. GIS data provided by the Archie Carr NWR and various SLR scenarios, provided by both the Intergovernmental Panel on Climate Change (IPCC) as well as leading scholars, were used to determine inundation area loss across the Refuge as well as nearby parcels targeted for possible acquisition. Inundation losses for the six scenarios were calculated to be in the 20-25% range. Approximately 26% of current lower priority parcels are reclassified as high priority when integrating this information. Therefore, a significant revision to future acquisition strategies is recommended.

Novel insights into the dynamics of green turtle fibropapillomatosis

Outbreaks of fibropapillomatosis (FP), a neoplastic infectious disease of marine turtles, have occurred worldwide since the 1980s. Its most likely aetiological agent is a virus, but disease expression depends on external factors, typically associated with altered environments. The scarcity of robust long-term data on disease prevalence has limited interpretations on the impacts of FP on turtle populations. Here we model the dynamics of FP at 2 green turtle foraging aggregations in Puerto Rico, through 18 yr of capture-mark-recapture data (1997−2014). We observed spatiotemporal variation in FP prevalence, potentially modulated via individual site-fidelity. FP ex pression was residency dependent, and FP-free individuals developed tumours after 1.8 ± 0.8 yr (mean ± SD) in the infected area. Recovery from the disease was likely, with complete tumour regression occurring in 2.7 ± 0.7 yr (mean ± SD). FP does not currently seem to be a major threat to marine turtle populations; however, disease prevalence is yet unknown in many areas. Systematic monitoring is highly advisable as human-induced stressors can lead to deviations in host− pathogen relationships and disease virulence. Finally, data collection should be standardized for a global assessment of FP dynamics and impacts.

Toxicity of polychlorinated biphenyls and N-phenyl-1-naphthylamine in the juvenile turtle, Chelydra serpentina

Polychlorinated biphenyls (PCBs) and substituted phenylamine antioxidants (SPAs) are two chemical groups that have been used in multiple Canadian industrial processes. Despite the production ban of PCBs in North America in 1977, they are still ubiquitous in the environment and in wildlife tissues. Previous studies of fish, amphibians, birds, and mammals have shown that PCBs are toxic and act as endocrine disruptors. In contrast, SPAs, specifically N-phenyl-1-naphthylamine (PANA), have received very little attention despite their current use in Canada and their expected environmental releases. The effects of PCB and PANA exposures in reptiles remain unknown thus, juvenile Chelydra serpentina were used in this thesis as a model vertebrate to fill in missing toxicity research gaps due to their importance as an environmental indicator. First, food pellets were spiked at an environmentally relevant concentration of the PCB mixture Aroclor 1254 (A1254) to model hepatic bioaccumulation (0.45 μg/g A1254 for 31 days) and depuration (clean food for 50 days) of PCBs in turtles. No significant differences in PCB concentrations were observed between the control and treated animals, suggesting that juvenile turtles exposed to environmentally relevant concentrations of PCBs can likely detoxify low concentrations of PCBs. Additionally, two dose-response experiments were performed using A1254 or PANA spiked food (0-12.7 μg/g and 0-3,446 μg/g, respectively) to determine hepatic toxicity and bioaccumulation in juvenile C. serpentina. An increase in hepatic cyp1a was observed when exposed to the highest dose of both chemicals: 1) for A1254, induction correlated to the significant increase in hepatic PCB congeners that are known to be metabolized by CYP1A; and 2) for PANA, induction suggested that CYP1A has a potential role in its detoxification. PCBs are known endocrine disruptors, but no significant changes were observed for both thyroid receptors (alpha and beta) or by estrogen and androgen receptors. This lack of response, also noted in the PANA exposure, suggests that C. serpentina is less sensitive to endocrine disruption than other vertebrates. Furthermore, the expression of genes involved in cellular stress was not altered in PCB and PANA exposed animals, supporting the resilience of turtles to oxidative stress. This is the first study to demonstrate the toxicity of PCBs and PANA in C. serpentina, demonstrating the turtle’s high tolerance to contamination.

Life history of a native emydid turtle (Malaclemys terrapin centrata) on the remote oceanic islands of Bermuda

Diamondback terrapins (Malaclemys terrapin) are native to the remote oceanic islands of Bermuda and presently inhabit only four small brackish water ponds on a private golf course. The life history of this species is poorly understood on Bermuda and so the aim of this study was to fill these knowledge gaps, to compare the results with what is known from other areas in the North American range, and to inform the development of a local management plan. The results of a mark-recapture census revealed that ca. 100 individuals ≥81 mm straight carapace length live on Bermuda, of which nearly half (48.5%) were considered sexually mature. The population is dominated by females (sex ratio 2.9:1) and annual recruitment over the three year period was found to be extremely low (approximately two terrapins). Female diamondback terrapins in Bermuda nest almost exclusively within a limited number of sand bunkers on the golf course. Nesting commenced in late March or early April and ended in late August. Peak oviposition was observed in May and June. Clutch size averaged 5.1 eggs (range 0-10; SD 2.4) and the incubation period averaged 61.8 days (range 49-83; SD 10.5). Delayed emergence was documented, with 43.8% of the hatchlings remaining in their natal nests over the winter months. The mean annual hatching success rate was determined to be 19% (range 17.6-21; SD 1.9). Radio-telemetry was used to investigate the movements and survivorship of postemergent hatchling diamondback terrapins. The results indicated that mangrove swamps and grass-dominated marshes adjacent to the ponds are important developmental habitats for hatchlings. Yellow-crowned night herons (Nyctanassa violacea) were found to be significant predators of small terrapins during spring emergence. Small aquatic gastropods comprised 66.7% of the faecal samples analysed from the Bermudian population. Scavenged fish and vertebrate animal remains, terrestrial arthropods, polychaete worms and bivalves were consumed in lesser amounts. Sediment from the pond environment was found in 74% of the faecal samples analysed and is believed to have been incidentally ingested while foraging for the small benthic gastropods. Eco-toxicological analyses of the pond sediment, prey and terrapin eggs showed that the Bermudian diamondback terrapins live and feed in wetland habitats characterised by chronic, multifactorial contamination; principally total petroleum hydrocarbons, polycyclic aromatic hydrocarbons and a variety of heavy metals. This study found that some of those contaminants are accumulating in the gastropod prey as well as being transferred to terrapin eggs. This may be reducing the incidence of successful embryonic development for this species in Bermuda and may likely contribute to the observed low hatching rates. These collective findings indicate that the Bermudian population is very vulnerable to local extirpation.